Intraosseous access in the resuscitation of patients with trauma: the good, the bad, the future

The timely restoration of lost blood in hemorrhaging patients with trauma, especially those who are hemodynamically unstable, is of utmost importance. While intravenous access has traditionally been considered the primary method for vascular access, intraosseous (IO) access is gaining popularity as an alternative for patients with unsuccessful attempts. Previous studies have highlighted the higher success rate and easier training process associated with IO access compared with peripheral intravenous (PIV) and central intravenous access. However, the effectiveness of IO access in the early aggressive resuscitation of patients remains unclear. This review article aims to comprehensively discuss various aspects of IO access, including its advantages and disadvantages, and explore the existing literature on the clinical outcomes of patients with trauma undergoing resuscitation with IO versus intravenous access.

Cardiorespiratory Instability after Percutaneous Patent Ductus Arteriosus Closure: A Multicenter Cohort Study

OBJECTIVE

To evaluate post-procedural clinical characteristics of preterm infants undergoing transcatheter patent ductus arteriosus (PDA) closure, including oxygenation/ventilation failure and cardiovascular compromise STUDY DESIGN: Multicenter retrospective cohort study of preterm infants who were ≤2 kg at the time of percutaneous PDA closure between August 2018 and July 2021. Indices of cardiorespiratory stability were collected pre-closure, immediately post-closure, and subsequently averaged every 4 hours for the first 24 hours post-procedure. The primary outcome was incidence of post-transcatheter cardiorespiratory syndrome: composite of: (i) hemodynamic instability (defined by systemic hypotension, systemic hypertension, or use of new inotropes/vasopressors in the first 24 hours after catheterization and at least one of the following: (i)ventilation failure or (ii) oxygenation failure.

RESULTS

A total of 197 patients were included with a median [IQR] age and weight at catheterization of 34 [25, 43] days and 1090 [900, 1367] grams, respectively. The primary composite outcome was reported in 46 (23.3%) patients and subcomponents of oxygenation and/or ventilation failure, systolic hypotension or systolic hypertension were noted in 81 (41.1%), 3 (1.5%) and 86 (43.6%) respectively. Logistic regression models showed weight at catheterization and respiratory severity score pre-closure to be significantly associated with post-transcatheter cardiorespiratory syndrome.

CONCLUSION

Post-transcatheter cardiorespiratory syndrome is characterized primarily by systemic hypertension and oxygenation failure, with a very low incidence of hypotension and need for inotropes.

Comparison between perfusion index, pleth variability index, and pulse pressure variability for prediction of hypotension during major abdominal surgery under general anaesthesia: A prospective observational study

Background and Aims

Short-term hypotension after general anaesthesia can negatively impact surgical outcomes. This study compared the predictive potential of the pleth variability index (PVI), pulse pressure variability (PPV), and perfusion index (PI) for anaesthesia-induced hypotension. This study's primary objective was to evaluate the predictive potential of PI, PVI, and PPV for hypotension.

Methods

This observational study included 140 adult patients undergoing major abdominal surgery under general anaesthesia. Mean arterial pressure, heart rate, PVI, PPV, and PI were collected at 1-min intervals up to 20 min post anaesthesia induction. Hypotension was assessed at 5-min and 15-min intervals. Receiver operating characteristic (ROC) curves were plotted to determine the diagnostic performance and best cut-off for continuous variables in predicting a dichotomous outcome. Statistical significance was kept at P < 0.05.

Results

Hypotension prevalence within 5 and 15 min of anaesthesia induction was 36.4% and 45%, respectively. A PI cut-off of <3.5 had an area under the ROC curve (AUROC) of 0.647 (P = 0.004) for a 5-min hypotension prediction. The PVI's AUROC was 0.717 (P = 0.001) at cut-off >11.5, while PPV's AUROC was 0.742 (P = 0.001) at cut-off >12.5. At 15 min, PVI's AUROC was 0.615 (95% confidence interval 0.521-0.708, P = 0.020), with 54.9% positive predictive value and 65.2% negative predictive value.

Conclusion

PVI, PPV, and PI predicted hypotension within 5 min after general anaesthesia induction. PVI had comparatively higher accuracy, sensitivity, specificity, and positive predictive value than PI and PPV when predicting hypotension at 15 min.

Impact of Using Blood Warmer During Continuous Kidney Replacement Therapy in Patients With Acute Kidney Injury

PURPOSE

We investigated the impact of blood warmer use on hypotensive episodes in patients with acute kidney injury (AKI) receiving continuous kidney replacement therapy (CKRT).

MATERIALS AND METHODS

We included patients with AKI undergoing CKRT between January 1, 2012, and January 1, 2021, at a tertiary academic hospital. Hypotensive episodes were defined as mean arterial pressure (MAP) <60 mm Hg or a decrease in MAP by ≥10 mm Hg, systolic blood pressure (SBP) < 90 mm Hg or a decrease in SBP by ≥20 mm Hg, or increased vasopressor requirement. These were analyzed by Poisson regression with repeated-measures analysis of variance using generalized estimation equation.

RESULTS

There were 669 patients with AKI that required CKRT. Use of blood warmer on first day of CKRT was in 324 (48%) patients. Incidence rate ratio of hypotensive episodes during the first 24-h of CKRT in patients where a blood warmer was used was 1.06 (95% confidence interval [CI]: 0.98-1.13) compared to those where blood warmer was not used. This did not change in adjusted model. Overall, the within-subject effect of temperature on hypotensive episodes showed that higher temperature was associated with fewer episodes (0.94, 95% CI: 0.9-0.99 per 10 degrees increase, P = .007).

CONCLUSION

Blood rewarming was not associated with hypotensive episodes during CKRT.

Anaesthetic efficacy and postinduction hypotension with remimazolam compared with propofol: a multicentre randomised controlled trial

Remimazolam, a short-acting benzodiazepine, may be used for induction and maintenance of total intravenous anaesthesia, but its role in the management of patients with multiple comorbidities remains unclear. In this phase 3 randomised controlled trial, we compared the anaesthetic efficacy and the incidence of postinduction hypotension during total intravenous anaesthesia with remimazolam vs. propofol. A total of 365 patients (ASA physical status 3 or 4) scheduled for elective surgery were assigned randomly to receive total intravenous anaesthesia with remimazolam (n = 270) or propofol (n = 95). Primary outcome was anaesthetic effect, quantified as the percentage of time with Narcotrend® Index values ≤ 60, during surgery (skin incision to last skin suture), with a non-inferiority margin of -10%. Secondary outcome was the incidence of postinduction hypotensive events. Mean (SD) percentage of time with Narcotrend Index values ≤ 60 during surgery across all patients receiving remimazolam (93% (20.7)) was non-inferior to propofol (99% (4.2)), mean difference (97.5%CI) -6.28% (-8.89-infinite); p = 0.003. Mean (SD) number of postinduction hypotension events was 62 (38.1) and 71 (41.1) for patients allocated to the remimazolam and propofol groups, respectively; p = 0.015. Noradrenaline administration events (requirement for a bolus and/or infusion) were also lower in patients allocated to remimazolam compared with propofol (14 (13.5) vs. 20 (14.6), respectively; p < 0.001). In conclusion, in patients who were ASA physical status 3 or 4, the anaesthetic effect of remimazolam was non-inferior to propofol.

Comparison of the effect of intravenous phenylephrine and norepinephrine boluses for post-spinal hypotension on neonatal outcome in elective caesarean section: A randomised controlled trial

Background and Aims

There is limited data on the effects of norepinephrine on neonatal outcomes and maternal complications relative to other vasopressors. The study aimed to compare neonatal outcomes and maternal complications after bolus intravenous doses of phenylephrine and norepinephrine for post-spinal hypotension in elective caesarean section women.

Methods

This randomised study was done on 100 elective caesarean section women under spinal anaesthesia. Block randomisation divided women into two groups to receive intravenous phenylephrine 50 μg bolus (Group A) or norepinephrine 5 μg bolus (Group B) following post-spinal hypotension. Groups were evaluated and compared for umbilical arterial blood gas analysis, birth weight, APGAR (appearance, pulse, grimace, activity, and respiration) score, maternal haemodynamics, and complications. Kolmogorov-Smirnov and Shapiro-Wilk tests were used to verify data normality. Independent samples t-test or Mann-Whitney U test was employed to compare continuous variables based on data normality, and the Chi-square test was used to determine categorical variable associations.

Results

Demographic characteristics of women were found to be comparable between groups. Umbilical arterial potential of hydrogen, partial pressure of oxygen, partial pressure of carbon dioxide, base excess, bicarbonate, birth weight, and APGAR scores were comparable across groups, showing no significant differences (P > 0.05). Groups had similar maternal haemodynamic characteristics and episodes of nausea, vomiting, and chest pain across groups without statistical significance (P > 0.05).

Conclusion

No notable distinction was found between neonatal outcomes and maternal complications between phenylephrine and norepinephrine bolus regimens. Norepinephrine can be used as an alternative to phenylephrine post-spinal hypotension in women undergoing elective caesarean section.

