Thoracic impedance pneumography in propofol-sedated patients undergoing percutaneous endoscopic gastrostomy (PEG) placement in gastrointestinal endoscopy: A prospective, randomized trial

STUDY OBJECTIVE

To assess the efficacy of an ECG-based method called thoracic impedance pneumography to reduce hypoxic events in endoscopy.

DESIGN

This was a single center, 1:1 randomized controlled trial.

SETTING

The trial was conducted during the placement of percutaneous endoscopic gastrostomy (PEG).

PATIENTS

173 patients who underwent PEG placement were enrolled in the present trial. Indication was oncological in most patients (89%). 58% of patients were ASA class II and 42% of patients ASA class III.

INTERVENTIONS

Patients were randomized in the standard monitoring group (SM) with pulse oximetry and automatic blood pressure measurement or in the intervention group with additional thoracic impedance pneumography (TIM). Sedation was performed with propofol by gastroenterologists or trained nurses.

MEASUREMENTS

Hypoxic episodes defined as SpO2 < 90% for >15 s were the primary endpoint. Secondary endpoints were minimal SpO2, apnea >10s/>30s and incurred costs.

MAIN RESULTS

Additional use of thoracic impedance pneumography reduced hypoxic episodes (TIM: 31% vs SM: 49%; p = 0.016; OR 0.47; NNT 5.6) and elevated minimal SpO2 per procedure (TIM: 90.0% ± 8.9; SM: 84.0% ± 17.6; p = 0.007) significantly. Apnea events >10s and > 30s were significantly more often detected in TIM (43%; 7%) compared to SM (1%; 0%; p < 0.001; p = 0.014) resulting in a time advantage of 17 s before the occurrence of hypoxic events. As a result, adjustments of oxygen flow were significantly more often necessary in SM than in TIM (p = 0.034) and assisted ventilation was less often needed in TIM (2%) compared with SM (9%; p = 0.053). Calculated costs for the additional use of thoracic impedance pneumography were 0.13$ (0.12 €/0.11 £) per procedure.

CONCLUSIONS

Additional thoracic impedance pneumography reduced the quantity and extent of hypoxic events with less need of assisted ventilation. Supplemental costs per procedure were negligible.

KEY WORDS

thoracic impedance pneumography, capnography, sedation, monitoring, gastrointestinal endoscopy, percutaneous endoscopic gastrostomy.

Krebs von den Lungen-6 levels at admission predicts exercise-induced hypoxemia before and after discharge in patients with COVID-19

BACKGROUND

There are no reports of exercise-induced hypoxemia in patients with coronavirus disease 2019 (COVID-19). Additionally, the predictive factors and prevalence of exercise-induced hypoxemia are unknown. This study investigated the incidence and predictive factors of exercise-induced hypoxemia before and after discharge in patients with COVID-19.

METHODS

We enrolled 77 patients diagnosed with COVID-19 who were hospitalized between November 2020 and October 2021 and who underwent a 6-min walk test before and after discharge. Based on the test results, we classified patients into exercise-induced and non-exercise-induced hypoxemia groups and investigated the predictive factors of exercise-induced hypoxemia using logistic regression analysis.

RESULTS

The incidences of exercise-induced hypoxemia in patients with COVID-19 were 37.7% and 19.5% before and after discharge, respectively. At admission, the Krebs von den Lungen-6 levels was the associated factor for exercise-induced hypoxemia in patients with COVID-19 before and after discharge, with cut-off values of 314 U/mL and 367 U/mL, respectively. Age and lactate dehydrogenase levels were the associated factors for exercise-induced hypoxemia in patients with COVID-19 before discharge, with cut-off values of 61 years and 492 U/L, respectively.

CONCLUSIONS

Some patients with COVID-19 may continue to experience exercise-induced hypoxemia after discharge. Age, lactate dehydrogenase, and Krebs von den Lungen-6 levels at admission could serve as predictive markers of exercise-induced hypoxemia before and after discharge in these patients.

Effects of bradycardia, hypoxemia and early intubation on bronchopulmonary dysplasia in very preterm infants: An observational study

BACKGROUND

Bronchopulmonary dysplasia (BPD) is the most common pulmonary complication in preterm infants.

OBJECTIVES

The study aimed to explore the effects of bradycardia, hypoxemia, and early intubation on BPD in very preterm infants.

METHODS

This is a prospective observational cohort study. Preterm infants with a mean gestational age of 28.67 weeks were recruited from two level III neonatal intensive care units (NICUs) in Taiwan. Continuous electrocardiography was used to monitor heart rates and oxygen saturation (SpO2). Infants were monitored for heart rates of <100 beats per minute and SpO2 levels of <90 % lasting for 30 s. Generalized estimating equations were used to analyze the effects of bradycardia, hypoxemia, and early intubation on BPD in very preterm infants. Model fit was visually assessed using receiver operating characteristic curve analysis.

RESULTS

Bradycardia, hypoxemia, and early intubation significantly increased the odds of BPD among the preterm infants (N = 39) during NICU stay; the odds ratios for bradycardia, hypoxemia, and early intubation for BPD versus non-BPD were 1.058, 1.013, and 29.631, respectively (all p < 0.05). A model combining bradycardia, hypoxemia, and early intubation accurately predicted BPD development (area under the curve = 0.919).

CONCLUSIONS

Bradycardia, hypoxemia, and early intubation significantly increased the odds of BPD among very preterm infants during NICU stay. The model combining bradycardia, hypoxemia, and early intubation accurately predicted BPD development.

A Nationwide, Prospective Study of Tracheal Intubation in Critically Ill Adults in Spain: Management, Associated Complications, and Outcomes

OBJECTIVES

Our aims were to explore current intubation practices in Spanish ICUs to determine the incidence and risk factors of peri-intubation complications (primary outcome measure: major adverse events), the rate and factors associated with first-pass success, and their impact on mortality as well as the changes of the intubation procedure observed in the COVID-19 pandemic.

DESIGN

Prospective, observational, and cohort study.

SETTING

Forty-three Spanish ICU.

PATIENTS

A total of 1837 critically ill adult patients undergoing tracheal intubation. The enrollment period was six months (selected by each center from April 16, 2019, to October 31, 2020).

INTERVENTIONS

None.

