Postoperative nausea and vomiting at Landspitali: A prospective study

BACKGROUND

In the last decade, anaesthesia practice has changed at Landspitali, where the majority of patients now receive antiemetic prophylaxis, and the use of total intravenous anaesthesia is the dominant mode for maintenance of anaesthesia. The aim of this study was to assess the incidence of postoperative nausea and vomiting (PONV) in a prospective way, the use of PONV prophylaxis, and clinical risk factors associated with PONV during this era.

METHODS

A prospective cohort study using a convenience sample of 438 patients ≥18 years old admitted to the postoperative care unit (PACU) after elective or emergency operations in May-July 2022 at Landspitali University Hospital in Iceland. Patients answered questionnaires in the PACU and 24 h after discharge from PACU.

RESULTS

The incidence of self-reported moderate/severe nausea (5/10 or higher on NRS) in PACU was 4% and 3% on postoperative day 1. A total of 91% of delivered anaesthetics were with intravenous medications only, and 82% of patients received at least one prophylactic medication for PONV. When asked to rate the worst nausea experienced, this was described as moderate/severe by 7% in PACU and 17% on postoperative day 1. Risk factors associated with PONV were female gender (OR 1.90, 95% CI 1.04-3.53) and a history of motion sickness or PONV (2.74, 1.51-4.94), but increasing age was protective (0.83 per decade, 0.71-0.98). Despite a more liberal administration of antiemetics, patients with more risk factors per Apfel PONV risk classification had a higher incidence of PONV.

CONCLUSION

The incidence of PONV is generally low in this diverse surgical population where anaesthesia is mostly maintained with total intravenous anaesthesia and PONV prophylaxis is common. PONV remains a predictable complication following anaesthesia, suggesting further improvement in its prevention is possible.

The association of degree of polypharmacy before and after among hospitalised internal medicine patients and clinical outcomes: a retrospective, population-based cohort study

OBJECTIVES

To determine the prevalence and incidence of polypharmacy/hyperpolypharmacy and which medications are most prescribed to patients with varying burden of polypharmacy.

DESIGN

Retrospective, population-based cohort study.

SETTING

Iceland.

PARTICIPANTS

Including patients (≥18 years) admitted to internal medicine services at Landspitali - The National University Hospital of Iceland, between 1 January 2010 with a follow-up of clinical outcomes through 17 March 2022.

MAIN OUTCOMES MEASURES

Participants were categorised into medication use categories of non-polypharmacy (<5), polypharmacy (5-10) and hyperpolypharmacy (>10) based on the number of medications filled in the year predischarge and postdischarge. The primary outcome was prevalence and incidence of new polypharmacy. Secondary outcomes were mortality, length of hospital stay and re-admission.

RESULTS

Among 85 942 admissions (51% male), the median (IQR) age was 73 (60-83) years. The prevalence of preadmission non-polypharmacy was 15.1% (95% CI 14.9 to 15.3), polypharmacy was 22.9% (95% CI 22.6 to 23.2) and hyperpolypharmacy was 62.5% (95% CI 62.2 to 62.9). The incidence of new postdischarge polypharmacy was 33.4% (95% CI 32.9 to 33.9), and for hyperpolypharmacy was 28.9% (95% CI 28.3 to 29.5) for patients with preadmission polypharmacy. Patients with a higher level of medication use were more likely to use multidose drug dispensing and have a diagnosis of adverse drug reaction. Other comorbidities, including responsible subspeciality and estimates of comorbidity and frailty burden, were identical between groups of varying polypharmacy. There was no difference in length of stay, re-admission rate and mortality.

CONCLUSIONS

Preadmission polypharmacy/hyperpolypharmacy and postdischarge new polypharmacy/hyperpolypharmacy is common amongst patients admitted to internal medicine. A higher level of medication use category was not found to be associated with demographic, comorbidity and clinical outcomes. Medications that are frequently inappropriately prescribed were among the most prescribed medications in the group. An increased focus on optimising medication usage is needed after hospital admission.

TRIAL REGISTRATION NUMBER

NCT05756400.

Postoperative pain at Landspitali: A prospective study

BACKGROUND

Moderate or severe postoperative pain is common despite advances in surgical technique and perioperative analgesia. This study aimed to assess the prevalence and severity of postoperative pain following procedures requiring anaesthesia and identify factors associated with increased risk of postoperative pain.

METHODS

Surgical patients ≥18 years of age were prospectively questioned on level of current pain on a numerical rating scale (NRS) from 0 to 10 in the post-anaesthesia care unit (PACU) and on resting, active and worst pain experienced in the first 24 h postoperatively. Clinical data was obtained from medical records. Descriptive statistics were applied, and predictors of worst pain assessed as moderate/severe (NRS≥ $$ \ge $$ 5) on postoperative day one were assessed using multivariable logistic regression.

RESULTS

Of 438 included participants, moderate/severe pain occurred in 29% on the day of surgery and 70% described their worst pain as moderate/severe on postoperative day one. Procedures with the highest incidence of moderate/severe pain on the day of surgery were gynaecology-, plastic-, abdominal-, breast-, and orthopaedic procedures. On postoperative day one, patients undergoing vascular-, orthopaedic-, and abdominal operations most commonly rated their worst pain as moderate/severe. Female sex (OR = 2.15, 95% Cl 1.21-3.88, p = .010), chronic preoperative pain (OR = 4.20, 95% Cl 2.41-7.51, p < .001), undergoing a major procedure (OR = 2.07, 95% Cl 1.15-3.80, p = .017), and any intraoperative remifentanil administration (OR = 2.16, 95% Cl 1.20-3.94, p = .01) had increased odds of rating the worst pain as moderate/severe. Increased age (OR = 0.66 per 10 years (95% Cl 0.55-0.78, p < .001)) and undergoing breast-, gynaecology-, otolaryngology-, and neurosurgery (OR = 0.15-0.34, p < .038) was associated with lower odds of moderate/severe pain on postoperative day one.

DISCUSSION

In our cohort, patients rated their current pain in the PACU similarly to other studies. However, the ratio of patients rating the worst pain experienced as moderate/severe on postoperative day one was relatively high. The identified patient- and procedural-related factors associated with higher odds of postoperative pain highlight a subgroup of patients who may benefit from enhanced perioperative monitoring and pain management strategies.

The epidemiology and outcomes of acute kidney injury following orthopaedic procedures: A retrospective cohort study

BACKGROUND

Acute kidney injury (AKI) is a serious complication following major surgery. This study examined the incidence and risk factors of AKI following orthopaedic surgeries in an Icelandic cohort, as well as the association between AKI and patient- and surgery-related factors.

METHODS

This retrospective cohort study comprised all patients 18 years and older who underwent orthopaedic surgeries at Landspitali - The National University Hospital in the years 2006-2018 with available serum creatinine (SCr) measurements adjacent to the surgery to stage AKI. AKI was defined according to SCr portion of the KDIGO criteria. Logistic regression was used to identify patient- and surgical factors related to progression of AKI and Poisson-regression was used to explore changes in incidence.

RESULTS

A total of 222 cases of AKI following 3208 surgeries (6.9%) were identified in the study period with a rise in the incidence by about 17% per year. Higher age (odds ratio (OR), 1.02, 95% confidence interval (CI), 1.01-1.04 per year) and underlying reduction in kidney function (OR 1.93 (1.30-2.81), 3.24 (2.08-4.96) and 4.08 (2.35-6.96) for estimated glomerular filtration rate (eGFR) of 30-59, 15-29 and <15 mL/min/1.73 m2 compared with eGFR >60 mL/min/1.73 m2 ) were associated with higher risk of AKI, but female sex was associated with decreased odds (OR = 0.73; 95% CI, 0.54-0.98). After correcting for age, sex, preoperative kidney function, emergency surgery and underlying comorbidities and frailty, there was an increased risk of long-term mortality in patients with AKI (HR 1.41, 95% CI 1.08-1.85), and patients who developed AKI also had accelerated progression of chronic kidney disease compared with patients who did not develop AKI.

CONCLUSIONS

The incidence of AKI following orthopaedic surgeries is increasing and is associated with adverse outcomes. It is important that elderly individuals and patients who have reduced kidney function receive adequate monitoring and surveillance in the perioperative period.

Furosemide versus placebo for fluid overload in intensive care patients-The randomised GODIF trial second version: Statistical analysis plan

BACKGROUND

Fluid overload is associated with increased mortality in intensive care unit (ICU) patients. The GODIF trial aims to assess the benefits and harms of fluid removal with furosemide versus placebo in stable adult patients with moderate to severe fluid overload in the ICU. This article describes the detailed statistical analysis plan for the primary results of the second version of the GODIF trial.

METHODS

The GODIF trial is an international, multi-centre, randomised, stratified, blinded, parallel-group, pragmatic clinical trial, allocating 1000 adult ICU patients with moderate to severe fluid overload 1:1 to furosemide versus placebo. The primary outcome is days alive and out of hospital within 90 days post-randomisation. With a power of 90% and an alpha level of 5%, we may reject or detect an improvement of 8%. The primary analyses of all outcomes will be performed in the intention-to-treat population. For the primary outcome, the Kryger Jensen and Lange method will be used to compare the two treatment groups adjusted for stratification variables supplemented with sensitivity analyses in the per-protocol population and with further adjustments for prognostic variables. Secondary outcomes will be analysed with multiple linear regressions, logistic regressions or the Kryger Jensen and Lange method as suitable with adjustment for stratification variables.