Safety Indicators in Patients Receiving High-intensity Care After Hospital Admission for Acute Heart Failure: The STRONG-HF Trial

BACKGROUND

Safety, Tolerability and Efficacy of Rapid Optimization, Helped by NT-proBNP Testing, of Heart Failure Therapies (STRONG-HF) demonstrated the safety and efficacy of rapid up-titration of guideline-directed medical therapy (GDMT) with high-intensity care (HIC) compared with usual care in patients hospitalized for acute heart failure (HF). In the HIC group, the following safety indicators were used to guide up-titration: estimated glomerular filtration rate of <30 mL/min/1.73 m2, serum potassium of >5.0 mmol/L, systolic blood pressure (SBP) of <95 mmHg, heart rate of <55 bpm, and N-terminal pro-B-type natriuretic peptide concentration of >10% higher than predischarge values.

METHODS AND RESULTS

We examined the impact of protocol-specified safety indicators on achieved dose of GDMT and clinical outcomes. Three hundred thirteen of the 542 patients in the HIC arm (57.7%) met ≥1 safety indicator at any follow-up visit 1-6 weeks after discharge. As compared with those without, patients meeting ≥1 safety indicator had more severe HF symptoms, lower SBP, and higher heart rate at baseline and achieved a lower average percentage of GDMT optimal doses (mean difference vs the HIC arm patients not reaching any safety indicator, -11.0% [95% confidence interval [CI] -13.6 to -8.4%], P < .001). The primary end point of 180-day all-cause death or HF readmission occurred in 15.0% of patients with any safety indicator vs 14.2% of those without (adjusted hazard ratio 0.84, 95% CI 0.48-1.46, P = .540). None of each of the safety indicators, considered alone, was significantly associated with the primary end point, but an SBP of <95 mm Hg was associated with a trend toward increased 180-day all-cause mortality (adjusted hazard ratio 2.68, 95% CI 0.94-7.64, P = .065) and estimated glomerular filtration rate decreased to <30 mL/min/1.73 m2 with more HF readmissions (adjusted hazard ratio 3.60, 95% CI 1.22-10.60, P = .0203). The occurrence of a safety indicator was associated with a smaller 90-day improvement in the EURO-QoL 5-Dimension visual analog scale (adjusted mean difference -3.32 points, 95% CI -5.97 to -0.66, P = .015).

CONCLUSIONS

Among patients with acute HF enrolled in STRONG-HF in the HIC arm, the occurrence of any safety indicator was associated with the administration of slightly lower GDMT doses and less improvement in quality of life, but with no significant increase in the primary outcome of 180-day HF readmission or death when appropriately addressed according to the study protocol.

Potential Therapeutic Targets for Hypotension in Duchenne Muscular Dystrophy

Duchenne Muscular Dystrophy (DMD) is marked by genetic mutations occurring in the DMD gene, which is widely expressed in the cardiovascular system. In addition to developing cardiomyopathy, patients with DMD have been reported to be susceptible to the development of symptomatic hypotension, although the mechanisms are unclear. Analysis of single-cell RNA sequencing data has identified potassium voltage-gated channel subfamily Q member 5 (KCNQ5) and possibly ryanodine receptor 2 (RyR2) as potential candidate hypotension genes whose expression is significantly upregulated in the vascular smooth muscle cells of DMD mutant mice. We hypothesize that heightened KCNQ5 and RyR2 expression contributes to decreased arterial blood pressure in patients with DMD. Exploring pharmacological approaches to inhibit the KCNQ5 and RyR2 channels holds promise in managing the systemic hypotension observed in individuals with DMD. This avenue of investigation presents new prospects for improving clinical outcomes for these patients.

Use and Outcomes of Peripheral Vasopressors in Early Sepsis-Induced Hypotension Across Michigan Hospitals: A Retrospective Cohort Study

BACKGROUND

Vasopressors traditionally are administered via central access, but newer data suggest that peripheral administration may be safe and may avoid delays and complications associated with central line placement.

RESEARCH QUESTION

How commonly are vasopressors initiated through peripheral IV lines in routine practice? Is vasopressor initiation route associated with in-hospital mortality?

STUDY DESIGN AND METHODS

This retrospective cohort study included adults hospitalized with sepsis (November 2020-September 2022) at 29 hospitals in the Michigan Hospital Medicine Safety Consortium, a Collaborative Quality Initiative sponsored by Blue Cross Blue Shield of Michigan. We assessed route of early vasopressor initiation, factors and outcomes associated with peripheral initiation, and timing of central line placement.

RESULTS

Five hundred ninety-four patients received vasopressors within 6 h of hospital arrival and were included in this study. Peripheral vasopressor initiation was common (400/594 [67.3%]). Patients with peripheral vs central initiation were similar; BMI was the only patient factor associated independently with initiation route (adjusted OR [aOR] of peripheral initiation [per 1-kg/m2 increase], 0.98; 95% CI, 0.97-1.00; P = .015). The specific hospital showed a large impact on initiation route (median OR, 2.19; 95% CI, 1.31-3.07). Compared with central initiation, peripheral initiation was faster (median, 2.5 h vs 2.7 h from hospital arrival; P = .002), but was associated with less initial norepinephrine use (84.3% vs 96.8%; P = .001). We found no independent association between initiation route and in-hospital mortality (32.3% vs 42.2%; aOR, 0.66; 95% CI, 0.39-1.12). No tissue injury from peripheral vasopressors was documented. Of patients with peripheral initiation, 135 of 400 patients (33.8%) never received a central line.

INTERPRETATION

Peripheral vasopressor initiation was common across Michigan hospitals and had practical benefits, including expedited vasopressor administration and avoidance of central line placement in one-third of patients. However, the findings of wide practice variation that was not explained by patient case mix and lower use of first-line norepinephrine with peripheral administration suggest that additional standardization may be needed.

Early Vital Sign Thresholds Associated with 24-Hour Mortality among Trauma Patients: A Trauma Quality Improvement Program (TQIP) Study

BACKGROUND

Identifying patients at imminent risk of death is critical in the management of trauma patients. This study measures the vital sign thresholds associated with death among trauma patients.

METHODS

This study included data from patients ≥15 years of age in the American College of Surgeons Trauma Quality Improvement Program (TQIP) database. Patients with vital signs of zero were excluded. Documented prehospital and emergency department (ED) vital signs included systolic pressure, heart rate, respiratory rate, and calculated shock index (SI). The area under the receiver operator curves (AUROC) was used to assess the accuracy of these variables for predicting 24-hour survival. Optimal thresholds to predict mortality were identified using Youden's Index, 90% specificity, and 90% sensitivity. Additional analyses examined patients 70+ years of age.

RESULTS

There were 1,439,221 subjects in the 2019-2020 datasets that met inclusion for this analysis with <0.1% (10,270) who died within 24 hours. The optimal threshold for prehospital systolic pressure was 110, pulse rate was 110, SI was 0.9, and respiratory rate was 15. The optimal threshold for the ED systolic was 112, pulse rate was 107, SI was 0.9, and respiratory rate was 21. Among the elderly sub-analysis, the optimal threshold for prehospital systolic was 116, pulse rate was 100, SI was 0.8, and respiratory rate was 21. The optimal threshold for ED systolic was 121, pulse rate was 95, SI was 0.8, and respiratory rate was 0.8.

CONCLUSIONS

Systolic blood pressure (SBP) and SI offered the best predictor of mortality among trauma patients. The SBP values predictive of mortality were significantly higher than the traditional 90mmHg threshold. This dataset highlights the need for better methods to guide resuscitation as initial vital signs have limited accuracy in predicting subsequent mortality.

Outcomes of Vasopressin-Receptor Agonists Versus Norepinephrine in Adults With Perioperative Hypotension: A Systematic Review

Consensus statements recommend the use of norepinephrine and/or vasopressin for hypotension in cardiac surgery. However, there is a paucity of data among other surgical subgroups and vasopressin analogs. Therefore, the authors conducted a systematic review of randomized controlled trials (RCTs) to compare vasopressin-receptor agonists with norepinephrine for hypotension among those undergoing surgery with general anesthesia. This review was registered prospectively (CRD42022316328). Literature searches were conducted by a medical librarian to November 28, 2023, across MEDLINE, EMBASE, CENTRAL, and Web of Science. The authors included RCTs enrolling adults (≥18 years of age) undergoing any surgery under general anesthesia who developed perioperative hypotension and comparing vasopressin receptor agonists with norepinephrine. The risk of bias was assessed by the Cochrane risk of bias tool for randomized trials (RoB-2). Thirteen (N = 719) RCTs were included, of which 8 (n = 585) enrolled patients undergoing cardiac surgery. Five trials compared norepinephrine with vasopressin, 4 trials with terlipressin, 1 trial with ornipressin, and the other 3 trials used vasopressin as adjuvant therapy. There was no significant difference in all-cause mortality. Among patients with vasoplegic shock after cardiac surgery, vasopressin was associated with significantly lower intensive care unit (N = 385; 2 trials; mean 100.8 v 175.2 hours, p < 0.005; median 120 [IQR 96-168] v 144 [96-216] hours, p = 0.007) and hospital lengths of stay, as well as fewer cases of acute kidney injury and atrial fibrillation compared with norepinephrine. One trial also found that terlipressin was associated with a significantly lower incidence of acute kidney injury versus norepinephrine overall. Vasopressin and norepinephrine restored mean arterial blood pressure with no significant differences; however, the use of vasopressin with norepinephrine was associated with significantly higher mean arterial blood pressure versus norepinephrine alone. Further high-quality trials are needed to determine pooled treatment effects, especially among noncardiac surgical patients and those treated with vasopressin analogs.