MEASUREMENT AND MAIN RESULTS

At least one major adverse peri-intubation event occurred in 40.4 % of the patients (973 major adverse events were registered) the most frequent being hemodynamic instability (26.5%) and severe hypoxemia (20.3%). The multivariate analysis identified seven variables independently associated with a major adverse event whereas the use of neuromuscular blocking agents (NMBAs) was associated with reduced odds of major adverse events. Intubation on the first attempt was achieved in 70.8% of the patients. The use of videolaryngoscopy at the first attempt was the only protective factor (odds ratio 0.43; 95% CI, 0.28-0.66; p < 0.001) for first-attempt intubation failure. During the COVID-19 pandemic, the use of videolaryngoscopy and NMBAs increased significantly. The occurrence of a major peri-intubation event was an independent risk factor for 28-day mortality. Cardiovascular collapse also posed a serious threat, constituting an independent predictor of death.

CONCLUSIONS

A major adverse event occurred in up to 40% of the adults intubated in the ICU. Peri-intubation hemodynamic instability but not severe hypoxemia was identified as an independent predictor of death. The use of NMBAs was a protective factor for major adverse events, whereas the use of videolaringoscopy increases the first-pass success rate of intubation. Intubation practices changed during the COVID-19 pandemic.

Dexmedetomidine improves pulmonary outcomes in thoracic surgery under one-lung ventilation: A meta-analysis

INTRODUCTION

Dexmedetomidine improves intrapulmonary shunt in thoracic surgery and minimizes inflammatory response during one-lung ventilation (OLV). However, it is unclear whether such benefits translate into less postoperative pulmonary complications (PPCs). Our objective was to determine the impact of dexmedetomidine on the incidence of PPCs after thoracic surgery.

METHODS

Major databases were used to identify randomized trials that compared dexmedetomidine versus placebo during thoracic surgery in terms of PPCs. Our primary outcome was atelectasis within 7 days after surgery. Other specific PPCs included hypoxemia, pneumonia, and acute respiratory distress syndrome (ARDS). Secondary outcome included intraoperative respiratory mechanics (respiratory compliance [Cdyn]) and postoperative lung function (forced expiratory volume [FEV1]). Random effects models were used to estimate odds ratios (OR).

RESULTS

Twelve randomized trials, including 365 patients in the dexmedetomidine group and 359 in the placebo group, were analyzed in this meta-analysis. Patients in the dexmedetomidine group were less likely to develop postoperative atelectasis (2.3% vs 6.8%, OR 0.42, 95%CI 0.18-0.95, P = 0.04; low certainty) and hypoxemia (3.4% vs 11.7%, OR 0.26, 95%CI 0.10-0.68, P = 0.01; moderate certainty) compared to the placebo group. The incidence of postoperative pneumonia (3.2% vs 5.8%, OR 0.57, 95%CI 0.25-1.26, P = 0.17; moderate certainty) or ARDS (0.9% vs 3.5%, OR 0.39, 95%CI 0.07-2.08, P = 0.27; moderate certainty) was comparable between groups. Both intraoperative Cdyn and postoperative FEV1 were higher among patients that received dexmedetomidine with a mean difference of 4.42 mL/cmH2O (95%CI 3.13-5.72) and 0.27 L (95%CI 0.12-0.41), respectively.

CONCLUSION

Dexmedetomidine administration during thoracic surgery may potentially reduce the risk of postoperative atelectasis and hypoxemia. However, current evidence is insufficient to demonstrate an effect on pneumonia or ARDS.

Occurrence of hyperoxia during iNO treatment for persistent pulmonary hypertension of the newborn: a cohort study

High concentrations of oxygen are often needed to optimize oxygenation in infants with persistent pulmonary hypertension (PPHN), but this can also increase the risk of hyperoxemia. We determined the occurrence of hyperoxemia in infants treated for PPHN. Medical records of infants ≥ 34 + 0 weeks gestational age (GA) who received inhaled nitric oxide (iNO) were retrospectively reviewed for oxygenation parameters during iNO therapy. Oxygen was manually titrated to target arterial oxygen tension (PaO2) 10-13 kPa and peripheral oxygen saturation (SpO2) 92-98%. The main study outcomes were the incidence and duration of hyperoxemia and hypoxemia and the fraction of inspired oxygen (FiO2). A total of 181 infants were included. The median FiO2 was 0.43 (IQR 0.34-0.56) and the maximum FiO2 was 1.0 in 156/181 (86%) infants, resulting in at least one PaO2 > 13 kPa in 149/181 (82%) infants, of which 46/149 (31%) infants had minimal one PaO2 > 30 kPa. SpO2 was > 98% in 179/181 (99%) infants for 17.7% (8.2-35.6%) of the iNO time. PaO2 < 10 kPa occurred in 160/181 (88%) infants, of which 81/160 (51%) infants had minimal one PaO2 < 6.7 kPa. SpO2 was < 92% in 169/181 (93%) infants for 1.6% (0.5-4.3%) of the iNO time.    Conclusion: While treatment of PPHN is focused on preventing and reversing hypoxemia, hyperoxemia occurs inadvertently in most patients. What is Known: • High concentrations of oxygen are often needed to prevent hypoxemia-induced deterioration of PPHN, but this can also increase the risk of hyperoxemia. • Infants with persistent pulmonary hypertension may be particularly vulnerable to the toxic effects of oxygen, and hyperoxemia could further induce pulmonary vasoconstriction, potentially worsening the condition. What is New: • Hyperoxemia occurs in the majority of infants with PPHN during treatment with iNO. • Infants with PPHN spent a considerably longer period with saturations above the target range compared to saturations below the target range.

Urinary oxygen tension and its role in predicting acute kidney injury: A narrative review

Acute kidney injury occurs frequently in the perioperative setting. The renal medulla often endures hypoxia or hypoperfusion and is susceptible to the imbalance between oxygen supply and demand due to the nature of renal blood flow distribution and metabolic rate in the kidney. The current available evidence demonstrated that the urine oxygen pressure is proportional to the variations of renal medullary tissue oxygen pressure. Thus, urine oxygenation can be a candidate for reflecting the change of oxygen in the renal medulla. In this review, we discuss the basic physiology of acute kidney injury, as well as techniques for monitoring urine oxygen tension, confounding factors affecting the reliable measurement of urine oxygen tension, and its clinical use, highlighting its potential role in early detection and prevention of acute kidney injury.

Recovery and safety with prolonged high-frequency jet ventilation for catheter ablation of atrial fibrillation: A hospital registry study from a New England healthcare network

STUDY OBJECTIVE

To investigate post-procedural recovery as well as peri-procedural respiratory and hemodynamic safety parameters with prolonged use of high-frequency jet ventilation (HFJV) versus conventional ventilation in patients undergoing catheter ablation for atrial fibrillation.

DESIGN

Hospital registry study.