CONCLUSION

The GODIF trial data will increase the certainty about the effects of fluid removal using furosemide in adult ICU patients with fluid overload.

TRIAL REGISTRATIONS

EudraCT identifier: 2019-004292-40 and ClinicalTrials.org: NCT04180397.

A survey of preferences for respiratory support in the intensive care unit for patients with acute hypoxaemic respiratory failure

BACKGROUND

When caring for mechanically ventilated adults with acute hypoxaemic respiratory failure (AHRF), clinicians are faced with an uncertain choice between ventilator modes allowing for spontaneous breaths or ventilation fully controlled by the ventilator. The preferences of clinicians managing such patients, and what motivates their choice of ventilator mode, are largely unknown. To better understand how clinicians' preferences may impact the choice of ventilatory support for patients with AHRF, we issued a survey to an international network of intensive care unit (ICU) researchers.

METHODS

We distributed an online survey with 32 broadly similar and interlinked questions on how clinicians prioritise spontaneous or controlled ventilation in invasively ventilated patients with AHRF of different severity, and which factors determine their choice.

RESULTS

The survey was distributed to 1337 recipients in 12 countries. Of these, 415 (31%) completed the survey either fully (52%) or partially (48%). Most respondents were identified as medical specialists (87%) or physicians in training (11%). Modes allowing for spontaneous ventilation were considered preferable in mild AHRF, with controlled ventilation considered as progressively more important in moderate and severe AHRF. Among respondents there was strong support (90%) for a randomised clinical trial comparing spontaneous with controlled ventilation in patients with moderate AHRF.

CONCLUSIONS

The responses from this international survey suggest that there is clinical equipoise for the preferred ventilator mode in patients with AHRF of moderate severity. We found strong support for a randomised trial comparing modes of ventilation in patients with moderate AHRF.

Physical and cognitive impact following SARS-CoV-2 infection in a large population-based case-control study

BACKGROUND

Persistent symptoms are common after SARS-CoV-2 infection but correlation with objective measures is unclear.

METHODS

We invited all 3098 adults who tested SARS-CoV-2 positive in Iceland before October 2020 to the deCODE Health Study. We compared multiple symptoms and physical measures between 1706 Icelanders with confirmed prior infection (cases) who participated, and 619 contemporary and 13,779 historical controls. Cases participated in the study 5-18 months after infection.

RESULTS

Here we report that 41 of 88 symptoms are associated with prior infection, most significantly disturbed smell and taste, memory disturbance, and dyspnea. Measured objectively, cases had poorer smell and taste results, less grip strength, and poorer memory recall. Differences in grip strength and memory recall were small. No other objective measure associated with prior infection including heart rate, blood pressure, postural orthostatic tachycardia, oxygen saturation, exercise tolerance, hearing, and traditional inflammatory, cardiac, liver, and kidney blood biomarkers. There was no evidence of more anxiety or depression among cases. We estimate the prevalence of long Covid to be 7% at a median of 8 months after infection.

CONCLUSIONS

We confirm that diverse symptoms are common months after SARS-CoV-2 infection but find few differences between cases and controls in objective parameters measured. These discrepancies between symptoms and physical measures suggest a more complicated contribution to symptoms related to prior infection than is captured with conventional tests. Traditional clinical assessment is not expected to be particularly informative in relating symptoms to a past SARS-CoV-2 infection.

The epidemiology of new persistent hypnotic/sedative use after surgical procedures: a retrospective cohort study

The use of hypnotic and sedative medication for sleep improvement is common and long-term use has been associated with an increased risk of adverse events and mortality. A proportion of patients might develop long-term use after initiating new persistent use following surgery. This retrospective cohort study aimed to determine the incidence of new persistent hypnotic/sedative use after surgical procedures and associated patient and procedural factors. Data on prescriptions for hypnotic and sedative medications used for sleep improvement were retrieved from the National Prescription Medicine Registry. Medication naivety was defined as not filling a prescription for hypnotics/sedatives from 365 days through 31 days preceding surgery, new use was defined as medication naivety followed by filling a prescription for hypnotic/sedative medication from 30 days before surgery through 14 days after surgery. New persistent hypnotic/sedative use was defined as new use followed by filling another hypnotic/sedative prescription from 15 days through 365 days after surgery. Of 55,414 patients included in the study, 43,297 were naive to hypnotic/sedative medications. Of those naive patients, 4.6% met the criteria for new peri-operative use, of whom 51.6% developed new persistent hypnotic/sedative use. Patient and procedural factors associated with increased risk of new persistent use were older age; female sex; the presence of malignant neoplasm; ischaemic heart disease; and having undergone either cardiac or thoracic surgery. The hazard of long-term mortality was higher for patients with new persistent use (1.39, 95%CI 1.22-1.59) compared with patients who remained naive. While a small ratio of surgical patients initiates the use of hypnotics/sedatives in the peri-operative period, a substantial proportion of these develop persistent use, which is associated with adverse outcomes. Over time, the proportion of patients using hypnotics/sedatives has declined, but the risk of persistent use within this group has remained stable.

Haemoglobin levels and outcomes of subgroups of patients with pre-operative anaemia based on red cell size: A retrospective cohort study

BACKGROUND

Pre-operative anaemia is common and associated with adverse outcomes. We hypothesised that pre-operative anaemia would be evident more than 1 month pre-operatively, and that peri-operative changes in haemoglobin and post-operative outcomes differed between red cell size-based subsets of anaemia.

METHODS

A retrospective single-centre cohort study, including all patients 18 years and older undergoing their first surgery at Landspitali between January 2006 and December 2018 with available measurement of haemoglobin (Hb) within 30 days preceding surgery. Clinical data were compared between patients with subgroups of anaemia classified by mean corpuscular volume (MCV) into microcytic (MCV < 80 fl), normocytic (MCV 80-100 fl), and macrocytic (MCV > 100 fl) anaemia. The development of haemoglobin measurements from a nationwide database was plotted from 1 year pre-operatively to 2 years post-operatively.

RESULTS

Of 40,979 patients, 10,505 (25.6%) had pre-operative anaemia, of which 1089 (10.4%) had microcytic anaemia, 9243 (88.0%) had normocytic anaemia, and 173 (1.6%) had macrocytic anaemia. Patients within all subgroups of pre-operative anaemia had a higher degree of comorbidity and frailty burden and a low haemoglobin evident for more than 100 days pre-operatively and similar changes post-operatively. Post-operative prolonged recovery of haemoglobin was slower for macrocytic anaemia than other types of anaemia. All groups of patients with anaemia had a higher incidence of 30-day mortality, acute kidney injury, and rate of readmission compared with patients without anaemia.

CONCLUSIONS

Pre-operative anaemia is evident long prior to the procedure and its association with worse outcomes is similar regardless of red cell size.

The incidence of new and persistent benzodiazepine use after surgery

BACKGROUND

It is possible that a portion of new and new persistent use of benzodiazepines is among individuals who start using the medications before or after surgery. We studied the incidence of new and new persistent benzodiazepine use among patients undergoing surgery.

METHODS

Retrospective, single-center, population-based cohort of all individuals ≥18 years undergoing first surgery between January 2, 2006 and December 31, 2018 with a year of follow-up for filled medications. Benzodiazepine-naïve patients were defined as not filling a prescription from a year to 31 days before surgery. Patients with new use were naïve patients who filled a prescription between 30 days before and 14 days after surgery, and patients with new persistent use were patients with new use who filled a prescription between 15 days and a year after surgery. Patient and procedural characteristics and prescription filling patterns between the groups were compared.

RESULTS

A total of 55,997 patients (32,136 women [57.4%]; median [interquartile range] age, 55 [39, 69] years) were included. The incidence of new use among naïve patients was 2.7% (95% confidence interval, 2.6%-2.8%; n = 1,311), and, of those, 43.7% (95% confidence interval, 41.0%-46.5%; n = 571) had new persistent benzodiazepine use. Approximately 10% of patients with new use filled a prescription for benzodiazepine in every 30-day window during the follow-up period.

CONCLUSION

A small portion of surgical patients begin benzodiazepine use perioperatively, but subsequently half fill criteria for persistent use. This highlights the importance of identifying strategies to minimize both new use and the progression of new use into persistent use in surgical patients.

Frailty assessment tools and associated postoperative outcomes in older patients undergoing elective surgery: A prospective pilot study

BACKGROUND

There is a need for a feasible tool to assess the risk of frailty prior to surgery. We aimed to identify the ratio of abnormal results for three clinically applicable screening tools to assess the risk of frailty, and their association with adverse outcomes in a cohort of elderly surgical patients.

METHODS

In this prospective pilot study, patients ≥65 years undergoing preoperative evaluation for elective surgery were included and subjected to three frailty screening tests; Program of Research to Integrate Services for the Maintenance of Autonomy 7-item questionnaire (PRISMA7), Timed Up and Go (TUG), and Clock Drawing Test (CDT). The primary outcome was the incidence of abnormal testing, and secondary outcomes were the association between abnormal tests and mortality, readmission, delirium, surgical complications and non-home discharge.