Vasoplegia Following Complex Spine Surgery: Incidence and Risk

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

Vasoplegia is a life-threatening form of distributive or vasodilatory shock that is characterized by reduced systemic vascular resistance with resultant hypotension and normal to elevated cardiac output affecting morbidity and mortality. Vasoplegia in the context of Spine Surgery has not been described previously. The purpose of this case series is to determine incidence, risk factors, complications and postoperative outcome in patients with vasoplegia after complex multi-level thoraco-lumbar spine surgery.

METHODS

A retrospective review of the electronic medical records at our institution was conducted between January 2014 and June 2018. All patients undergoing multi-level spine surgery (>6 levels) were screened for intraoperative hypotension. Patient demographics, surgical characteristics, neurological status, blood loss, risk factors, medical treatment, complications, hospital course and mortality were collected. All patients included in this study had a minimum follow-up period of 3 months.

RESULTS

Out of 8521 surgically treated patients, 994 patients with multi-level thoraco-lumbar spine surgery were identified. A total of 41 patients had intraoperative hypotensive events. Of those, 5 patients with vasoplegia could be identified after elimination of all other potential contributing factors. Vasoplegia did not influence the neurological outcome. One major and three minor complications occurred. All patients showed full recovery. The risk factors identified for vasoplegia include prolonged surgery with osteotomies.

CONCLUSIONS

Vasoplegia is a rare condition with an incidence of .6%. Patients experiencing vasoplegia did not appear to experience worse surgical outcomes. The use of special intraoperative hemodynamic monitoring should be considered in selected cases.

The influence of hypoxaemia, hypotension and hypercapnia (among other factors) on quality of recovery from general anaesthesia in horses

OBJECTIVE

To investigate the effect of hypoxaemia, hypotension and hypercapnia, among others, on quality of recovery from general anaesthesia in horses.

STUDY DESIGN

Retrospective, single-centre study.

ANIMALS

A sample of 1226 horses that underwent general anaesthesia between June 2017 and June 2021.

METHODS

Horses and ponies weighing > 200 kg, aged > 6 months, anaesthetized using a xylazine- or medetomidine-isoflurane balanced anaesthesia protocol and presenting a complete anaesthetic record were included. Data were extracted from the clinic record system and from the original anaesthesia records. Recoveries were divided into 'good' and 'bad' based on the available recovery scores. Influence of hypoxaemia [PaO2 < 60 mmHg (7.99 kPa)], hypotension (mean arterial pressure < 70 mmHg for at least 15 minutes) and hypercapnia [PaCO2 > 60 mmHg (7.99 kPa)], anaesthesia protocol, body weight, age, breed, sex, American Society of Anesthesiologists status, type of procedure, emergency or nonemergency, duration of anaesthesia, positioning, times spent in lateral and sternal recumbency during recovery, time until standing and nonassisted or assisted recovery on the assigned recovery score (good/bad) were investigated using generalized linear regression analysis (p < 0.05).

RESULTS

Hypoxaemia and prolonged duration of anaesthesia were significantly associated with a bad recovery score. No other factors had a significant influence on recovery quality.

CONCLUSION AND CLINICAL RELEVANCE

Hypoxaemia and prolonged anaesthesia duration have a negative effect on quality of anaesthetic recovery in horses. Clinically, this highlights the importance of keeping anaesthetic time as short as possible and to monitor oxygenation and treat hypoxaemia as soon as possible.

Incidence and predictors of intraoperative hypotension during transurethral bladder tumor resection with oral 5-aminolevulinic acid

OBJECTIVES

To analyze the incidence and risk factors of intraoperative hypotension related to photodynamic diagnosis-assisted transurethral resection of bladder tumor (PDD-TURBT) with oral 5-aminolevulinic acid (5-ALA).

METHODS

We retrospectively analyzed 487 patients with bladder tumors who underwent PDD-TURBT (n = 184) or conventional TURBT (conv-TURBT) (n = 303) between 2018 and 2021. Intraoperative hypotension was defined as hypotension requiring vasopressors during TURBT, and its incidence was compared between the two groups. Potential risk factors of intraoperative hypotension, including preoperative change in mean arterial pressure (MAP), were further investigated in patients receiving PDD-TURBT.

RESULTS

The median age was 72 years, 392 patients (81%) were male, and 203 (42%) had hypertension. TURBT was performed under general and spinal anesthesia in 76 (16%) and 411 (84%) patients, respectively. The incidence of intraoperative hypotension was significantly higher in PDD-TURBT compared to conv-TURBT (43% vs. 17%, respectively). The median change in MAP until the induction of anesthesia was +6.5 mmHg (range: -29.0 to +46.3) in the PDD-TURBT group and +14.7 mmHg (range: -35.3 to +67.7) in the conv-TURBT group, showing a significantly smaller increase in the PDD-TURBT group (p < 0.001). In the multivariable analysis for PDD-TURBT patients, advanced age, general anesthesia, and lower MAP change (<+6.5 mmHg) until anesthesia induction were significantly associated with intraoperative hypotension (p = 0.0104, <0.001, and <0.001, respectively).

CONCLUSIONS

Intraoperative hypotension occurred more frequently in patients who underwent PDD-TURBT than in those who underwent conv-TURBT. Using oral 5-ALA decreases preoperative blood pressure elevation and may be responsible for intraoperative hypotension.

Comparison of the negative effect of remimazolam and propofol on cardiac contractility: Analysis of a randomised parallel-group trial and a preclinical ex vivo study

Remimazolam is a newly developed ultra-short-acting benzodiazepine that exerts sedative effects. This study aimed to clarify the effects of remimazolam on cardiac contractility. In a randomised-parallel group trial, haemodynamic parameters were compared between propofol (n = 11) and remimazolam (n = 12) groups during the induction of general anaesthesia in patients undergoing non-cardiac surgery. In a preclinical study, the direct effects of remimazolam on cardiac contractility were also evaluated using isolated rat hearts. RNA sequence data obtained from rat and human hearts were analysed to assess the expression patterns of the cardiac γ-aminobutyric acid type A (GABAA ) receptor subunits. In a clinical study, the proportional change of the maximum rate of arterial pressure rise was milder during the study period in the remimazolam group (propofol: -52.6 [10.2] (mean [standard deviation])% vs. remimazolam: -39.7% [10.5%], p = 0.007). In a preclinical study, remimazolam did not exert a negative effect on left ventricle developed pressure, whereas propofol did exert a negative effect after bolus administration of a high dose (propofol: -26.9% [3.5%] vs. remimazolam: -1.1 [6.9%], p < 0.001). Analysis of the RNA sequence revealed a lack of γ subunits, which are part of the major benzodiazepine binding site of the GABAA receptor, in rat and human hearts. These results indicate that remimazolam does not have a direct negative effect on cardiac contractility, which might contribute to its milder effect on cardiac contractility during the induction of general anaesthesia. The expression patterns of cardiac GABAA receptor subunits might be associated with the unique pharmacokinetics of benzodiazepines in the heart.

Safety of Levosimendan in Pediatric Patients: An Up-to-Date Systematic Review

BACKGROUND

The potential risks associated with the use of levosimendan in the pediatric population has not been systematically evaluated. This study aimed to review the available evidence regarding the safety of this treatment.

METHODS

Bio Med Central, PubMed, Embase, and the Cochrane Central Register of clinical trials were searched for studies describing levosimendan administration in the pediatric population in any setting. Relevant studies were independently screened, selected, and their data extracted by two investigators. The authors excluded: reviews, meta-analyses, as well as basic research and trials involving patients >18 years old. The primary outcome was the number and the type of adverse side effects reported during levosimendan administration.

RESULTS

The updated systematic review included 48 studies, enrolling a total of 1,271 pediatric patients who received levosimendan as treatment (790 patients in the 11 studies that reported side effects). The primary adverse effects of levosimendan administration were hypotension and cardiac arrhythmias, particularly tachycardia. Hypotension occurred in approximately 28.9% of patients, while arrhythmia occurred in about 12.3% of patients. Meta analysis of RCTs revealed a rate of all-cause mortality of 2.0% (8 out of 385) in the levosimendan group compared to 3.9% (15 out of 378) in the control group (dobutamine, milrinone or placebo) (risk ratio [RR] = 0.55; 95% confidence interval [CI] = 0.25-1.21; P = 0.14; I2 = 0%) CONCLUSIONS: Hypotension and cardiac arrhythmia are the most reported side effects of levosimendan in pediatric patients. However, adverse events remain underreported, especially in randomized trials.