SETTING

Tertiary academic teaching hospital in New England.

PATIENTS

1822 patients aged 18 years and older undergoing catheter ablation between January 2013 and June 2020.

INTERVENTIONS

HFJV versus conventional mechanical ventilation.

MEASUREMENTS

The primary outcome was post-anesthesia care unit (PACU) length of stay. In secondary analyses we assessed the effect of HFJV on intra-procedural hypoxemia, defined as the occurrence of peripheral hemoglobin oxygen saturation (SpO2) <90%, post-procedural respiratory complications (PRC) as well as intra-procedural hypocarbia and hypotension. Multivariable negative binomial and logistic regression analyses, adjusted for patient and procedural characteristics, were applied.

MAIN RESULTS

1157 patients (63%) received HFJV for a median (interquartile range [IQR]) duration of 307 (253-360) minutes. The median (IQR) length of stay in the PACU was 244 (172-370) minutes in patients who underwent ablation with conventional mechanical ventilation and 226 (163-361) minutes in patients receiving HFJV. In adjusted analyses, patients undergoing HFJV had a longer PACU length of stay (adjusted absolute difference: 37.7 min; 95% confidence interval [CI] 9.7-65.8; p = 0.008). There was a higher risk of intra-procedural hypocarbia (adjusted odds ratio [ORadj] 5.90; 95%CI 2.63-13.23; p < 0.001) and hypotension (ORadj 1.88; 95%CI 1.31-2.72; p = 0.001) in patients undergoing HFJV. No association was found between the use of HFJV and intra-procedural hypoxemia or PRC (p = 0.51, and p = 0.97, respectively).

CONCLUSION

After confounder adjustment, HFJV for catheter ablation procedures for treatment of atrial fibrillation was associated with a longer length of stay in the PACU. It was further associated with an increased risk of intra-procedural abnormalities including abnormal carbon dioxide homeostasis, as well as intra-procedural arterial hypotension.

Significance of Persistent Systemic Support in the Clinical Course of Delayed Post-hypoxic Leukoencephalopathy Following Severe Coronavirus Disease 2019

A 45-year-old woman was hospitalized with severe coronavirus disease 2019 pneumonia. Following cytokine storm-induced multiorgan failure and lethal arrhythmia, the patient developed a sustained coma with flaccid quadriplegia. A cerebrospinal fluid examination excluded infectious and immunogenic encephalopathies, and diffusion-weighted magnetic resonance imaging demonstrated high-intensity areas in the white matter with a cortex-sparing distribution, suggesting delayed post-hypoxic leukoencephalopathy. As a result of intensive cardiopulmonary support for a month, the neurological function gradually recovered. Based on the reversible clinical course noted in this patient, accurate diagnosis and persistent medical approaches are important for the management of coronavirus disease 2019-related delayed post-hypoxic leukoencephalopathy.

Role of oxygen reserve index monitoring in patients undergoing robot-assisted radical prostatectomy: a retrospective study

PURPOSE

Robot-assisted radical prostatectomy (RARP) is a common surgical procedure for the treatment of prostate cancer. Although beneficial, it can lead to intraoperative hypoxia due to high-pressure pneumoperitoneum and Trendelenburg position. This study explored the use of oxygen reserve index (ORi) to monitor and predict hypoxia during RARP.

METHODS

A retrospective analysis was conducted on 329 patients who underwent RARP at the Seoul National University Bundang Hospital between July 2021 and March 2023. Various pre- and intraoperative variables were collected, including ORi values. The relationship between ORi values and hypoxia occurrence was assessed using receiver operating characteristic curves and logistic regression analysis.

RESULTS

Intraoperative hypoxia occurred in 18.8% of the patients. The receiver operating characteristic curve showed a satisfactory area under the curve of 0.762, with the ideal ORi cut-off value for predicting hypoxia set at 0.16. Sensitivity and specificity were 64.5% and 75.7%, respectively. An ORi value of < 0.16 and a higher body mass index were identified as independent risk factors of hypoxia during RARP.

CONCLUSIONS

ORi monitoring provides a non-invasive approach to predict intraoperative hypoxia during RARP, enabling early management. Additionally, the significant relationship between a higher body mass index and hypoxia underscores the importance of individualized patient assessment.

Lower vs Higher Oxygenation Target and Days Alive Without Life Support in COVID-19: The HOT-COVID Randomized Clinical Trial

Importance

Supplemental oxygen is ubiquitously used in patients with COVID-19 and severe hypoxemia, but a lower dose may be beneficial.

Objective

To assess the effects of targeting a Pao2 of 60 mm Hg vs 90 mm Hg in patients with COVID-19 and severe hypoxemia in the intensive care unit (ICU).

Design, Setting, and Participants

Multicenter randomized clinical trial including 726 adults with COVID-19 receiving at least 10 L/min of oxygen or mechanical ventilation in 11 ICUs in Europe from August 2020 to March 2023. The trial was prematurely stopped prior to outcome assessment due to slow enrollment. End of 90-day follow-up was June 1, 2023.

Interventions

Patients were randomized 1:1 to a Pao2 of 60 mm Hg (lower oxygenation group; n = 365) or 90 mm Hg (higher oxygenation group; n = 361) for up to 90 days in the ICU.

Main Outcomes and Measures

The primary outcome was the number of days alive without life support (mechanical ventilation, circulatory support, or kidney replacement therapy) at 90 days. Secondary outcomes included mortality, proportion of patients with serious adverse events, and number of days alive and out of hospital, all at 90 days.

Results

Of 726 randomized patients, primary outcome data were available for 697 (351 in the lower oxygenation group and 346 in the higher oxygenation group). Median age was 66 years, and 495 patients (68%) were male. At 90 days, the median number of days alive without life support was 80.0 days (IQR, 9.0-89.0 days) in the lower oxygenation group and 72.0 days (IQR, 2.0-88.0 days) in the higher oxygenation group (P = .009 by van Elteren test; supplemental bootstrapped adjusted mean difference, 5.8 days [95% CI, 0.2-11.5 days]; P = .04). Mortality at 90 days was 30.2% in the lower oxygenation group and 34.7% in the higher oxygenation group (risk ratio, 0.86 [98.6% CI, 0.66-1.13]; P = .18). There were no statistically significant differences in proportion of patients with serious adverse events or in number of days alive and out of hospital.

Conclusion and Relevance

In adult ICU patients with COVID-19 and severe hypoxemia, targeting a Pao2 of 60 mm Hg resulted in more days alive without life support in 90 days than targeting a Pao2 of 90 mm Hg.