RESULTS

Out of 99 patients, 41%, 37%, and 43% had abnormal PRISMA7, TUG, and CDT screening, respectively. Postoperative delirium was more likely to occur in patients with abnormal TUG screening (19% vs. 3%, p = .011) and CDT (17% vs. 2%, p = .019). When analyzing screening tool combinations, patients with abnormal PRISMA7 and TUG had a higher rate of non-home discharge (38% vs. 17%, p = .029); and patients with abnormal TUG and CDT had a higher rate of postoperative delirium (25% vs. 3%, p = .006) and any surgical complication (58% vs. 38%, p = .037); and patients with abnormal results from all three tools had a higher rate of postoperative delirium (21% vs. 5%, p = .045) and non-home discharge (42% vs. 18%, p = .034).

CONCLUSION

Approximately 40% of elderly surgical patients have abnormal PRISMA7, TUG, and CDT screening tests for frailty, and they are associated individually or in combination with increased risk of adverse postoperative outcomes. The results will aid in designing studies to further risk-stratify patients at risk of frailty and attempt to modify associated outcomes.

Postoperative Acute Kidney Injury by Age and Sex: A Retrospective Cohort Association Study

BACKGROUND

Acute kidney injury (AKI) after noncardiac surgery is common and has substantial health impact. Preclinical and clinical studies examining the influence of sex on AKI have yielded conflicting results, although they typically do not account for age-related changes. The objective of the study was to determine the association of age and sex groups on postoperative AKI. The authors hypothesized that younger females would display lower risk of postoperative AKI than males of similar age, and the protection would be lost in older females.

METHODS

This was a multicenter retrospective cohort study across 46 institutions between 2013 and 2019. Participants included adult inpatients without pre-existing end-stage kidney disease undergoing index major noncardiac, nonkidney/urologic surgeries. The authors' primary exposure was age and sex groups defined as females 50 yr or younger, females older than 50 yr, males 50 yr or younger, and males older than 50 yr. The authors' primary outcome was development of AKI by Kidney Disease-Improving Global Outcomes serum creatinine criteria. Exploratory analyses included associations of ascending age groups and hormone replacement therapy home medications with postoperative AKI.

RESULTS

Among 390,382 patients, 25,809 (6.6%) developed postoperative AKI (females 50 yr or younger: 2,190 of 58,585 [3.7%]; females older than 50 yr: 9,320 of 14,4047 [6.5%]; males 50 yr or younger: 3,289 of 55,503 [5.9%]; males older than 50 yr: 11,010 of 132,447 [8.3%]). When adjusted for AKI risk factors, compared to females younger than 50 yr (odds ratio, 1), the odds of AKI were higher in females older than 50 yr (odds ratio, 1.51; 95% CI, 1.43 to 1.59), males younger than 50 yr (odds ratio, 1.90; 95% CI, 1.79 to 2.01), and males older than 50 yr (odds ratio, 2.06; 95% CI, 1.96 to 2.17).

CONCLUSIONS

Younger females display a lower odds of postoperative AKI that gradually increases with age. These results suggest that age-related changes in women should be further studied as modifiers of postoperative AKI risk after noncardiac surgery.

EDITOR’S PERSPECTIVE

Management of patients with left main stem stenosis in Iceland 2010–2020: PCI or CABG?

Introduction

Coronary artery bypass surgery (CABG) has been standard treatment for patients with left main coronary artery disease (LMCAD) but percutaneous coronary intervention (PCI) is a good alternative in selected patients.

Our purpose was to evaluate the prevalence of LMCAD in Iceland, the impact of background factors on treatment choices, and treatment changes in recent years with respect to current guidelines.

Methods

This retrospective, population-based study analyzed data from the SCAAR-SWEDEHEART database. Patients with significant LMCAD on coronary angiography in Iceland 2010–2020, without previous history of CABG or contraindication for surgery were enrolled. Survival analysis was estimated with Kaplan-Meier and COX regression analysis for investigating the association between survival time and predictor variables.

Findings

Of 702 patients with LMCAD, 195 were treated with PCI, 460 with CABG and 47 with medical treatment only. The widest age range was in the PCI group and the mean age was highest in the medical therapy only group (p&lt;0.001). Patients with LMCAD and either three vessel disease or heart valve disease were most often treated with CABG (76.1% and 84.4%, p&lt;0.001).The majority of patients with LMCAD only were treated with PCI, as were patients with STEMI or cardiogenic shock (67.1% and 70.0%, p&lt;0.001). The proportion of patients treated with PCI increased from 19.8% in 2010–2015 to 42.7% in 2016–2020. There was no significant difference in survival between PCI and CABG (p=0.41).

Conclusions

In patients with LMCAD the main factors that affect treatment choice are age, anatomical complexity and acuteness. Treatment choice appears to be in keeping with current guidelines. There is no significant difference in long term survival between PCI and CABG groups but the groups are different. There has been a significant increase in patients treated with PCI in recent years.

Funding Acknowledgement

Type of funding sources: None.

Development of a prognostic model of COVID-19 severity: a population-based cohort study in Iceland

BACKGROUND

The severity of SARS-CoV-2 infection varies from asymptomatic state to severe respiratory failure and the clinical course is difficult to predict. The aim of the study was to develop a prognostic model to predict the severity of COVID-19 in unvaccinated adults at the time of diagnosis.

METHODS

All SARS-CoV-2-positive adults in Iceland were prospectively enrolled into a telehealth service at diagnosis. A multivariable proportional-odds logistic regression model was derived from information obtained during the enrollment interview of those diagnosed between February 27 and December 31, 2020 who met the inclusion criteria. Outcomes were defined on an ordinal scale: (1) no need for escalation of care during follow-up; (2) need for urgent care visit; (3) hospitalization; and (4) admission to intensive care unit (ICU) or death. Missing data were multiply imputed using chained equations and the model was internally validated using bootstrapping techniques. Decision curve analysis was performed.

RESULTS

The prognostic model was derived from 4756 SARS-CoV-2-positive persons. In total, 375 (7.9%) only required urgent care visits, 188 (4.0%) were hospitalized and 50 (1.1%) were either admitted to ICU or died due to complications of COVID-19. The model included age, sex, body mass index (BMI), current smoking, underlying conditions, and symptoms and clinical severity score at enrollment. On internal validation, the optimism-corrected Nagelkerke's R² was 23.4% (95%CI, 22.7-24.2), the C-statistic was 0.793 (95%CI, 0.789-0.797) and the calibration slope was 0.97 (95%CI, 0.96-0.98). Outcome-specific indices were for urgent care visit or worse (calibration intercept -0.04 [95%CI, -0.06 to -0.02], E_max 0.014 [95%CI, 0.008-0.020]), hospitalization or worse (calibration intercept -0.06 [95%CI, -0.12 to -0.03], E_max 0.018 [95%CI, 0.010-0.027]), and ICU admission or death (calibration intercept -0.10 [95%CI, -0.15 to -0.04] and E_max 0.027 [95%CI, 0.013-0.041]).

CONCLUSION

Our prognostic model can accurately predict the later need for urgent outpatient evaluation, hospitalization, and ICU admission and death among unvaccinated SARS-CoV-2-positive adults in the general population at the time of diagnosis, using information obtained by telephone interview.

Identifying Patients Vulnerable to Inadequate Pain Resolution After Cardiac Surgery

Acute postoperative pain (APOP) is often evaluated through granular parameters, though monitoring postoperative pain using trends may better describe pain state. We investigated acute postoperative pain trajectories in cardiac surgical patients to identify subpopulations of pain resolution and elucidate predictors of problematic pain courses. We examined retrospective data from 2810 cardiac surgical patients at a single center. The k-means algorithm for longitudinal data was used to generate clusters of pain trajectories over the first 5 postoperative days. Patient characteristics were examined for association with cluster membership using ordinal and multinomial logistic regression. We identified 3 subgroups of pain resolution after cardiac surgery: 37.7% with good resolution, 44.2% with moderate resolution, and 18.2% exhibiting poor resolution. Type I diabetes (2.04 [1.00-4.16], p = 0.05), preoperative opioid use (1.65 [1.23-2.22], p = 0.001), and illicit drug use (1.89 [1.26-2.83], p = 0.002) elevated risk of membership into worse pain trajectory clusters. Female gender (1.72 [1.30-2.27], p < 0.001), depression (1.60 [1.03-2.50], p = 0.04) and chronic pain (3.28 [1.79-5.99], p < 0.001) increased risk of membership in the worst pain resolution cluster. This study defined 3 APOP resolution subgroups based on pain score trend after cardiac surgery and identified factors that predisposed patients to worse resolution. Patients with moderate or poor pain trajectory consumed more opioids and received them for longer before discharge. Future studies are warranted to determine if altering postoperative pain monitoring and management improve postoperative course of patients at risk of moderate or poor pain resolution.

HLA alleles, disease severity, and age associate with T-cell responses following infection with SARS-CoV-2

Memory T-cell responses following SARS-CoV-2 infection have been extensively investigated but many studies have been small with a limited range of disease severity. Here we analyze SARS-CoV-2 reactive T-cell responses in 768 convalescent SARS-CoV-2-infected (cases) and 500 uninfected (controls) Icelanders. The T-cell responses are stable three to eight months after SARS-CoV-2 infection, irrespective of disease severity and even those with the mildest symptoms induce broad and persistent T-cell responses. Robust CD4⁺ T-cell responses are detected against all measured proteins (M, N, S and S1) while the N protein induces strongest CD8⁺ T-cell responses. CD4⁺ T-cell responses correlate with disease severity, humoral responses and age, whereas CD8⁺ T-cell responses correlate with age and functional antibodies. Further, CD8⁺ T-cell responses associate with several class I HLA alleles. Our results, provide new insight into HLA restriction of CD8⁺ T-cell immunity and other factors contributing to heterogeneity of T-cell responses following SARS-CoV-2 infection.