Randomized Double-Blinded Comparison of Intermittent Boluses Phenylephrine and Norepinephrine for the Treatment of Postspinal Hypotension in Patients with Severe Pre-Eclampsia During Cesarean Section

Background

Norepinephrine has fewer negative effects on heart rate (HR) and cardiac output (CO) for treating postspinal hypotension (PSH) compared with phenylephrine during cesarean section. However, it remains unclear whether fetuses from patients with severe pre-eclampsia could benefit from the superiority of CO. The objective of this study was to compare the safety and efficacy of intermittent intravenous boluses of phenylephrine and norepinephrine used in equipotent doses for treating postspinal hypotension in patients with severe pre-eclampsia during cesarean section.

Methods

A total of 80 patients with severe pre-eclampsia who developed PSH predelivery during cesarean section were included. Eligible patients were randomized at a 1:1 ratio to receive either phenylephrine or norepinephrine for treating PSH. The primary outcome was umbilical arterial pH. Secondary outcomes included other umbilical cord blood gas values, Apgar scores at 1 and 5 min, changes in hemodynamic parameters including CO, mean arterial pressure (MAP), HR, stroke volume (SV), and systemic vascular resistance (SVR), the number of vasopressor boluses required, and the incidence of bradycardia, hypertension, nausea, vomiting, and dizziness.

Results

No significant difference was observed in umbilical arterial pH between the phenylephrine and norepinephrine groups (7.303±0.38 vs 7.303±0.44, respectively; P=0.978). Compared with the phenylephrine group, the overall CO (P=0.009) and HR (P=0.015) were greater in the norepinephrine group. The median [IQR] total number of vasopressor boluses required was comparable between the two groups (2 [1 to 3] and 2 [1 to 3], respectively; P=0.942). No significant difference was found in Apgar scores or the incidence of maternal complications between groups.

Conclusion

A 60 µg bolus of phenylephrine and a 4.5 µg bolus of norepinephrine showed similar neonatal outcomes assessed by umbilical arterial pH and were equally effective when treating PSH during cesarean section in patients with severe pre-eclampsia. Norepinephrine provided a higher maternal CO and a lower incidence of bradycardia.

Association of Shock Indices with Peri-Intubation Hypotension and Other Outcomes: A Sub-Study of the KEEP PACE Trial

BACKGROUND

Based on current evidence, there appears to be an association between peri-intubation hypotension and patient morbidity and mortality. Studies have identified shock indices as possible pre-intubation risk factors for peri-intubation hypotension. Thus, we sought to evaluate the association between shock index (SI), modified shock index (MSI), and diastolic shock index (DSI) and peri-intubation hypotension along with other outcomes.

METHODS

The present study is a sub-study of a randomized controlled trial involving critically ill patients undergoing intubation. We defined peri-intubation hypotension as a decrease in mean arterial pressure <65 mm Hg and/or a reduction of 40% from baseline; or the initiation of, or increase in infusion dosage of, any vasopressor medication (bolus or infusion) during the 30-min period following intubation. SI, MSI, and DSI were analyzed as continuous variables and categorically using pre-established cut-offs. We also explored the effect of age on shock indices.

RESULTS

A total of 151 patients were included in the analysis. Mean pre-intubation SI was 1.0  ±  0.3, MSI 1.5  ±  0.5, and DSI 1.9  ±  0.7. Increasing SI, MSI, and DSI were significantly associated with peri-intubation hypotension (OR [95% CI] per 0.1 increase  =  1.16 [1.04, 1.30], P  =  .009 for SI; 1.14 [1.05, 1.24], P  =  .003 for MSI; and 1.11 [1.04, 1.19], P  =  .003 for DSI). The area under the ROC curves did not differ across shock indices (0.66 vs 0.67 vs 0.69 for SI, MSI, and DSI respectively; P  =  .586). Increasing SI, MSI, and DSI were significantly associated with worse sequential organ failure assessment (SOFA) score (spearman rank correlation: r  =  0.30, r  =  0.40, and r  =  0.45 for SI, MSI, and DSI, respectively, all P < .001) but not with other outcomes. There was no significant impact when incorporating age.

CONCLUSIONS

Increasing SI, MSI, and DSI were all significantly associated with peri-intubation hypotension and worse SOFA scores but not with other outcomes. Shock indices remain a useful bedside tool to assess the potential likelihood of peri-intubation hypotension.

TRIAL REGISTRATION

ClinicalTrials.gov identifier - NCT02105415.

Effect of a Salt Substitute on Incidence of Hypertension and Hypotension Among Normotensive Adults

BACKGROUND

Reports on the effects of salt substitution among individuals with normal blood pressure are scarce and controversial.

OBJECTIVES

This study sought to assess the effects of a salt substitute (62.5% NaCl, 25% KCl, and 12.5% flavorings) on incidence of hypertension and hypotension among older adults with normal blood pressure.

METHOD

A post hoc analysis was conducted among older adults with normal blood pressure participating in DECIDE-Salt, a large, multicenter, cluster-randomized trial in 48 elderly care facilities for 2 years. We used the frailty survival model to compare risk of incident hypertension and the generalized linear mixed model to compare risk of hypotension episodes.

RESULTS

Compared with usual salt group (n = 298), the salt substitute group (n = 313) had a lower hypertension incidence (11.7 vs 24.3 per 100 person-years; adjusted HR: 0.60; 95% CI: 0.39 to 0.92; P = 0.02) but did not increase incidence of hypotension episodes (9.0 vs 9.7 per 100 person-years; P = 0.76). Mean systolic/diastolic blood pressure did not increase from the baseline to the end of intervention in the salt substitute group (mean changes: -0.3 ± 11.9/0.2 ± 7.1 mm Hg) but increased in the usual salt group (7.0 ± 14.3/2.1 ± 7.5 mm Hg), resulting in a net reduction of -8.0 mm Hg (95% CI: -12.4 to -3.7 mm Hg) in systolic and -2.0 mm Hg (95% CI: -4.1 to 0.1 mm Hg) in diastolic blood pressure between intervention groups.

CONCLUSIONS

In Chinese older adults with normal blood pressure, replacing usual salt with a salt substitute may reduce the incidence of hypertension without increasing hypotension episodes. This suggests a desirable strategy for population-wide prevention and control of hypertension and cardiovascular disease, deserving further consideration in future studies. (Diet Exercise and Cardiovascular Health [DECIDE]-Salt Reduction Strategies for the Elderly in Nursing Homes in China [DECIDE-Salt]; NCT03290716).

Effect of Hypotension and Dobutamine on Gastrointestinal Microcirculations of Healthy, Anesthetized Horses

Horses undergoing abdominal exploratory surgery are at risk of hypotension and hypoperfusion. Normal mean arterial pressure is used as a surrogate for adequate tissue perfusion. However, measures of systemic circulation may not be reflective of microcirculation. This study measured the mean arterial pressure, cardiac index, lactate, and four microcirculatory indices in six healthy, anesthetized adult horses undergoing elective laparotomies. The microcirculatory parameters were measured at three different sites along the gastrointestinal tract (oral mucosa, colonic serosa, and rectal mucosa) with dark-field microscopy. All macro- and microcirculatory parameters were obtained when the horses were normotensive, hypotensive, and when normotension returned following treatment with dobutamine. Hypotension was induced with increases in inhaled isoflurane. The horses successfully induced into hypotension did not demonstrate consistent, expected changes in systemic perfusion or microvascular perfusion parameters at any of the three measured gastrointestinal sites. Normotension was successfully restored with the use of dobutamine, while the systemic perfusion and microvascular perfusion parameters remained relatively unchanged. These findings suggest that the use of mean arterial pressure to make clinical decisions regarding perfusion may or may not be accurate.

Performance of a Machine Learning Algorithm to Predict Hypotension in Spontaneously Breathing Non-Ventilated Post-Anesthesia and ICU Patients

Background: Hypotension is common in the post-anesthesia care unit (PACU) and intensive care unit (ICU), and is associated with adverse patient outcomes. The Hypotension Prediction Index (HPI) algorithm has been shown to accurately predict hypotension in mechanically ventilated patients in the OR and ICU and to reduce intraoperative hypotension (IOH). Since positive pressure ventilation significantly affects patient hemodynamics, we performed this validation study to examine the performance of the HPI algorithm in a non-ventilated PACU and ICU population. Materials & Methods: The performance of the HPI algorithm was assessed using prospectively collected blood pressure (BP) and HPI data from a PACU and a mixed ICU population. Recordings with sufficient time (≥3 h) spent without mechanical ventilation were selected using data from the electronic medical record. All HPI values were evaluated for sensitivity, specificity, predictive value, and time-to-event, and a receiver operating characteristic (ROC) curve was constructed. Results: BP and HPI data from 282 patients were eligible for analysis, of which 242 (86%) were ICU patients. The mean age (standard deviation) was 63 (13.5) years, and 186 (66%) of the patients were male. Overall, the HPI predicted hypotension accurately, with an area under the ROC curve of 0.94. The most used HPI threshold cutoff in research and clinical use, 85, showed a sensitivity of 1.00, specificity of 0.79, median time-to-event of 160 s [60-380], PPV of 0.85, and NPV of 1.00. Conclusion: The absence of positive pressure ventilation and the influence thereof on patient hemodynamics does not negatively affect the performance of the HPI algorithm in predicting hypotension in the PACU and ICU. Future research should evaluate the feasibility and influence on hypotension and outcomes following HPI implementation in non-ventilated patients at risk of hypotension.