Trial Registration

ClinicalTrials.gov Identifier: NCT04425031.

Hypoxaemia and risk of asphyxia during underground work in artisanal cobalt mines

BACKGROUND

More than half the cobalt needed for vehicle electrification originates from the southern part of the Democratic Republic of the Congo (DRC), with a substantial part being extracted by artisanal miners.

AIMS

To investigate oxygen saturation during underground work among cobalt artisanal miners.

METHODS

In a field survey, we measured oxygen saturation (SpO2) and heart rate by pulse oximetry in 86 miners from two underground mines and 24 miners from a surface mine at four different time points: before descent into the mine (T1), at 50 minutes in the mine (T2), upon leaving the shaft (T3), and 10 minutes after having left the mine (T4).

RESULTS

Miners working underground (-36 to -112 meters) were somewhat older (34.8 ± 6.7 years) than those working in the surface mine (32.0 ± 6.5 years), and they worked more hours daily (12.6 ± 1.2 hours) than controls (9.0 ± 0.0 hours). All participants had SpO2 >95% at T1 and T4. At T2, SpO2 dropped below 93% and 80% in 35% and 10% underground miners, respectively; SpO2 was still <93% at T3 in 13%. SpO2 remained stable among surface miners. Later, we showed that underground ambient oxygen levels decreased well below 21% in several pits.

CONCLUSIONS

Pulse oximetry revealed relevant hypoxaemia during underground work in a substantial proportion of artisanal miners. Such hypoxaemia without evidence of underlying cardiovascular disease is indicative of low ambient oxygen, due to insufficient mine ventilation. This may cause deaths from asphyxia. The hazards of low ambient oxygen in artisanal mines must be prevented by appropriate technical measures ensuring the supply of sufficient fresh air.

Safety and efficacy of dexmedetomidine vs. midazolam in complex gastrointestinal endoscopy: A systematic review and meta-analysis

OBJECTIVE

This study aims to perform a meta-analysis to evaluate the safety and efficacy of dexmedetomidine versus midazolam for complex digestive endoscopy procedures, with the goal of offering comprehensive clinical evidence.

METHODS

Following predefined inclusion criteria, five databases were systematically searched, with a focus on identifying randomized controlled trials (RCTs) that compared the administration of dexmedetomidine and midazolam during complex digestive endoscopy procedures. The statistical software Stata 15.1 was employed for meticulous data analysis.

RESULTS

Sixteen RCTs were encompassed, involving a total of 1218 patients. In comparison to the midazolam group, dexmedetomidine administration was associated with a reduced risk of respiratory depression (RR=0.25, 95 %CI: 0.11-0.56) and hypoxemia (RR=0.22, 95 %CI: 0.12-0.39). Additionally, the dexmedetomidine group exhibited lower incidence rates of choking (RR=0.27, 95 %CI: 0.16-0.47), physical movement (RR=0.16, 95 %CI: 0.09-0.27), and postoperative nausea and vomiting (RR=0.56,95 %CI: 0.34-0.92). Patients and endoscopists in the dexmedetomidine group reported higher levels of satisfaction (patient satisfaction: SMD=0.73, 95 %CI: 0.26-1.21; endoscopist satisfaction: SMD=0.84, 95 %CI: 0.24-1.44). The incidence of hypotension and anesthesia recovery time did not significantly differ between the two groups (hypotension: RR=1.73,95 %CI:0.94-3.20; anesthesia recovery time: SMD=0.02, 95 %Cl: 0.44-0.49). It is noteworthy that the administration of dexmedetomidine was associated with a significant increase in the incidence of bradycardia in patients.

CONCLUSION

Compared to midazolam, dexmedetomidine exhibits a favorable safety profile for use in complex gastrointestinal endoscopy by significantly reducing the risk of respiratory depression and hypoxemia. Despite this, dexmedetomidine is associated with a higher incidence of bradycardia. These findings underscore the need for further research through larger, multi-center studies to thoroughly investigate dexmedetomidine's safety and efficacy.

Effects of sleep-disordered breathing on serum lipid levels in children:a case control study

BACKGROUND

Sleep-disordered breathing (SDB) during childhood is common and includes a range of breathing abnormalities that range from primary snoring (PS) to obstructive sleep apnea syndrome (OSAS).Studies have shown that not only OSAS, but also PS, which is originally considered harmless, could cause cardiovascular, cognitive, behavioral, and psychosocial problems. Many researches are focused on the relation of OSA and serum lipid levels. However, little studies are focused on PS and serum lipid levels in children.We evaluated whether serum lipid (total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C),low-density lipoprotein cholesterol (LDL-C)) concentrations were associated with specific components of SDB, including indices of oxygen reduction index, lowest oxygen saturation, mean oxygen saturation. And we explored whether serum lipid levels were associated with different degree sleep disordered (PS and OSA group) and obese.

METHODS

This was a cross-sectional study. Children who were complained by their guardians with habitual snoring and(or) mouth breathing were collected in the SDB group. Normal children without sleep problem were matched in the control group. Subjects in the SDB group underwent polysomnography. The serum lipid profiles of all the children included TC, TG, HDL-C and LDL-C concentrations were measured by appropriate enzymatic assays.

RESULTS

A total of 241 with Apnea/Hypopnea Index ≥ 5 (AHI) were assigned to the OSAS group and the remaining 155 with normal AHI were assigned to the PS group. The values of TC, TG, LDL-C and LDL/HDL were significantly higher in the OSAS group than in the PS group, and the values in the PS group were significantly higher than the control group. Multiple regression analysis revealed serum TG only correlated negatively with lowest oxygen saturation. Body mass index-z score has a positive effect on TG in all the 1310 children (P = 0.031) and in SDB 396 children(P = 0.012). The level of serum TG in obese group was significantly higher than that in non-obese group.

CONCLUSIONS

SDB had a very obvious effect on blood lipids, whereas PS without apnea and hypoxia. Obese only affects the aggregation of TG.

TRIAL REGISTRATION

ChiCTR1900026807(2019.10.23).