A study of 768 convalescent SARS CoV-2-infected and 500 uninfected Icelanders reveals broad and stable T-cell responses 3-8 months from infection. HLA alleles, disease severity, and age contribute to the heterogeneity of cellular immunity.

Rate of SARS-CoV-2 Reinfection During an Omicron Wave in Iceland

This cohort study estimates the proportion of persons who became reinfected with SARS-CoV-2 during the Omicron wave in Iceland.

Goal directed fluid removal with furosemide versus placebo in intensive care patients with fluid overload: a trial protocol for a randomised, blinded trial (GODIF Trial)

Background

Fluid overload is a risk factor for mortality in intensive care unit (ICU) patients. Administration of loop diuretics is the predominant treatment of fluid overload, but evidence for its benefit is very uncertain when assessed in a systematic review of randomised clinical trials. The GODIF trial will assess the benefits and harms of goal directed fluid removal with furosemide versus placebo in ICU patients with fluid overload.

Methods

An investigator‐initiated, international, randomised, stratified, blinded, parallel‐group trial allocating 1000 adult ICU patients with fluid overload to infusion of furosemide versus placebo. The goal is to achieve a neutral fluid balance. The primary outcome is days alive and out of hospital 90 days after randomisation. Secondary outcomes are all‐cause mortality at day 90 and 1‐year after randomisation; days alive at day 90 without life support; number of participants with one or more serious adverse events or reactions; health‐related quality of life and cognitive function at 1‐year follow‐up. A sample size of 1000 participants is required to detect an improvement of 8% in days alive and out of hospital 90 days after randomisation with a power of 90% and a risk of type 1 error of 5%. The conclusion of the trial will be based on the point estimate and 95% confidence interval; dichotomisation will not be used. ClinicalTrials.gov identifier: NCT04180397.

Perspective

The GODIF trial will provide important evidence of possible benefits and harms of fluid removal with furosemide in adult ICU patients with fluid overload.

Longitudinal changes in inflammatory biomarkers among patients with COVID-19: a nationwide study in Iceland

OBJECTIVES

All SARS-CoV-2-positive persons in Iceland were prospectively monitored and those who required outpatient evaluation or were admitted to hospital underwent protocolized evaluation that included a standardized panel of biomarkers. The aim was to describe longitudinal changes in inflammatory biomarkers throughout the infection period of patients with COVID-19 requiring different levels of care.

DESIGN

Registry-based study SETTING: Nationwide study in Iceland PATIENTS: All individuals who tested positive for SARS-CoV-2 by real-time polymerase chain reaction (RT-PCR) from 28 February to 31 December 2020 in Iceland and had undergone blood tests between five days prior to and 21 days following onset of symptoms.

MEASUREMENTS AND MAIN RESULTS

Data were collected from the electronic medical record system of Landspitali-The National University Hospital of Iceland. Data analyses were descriptive and the evolution of biomarkers was visualized using Locally Weighted Scatterplot Smoothing (LOWESS) curves stratified by the worst clinical outcome experienced by the patient: outpatient evaluation only, hospitalization, and either intensive care unit (ICU) admission or death. Of 571 included patients, 310 (54.3%) only required outpatient evaluation or treatment, 202 (35.4%) were hospitalized and 59 (10.3%) were either admitted to the ICU or died. An early and persistent separation of the mean lymphocyte count, plasma C-reactive protein (CRP) and ferritin levels was observed between the three outcome groups, which occurred prior to hospitalization for those who later were admitted to ICU or died. Lower lymphocyte count, and higher CRP and ferritin levels correlated with worse clinical outcomes. Patients who were either admitted to the ICU or died had sustained higher white blood cell (WBC) and neutrophil counts, and elevated plasma levels of PCT and D-dimer compared with the other groups.

CONCLUSIONS

Lymphocyte count and plasma CRP and ferritin levels might be suitable parameters to assess disease severity early during COVID-19 and may serve as predictors of worse outcome.

Utilization and outcomes of tracheostomies in the intensive care unit in Iceland in 2007-2020: A descriptive study

BACKGROUND

Tracheostomies are commonly utilized in ICU patients due to prolonged mechanical ventilation, upper airway obstruction, or surgery in the face/neck region. However, practices regarding the timing of placement and utilization vary. This study provides a nationwide overview of tracheostomy utilization and outcomes in the ICU over a 14-year period.

METHODS

A retrospective study including all patients that received a tracheostomy during their ICU stay in Iceland between 2007 and 2020. Data were retrieved from hospital records on admission cause, comorbidities, indication for tracheostomy insertion, duration of mechanical ventilation before and after tracheostomy placement, extubation attempts, complications, length of ICU and hospital stay and survival. Descriptive statistics were provided, and survival analysis was performed using Cox regression.

RESULTS

A total of 336 patients (median age 64 years, 33% females) received a tracheostomy during the study period. The most common indication for tracheostomy insertion was respiratory failure, followed by neurological disorders. The median duration of mechanical ventilation prior to tracheostomy insertion was 9 days and at least one extubation had been attempted in 35% of the cases. Percutaneous tracheostomies were 32%. The overall rate of complications was 25% and the most common short-term complication was bleeding (5%). In-hospital mortality was 33%. The one- and five-year survival rate was 60% and 44%, respectively.

CONCLUSIONS

We describe a whole-nation practice of tracheostomies. A notable finding is the relatively low rate of extubation attempts prior to tracheostomy insertion. Future work should focus on standardization of assessing the need for tracheostomy and the role of extubation attempts prior to tracheostomy placement.

Long-term survival of Icelandic women following acute myocardial infarction

Objective. To evaluate the impact of sex on treatment and survival after acute myocardial infarction (AMI) in Iceland. Methods. A retrospective, nationwide cohort study of patients with STEMI (2008-2018) and NSTEMI (2013-2018) and obstructive coronary artery disease. Patient and procedural information were obtained from a registry and electronic health records. Survival was estimated with Kaplan-Meier method and Cox regression analysis used to identify risk factors for long-term mortality. Excess mortality from the AMI episode was estimated by comparing the survival with age- and sex-matched population in Iceland at 30-day interval. Results. A total of 1345 STEMI-patients (24% women) and 1249 NSTEMI-patients (24% women) were evaluated. Women with STEMI (mean age: 71 ± 11 vs. 67 ± 12) and NSTEMI (mean age: 69 ± 13 vs. 62 ± 12) were older and less likely to have previous cardiovascular disease. There was neither sex difference in the extent of coronary artery disease nor treatment. Although crude one-year post-STEMI survival was lower for women (88.7% vs. 93.4%, p = .006), female sex was not an independent risk factor after adjusting for age and co-morbidities after STEMI and was protective for NSTEMI (HR 0.67, 95% CI: 0.46-0.97). There was excess 30-day mortality in both STEMI and NSTEMI for women compared with sex-, age- and inclusion year-matched Icelandic population, but thereafter the mortality rate was similar. Conclusion. Women and men with AMI in Iceland receive comparable treatment including revascularization and long-term survival appears similar. Prognosis after NSTEMI is better in women, whereas higher early mortality after STEMI may be caused by delays in presentation and diagnosis.

Reconstruction of a large-scale outbreak of SARS-CoV-2 infection in Iceland informs vaccination strategies

OBJECTIVES

The spread of SARS-CoV-2 is dependent on several factors, both biological and behavioural. The effectiveness of nonpharmaceutical interventions can be attributed largely to changes in human behaviour, but quantifying this effect remains challenging. Reconstructing the transmission tree of the third wave of SARS-CoV-2 infections in Iceland using contact tracing and viral sequence data from 2522 cases enables us to directly compare the infectiousness of distinct groups of persons.

METHODS

The transmission tree enables us to model the effect that a given population prevalence of vaccination would have had on the third wave had one of three different vaccination strategies been implemented before that time. This allows us to compare the effectiveness of the strategies in terms of minimizing the number of cases, deaths, critical cases, and severe cases.

RESULTS

We found that people diagnosed outside of quarantine (Rˆ=1.31) were 89% more infectious than those diagnosed while in quarantine (Rˆ=0.70) and that infectiousness decreased as a function of time spent in quarantine before diagnosis, with people diagnosed outside of quarantine being 144% more infectious than those diagnosed after ≥3 days in quarantine (Rˆ=0.54). People of working age, 16 to 66 years (Rˆ=1.08), were 46% more infectious than those outside of that age range (Rˆ=0.74).

DISCUSSION

We found that vaccinating the population in order of ascending age or uniformly at random would have prevented more infections per vaccination than vaccinating in order of descending age, without significantly affecting the expected number of deaths, critical cases, or severe cases.

Management of acute atrial fibrillation in the intensive care unit: An international survey

BACKGROUND

Atrial fibrillation (AF) is common in intensive care unit (ICU) patients and is associated with poor outcomes. Different management strategies exist, but the evidence is limited and derived from non-ICU patients. This international survey of ICU doctors evaluated the preferred management of acute AF in ICU patients.

METHOD

We conducted an international online survey of ICU doctors with 27 questions about the preferred management of acute AF in the ICU, including antiarrhythmic therapy in hemodynamically stable and unstable patients and use of anticoagulant therapy.