Dynamic arterial elastance as a predictor of arterial pressure response to norepinephrine weaning in mechanically ventilated patients with vasoplegic syndrome-a systematic review and meta-analysis

Introduction

During the de-escalation phase of circulatory shock, norepinephrine weaning may induce diverse arterial pressure responses in patients with different vasomotor tones. Dynamic arterial elastance (Eadyn) has been extensively studied to predict the arterial pressure response to interventions. We conducted this meta-analysis to systematically assess the predictive performance of Eadyn for the mean arterial pressure (MAP) response to norepinephrine weaning in mechanically ventilated patients with vasoplegic syndrome.

Materials and methods

A systematic literature search was conducted on May 29, 2023 (updated on January 21, 2024), to identify relevant studies from electronic databases. The area under the hierarchical summary receiver operating characteristic curve (AUHSROC) was estimated as the primary measure of diagnostic accuracy because of the varied thresholds reported. Additionally, we observed the distribution of the cutoff values of Eadyn, while computing the optimal value and its corresponding 95% confidential interval (CI).

Results

A total of 5 prospective studies met eligibility, comprising 183 participants, of whom 67 (37%) were MAP responders. Eadyn possessed an excellent ability to predict the MAP response to norepinephrine weaning in patients with vasoplegic syndrome, with an AUHSROC of 0.93 (95% CI: 0.91-0.95), a pooled sensitivity of 0.94 (95% CI: 0.85-0.98), a pooled specificity of 0.73 (95% CI: 0.65-0.81), and a pooled diagnostic odds ratio of 32.4 (95% CI: 11.7-89.9). The cutoff values of Eadyn presented a nearly conically symmetrical distribution; the mean and median cutoff values were 0.89 (95% CI: 0.80-0.98) and 0.90 (95% CI: not estimable), respectively.

Conclusions

This meta-analysis with limited evidences demonstrates that Eadyn may be a reliable predictor of the MAP response to norepinephrine weaning in mechanically ventilated patients with vasoplegic syndrome.

Systematic Review Registration

PROSPERO CRD42023430362.

Exploring the Efficacy of Midodrine for Tapering Off Vasopressors

Sepsis and septic shock represent critical conditions, often necessitating vasopressor support in the intensive care unit (ICU). Midodrine, an oral vasopressor, has gathered attention as a potential adjunct to vasopressor therapy, aiming to facilitate weaning and improve clinical outcomes. However, the efficacy of midodrine remains questionable, with conflicting evidence from clinical trials and meta-analyses. This article provides a comprehensive review of the literature on midodrine's role in ICU settings by gathering evidence from multicenter trials, retrospective studies, and meta-analyses. While some studies suggest a limited benefit of midodrine in expediting vasopressor weaning and reducing ICU/hospital stays, others report potential advantages, particularly in reducing mortality rates among septic shock patients. Ongoing efforts aim to address knowledge gaps surrounding midodrine's efficacy and safety.

Comparative dose-response study on the infusion of norepinephrine combined with intravenous ondansetron versus placebo for preventing hypotension during spinal anesthesia for cesarean section: a randomised controlled trial

BACKGROUND

Ondansetron has been reported to attenuate the incidence of spinal anaesthesia-induced hypotension (SAIH) and norepinephrine requirement during caesarean section. However, no quantitative study has evaluated the extent of this effect. This study aimed to determine the dose-response of prophylactic infusion of norepinephrine to prevent SAIH in parturients who received intravenous ondansetron or placebo before spinal anaesthesia for caesarean section. The median effective dose (ED 50 ) and 90% effective dose (ED 90 ) were compared to evaluate the effect of ondansetron versus placebo on the norepinephrine requirement.

MATERIALS AND METHODS

One hundred fifty parturients undergoing caesarean section were randomized to receive either 0.1 mg/kg ondansetron (group O) or saline control (group C) 10 min before spinal anaesthesia. The parturients were randomly assigned to one of five different norepinephrine infusion groups: 0.02, 0.04, 0.06, 0.08 or 0.10 µg/kg/min. An effective infusion dose of norepinephrine was defined as non-occurrence of hypotension during the study period. The values for ED 50 and ED 90 of norepinephrine infusion were determined using probit regression. Differences between the two groups were evaluated by comparing the relative median potency with 95% CIs.

RESULTS

The ED 50 values were 0.033 (95% CIs, 0.024-0.043) µg/kg/min in group C and 0.021 (95% CIs, 0.013-0.029) µg/kg/min in group O. The ED 90 values were 0.091 (95% CIs 0.068-0.147) µg/kg/min in group C and 0.059 (95% CIs 0.044-0.089) µg/kg/min in group O, respectively. The estimate of the relative median potency for norepinephrine in group C versus group O was 0.643 (95% CIs, 0.363-0.956). The incidence of side effects was comparable between groups. No significant difference in neonatal outcomes.

CONCLUSION

Intravenous ondansetron 0.1 mg/kg before spinal anaesthesia significantly reduced the dose requirement of prophylactic norepinephrine infusion in parturients undergoing elective caesarean section. This finding is potentially useful for clinical practice and further research.

Intrathecal ropivacaine versus bupivacaine in a non-obstetric population- A meta-analysis and trial sequential analysis

Background and Aims

Intrathecal bupivacaine is used for anaesthesia and analgesia but is associated with hypotension. Ropivacaine is an alternative drug that may have fewer cardiotoxic and neurotoxic events. This meta-analysis investigated whether intrathecal ropivacaine is associated with reduced hypotension as compared to bupivacaine.

Methods

The meta-analysis is registered in the International Prospective Register of Systematic Reviews (PROSPERO). The databases PubMed, Cinahl Plus, Google Scholar, and Scopus were searched, and papers from January 1980 to January 2023 were deemed eligible and filtered using predetermined inclusion and exclusion criteria. The primary outcome was the incidence of hypotension. Secondary outcomes were the duration of sensory block, duration of motor block, incidence of bradycardia, ephedrine usage, and duration of analgesia. Jadad scores were used to evaluate the quality of the papers. RevMan statistical software® utilised inverse variance and a random effect model to calculate the standardised mean difference with 95% confidence intervals for continuous variables and the Mantel-Haenszel test and the random effect model to calculate the odds ratio for dichotomous variables.

Results

Thirty-three papers, including 2475 patients in total, were included. The Jadad score was between 1 and 5. The incidence of hypotension was significantly higher with intrathecal bupivacaine than with ropivacaine (P = 0.02). The duration of sensory block (P < 0.001) and motor block (P < 0.001) was prolonged with intrathecal bupivacaine. The duration of analgesia favoured intrathecal bupivacaine (P = 0.003).

Conclusion

Intrathecal ropivacaine has a reduced incidence of hypotension and a reduced duration of sensory block compared to bupivacaine.

Diagnostic accuracy of left ventricular outflow tract velocity time integral versus inferior vena cava collapsibility index in predicting post-induction hypotension during general anesthesia: an observational study

BACKGROUND

Point of care ultrasound (POCUS) is being explored for dynamic measurements like inferior vena cava collapsibility index (IVC-CI) and left ventricular outflow tract velocity time integral (LVOT-VTI) to guide anesthesiologists in predicting fluid responsiveness in the preoperative period and in treating post-induction hypotension (PIH) with varying accuracy.

METHODS

In this prospective, observational study on included 100 adult patients undergoing elective surgery under general anesthesia, the LVOT-VTI and IVC-CI measurements were performed in the preoperative room 15 minutes prior to surgery, and PIH was measured for 20 minutes in the post-induction period.

RESULTS

The incidence of PIH was 24%. The area under the curve, sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of the two techniques at 95% confidence interval was 0.613, 30.4%, 93.3%, 58.3%, 81.4%, 73.6% for IVC-CI and 0.853, 83.3%, 80.3%, 57.1%, 93.8%, 77.4% for LVOT-VTI, respectively. In multivariate analysis, the cutoff value for IVC-CI was >51.5 and for LVOT-VTI it was ≤17.45 for predicting PIH with odd ratio [OR] of 8.491 (P=0.025) for IVCCI and OR of 17.427 (P<0.001) for LVOT. LVOT-VTI assessment was possible in all the patients, while 10% of patients were having poor window for IVC measurements.