Nocturnal hypoxaemia is common in adults with sickle cell anaemia

The symptoms and sequelae of sickle cell anaemia (SCA) are caused by the polymerization of deoxygenated sickle haemoglobin, and people with SCA may be uniquely susceptible to adverse outcomes from hypoxia and haemoglobin desaturation. We examined by oximetry adults (aged 18-45 years) with SCA presenting symptoms indicative of polysomnography, at a single institution, irrespective of treatment, for nocturnal hypoxaemia. Clinical labs and blood for in vitro assessments were taken upon enrolment and after 8-12 weeks of oxygen therapy or observation. Of 21 screened participants, nine (43%) had sufficient nocturnal hypoxaemia to warrant oxygen therapy (≥5 min at SpO2 ≤ 88%). Time spent at SpO2 ≤ 88% associated with age (p = 0.0092), annual hospitalizations (p = 0.0018) and anaemia (p = 0.0139), as well as plasma levels of TNFα (p = 0.0019) and IL-4 (p = 0.0147). Longitudinal analysis showed that WBC significantly decreased during the follow-up period in hypoxic individuals but not in non-hypoxic individuals (p = 0.0361 and p = 0.6969 respectively). Plasma levels of CCL2 and IL-1ra tended to increase, while levels of red blood cell reactive oxygen species tended to decrease with oxygen therapy. Overall, nocturnal hypoxaemia was common in this pilot study population and associated with plausible clinical comorbidities; oxygen therapy may decrease inflammation and oxidative damage in hypoxic individuals.

The paradox of platypnoea-orthodeoxia syndrome

Platypnoea-orthodeoxia is a rare clinical syndrome characterised by dyspnoea and oxygen desaturation in the upright position which improves when supine. It requires two components: a sufficiently sized anatomical vascular defect (typically intra-cardiac or intra-pulmonary) combined with a functional component that promotes positional right-to-left shunting. We describe the rare occurrence of a patient with platypnoea-orthodeoxia syndrome (POS) because of a paradoxical shunt through a patent foramen ovale caused by a large right atrial line-associated thrombus in a male with metastatic oesophageal cancer undergoing chemotherapy. This case is a timely reminder to consider POS amongst differentials for hypoxia as it is often treatable if recognised.

Individualized Thresholds of Hypoxemia and Hyperoxemia and their Effect on Outcome in Acute Brain Injured Patients: A Secondary Analysis of the ENIO Study

BACKGROUND

In acute brain injury (ABI), the effects of hypoxemia as a potential cause of secondary brain damage and poor outcome are well documented, whereas the impact of hyperoxemia is unclear. The primary aim of this study was to assess the episodes of hypoxemia and hyperoxemia in patients with ABI during the intensive care unit (ICU) stay and to determine their association with in-hospital mortality. The secondary aim was to identify the optimal thresholds of arterial partial pressure of oxygen (PaO2) predicting in-hospital mortality.

METHODS

We conducted a secondary analysis of a prospective multicenter observational cohort study. Adult patients with ABI (traumatic brain injury, subarachnoid aneurysmal hemorrhage, intracranial hemorrhage, ischemic stroke) with available data on PaO2 during the ICU stay were included. Hypoxemia was defined as PaO2 < 80 mm Hg, normoxemia was defined as PaO2 between 80 and 120 mm Hg, mild/moderate hyperoxemia was defined as PaO2 between 121 and 299 mm Hg, and severe hyperoxemia was defined as PaO2 levels ≥ 300 mm Hg.

RESULTS

A total of 1,407 patients were included in this study. The mean age was 52 (±18) years, and 929 (66%) were male. Over the ICU stay, the fractions of patients in the study cohort who had at least one episode of hypoxemia, mild/moderate hyperoxemia, and severe hyperoxemia were 31.3%, 53.0%, and 1.7%, respectively. PaO2 values below 92 mm Hg and above 156 mm Hg were associated with an increased probability of in-hospital mortality. Differences were observed among subgroups of patients with ABI, with consistent effects only seen in patients without traumatic brain injury.

CONCLUSIONS

In patients with ABI, hypoxemia and mild/moderate hyperoxemia were relatively frequent. Hypoxemia and hyperoxemia during ICU stay may influence in-hospital mortality. However, the small number of oxygen values collected represents a major limitation of the study.

High-Flow Nasal Oxygen versus Conventional Nasal Cannula in Preventing Hypoxemia in Elderly Patients Undergoing Gastroscopy with Sedation: A Randomized Controlled Trial

Background: We aimed to compare the prevention of hypoxemia using High-flow nasal oxygen (HFNO) or regular nasal tubing (CNC) in elderly patients undergoing gastroscopy with sedation. Methods: This study was a prospective, randomized, controlled trial conducted at a single center. We included elective patients aged 65 and above who were undergoing gastroscopy with sedation. In the intervention group (HFNO), we set the oxygen flow rate to 60 liters per minute with an oxygen fraction (FiO2) of 0.6, while in the control group (CNC), it was 6 liters per minute. The primary outcome was the occurrence of hypoxemia (defined as Spo2 < 90%). Results: A total of 125 participants were enrolled (HFNO group: n = 63; CNC group: n = 62). The occurrence of hypoxemia was found to be significantly lower in the HFNO group compared to the CNC group (3.2% vs. 22.6%, p = 0.001). Additionally, a significantly shorter duration of low oxygen levels was observed in the HFNO group [0.0 seconds (0.0-13.0)] compared to the CNC group [0.0 seconds (0.0-124.0), p<0.001]. Moreover, a higher minimum Spo2 value was achieved in the HFNO group [99.0% (98.0-100.0) vs. 96.5% (91.0-99.0), p < 0.001], and a shorter recovery time was recorded [0.5 minutes (0.0-0.5) vs. 0.5 minutes (0.0-1.0), p = 0.016] in comparison to the CNC group. There were no differences in terms of comfort level [0 (0-4) vs. 0 (0-5), p = 0.268] between the two groups. Conclusions: The HFNO system was determined to be a safe and highly effective method for oxygen delivery, leading to a reduction in the occurrence of hypoxemia in elderly patients undergoing gastroscopy with sedation. It is recommended that HFNO be considered as the standard approach for management in this population.

High-flow nasal oxygenation versus face mask oxygenation for preoxygenation in patients undergoing double-lumen endobronchial intubation: protocol of a randomised controlled trial

INTRODUCTION

With the growing emphasis on swift recovery, minimally invasive thoracic surgery has advanced significantly. Video-assisted thoracoscopic surgery (VATS) has seen rapid development, and the double-lumen tube (DLT) remains the most dependable method for tracheal intubation in VATS. However, hypoxaemia during DLT intubation poses a threat to the perioperative safety of thoracic surgery patients. Recently, transnasal high-flow nasal oxygen (HFNO) has shown promise in anaesthesia, particularly in handling short-duration hypoxic airway emergencies. Yet, its application in the perioperative period for patients undergoing pulmonary surgery with compromised cardiopulmonary function lacks evidence, and there are limited reliable clinical data.