RESULTS

A total of 910 respondents from 70 ICUs in 14 countries participated in the survey with 24%-100% of doctors from sites responding. Most ICUs (80%) did not have a local guideline for the management of acute AF. The preferred first-line strategy for the management of hemodynamically stable patients with acute AF was observation (95% of respondents), rhythm control (3%), or rate control (2%). For hemodynamically unstable patients, the preferred strategy was observation (48%), rhythm control (48%), or rate control (4%). Overall, preferred antiarrhythmic interventions included amiodarone, direct current cardioversion, beta-blockers other than sotalol, and magnesium in that order. A total of 67% preferred using anticoagulant therapy in ICU patients with AF, among whom 61% preferred therapeutic dose anticoagulants and 39% prophylactic dose anticoagulants.

CONCLUSION

This international survey indicated considerable practice variation among ICU doctors in the clinical management of acute AF, including the overall management strategies and the use of antiarrhythmic interventions and anticoagulants.

A descriptive study of the surge response and outcomes of ICU patients with COVID-19 during first wave in Nordic countries

Background

We sought to provide a description of surge response strategies and characteristics, clinical management and outcomes of patients with severe COVID‐19 in the intensive care unit (ICU) during the first wave of the pandemic in Denmark, Finland, Iceland, Norway and Sweden.

Methods

Representatives from the national ICU registries for each of the five countries provided clinical data and a description of the strategies to allocate ICU resources and increase the ICU capacity during the pandemic. All adult patients admitted to the ICU for COVID‐19 disease during the first wave of COVID‐19 were included. The clinical characteristics, ICU management and outcomes of individual countries were described with descriptive statistics.

Results

Most countries more than doubled their ICU capacity during the pandemic. For patients positive for SARS‐CoV‐2, the ratio of requiring ICU admission for COVID‐19 varied substantially (1.6%–6.7%). Apart from age (proportion of patients aged 65 years or over between 29% and 62%), baseline characteristics, chronic comorbidity burden and acute presentations of COVID‐19 disease were similar among the five countries. While utilization of invasive mechanical ventilation was high (59%–85%) in all countries, the proportion of patients receiving renal replacement therapy (7%–26%) and various experimental therapies for COVID‐19 disease varied substantially (e.g. use of hydroxychloroquine 0%–85%). Crude ICU mortality ranged from 11% to 33%.

Conclusion

There was substantial variability in the critical care response in Nordic ICUs to the first wave of COVID‐19 pandemic, including usage of experimental medications. While ICU mortality was low in all countries, the observed variability warrants further attention.

Postoperative Acute Kidney Injury Is Associated With Progression of Chronic Kidney Disease Independent of Severity

BACKGROUND

Both postoperative acute kidney injury (AKI) and preoperative chronic kidney disease (CKD) are associated with significantly worse outcomes following surgery. The relationship of both of these conditions with each other and with CKD progression after surgery remains poorly studied. Our objective was to assess if there was an interaction between preoperative kidney function estimated by preoperative estimated glomerular filtration rate (eGFR)/CKD stage, postoperative AKI, and eGFR/CKD progression within 1 year of surgery. Our hypothesis was that AKI severity would be associated with a faster time to eGFR/CKD stage progression within 1 year of surgery in a graded-fashion, which would be exacerbated by preoperative kidney dysfunction.

METHODS

This was a retrospective cohort study at Landspitali University Hospital in Iceland, which serves about 75% of the population. Participants included adults receiving their first major anesthetic between 2005 and 2018. Patients with CKD stage 5, undergoing major urologic procedures, or having missing creatinine values for follow-up of eGFR stage were excluded from analysis. The primary exposure was postoperative AKI stage within 7 days after surgery classified by the kidney disease improving global outcome (KDIGO) criteria. The primary outcome was time to progression of CKD by at least 1 eGFR/CKD stage within 1-year following surgery. Multivariable Cox proportional hazards models were used to estimate hazard of eGFR/CKD stage progression, including an interaction between AKI and preoperative CKD on eGFR/CKD stage progression.

RESULTS

A total of 5548 patients were studied. In the multivariable model adjusting for baseline eGFR/CKD stage, when compared to patients without AKI, postoperative AKI stage 1 (hazard ratio [HR], 5.91; 95% confidence interval [CI], 4.34-8.05), stage 2 (HR, 3.86; 95% CI, 1.82-8.16), and stage 3 (HR, 3.61; 95% CI, 1.49-8.74) were all independently associated with faster time to eGFR/CKD stage progression within 1 year following surgery, though increasing AKI severity did not confer additional risk. The only significant interaction between the degree of AKI and the preexisting renal function was for stage 1 AKI, where the odds of 1-year eGFR/CKD stage progression actually decreased in patients with preoperative CKD categories 3a, 3b, and 4.

CONCLUSIONS

KDIGO-AKI was independently associated with eGFR/CKD stage progression within the year following surgery after adjustment for baseline eGFR/CKD stage and without an interaction between worse preoperative kidney function and higher stage AKI. Our observations suggest that further studies are warranted to test whether CKD progression could be prevented by the adoption of perioperative kidney protective practices.

Novel and Annotated Long Noncoding RNAs Associated with Ischemia in the Human Heart

BACKGROUND

Long noncoding RNAs (lncRNAs) have been implicated in the pathogenesis of cardiovascular diseases. We aimed to identify novel lncRNAs associated with the early response to ischemia in the heart.

METHODS AND RESULTS

RNA sequencing data gathered from 81 paired left ventricle samples from patients undergoing cardiopulmonary bypass was collected before and after a period of ischemia. Novel lncRNAs were validated with Oxford Nanopore Technologies long-read sequencing. Gene modules associated with an early ischemic response were identified and the subcellular location of selected lncRNAs was determined with RNAscope. A total of 2446 mRNAs, 270 annotated lncRNAs and one novel lncRNA differed in response to ischemia (adjusted p < 0.001, absolute fold change >1.2). The novel lncRNA belonged to a gene module of highly correlated genes that also included 39 annotated lncRNAs. This module associated with ischemia (Pearson correlation coefficient = -0.69, p = 1 × 10^-23) and activation of cell death pathways (p < 6 × 10^-9). A further nine novel cardiac lncRNAs were identified, of which, one overlapped five cis-eQTL eSNPs for the gene RWD Domain-Containing Sumoylation Enhancer (RWDD3) and was itself correlated with RWDD3 expression (Pearson correlation coefficient -0.2, p = 0.002).

CONCLUSION

We have identified 10 novel lncRNAs, one of which was associated with myocardial ischemia and may have potential as a novel therapeutic target or early marker for myocardial dysfunction.

Validation of the Hospital Frailty Risk Score in older surgical patients: A population-based retrospective cohort study

BACKGROUND

There is a need for standardized and cost-effective identification of frailty risk. The objective was to validate the Hospital Frailty Risk Score which utilizes International Classification Diagnoses in a cohort of older surgical patients, assess the score as an independent risk factor for adverse outcomes and compare discrimination properties of the frailty risk score with other risk stratification scores.

METHODS

Data were analysed from all patients ≥65 years undergoing primary surgical procedures from 2006-2018. Patients were categorized based on the frailty risk score. The primary outcomes were 30-day mortality and 180-day risk of readmission.

RESULTS

Of 16 793 patients evaluated, 7480 (45%), 7605 (45%) and 1708 (10%) had a low, intermediate and high risk of frailty. There was a higher incidence of 30-day mortality for individuals with intermediate (2.9%) and high (8.3%) compared with low (1.4%) risk of frailty (P < .001 for both comparisons). Similarly, the hazard of readmission within the first 180 days was higher for intermediate (HR 1.25; 95% CI: 1.16-1.34) and high (HR 1.84; 95% CI: 1.66-2.03) compared with low (HR 1.00, P < .001 for both comparisons) risk of frailty. The hazard of long-term mortality was higher for intermediate (HR 1.70; 95% CI: 1.61-1.80) and high (HR 4.16; 95% CI: 3.84-4.49) compared with low (HR 1.00, P < .001 for both comparisons) risk of frailty. Finally, long length of primary hospitalization occurred for 9.3%, 15.0% and 27.3% of individuals with low, intermediate and high frailty risk (P < .001 for all comparisons). A model including age and ASA classification had the best discrimination for 30-day mortality (AUC 0.862; 95% CI: 0.847-0.877).

CONCLUSION

Our findings suggest that the Hospital Frailty Risk Score might be used to screen older surgical patients for risk of frailty. While only slightly improving prediction of 30-day mortality using the ASA classification, the Hospital Frailty Risk Score can be used to independently classify older patients for the risk of important outcomes using pre-existing readily available electronic data.

Sepsis after elective surgery - Incidence, aetiology and outcome

BACKGROUND

Sepsis requiring admission to intensive care (ICU) is a rare complication of elective surgery, but is associated with high morbidity and mortality. The aim of this study was to describe the incidence and outcome of sepsis following elective surgery.

METHODS

This was a retrospective, observational study where all admissions to Icelandic ICUs during calendar years 2006, 2008, 2010, 2012, 2014 and 2016 were screened, identifing patients with sepsis following elective surgery (ACCP/SCCM criteria). The number of elective operations performed at the largest center (Landspitali) during the study years were collected. Descriptive statistics were used to assess the incidence and outcome of patients with sepsis after elective surgery.