CONCLUSIONS

We recommend the use of POCUS using LVOT-VTI or IVC-CI to predict PIH, to decrease the morbidity of patients undergoing surgery. Out of these, we recommend LVOT-VTI measurements as it has showed a better diagnostic accuracy (77.4%) with no failure rate.

Reticulon 3 regulates sphingosine-1-phosphate synthesis in endothelial cells to control blood pressure

The discovery of the endothelium as a major regulator of vascular tone triggered intense research among basic and clinical investigators to unravel the physiologic and pathophysiologic significance of this phenomenon. Sphingosine-l-phosphate (S1P), derived from the vascular endothelium, is a significant regulator of blood pressure. However, the mechanisms underlying the regulation of S1P biosynthetic pathways in arteries remain to be further clarified. Here, we reported that Reticulon 3 (RTN3) regulated endothelial sphingolipid biosynthesis and blood pressure. We employed public datasets, patients, and mouse models to explore the pathophysiological roles of RTN3 in blood pressure control. The underlying mechanisms were studied in human umbilical vein endothelial cells (HUVECs). We reported that increased RTN3 was found in patients and that RTN3-null mice presented hypotension. In HUVECs, RTN3 can regulate migration and tube formation via the S1P signaling pathway. Mechanistically, RTN3 can interact with CERS2 to promote the selective autophagy of CERS2 and further influence S1P signals to control blood pressure. We also identified an RTN3 variant (c.116C>T, p.T39M) in a family with hypertension. Our data provided the first evidence of the association between RTN3 level changes and blood pressure anomalies and preliminarily elucidated the importance of RTN3 in S1P metabolism and blood pressure regulation.

Hypotensive Levels on Endoscopic Sinus Surgery Visibility: A Randomized Non-Inferiority Trial

OBJECTIVE

Optimization of endoscopic sinus surgery (ESS) conditions is a common focus of interest for otolaryngologists and anesthesiologists. Relying on hypotension alone to achieve a bloodless field may not without risks. We sought to determine whether ESS is feasible in the context of moderate hypotension.

METHODS

This randomized non-inferiority trial enrolled 96 adult patients who were to undergo ESS. The patients were divided into two groups: Controlled hypotension group (n = 48, MAP reduction to 55-65 mmHg, minimum of 60% of baseline blood pressure) or Individualized hypotension group (n = 48, MAP reduction to 75-80% of baseline blood pressure). All participants were placed in 10° reverse Trendelenburg position during ESS, and cottonoid patties dammed with epinephrine was recommended to clear the operative field of bleeding. The two groups were compared according to Boezaart grading scale (BS) score, estimated blood loss, blood loss rate, arterial lactate level and postoperative recovery.

RESULTS

Both levels of intraoperative hypotension (62.2 ± 2.3 mmHg vs. 74.0 ± 2.8 mmHg) provided acceptable surgical conditions with no difference in mean BS scores [2.00 (1.88-2.33) vs. 2.00 (1.85-2.45), p = 0.926]. The 95% CI for median value differences in mean BS scores is lower than the preset non-inferiority margin. There were no differences in blood loss rate and estimated blood loss between two groups (p > 0.05) Postoperative arterial lactate and Ramsay sedation scores were significantly different between the two groups (p < 0.05).

CONCLUSIONS

In ESS, both levels of intraoperative hypotension, combined with position adjustment and low-concentration adrenaline to constrict nasal mucosal blood vessels, provided acceptable surgical conditions.

LEVEL OF EVIDENCE

2 Laryngoscope, 134:569-576, 2024.

Prevention of post-spinal anaesthesia hypotension in caesarean delivery using delayed supine positioning - A randomised controlled trial

Background and Aims

Maternal hypotension is a common and dangerous consequence after a subarachnoid block for a caesarean section. Combining pharmacological methods such as norepinephrine infusion, ondansetron and non-pharmacological methods in delayed supine positioning better impacts the maternal haemodynamic profile. The present study assessed the benefits and adverse effects of combining pharmacological and non-pharmacological methods in hypotension prophylaxis.

Methods

This randomised controlled trial was conducted at Cairo University Hospital's obstetric theatre from January to October 2020. The study included 85 parturients who were randomised to two groups. Group Sitting was left seated for 2 min after injection, and Group Control was made to lie down in the supine position immediately after the subarachnoid block. Both groups received prophylactic intravenous norepinephrine infusion, in addition to an ondansetron bolus, before surgery. Patients' systolic blood pressure (SBP) from intrathecal injection until delivery of the foetus, was documented.

Results

The Sitting group's SBP (122 (14) mmHg) till delivery was statistically higher than the Control group's readings (114 (10) mmHg) (P = 0.004). The Sitting group's intraoperative SBP values were often greater than the Control group values. In addition, the Sitting group had a reduced hypotension incidence and a lower rate of ephedrine use than the other group, but bradycardia incidence was comparable between both groups.

Conclusion

In elective caesarean delivery, combining pharmacological and non-pharmacological methods achieve better results regarding maternal hypotension, vasopressor consumption, nausea and vomiting, and foetal outcomes.

Peripheral Administration of Norepinephrine: A Prospective Observational Study

BACKGROUND

Historically, norepinephrine has been administered through a central venous catheter (CVC) because of concerns about the risk of ischemic tissue injury if extravasation from a peripheral IV catheter (PIVC) occurs. Recently, several reports have suggested that peripheral administration of norepinephrine may be safe.

RESEARCH QUESTION

Can a protocol for peripheral norepinephrine administration safely reduce the number of days a CVC is in use and frequency of CVC placement?

STUDY DESIGN AND METHODS

This was a prospective observational cohort study conducted in the medical ICU at a quaternary care academic medical center. A protocol for peripheral norepinephrine administration was developed and implemented in the medical ICU at the study site. The protocol was recommended for use in patients who met prespecified criteria, but was used at the treating clinician's discretion. All adult patients admitted to the medical ICU receiving norepinephrine through a PIVC from February 2019 through June 2021 were included.

RESULTS

The primary outcome was the number of days of CVC use that were avoided per patient, and the secondary safety outcomes included the incidence of extravasation events. Six hundred thirty-five patients received peripherally administered norepinephrine. The median number of CVC days avoided per patient was 1 (interquartile range, 0-2 days per patient). Of the 603 patients who received norepinephrine peripherally as the first norepinephrine exposure, 311 patients (51.6%) never required CVC insertion. Extravasation of norepinephrine occurred in 35 patients (75.8 events/1,000 d of PIVC infusion [95% CI, 52.8-105.4 events/1,000 d of PIVC infusion]). Most extravasations caused no or minimal tissue injury. No patient required surgical intervention.

INTERPRETATION

This study suggests that implementing a protocol for peripheral administration of norepinephrine safely can avoid 1 CVC day in the average patient, with 51.6% of patients not requiring CVC insertion. No patient experienced significant ischemic tissue injury with the protocol used. These data support performance of a randomized, prospective, multicenter study to characterize the net benefits of peripheral norepinephrine administration compared with norepinephrine administration through a CVC.

Side effects from epidural analgesia in laboring women and risk of cesarean delivery

BACKGROUND

Epidural analgesia may cause maternal hypotension and changes in the fetal heart rate. The implications of such side effects on the course of labor and delivery are incompletely understood.

OBJECTIVE

This study aimed to assess whether the occurrence of maternal or fetal side effects associated with labor epidural analgesia increased the risk for cesarean delivery.

STUDY DESIGN

This was a cohort study of all women who underwent epidural analgesia during labor for the period October 1, 2020 to December 31, 2020. Excluded were cases of multiples, fetal death, noncephalic presentation, and gestational age at birth <37.0 weeks. Maternal vital signs and fetal heart rate tracings for the 1 hour before and 1 hour after epidural analgesia was administered were reviewed. The occurrence of maternal hypotension, defined as a continuous variable and dichotomized into a decrease in maternal systolic blood pressure to <90 mm Hg or a drop in systolic blood pressure by >20% below the last value before epidural analgesia was administered, was related to changes in the fetal heart rate category. The principal outcome was cesarean delivery rate; binary logistic regression analysis was used to control for confounders, and mediation model analysis was used to quantify the extent to which significant variables participated in the causation pathway to cesarean delivery (SPSS version 28 was used for the analyses).

RESULTS

A total of 439 women met the study criteria. Significant adverse reactions owing to epidural occurred in 184 of 439 women (41.9%) and included severe maternal hypotension in 159 of 439 participants (36.2%) and worsening fetal heart rate category in 50 of 439 participants (11.4%). The logistic regression analysis revealed that cervical dilation at epidural (P=.03), the duration of labor after epidural (P<.001), and worsening fetal heart rate category within 60 minutes of epidural administration (P=.01) were independently associated with recourse to cesarean delivery. The mediation analysis showed that both cervical dilatation at epidural administration and worsening fetal heart rate category had significant direct and indirect effects in the pathway to cesarean delivery.