METHODS AND ANALYSIS

A prospective, randomised, controlled, single-blind design will be employed in this study. 112 patients aged 18-60 years undergoing elective VATS-assisted pulmonary surgery will be enrolled and randomly divided into two groups: the nasal high-flow oxygen group (H group) and the traditional mask transnasal oxygen group (M group) in a 1:1 ratio. HFNO will be used during DLT intubation for the prevention of asphyxia in group H, while conventional intubation procedures will be followed by group M. Comparison will be made between the two groups in terms of minimum oxygen saturation during intubation, hypoxaemia incidence during intubation, perioperative complications and postoperative hospital days.

ETHICS AND DISSEMINATION

Approval for this study has been granted by the local ethics committee at Shenzhen Second People's Hospital. The trial results will be disseminated through peer-reviewed journals and scientific conferences.

TRIAL REGISTRATION NUMBER

NCT05666908.

Factors predicting mortality in hospitalised HIV-negative children with lower-chest-wall indrawing pneumonia and implications for management

INTRODUCTION

In 2012, the World Health Organization revised treatment guidelines for childhood pneumonia with lower chest wall indrawing (LCWI) but no 'danger signs', to recommend home-based treatment. We analysed data from children hospitalized with LCWI pneumonia in the Pneumonia Etiology Research for Child Health (PERCH) study to identify sub-groups with high odds of mortality, who might continue to benefit from hospital management but may not be admitted by staff implementing the 2012 guidelines. We compare the proportion of deaths identified using the criteria in the 2012 guidelines, and the proportion of deaths identified using an alternative set of criteria from our model.

METHODS

PERCH enrolled a cohort of 2189 HIV-negative children aged 2-59 months who were admitted to hospital with LCWI pneumonia (without obvious cyanosis, inability to feed, vomiting, convulsions, lethargy or head nodding) between 2011-2014 in Kenya, Zambia, South Africa, Mali, The Gambia, Bangladesh, and Thailand. We analysed risk factors for mortality among these cases using predictive logistic regression. Malnutrition was defined as mid-upper-arm circumference <125mm or weight-for-age z-score <-2.

RESULTS

Among 2189 cases, 76 (3·6%) died. Mortality was associated with oxygen saturation <92% (aOR 3·33, 1·99-5·99), HIV negative but exposed status (4·59, 1·81-11·7), moderate or severe malnutrition (6·85, 3·22-14·6) and younger age (infants compared to children 12-59 months old, OR 2·03, 95%CI 1·05-3·93). At least one of three risk factors: hypoxaemia, HIV exposure, or malnutrition identified 807 children in this population, 40% of LCWI pneumonia cases and identified 86% of the children who died in hospital (65/76). Risk factors identified using the 2012 WHO treatment guidelines identified 66% of the children who died in hospital (n = 50/76).

CONCLUSIONS

Although it focuses on treatment failure in hospital, this study supports the proposal for better risk stratification of children with LCWI pneumonia. Those who have hypoxaemia, any malnutrition or those who were born to HIV positive mothers, experience poorer outcomes than other children with LCWI pneumonia. Consistent identification of these risk factors should be prioritised and children with at least one of these risk factors should not be managed in the community.

Hypoxia-Directed Treatment of Human Papillomavirus-Related Oropharyngeal Carcinoma

PURPOSE

Standard curative-intent chemoradiotherapy for human papillomavirus (HPV)-related oropharyngeal carcinoma results in significant toxicity. Since hypoxic tumors are radioresistant, we posited that the aerobic state of a tumor could identify patients eligible for de-escalation of chemoradiotherapy while maintaining treatment efficacy.

METHODS

We enrolled patients with HPV-related oropharyngeal carcinoma to receive de-escalated definitive chemoradiotherapy in a phase II study (ClinicalTrials.gov identifier: NCT03323463). Patients first underwent surgical removal of disease at their primary site, but not of gross disease in the neck. A baseline 18F-fluoromisonidazole positron emission tomography scan was used to measure tumor hypoxia and was repeated 1-2 weeks intratreatment. Patients with nonhypoxic tumors received 30 Gy (3 weeks) with chemotherapy, whereas those with hypoxic tumors received standard chemoradiotherapy to 70 Gy (7 weeks). The primary objective was achieving a 2-year locoregional control (LRC) of 95% with a 7% noninferiority margin.

RESULTS

One hundred fifty-eight patients with T0-2/N1-N2c were enrolled, of which 152 patients were eligible for analyses. Of these, 128 patients met criteria for 30 Gy and 24 patients received 70 Gy. The 2-year LRC was 94.7% (95% CI, 89.8 to 97.7), meeting our primary objective. With a median follow-up time of 38.3 (range, 22.1-58.4) months, the 2-year progression-free survival (PFS) and overall survival (OS) rates were 94% and 100%, respectively, for the 30-Gy cohort. The 70-Gy cohort had similar 2-year PFS and OS rates at 96% and 96%, respectively. Acute grade 3-4 adverse events were more common in 70 Gy versus 30 Gy (58.3% v 32%; P = .02). Late grade 3-4 adverse events only occurred in the 70-Gy cohort, in which 4.5% complained of late dysphagia.

CONCLUSION

Tumor hypoxia is a promising approach to direct dosing of curative-intent chemoradiotherapy for HPV-related carcinomas with preserved efficacy and substantially reduced toxicity that requires further investigation.

Outcomes and Functional Deterioration in Hospital Admissions with Acute Hypoxemia

BACKGROUND

Many hospitalized patients decline in functional status after discharge, but functional decline in emergency admissions with hypoxemia is unknown. The primary aim of this study was to study functional outcomes as a clinical endpoint in a cohort of patients with acute hypoxemia.

METHODS

A multicenter prospective observational study was conducted in patients with new-onset hypoxemia emergently admitted to two respiratory departments at a university hospital and an academic teaching hospital. Using the WHO scale, the patients' functional status 4 weeks before admission and at hospital discharge was assessed. The type and duration of oxygen therapy, hospital length of stay and survival and risk of hypercapnic failure were recorded.

RESULTS

A total of 151 patients with a median age of 74 were included. Two-thirds declined in functional status by at least one grade at discharge. A good functional status (OR 4.849 (95% CI 2.209-10.647)) and progressive cancer (OR 6.079 (1.197-30.881)) were more associated with functional decline. Most patients were treated with conventional oxygen therapy (n = 95, 62%). The rates of in-hospital mortality and need for intubation were both 8%.

CONCLUSIONS

Patients with acute hypoxemia in the emergency room have a poorer functional status after hospital discharge. This decline may be of multifactorial origin.