RESULTS

During the study years, 88 patients were admitted to Icelandic ICUs with sepsis following elective surgery. Of those, 80 were operated at Landspitali, where the incidence of sepsis was 0.19% per elective procedure, highest following pancreaticoduodenectomies (14%, CI 6-25) and esophagectomies (13%, CI 4-27), but the greatest number of patients (30% (26/88)) developed sepsis after a colorectal procedure. The most common infection sources were the abdomen (65% (57/88)) and lungs/mediastinum (22% (19/88)), frequently polymicrobial (58% (36/62) of patients with cultures). The incidence of insufficient empirical antibiotics was high (50% (30/60)). The median ICU and hospital length-of-stay were 5.5 and 26 days and the 28-day and 1-year mortality rates were 16% (14/88) and 41% (36/87), respectively.

CONCLUSIONS

Incidence of sepsis following elective surgery is low in Iceland but mortality is high. Initial antimicrobial therapy needs careful consideration in these hospital-acquired, often polymicrobial infections.

Clinical spectrum of coronavirus disease 2019 in Iceland: population based cohort study

OBJECTIVE

To characterise the symptoms of coronavirus disease 2019 (covid-19).

DESIGN

Population based cohort study.

SETTING

Iceland.

PARTICIPANTS

All individuals who tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by reverse transcription polymerase chain reaction (RT-PCR) between 17 March and 30 April 2020. Cases were identified by three testing strategies: targeted testing guided by clinical suspicion, open invitation population screening based on self referral, and random population screening. All identified cases were enrolled in a telehealth monitoring service, and symptoms were systematically monitored from diagnosis to recovery.

MAIN OUTCOME MEASURES

Occurrence of one or more of 19 predefined symptoms during follow-up.

RESULTS

Among 1564 people positive for SARS-CoV-2, the most common presenting symptoms were myalgia (55%), headache (51%), and non-productive cough (49%). At the time of diagnosis, 83 (5.3%) individuals reported no symptoms, of whom 49 (59%) remained asymptomatic during follow-up. At diagnosis, 216 (14%) and 349 (22%) people did not meet the case definition of the Centers for Disease Control and Prevention and the World Health Organization, respectively. Most (67%) of the SARS-CoV-2-positive patients had mild symptoms throughout the course of their disease.

CONCLUSION

In the setting of broad access to RT-PCR testing, most SARS-CoV-2-positive people were found to have mild symptoms. Fever and dyspnoea were less common than previously reported. A substantial proportion of SARS-CoV-2-positive people did not meet recommended case definitions at the time of diagnosis.

Humoral Immune Response to SARS-CoV-2 in Iceland

BACKGROUND

Little is known about the nature and durability of the humoral immune response to infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

METHODS

We measured antibodies in serum samples from 30,576 persons in Iceland, using six assays (including two pan-immunoglobulin [pan-Ig] assays), and we determined that the appropriate measure of seropositivity was a positive result with both pan-Ig assays. We tested 2102 samples collected from 1237 persons up to 4 months after diagnosis by a quantitative polymerase-chain-reaction (qPCR) assay. We measured antibodies in 4222 quarantined persons who had been exposed to SARS-CoV-2 and in 23,452 persons not known to have been exposed.

RESULTS

Of the 1797 persons who had recovered from SARS-CoV-2 infection, 1107 of the 1215 who were tested (91.1%) were seropositive; antiviral antibody titers assayed by two pan-Ig assays increased during 2 months after diagnosis by qPCR and remained on a plateau for the remainder of the study. Of quarantined persons, 2.3% were seropositive; of those with unknown exposure, 0.3% were positive. We estimate that 0.9% of Icelanders were infected with SARS-CoV-2 and that the infection was fatal in 0.3%. We also estimate that 56% of all SARS-CoV-2 infections in Iceland had been diagnosed with qPCR, 14% had occurred in quarantined persons who had not been tested with qPCR (or who had not received a positive result, if tested), and 30% had occurred in persons outside quarantine and not tested with qPCR.

CONCLUSIONS

Our results indicate that antiviral antibodies against SARS-CoV-2 did not decline within 4 months after diagnosis. We estimate that the risk of death from infection was 0.3% and that 44% of persons infected with SARS-CoV-2 in Iceland were not diagnosed by qPCR.

Humoral Immune Response to SARS-CoV-2 in Iceland

BACKGROUND

Little is known about the nature and durability of the humoral immune response to infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

METHODS

We measured antibodies in serum samples from 30,576 persons in Iceland, using six assays (including two pan-immunoglobulin [pan-Ig] assays), and we determined that the appropriate measure of seropositivity was a positive result with both pan-Ig assays. We tested 2102 samples collected from 1237 persons up to 4 months after diagnosis by a quantitative polymerase-chain-reaction (qPCR) assay. We measured antibodies in 4222 quarantined persons who had been exposed to SARS-CoV-2 and in 23,452 persons not known to have been exposed.

RESULTS

Of the 1797 persons who had recovered from SARS-CoV-2 infection, 1107 of the 1215 who were tested (91.1%) were seropositive; antiviral antibody titers assayed by two pan-Ig assays increased during 2 months after diagnosis by qPCR and remained on a plateau for the remainder of the study. Of quarantined persons, 2.3% were seropositive; of those with unknown exposure, 0.3% were positive. We estimate that 0.9% of Icelanders were infected with SARS-CoV-2 and that the infection was fatal in 0.3%. We also estimate that 56% of all SARS-CoV-2 infections in Iceland had been diagnosed with qPCR, 14% had occurred in quarantined persons who had not been tested with qPCR (or who had not received a positive result, if tested), and 30% had occurred in persons outside quarantine and not tested with qPCR.

CONCLUSIONS

Our results indicate that antiviral antibodies against SARS-CoV-2 did not decline within 4 months after diagnosis. We estimate that the risk of death from infection was 0.3% and that 44% of persons infected with SARS-CoV-2 in Iceland were not diagnosed by qPCR.

Acute Kidney Injury After Acute Repair of Type A Aortic Dissection

BACKGROUND

The aim of this study was to examine the incidence, risk factors, and outcomes of patients with acute kidney injury (AKI) after surgery for acute type A aortic dissection (ATAAD) using the Nordic Consortium for Acute Type A Aortic Dissection registry.

METHODS

Patients who underwent ATAAD surgery at 8 Nordic centers from 2005 to 2014 were analyzed for AKI according to the RIFLE criteria. Patients who died intraoperatively, those who had missing baseline or postoperative serum creatinine, and patients on preoperative renal replacement therapy were excluded.

RESULTS

AKI occurred in 382 of 941 patients (40.6%), and postoperative dialysis was required for 105 patients (11.0%). Renal malperfusion was present preoperatively in 42 patients (5.1%), of whom 69.0% developed postoperative AKI. In multivariable analysis patient-related predictors of AKI included age (per 10 years; odds ratio [OR], 1.30; 95% confidence interval [CI], 1.15-1.48), body mass index >30 kg/m² (OR, 2.16; 95% CI, 1.51-3.09), renal malperfusion (OR, 4.39; 95% CI, 2.23-9.07), and other malperfusion (OR, 2.10; 95% CI, 1.55-2.86). Perioperative predictors were cardiopulmonary bypass time (per 10 minutes; OR, 1.04; 95% CI, 1.02-1.07) and red blood cell transfusion (OR per transfused unit, 1.08; 95% CI, 1.06-1.10). Rates of 30-day mortality were 17.0% in the AKI group compared with 6.6% in the non-AKI group (P < .001). In 30-day survivors AKI was an independent predictor of long-term mortality (hazard ratio, 1.86; 95% CI; 1.24-2.79).

CONCLUSIONS

AKI is a common complication after surgery for ATAAD and independently predicts adverse long-term outcome. Of note one-third of patients presenting with renal malperfusion did not develop postoperative AKI, possibly because of restoration of renal blood flow with surgical repair. Mortality risk persists beyond the perioperative period, indicating that close clinical follow-up of these patients is required.

Reoperation for bleeding following coronary artery bypass surgery with special focus on long-term outcomes

Objectives: We studied the incidence and risk factors of reoperation for bleeding following CABG in a nationwide cohort with focus on long-term complications and survival. Design: A retrospective study on 2060 consecutive, isolated CABG patients operated 2001-2016. Outcome of reoperated patients (n = 130) were compared to non-reoperated ones (n = 1930), including major adverse cardiac and cerebrovascular events (MACCE) and overall survival. Risk factors for reoperation were determined using multivariate logistic regression and a Cox proportional hazards model to assess prognostic factors of long-term survival. Median follow-up was 7.6 years. Results: One hundred thirty patients (6.3%) were reoperated with an annual decrease of 4.1% per year over the study period (p=.04). Major complications (18.5 vs. 9.6%) and 30-day mortality (8.5 vs. 1.9%,) were higher in the reoperation group (p<.001). The use of clopidogrel preoperatively (OR 3.62, 95% CI: 1.90-6.57) and reduced left ventricular ejection fraction (OR 2.23, 95% CI: 1.25-3.77) were the strongest predictors of reoperation, whereas off-pump surgery was associated with a lower reoperation risk (OR 0.44, 95% CI: 0.22-0.85). After exluding patients that died within 30 days postoperatively, no difference in long-term survival or freedom from MACCE was found between groups, and reoperation was not an independent risk factor for long-term mortality in multivariate analysis. Conclusions: The reoperation rate in this study was relatively high but decreased significantly over time. Reoperation was associated with twofold increased risk for major complications and fourfold 30-day mortality, but comparable long-term MACCE and survival rates. This implies that if patients survive the first 30 days following reoperation, their long-term outcome is comparable to non-reoperated patients.