CONCLUSION

Worsening fetal heart rate category related to labor epidural independently increased the risk for cesarean delivery.

Intraoperative blood pressure and cardiac complications after aneurysmal subarachnoid hemorrhage: a retrospective cohort study

BACKGROUND

Previous studies report that intraoperative hypotension worsens outcomes after aneurysmal subarachnoid hemorrhage (aSAH). However, the hypotensive harm threshold for major adverse cardiovascular events (MACE) remains unclear.

METHODS

The authors included aSAH patients who had general anesthesia for aneurysmal clipping/coiling. MACE were defined by a composite of acute myocardial injury, acute myocardial infarction, and other cardiovascular complications identified by electrocardiogram and echocardiography. The authors initially used logistic regression and change-point analysis based on the second derivative to identify mean arterial pressure (MAP) of 75 mmHg as the harm threshold. Thereafter, our major exposure was MAP below 75 mmHg characterized by area, duration, and time-weighted average. The area below 75 mmHg represents the severity and duration of exposure and was defined as the sum of all areas below a specified threshold using the trapezoid rule. Time-weighted average MAP was derived by dividing area below the threshold by the duration of anesthesia. All analyses were adjusted for baseline risk factors including age greater than 70 years, female sex, severity of intracerebral hemorrhage, history of cardiovascular disease, and preoperative elevated myocardial enzymes.

RESULTS

Among 1029 patients enrolled, 254 (25%) developed postoperative MACE. Patients who experienced MACE were slightly older (59±11 vs. 54±11 years), were slightly more often women (69 vs. 58%), and had a higher prevalence of cardiovascular history (65 vs. 47%). Adjusted cardiovascular risk increased nearly linearly over the entire range of observed MAP. However, there was a slight inflexion at MAP of 75 mmHg. MACE was significantly associated with area [adjusted odds ratios (aOR) 1.004 per 10 mmHg.min, 95% CI: 1.001-1.007, P =0.002), duration (aOR 1.031 per 10 min, 95% CI: 1.009-1.054, P =0.006), and time-weighted average (aOR 3.516 per 10 mmHg, 95% CI: 1.818-6.801, P <0.001) of MAP less than 75 mmHg.

CONCLUSIONS

Lower blood pressures were associated with cardiovascular complications over the entire observed range, but worsened when MAP was less than 75 mmHg. Pending trial data to establish causality, it may be prudent to keep MAP above 75 mmHg in patients having surgical aSAH repairs to reduce the risk of MACE.

Intranasal dexmedetomidine as premedication for magnetic resonance imaging examinations in dogs with neurological disorders mitigates hypotension and hypothermia

OBJECTIVE

This study aimed to evaluate the safety and feasibility of intranasal administration of dexmedetomidine as a premedication for preventing hypotension and hypothermia in canine patients undergoing MRI examinations.

ANIMALS

Dogs undergoing MRI examinations for neurological disorders were enrolled in this study. The dogs were randomly assigned: 15 to the N-Dex group (without premedication) and 13 to the Dex group (125 μg/m2 of dexmedetomidine, intranasally, as a premedication).

METHODS

During the examination, pulse rate, systolic blood pressure, diastolic blood pressure, and mean arterial blood pressure were recorded every 5 minutes for the first 30 minutes. Body temperature was measured before and after the examination. Any adverse events during the procedure were documented.

RESULTS

Significant changes in pulse rate during the examination were not distinguishable. Although blood pressure and body temperature decreased in both groups under anesthesia, dogs in the Dex group had a significantly smaller drop in blood pressure and body temperature and fewer hypotension events than those in the N-Dex group MRI examinations of 1 hour's duration. Two dogs in the Dex group exhibited bradycardia at 45 and 60 minutes of MRI examination, which resolved after receiving atipamezole.

CLINICAL RELEVANCE

Our results indicate that intranasal administration of 125 μg/m2 of dexmedetomidine as premedication is safe and can potentially mitigate hypothermia and hypotension in dogs with neurological disorders during MRI examinations.

Renal Replacement Therapy in Idiopathic Systemic Capillary Leak Syndrome: A Case Report

Idiopathic systemic capillary leak syndrome (ISCLS) is a rare disease characterized by hypotensive shock, anasarca, hemoconcentration, and hypoalbuminemia. Despite the life-threatening course of the disease, no treatment strategy has been established. A 68-year-old man presented with hypotensive shock following a prodrome. Based on the characteristic blood test findings, ISCLS was suspected. The patient was resuscitated by administering massive amounts of fluids and inotropic and vasopressor agents. After his blood pressure had stabilized, renal replacement therapy (RRT) was promptly initiated to facilitate the removal of excess fluid, despite the presence of urine output. Typically, ISCLS has three phases: prodromal, leak, and post-leak. Diuresis should be promptly induced during the transition from the leak phase to the post-leak phase to avoid fatal complications such as pulmonary edema. We propose that in patients with ISCLS, early introduction of RRT is recommended if indicated.

Neonatal Renal Failure Following Intrauterine Exposure to an Angiotensin-Converting Enzyme Inhibitor

The renin-angiotensin-aldosterone system (RAAS) plays a crucial role in the normal development of the fetal kidney. Late pregnancy blockage of the RAAS, through in-utero exposure to angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II receptor blockers, is associated with poor fetal outcomes, including oligohydramnios, renal tubular dysplasia, postnatal anuric renal failure, and hypotension. The present case describes a 39-year-old primigravida that was referred to the emergency department, at 37 weeks, for the evaluation of intrauterine growth restriction and suspected coarctation of the aorta (CoA). She was medicated with enalapril since the 35th week of gestation. She delivered a male infant, weighing 2,110 g, with no apparent malformations. CoA was excluded. During his first day of life, the patient developed anuria, acute renal failure, and hypotension, requiring ionotropic support. Renal ultrasound appeared normal. Diuresis was reinitiated at 48 hours of life after continued supportive measures. Kidney function tests progressively normalized. Additional investigations revealed a low concentration of angiotensin-converting enzyme. The patient is currently 12 months old and has had a favorable evolution. This case highlights the fact that even brief exposure to enalapril in the third trimester may cause RAAS blocker fetopathy. As long-term sequelae of ACEI-exposed infants are poorly described, close follow-up of renal complications is essential. Physicians should be aware of the deleterious effects of RAAS blockers in pregnancy.

Hypotension During Vasopressor Infusion Occurs in Predictable Clusters: A Multicenter Analysis

Background: Published evidence indicates that mean arterial pressure (MAP) below a goal range (hypotension) is associated with worse outcomes, though MAP management failures are common. We sought to characterize hypotension occurrences in ICUs and consider the implications for MAP management. Methods: Retrospective analysis of 3 hospitals' cohorts of adult ICU patients during continuous vasopressor infusion. Two cohorts were general, mixed ICU patients and one was exclusively acute spinal cord injury patients. "Hypotension-clusters" were defined where there were ≥10 min of cumulative hypotension over a 60-min period and "constant hypotension" was ≥10 continuous minutes. Trend analysis was performed (predicting future MAP using 14 min of preceding MAP data) to understand which hypotension-clusters could likely have been predicted by clinician awareness of MAP trends. Results: In cohorts of 155, 66, and 16 ICU stays, respectively, the majority of hypotension occurred within the hypotension-clusters. Failures to keep MAP above the hypotension threshold were notable in the bottom quartiles of each cohort, with hypotension durations of 436, 167, and 468 min, respectively, occurring within hypotension-clusters per day. Mean arterial pressure trend analysis identified most hypotension-clusters before any constant hypotension occurred (81.2%-93.6% sensitivity, range). The positive predictive value of hypotension predictions ranged from 51.4% to 72.9%. Conclusions: Across 3 cohorts, most hypotension occurred in temporal clusters of hypotension that were usually predictable from extrapolation of MAP trends.

Evaluation of Blood Lactate, Heart Rate, Blood Pressure, and Shock Index, and Their Association with Prognosis in Calves

Diseases in young calves received as emergencies are often associated with hypovolemic and/or septic shocks. The objectives of our study were to (1) assess the correlation between clinical hemodynamic parameters and blood L-lactates (LAC), systolic blood pressure (SBP), and the shock index (SI) recorded upon arrival; and (2) to evaluate how these parameters were related to short-term outcomes in calves under 4 months of age presented as emergencies. We conducted a single-observer prospective observational study on calves aged from 1 day to 4 months, presented to the Veterinary Clinic for Ruminants of Liège from December 2020 to May 2022. Forty-five calves were included in the study. The statistical analysis revealed a significant correlation between LAC and heart rate (r = 0.570; p < 0.05) and LAC and SI (r = 0.373; p < 0.05). A high LAC value at admission was significantly associated with a negative outcome (death) (p < 0.05). In calves suffering from obstructive digestive diseases, the SI was related to the outcome and the analysis indicated a cut-off value of 1.13 (Se = 0.77, Spe = 1). In conclusion, in our study, the initial blood L-lactate value was correlated with heart rate, the shock index, and the clinical shock score, and admission hyperlactatemia was associated with a poor prognosis in calves under 4 months of age. In this cohort, the shock index in calves suffering from digestive diseases was linked with mortality.