Effects of trimetazidine on cardiac function in adult cyanotic congenital heart disease patients: Protocol for a 3-month multicenter, randomized, double-blind controlled trial

BACKGROUND

Nearly 20% Patients with cyanotic congenital heart disease (CCHD) are not able to receive surgery. These patients experience a decline in cardiac function as they age, which has been demonstrated to be associated with changes in energy metabolism in cardiomyocytes. Trimetazidine (TMZ), a metabolic regulator, is supposed to alleviate such maladaptation and reserve cardiac function in CCHD patients.

METHODS

This is a randomized, double-blind, placebo-controlled clinical trial. Eighty adult CCHD patients will be recruited and randomized to the TMZ (20 mg TMZ 3 times a day for 3 months) or placebo group (placebo 3 times a day for 3 months). The primary outcome is the difference in cardiac ejection fractions (EF) measured by cardiac magnetic resonance (MRI) between baseline and after 3 months of TMZ treatment. The secondary outcomes include TMZ serum concentration, rate of cardiac events, NYHA grading, fingertip SpO2, NT-proBNP levels, 6-minute walking test (6MWT), KCCQ-CSS questionnaire score, echocardiography, ECG, routine blood examination, liver and kidney function test, blood pressure and heart rate.

DISCUSSION

This trial is designed to explore whether the application of TMZ in adult CCHD patients can improve cardiac function, reduce cardiac events, and improve exercise performance and quality of life. The results will provide targeted drug therapy for CCHD patients with hypoxia and support the application of TMZ in children with CCHD.

Rapid sequence induction of anesthesia: works in progress and steps forward with focus to oxygenation and monitoring techniques

The description of the main scientifically consolidated innovations in recent years on Rapid Sequence Induction have been the subject of this narrative review. Data sources were PubMed, EMBASE, Web of Science, the Cochrane Central Register of Controlled Trials, and ClinicaTrials.gov, searched up to March 21st, 2023; rapid sequence induction and anesthesia were used as key word for the research. In recent years at least three significant innovations which have improved the procedure: firstly the possibility of using drugs which rapidly reverse the action of the myorelaxants and which have made it possible to give up the use of succinylcholine, replaced by rocuronium; secondly, the possibility of using much more effective pre-oxygenation methods than in the past, also through apneic oxygenation techniques which allow longer apnea time, and finally new monitoring systems much more effective than pulse oximetry in identifying and predicting periprocedural hypoxemia and indicating the need for ventilation in patients at risk of hypoxemia and preventing it. The description of three main scientifically consolidated innovations in recent years, in pharmacology, oxygen method of administration and monitoring, have been the subject of this narrative review.

Asphyxia, Therapeutic Hypothermia, and Pulmonary Hypertension

Neonates with a perinatal hypoxic insult and subsequent neonatal encephalopathy are at risk of acute pulmonary hypertension (aPH) in the transitional period. The phenotypic contributors to aPH following perinatal asphyxia include a combination of hypoxic vasoconstriction of the pulmonary vascular bed, right heart dysfunction, and left heart dysfunction. Therapeutic hypothermia is the standard of care for neonates with moderate-to-severe hypoxic ischemic encephalopathy. This review summarizes the underlying risk factors, causes of aPH in neonates with perinatal asphyxia, discusses the unique phenotypical contributors to disease, and explores the impact of the initial insult and subsequent therapeutic hypothermia on aPH.

Hypoxia following warden procedure: evaluation and percutaneous treatment

Partial anomalous venous connection with sinus venosus atrial septal defect is repaired with different approaches including the Warden procedure. Complications include stenosis of the superior caval vein and pulmonary venous baffle; however, cyanosis is rarely seen post-operatively. We report a patient presenting with cyanosis 5 years after a Warden, which was treated with a transcatheter approach.

Platypnoea-orthodeoxia syndrome in COVID-19 pneumonia patients: An observational study

This retrospective observational study aimed to assess the clinical characteristics of platypnea-orthodeoxia syndrome in patients with coronavirus disease 2019 (COVID-19) treated using mechanical ventilation or high-flow nasal canula. We analyzed 42 consecutive patients with COVID-19 from January 2020 to March 2022. The primary outcomes were the incidence of platypnea-orthodeoxia syndrome, the time with required long-term oxygen therapy, and short-term prognosis. Additionally, we examined the relationships between platypnea-orthodeoxia syndrome and COVID-19 severity, the time with long-term oxygen therapy, and short-term prognosis. Of the 42 included patients, 15 (35.7 %) had platypnea-orthodeoxia syndrome. Although mortality was not significantly different between both groups, the oxygen withdrawal rate in the platypnea-orthodeoxia syndrome group was significantly lower than that in the group without this syndrome. Clinical staff should be aware of the possibility of platypnea-orthodeoxia syndrome during positional changes in patients with COVID-19. Recognizing POS can improve early detection, countermeasures, and safety during physiotherapy.

Clinical efficacy and biomarker analysis of neoadjuvant camrelizumab plus chemotherapy for early-stage triple-negative breast cancer: a experimental single-arm phase II clinical trial pilot study

BACKGROUND

Triple-negative breast cancer (TNBC) is associated with a dismal prognosis. Immune checkpoint inhibitors have shown promising antitumor activity in neoadjuvant settings. This single-arm, phase II trial aimed to evaluate the efficacy and safety of camrelizumab plus chemotherapy as the neoadjuvant therapy (NAT) in early TNBC.

METHODS

Patients received eight cycles of camrelizumab plus nonplatinum-based chemotherapy. The primary endpoint was total pathological complete response (pCR). Secondary endpoints included the breast pathological complete response (bpCR), adverse events (AEs). Multiomics biomarkers were assessed as exploratory objective.

RESULTS

Twenty of 23 TNBC patients receiving NAT underwent surgery, with the total pCR rate of 65% (13/20) and bpCR rate of 70% (14/20). Grade ≥3 treatment-related AEs were observed in 14 (60.9%) patients, with the most common AE being neutropenia (65.2%). Tumor immune microenvironment was analyzed between pCR and non-pCR samples before and after the NAT. Gene expression profiling showed a higher immune infiltration in pCR patients than non-pCR patients in pre-NAT samples. Through establishment of a predictive model for the NAT efficacy, TAP1 and IRF4 were identified as the potential predictive biomarkers for response to the NAT. Gene set enrichment analysis revealed the glycolysis and hypoxia pathways were significantly activated in non-pCR patients before the NAT, and this hypoxia was aggravated after the NAT.