A retrospective cohort study on the association between elevated preoperative red cell distribution width and all-cause mortality after noncardiac surgery

BACKGROUND

Elevated red cell distribution width (RDW) has been associated with worse outcomes in several medical patient populations. The aim of this study was to investigate the association of increased preoperative RDW and short- and long-term mortality after noncardiac surgery.

METHODS

This investigation was a retrospective cohort study including all patients undergoing noncardiac surgery between 2005 and 2015 at Landspitali-the National University Hospital in Iceland. Patients were separated into five predefined groups based on preoperative RDW (≤13.3%, 13.4-14.0%, 14.1-14.7%, 14.8-15.8%, and >15.8%). The primary outcome was all-cause long-term mortality and secondary outcomes included 30-day mortality, length of stay, and readmissions within 30 days, compared with propensity score matched (PSM) cohort from patients with RDW ≤13.3%.

RESULTS

There was a higher hazard of long-term mortality for patients with RDW between 14.8% and 15.8% (hazard ratio=1.33; 95% confidence interval, 1.15-1.59; P<0.001) and above 15.8% (hazard ratio=1.66; 95% confidence interval, 1.41-1.95; P<0.001), compared with matched controls with RDW ≤13.3%. This association held in multiple patient subgroups. For secondary outcomes, there was no difference in 30-day mortality, length of stay, or risk of readmission within 30 days.

CONCLUSIONS

Increased preoperative RDW is associated with increased long-term mortality after noncardiac surgery. RDW could be a composite biomarker of pre-existing chronic inflammation and poor nutritional status. Future studies should clarify if this is a modifiable risk factor for improved surgical outcomes.

The demographics of persistent opioid consumption following limb amputation

BACKGROUND

Patients who have limb amputation are at risk of chronic pain, including phantom limb pain that can be challenging to treat. The aim of this study was to describe the incidence of pre-operative opioid usage and the incidence and risk factors for new persistent post-operative opioid usage in opioid-naïve patients after limb amputation.

METHODS

A retrospective study of all patients 18 years and older underwent upper or lower extremity amputations in Landspitali University Hospital between 2005 and 2015. Patients were considered to use opioids pre-operatively if they filled an opioid prescription 1-6 months prior to amputation and were considered to have persistent opioid use if opioid prescriptions were filled between post-operative months four to twenty-four. In addition to incidence estimate, uni- and multivariate analysis was performed to identify risk factors for persistent post-operative opioid usage.

RESULTS

Of 328 total patients, 216 (66%) were opioid naïve and 112 (34%) were chronic opioid users. Of the opioid-naïve patients surviving more than 3 months 40 (20%) developed persistent post-operative opioid usage. In multivariate analysis, factors independently associated with persistent post-operative opioid usage were younger age, male gender, pre-operative use of neuropathic medications or benzodiazepines and lower (opposed to upper) extremity amputation.

CONCLUSION

Opioid naïve patients undergoing major amputation had a 20% chance of having a persistent opioid requirement following surgery. This could represent new-onset phantom limb pain or other chronic pain. Our findings should encourage perioperative multimodal efforts to reduce the burden of chronic pain after limb amputations.

Long-term survival after intensive care: A retrospective cohort study

Background Limited data exist on long-term survival of patients requiring admission to intensive care units (ICUs). The aim of this study was to investigate long-term survival of ICU patients in Iceland and assess changes over a 15-year period. Methods Data were collected on age, gender, admission cause, length of stay, comorbidities, mechanical ventilation and survival of patients 18 years and older admitted to the ICUs in Landspitali during 2002-2016. Long-term survival of patients surviving more than 30 days from admission was estimated and its predictors assessed with Cox regression analysis. Long-term survival was compared to the survival of an age- and gender-matched reference group from the general population. Results Of 15 832 ICU admissions, 55% was medical, 38% was surgical and 7% was due to trauma. The 5-year survival of medical, surgical and trauma patients was 66%, 76% and 92% respectively. Significant survival differences were found between admission subgroups. Higher age and comorbidity burden was related to decreased survival in all patient groups. After correcting for age, gender, comorbidities, length of ICU stay and mechanical ventilation, patient survival improved during the study period only for patients admitted for infections. There was a high variability in the estimated time point where the ICU admission had no residual effect on survival. Conclusions Long-term survival of ICU patients is substantially decreased compared to the general population, but varies based on admission causes. Improved long-term survival of patients admitted with infections could be explained by earlier detection and improved treatment of septic shock.

Association Between Preoperative Opioid and Benzodiazepine Prescription Patterns and Mortality After Noncardiac Surgery

Importance

The number of patients prescribed long-term opioids and benzodiazepines and complications from their long-term use have increased. Information regarding the perioperative outcomes of patients prescribed these medications before surgery is limited.

Objective

To determine whether patients prescribed opioids and/or benzodiazepines within 6 months preoperatively would have greater short- and long-term mortality and increased opioid consumption postoperatively.

Design, Setting, and Participants

This retrospective, single-center, population-based cohort study included all patients 18 years or older, undergoing noncardiac surgical procedures at a national hospital in Iceland from December 12, 2005, to December 31, 2015, with follow-up through May 20, 2016. A propensity score-matched control cohort was generated using individuals from the group that received prescriptions for neither medication class within 6 months preoperatively. Data analysis was performed from April 10, 2018, to March 9, 2019.

Exposures

Patients who filled prescriptions for opioids only, benzodiazepines only, both opioids and benzodiazepines, or neither medication within 6 months preoperatively.

Main Outcomes and Measures

Long-term survival compared with propensity score-matched controls. Secondary outcomes were 30-day survival and persistent postoperative opioid consumption, defined as a prescription filled more than 3 months postoperatively.

Results

Among 41 170 noncardiac surgical cases in 27 787 individuals (16 004 women [57.6%]; mean [SD] age, 56.3 [18.8] years), a preoperative prescription for opioids only was filled for 7460 cases (17.7%), benzodiazepines only for 3121 (7.4%), and both for 2633 (6.2%). Patients who filled preoperative prescriptions for either medication class had a greater comorbidity burden compared with patients receiving neither medication class (Elixhauser comorbidity index >0 for 16% of patients filling prescriptions for opioids only, 22% for benzodiazepines only, and 21% for both medications compared with 14% for patients filling neither). There was no difference in 30-day (opioids only: 1.3% vs 1.0%; P = .23; benzodiazepines only: 1.9% vs 1.5%; P = .32) or long-term (opioids only: hazard ratio [HR], 1.12 [95% CI, 1.01-1.24]; P = .03; benzodiazepines only: HR, 1.11 [95% CI, 0.98-1.26]; P = .11) survival among the patients receiving opioids or benzodiazepines only compared with controls. However, patients prescribed both opioids and benzodiazepines had greater 30-day mortality (3.2% vs 1.8%; P = .004) and a greater hazard of long-term mortality (HR, 1.41; 95% CI, 1.22-1.64; P < .001). The rate of persistent postoperative opioid consumption was higher for patients filling prescriptions for opioids only (43%), benzodiazepines only (23%), or both (66%) compared with patients filling neither (12%) (P < .001 for all).

Conclusions and Relevance

The findings suggest that opioid and benzodiazepine prescription fills in the 6 months before surgery are associated with increased short-and long-term mortality and an increased rate of persistent postoperative opioid consumption. These patients should be considered for early referral to preoperative clinic and medication optimization to improve surgical outcomes.

Venovenous extracorporeal membrane oxygenation treatment in a low-volume and geographically isolated cardiothoracic centre

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) treatment is generally offered in large tertiary cardiothoracic referral centres. Here we present the indications and outcome of venovenous-ECMO (VV-ECMO) treatment in a low-volume, geographically isolated single-centre in Iceland, a country of 350 000 inhabitants. Our hypothesis was that patient survival in such a centre can be similar to that at high-volume centres.

METHODS

A retrospective study that included all patients treated with VV-ECMO in Iceland from 1991-2016 (n = 17). Information on demographics, indications and in-hospital survival was collected from patient charts and APACHE II and Murray scores were calculated. Information on long-term survival was collected from a centralized registry.

RESULTS

Seventeen patients were treated with VV-ECMO (nine males, median age 33 years, range 14-74), the indication for 16 patients was severe acute respiratory distress syndrome, most often following pneumonia (n = 6), H1N1-infection (n = 3) or drowning (n = 2). Median APACHE-II and Murray-scores were 20 and 3.5, respectively, and median duration of VV-ECMO treatment was 9 days (range 2-40 days). In total 11 patients (64,7%) survived the treatment, with 10 patients (58,8%) surviving hospital discharge, all of who were still alive at long-term follow-up, with a median follow-up time of 9 years (August 15th, 2017).

CONCLUSION

Venovenous-ECMO service can be provided in a low-volume and geographically isolated centre, like Iceland, with short- and long-term outcomes comparable to larger centres.

Postoperative Acute Kidney Injury: Focus on Renal Recovery Definitions, Kidney Disease Progression and Survival

BACKGROUND

The aim of this study was to examine different definitions of renal recovery following postoperative acute kidney injury (AKI) and how these definitions associate with survival and the development and progression of chronic kidney disease (CKD).