Enriching Data Science and Health Care Education: Application and Impact of Synthetic Data Sets Through the Health Gym Project

Large-scale medical data sets are vital for hands-on education in health data science but are often inaccessible due to privacy concerns. Addressing this gap, we developed the Health Gym project, a free and open-source platform designed to generate synthetic health data sets applicable to various areas of data science education, including machine learning, data visualization, and traditional statistical models. Initially, we generated 3 synthetic data sets for sepsis, acute hypotension, and antiretroviral therapy for HIV infection. This paper discusses the educational applications of Health Gym's synthetic data sets. We illustrate this through their use in postgraduate health data science courses delivered by the University of New South Wales, Australia, and a Datathon event, involving academics, students, clinicians, and local health district professionals. We also include adaptable worked examples using our synthetic data sets, designed to enrich hands-on tutorial and workshop experiences. Although we highlight the potential of these data sets in advancing data science education and health care artificial intelligence, we also emphasize the need for continued research into the inherent limitations of synthetic data.

Prophylactic infusion of norepinephrine does not affect the rostral spread of spinal anesthesia in pregnancy: a prospective, randomized, double-blinded study

Background: The infusion of phenylephrine to prevent spinal-induced hypotension (SIH) in cesarean delivery may decrease the rostral spread of a spinal local anesthetic. We hypothesized that infusion of norepinephrine may decrease the rostral spread of spinal anesthesia, similar to that caused by phenylephrine. The aim of this study was to compare the block height of spinal anesthesia in the presence or absence of norepinephrine infusion administered to prevent SIH during cesarean delivery. Methods: Eighty patients were enrolled and allocated into groups receiving a norepinephrine infusion (group N) or saline infusion (group C). After intrathecal injection of hyperbaric bupivacaine 10 mg, the block height for cold and pinprick sensation was checked 10 and 20 min after the injection. The demographic characteristics, spinal anesthesia, side effects, and neonatal outcomes were also recorded. Results: The block height for cold and pinprick sensation was similar between the two groups, although the incidence of hypotension was significantly lower (p < 0.00) in group N than in group C. Systolic blood pressure was also more stable in group N than in group C, with the incidence of interventions being significantly lower in group N. There was no significant difference in patient satisfaction between the two groups. Conclusion: Evidence from this study suggested that prophylactic norepinephrine infusion does not reduce the rostral spread of spinal anesthesia in pregnancy. We suggest that it is not necessary to increase the dose of an intrathecal local anesthetic for cesarean delivery when prophylactic norepinephrine is administered. Clinical Trial Registration: https://www.chictr.org.cn/bin/project/edit?pid=152899, identifier [ChiCTR2200057439].

Use total portosystemic shunt to rescue an emergency PNF with intractable hypotension: A case report

RATIONALE

Living donor allogeneic liver transplantation is a surgical treatment for patients with end-stage liver disease, wherein a healthy liver is implanted in the patient, facilitating the recovery of the liver function in patients with end-stage liver disease. However, primary nonfunction (PNF) may occur as a result of this procedure.

PATIENT CONCERNS

A case of an 65-year-old Asian male with a medical history of cirrhosis and hepatocellular carcinoma is described. Intractable hypotension occurred after open hepatic portal anastomosis, and large doses of vasoactive substances did not improve the condition.

DIAGNOSIS

PNF was diagnosed during surgery and it caused intractable hypotension.

INTERVENTIONS

we promptly used the total portosystemic shunt to achieve a successful rescue.

OUTCOMES

The strengthening of perioperative management and active treatment allowed second liver transplantation and anhepatic phase of up to 10 hours, following which the patient was rescued.

LESSONS

The lesson we have learned is that total portosystemic shunt composited with careful anesthesia management can rescue the event of PNF with intractable hypotension in liver transplantation surgery. At the same time, we give attention to blood pressure, electrocardiogram, albumin, calcium, potassium, acidosis, coagulopathy, anti-infection, and protection of vital organs is essential for successful retransplant outcomes.

Tizanidine Induced Hypotension: Report of a Case and Review of the Literature

INTRODUCTION

Spasticity is a common sequelae of stroke, and often these patients receive anti-spastic drugs such as baclofen or tizanidine. Stroke patients have multiple co-morbidities such as hypertension, diabetes, and seizure. Tizanidine is an α2 and imidazole receptor agonist at a spinal and supraspinal level resulting in reduced central sympathetic outflow and causing hypotension rarely, especially in those receiving beta-blockers or angiotensin-converting enzyme inhibitors.

CASE PRESENTATION

We report a 56-year-old hypertensive male presenting with altered sensorium who had recurrent intracerebral hemorrhage with left spastic hemiplegia and focal seizures. He was on amlodipine, atenolol, telmisartan and oxcarbazepine. After 3 doses of tizanidine 2mg, his blood pressure dropped from 140/90 to 80/40 mmHg and pulse from 82 bpm to 44 bpm. His blood counts, serum chemistry, procalcitonin, and Trop I were normal. ECG revealed sinus bradycardia. After 8 hours of withdrawing tizanidine, his blood pressure became 110/70 mmHg, and on the next day, it became 140/82 mmHg. His attendants were taught physiotherapy to minimize spasticity.

CONCLUSION

This patient highlights the need for close monitoring of patients receiving tizanidine co-medication with angiotensin-converting enzyme inhibitors and angiotensin receptor blockers. These drugs have a synergistic effect on reducing the renin-angiotensin-aldosterone system, thereby hypotension and bradycardia.

The association of cumulative vasoactive drugs and neurodevelopmental outcomes in preterm Infants <29 weeks gestation

OBJECTIVE

To assess the effect of cardiovascular medications on the neurodevelopment of preterm infants, as measured by calculated cumulative time of vasoactive-inotropic score (VISct).

METHODS

A retrospective study was conducted on preterm infants who developed significant hypotension defined as a mean BP more than 2SDs below the mean for GA and received treatment with duration > 6 hours for each hypotensive episode, we calculated the vasoactive inotropic score (VIS) and cumulative exposure to cardiovascular medications over time (VISct). The composite Bayley III was reported from the high-risk follow-up clinic for the surviving infants between 18 to 21 months corrected age.

RESULTS

VISct was significantly higher in infants with abnormal neurodevelopment. Cognitive Bayley was the most affected component with median (IQR) VISct 882.5(249,2047) versus 309(143,471) (p-value 0.012), followed by language function with VISct 786(261,1563.5), versus 343(106.75,473.75) (p-value 0.016) when those with Bayley III <85 were compared with those with normal Bayley IIIs.

CONCLUSION

High VISct scores may have negative effect on cognitive and language neurodevelopmental outcomes.

Higher NT-proBNP levels and the risk of intradialytic hypotension at hemodialysis initiation

INTRODUCTION

Elevated N-terminal pro B-type natriuretic peptide (NT-proBNP) is a potent predictor of adverse outcomes in hemodialysis initiation. These patients often experience intradialytic hypotension, which may partially reflect cardiac dysfunction, but the association of NT-proBNP with intradialytic hypotension is not clear.

METHODS

We performed a post hoc analysis of a randomized trial that tested mannitol versus placebo in 52 patients initiating hemodialysis (NCT01520207). NT-proBNP was measured prior to the first and third sessions (n = 87). Mixed-effects models (adjusting for randomized treatment, sex, race, age, diabetes, heart failure, catheter use, pre-dialysis systolic blood pressure, pre-dialysis weight, ultrafiltration volume, serum sodium, bicarbonate, urea nitrogen, phosphate, albumin, hemoglobin, and session length) were fit to examine the association of NT-proBNP with systolic blood pressure decline (pre-dialysis minus nadir systolic blood pressure). Additionally, mixed-effects Poisson models were fit to examine the association with intradialytic hypotension (≥20 mmHg decline in systolic blood pressure).

FINDINGS

Mean age was 55 ± 16 years; 33% had baseline heart failure. The median NT-proBNP was 5498 [25th-75th percentile 2011, 14,790] pg/mL; 26 sessions (30%) were complicated by intradialytic hypotension. In adjusted models, each unit higher log-NT-proBNP was associated with 6.0 mmHg less decline in systolic blood pressure (95%CI -9.2 to -2.8). Higher pre-dialysis NT-proBNP, per log-unit, was associated with a 52% lower risk of intradialytic hypotension (IRR 0.48, 95%CI 0.23-0.97), without evidence for effect modification by randomized treatment (P-interaction = 0.17).

DISCUSSION

In patients initiating hemodialysis, higher NT-proBNP is associated with less decline in intradialytic systolic blood pressure and lower risk of intradialytic hypotension. Future studies should investigate if higher pre-dialysis NT-proBNP levels may identify patients who might tolerate more aggressive ultrafiltration.