METHODS

This was a retrospective study of all patients who underwent abdominal, cardiothoracic, vascular, or orthopedic surgery at a single university hospital between 1998 and 2015. Recovery of renal function following postoperative AKI was assessed comparing 4 different definitions: serum creatinine (SCr) (i) < 1.1 × baseline, (ii) 1.1-1.25 × baseline, (iii) 1.25-1.5 × baseline, and (iv) > 1.5 × baseline. One-year survival and the development or progression of CKD within 5 years was compared with a propensity score-matched control groups.

RESULTS

In total, 2,520 AKI patients were evaluated for renal recovery. Risk of incident and progressive CKD within 5 years was significantly increased if patients did not achieve a reduction in SCr to < 1.5 × baseline (hazard ratio [HR] 1.50; 95% CI 1.29-1.75) and if renal recovery was limited to a fall in SCr to 1.25-1.5 × baseline (HR 1.32; 95% CI 1.12-1.57) within 30 days. The definition of renal recovery that best predicted survival was a reduction in SCr to < 1.5 × baseline within 30 days. One-year survival of patients whose SCr decreased to < 1.5 × baseline within 30 days was significantly better than that of a propensity score-matched control group that did not achieve renal recovery (85 vs. 71%, p < 0.001).

CONCLUSIONS

These findings should be considered when a consensus definition of renal recovery after AKI is established.

Temporary autonomic modulation with botulinum toxin type A to reduce atrial fibrillation after cardiac surgery

BACKGROUND

Postoperative atrial fibrillation (POAF) frequently complicates cardiac surgery and is associated with worse outcomes. The cardiac autonomic nervous system is implicated in the pathogenesis of POAF.

OBJECTIVE

The purpose of this study was to determine the efficacy and safety of selective cardiac autonomic modulation in preventing POAF.

METHODS

In this randomized, double-blind, placebo-controlled trial, adults undergoing cardiac surgery were randomized 1:1 to intraoperative injection of 250 units onabotulinumtoxinA (botulinum toxin type A [BoNTA]) or placebo into epicardial fat pads. The study was powered to detect a 40% reduction in relative risk of POAF. Time to first episode of in-hospital POAF was the primary outcome, evaluated in patients receiving injection. Additionally, incidence of POAF, length of stay (LOS), and adverse events were examined.

RESULTS

The trial assigned 145 patients to injection, 15 of whom were dropped before treatment, leaving 130 patients for analysis. Overall, 36.5% (23/63) of BoNTA-treated patients developed POAF compared with 47.8% (32/67) of placebo-treated patients. The time-to-event analysis revealed a hazard ratio of 0.69 (95% confidence interval 0.41-1.19; P = .18) for the BoNTA vs placebo arm. There were no significant differences in postoperative hospital LOS (median [interquartile range] 6.0 [3.4] vs 6.2 [3.7] days; P = .51) or adverse events prolonging LOS (27/63 [42.9%] vs 30/67 [44.8%]; P = .83) in patients receiving BoNTA vs placebo.

CONCLUSION

Epicardial injection of onabotulinumtoxinA was without discernible adverse effects, but we failed to detect a significant difference in risk of POAF. Future large-scale studies of epicardial onabotulinumtoxinA injection as a potential POAF prevention strategy should be designed to study smaller, but clinically meaningful, treatment effects.

Utility of Angle Correction for Hemodynamic Measurements with Doppler Echocardiography

OBJECTIVES

The routine application angle correction (AnC) in hemodynamic measurements with transesophageal echocardiography currently is not recommended but potentially could be beneficial. The authors hypothesized that AnC can be applied reliably and may change grading of aortic stenosis (AS).

DESIGN

Retrospective analysis.

SETTING

Single institution, university hospital.

PARTICIPANTS

During phase I, use of AnC was assessed in 60 consecutive patients with intraoperative transesophageal echocardiography. During phase II, 129 images from a retrospective cohort of 117 cases were used to quantify AS by mean pressure gradient.

INTERVENTIONS

A panel of observers used custom-written software in Java to measure intra-individual and inter-individual correlation in AnC application, correlation with preoperative transthoracic echocardiography gradients, and regrading of AS after AnC.

MEASUREMENTS AND MAIN RESULTS

For phase I, the median AnC was 21 (16-35) degrees, and 17% of patients required no AnC. For phase II, the median AnC was 7 (0-15) degrees, and 37% of assessed images required no AnC. The mean inter-individual and intra-individual correlation for AnC was 0.50 (95% confidence interval [CI] 0.49-0.52) and 0.87 (95% CI 0.82-0.92), respectively. AnC did not improve agreement with the transthoracic echocardiography mean pressure gradient. The mean inter-rater and intra-rater agreement for grading AS severity was 0.82 (95% CI 0.81-0.83) and 0.95 (95% CI 0.91-0.95), respectively. A total of 241 (7%) AS gradings were reclassified after AnC was applied, mostly when the uncorrected mean gradient was within 5 mmHg of the severity classification cutoff.

CONCLUSIONS

AnC can be performed with a modest inter-rater and intra-rater correlation and high degree of inter-rater and intra-rater agreement for AS severity grading.

Should the dilated ascending aorta be repaired at the time of bicuspid aortic valve replacement?

OBJECTIVES

Bicuspid aortic valve (BAV) is the most common congenital valvular abnormality and frequently presents with accelerated calcific aortic valve disease, requiring aortic valve replacement (AVR) and thoracic aortic aneurysm and dissection. Supporting evidence for Association Guidelines of aortic dimensions for aortic resection is sparse. We sought to determine whether concurrent repair of dilated or aneurysmal aortic disease during AVR in patients with BAV substantially improves morbidity and mortality outcomes.

METHODS

Mortality and reoperation outcomes of 1301 adults with BAV and dilated aorta undergoing AVR-only surgery were compared to patients undergoing AVR with aortic resection (AVR-AR) using Cox proportional hazards modelling and patient matching.

RESULTS

Clinically important differences in patient characteristics, aortic valve function and aortic dimensions were identified between cohorts. Event rates were low, with rates of reoperation and death within 1 year of only 1.8% and 5.4%, respectively, and no aortic dissection observed during follow-up. There were no significant differences in reoperation or mortality outcomes between the AVR-only and AVR-AR cohorts. Age, aortic dimension or a combination thereof was not associated with better or worse outcomes after each AVR-AR compared with AVR.

CONCLUSIONS

We conclude AVR-only and AVR-AR surgery have low morbidity and mortality and have utility over a wide range of age and aortic sizes. Our results do not provide support for the 45-mm aortic dimension recommended in the current guidelines for aortic resection while performing AVR or any other specific dimension.

The Long Noncoding RNA Landscape of the Ischemic Human Left Ventricle

BACKGROUND

The discovery of functional classes of long noncoding RNAs (lncRNAs) has expanded our understanding of the variety of RNA species that exist in cells. In the heart, lncRNAs have been implicated in the regulation of development, ischemic and dilated cardiomyopathy, and myocardial infarction. Nevertheless, there is a limited description of expression profiles for these transcripts in human subjects.

METHODS AND RESULTS

We obtained left ventricular tissue from human patients undergoing cardiac surgery and used RNA sequencing to describe an lncRNA profile. We then identified a list of lncRNAs that were differentially expressed between pairs of samples before and after the ischemic insult of cardiopulmonary bypass. The expression of some of these lncRNAs correlates with ischemic time. Coding genes in close proximity to differentially expressed lncRNAs and coding genes that have coordinated expression with these lncRNAs are enriched in functional categories related to myocardial infarction, including heart function, metabolism, the stress response, and the immune system.

CONCLUSIONS

We describe a list of lncRNAs that are differentially expressed after ischemia in the human heart. These genes are predicted to function in pathways consistent with myocardial injury. As a result, lncRNAs may serve as novel diagnostic and therapeutic targets for ischemic heart disease.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00985049.

Favourable long-term outcome after coronary artery bypass grafting in a nationwide cohort

OBJECTIVES

In a nationwide cohort, we analyzed long-term outcome following coronary artery bypass grafting, using the combined strategy of left internal mammary artery to the left anterior descending artery and saphenous vein as secondary graft to other coronary targets.

METHODS

1,507 consecutive patients that underwent myocardial revascularization during 2001-2012 in Iceland. Mean follow-up was 6.8 years. Major adverse cardiac and cerebrovascular events were depicted using the Kaplan-Meier method. Cox-regression was used to define risk factors. Relative survival was estimated by comparing overall survival to the survival of Icelanders of the same age and gender.

RESULTS

Mean age was 66 years, 83% were males, mean EuroSCOREst was 4.5, and 23% of the procedures were performed off-pump. At 5 years, 19.7% had suffered a major adverse cardiac or cerebrovascular event, 4.5% a stroke, 2.2% myocardial infarction, and 6.2% needed repeat revascularization. Overall 5-year survival was 89.9%, with a relative survival of 0.990. Independent predictors of major adverse cardiac and cerebrovascular events were left ventricular ejection fraction ≤30%, a previous history of percutaneous coronary intervention, chronic obstructive lung disease, chronic kidney disease, diabetes, and old age. The same variables and an earlier year of operation were predictors of long-term mortality.

CONCLUSIONS

The long-term outcome following myocardial revascularization, using the left internal mammary artery and the great saphenous vein as conduits, is favourable and improving. This is reflected by the 5-year survival of 89.9%, deviating minimally from the survival rate of the general Icelandic population, together with a freedom from major adverse cardiac and cerebrovascular events of 80.3%.