CONCLUSION

Camrelizumab plus nonplatinum-based chemotherapy shows a promising pCR rate in early-stage TNBC, with an acceptable safety profile. TAP1 and IRF4 may serve as potential predictive biomarkers for response to the NAT. Aggravated hypoxia and activated glycolysis after the NAT may be associated with the treatment resistance.

Effect of a lower target oxygen saturation range on the risk of hypoxaemia and elevated NEWS2 scores at a university hospital: a retrospective study

BACKGROUND

The optimal target oxygen saturation (SpO2) range for hospital inpatients not at risk of hypercapnia is unknown. The objective of this study was to assess the impact on oxygen usage and National Early Warning Score 2 (NEWS2) of changing the standard SpO2 target range from 94-98% to 92-96%.

METHODS

In a metropolitan UK hospital, a database of electronic bedside SpO2 measurements, oxygen prescriptions and NEWS2 records was reviewed. Logistic regression was used to compare the proportion of hypoxaemic SpO2 values (<90%) and NEWS2 records ≥5 in 2019, when the target SpO2 range was 94-98%; with 2022, when the target range was 92-96%.

RESULTS

In 2019, 218 of 224 936 (0.10%) observations on room air and 162 of 11 328 (1.43%) on oxygen recorded an SpO2 <90%, and in 2022, 251 of 225 970 (0.11%) and 233 of 12 845 (1.81%), respectively (risk difference 0.04%, 95% CI 0.02% to 0.07%). NEWS2 ≥5 was observed in 3009 of 236 264 (1.27%) observations in 2019 and 4061 of 238 815 (1.70%) in 2022 (risk difference 0.43%, 0.36% to 0.50%; p<0.001). The proportion of patients using supplemental oxygen with hyperoxaemia (SpO2 100%) was 5.4% in 2019 and 3.9% in 2022 (OR 0.71, 0.63 to 0.81; p<0.001).

DISCUSSION

The proportion of observations with SpO2 <90% or NEWS2 ≥5 was greater with the 92-96% range; however, absolute differences were very small and of doubtful clinical relevance, in contrast to hyperoxaemia for which the proportion was markedly less in 2022. These findings support proposals that the British Thoracic Society oxygen guidelines could recommend a lower target SpO2 range.

Solar-powered O2 delivery for the treatment of children with hypoxaemia in Uganda: a stepped-wedge, cluster randomised controlled trial

BACKGROUND

Supplemental O2 is not always available at health facilities in low-income and middle-income countries (LMICs). Solar-powered O2 delivery can overcome gaps in O2 access, generating O2 independent of grid electricity. We hypothesized that installation of solar-powered O2 systems on the paediatrics ward of rural Ugandan hospitals would lead to a reduction in mortality among hypoxaemic children.

METHODS

In this pragmatic, country-wide, stepped-wedge, cluster randomised controlled trial, solar-powered O2 systems (ie, photovoltaic cells, battery bank, and O2 concentrator) were sequentially installed at 20 rural health facilities in Uganda. Sites were selected for inclusion based on the following criteria: District Hospital or Health Centre IV with paediatric inpatient services; supplemental O2 on the paediatric ward was not available or was unreliable; and adequate space to install solar panels, a battery bank, and electrical wiring. Allocation concealment was achieved for sites up to 2 weeks before installation, but the study was not masked overall. Children younger than 5 years admitted to hospital with hypoxaemia and respiratory signs were included. The primary outcome was mortality within 48 h of detection of hypoxaemia. The statistical analysis used a linear mixed effects logistic regression model accounting for cluster as random effect and calendar time as fixed effect. The trial is registered at ClinicalTrials.gov, NCT03851783.

FINDINGS

Between June 28, 2019, and Nov 30, 2021, 2409 children were enrolled across 20 hospitals and, after exclusions, 2405 children were analysed. 964 children were enrolled before site randomisation and 1441 children were enrolled after site randomisation (intention to treat). There were 104 deaths, 91 of which occurred within 48 h of detection of hypoxaemia. The 48 h mortality was 49 (5·1%) of 964 children before randomisation and 42 (2·9%) of 1440 (one individual did not have vital status documented at 48 h) after randomisation (adjusted odds ratio 0·50, 95% CI 0·27-0·91, p=0·023). Results were sensitive to alternative parameterisations of the secular trend. There was a relative risk reduction of 48·7% (95% CI 8·5-71·5), and a number needed to treat with solar-powered O2 of 45 (95% CI 28-230) to save one life. Use of O2 increased from 484 (50·2%) of 964 children before randomisation to 1424 (98·8%) of 1441 children after randomisation (p<0·0001). Adverse events were similar before and after randomisation and were not considered to be related to the intervention. The estimated cost-effectiveness was US$25 (6-505) per disability-adjusted life-year saved.

INTERPRETATION

This stepped-wedge, cluster randomised controlled trial shows the mortality benefit of improving O2 access with solar-powered O2. This study could serve as a model for scale-up of solar-powered O2 as one solution to O2 insecurity in LMICs.

FUNDING

Grand Challenges Canada and The Women and Children's Health Research Institute.

Stubborn hypoxemia after mild to moderate sedation and analgesia: A case report

INTRODUCTION

Atelectasis typically denotes the partial or complete collapse of lung segments, lobes, or lobules in individuals, leading to a compromised respiratory function. The prevalence of perioperative atelectasis may be significantly underestimated, particularly among patients subjected to general anesthesia.

PATIENT CONCERNS

This article conducts a retrospective analysis of a case involving refractory hypoxemia in a patient with a liver tumor who was admitted to Yanbian University Affiliated Hospital (Yanbian Hospital) after undergoing mild-to-moderate sedation and analgesia outside the operating room.

DIAGNOSIS

Based on the results of CT examination and present history, the patient was diagnosed with intraoperative atelectasis.

INTERVENTION

After the surgery, the patient was transferred to the recovery ward, where nasal oxygen therapy and nebulized inhalation treatment were administered. Vital signs were closely monitored at the bedside, gradually returning to the preoperative baseline.

OUTCOME

Postoperatively, the patient developed atelectasis, with the percentage of lung opacity shown in the image decreasing from 9.2% of the total thoracic cage area to 8.4%.

CONCLUSION

During non-intubated intravenous anesthesia, patients with compromised pulmonary conditions are more susceptible to refractory hypoxemia. Therefore, a personalized approach should be adopted regarding oxygen concentration and the dosage and type of medication. Additionally, preparations for appropriate airway management measures are essential to safeguard patient safety in the event of respiratory issues.

Retrospective analysis of referrals for hypoxic challenge testing in children born preterm

INTRODUCTION

Children with a history of bronchopulmonary dysplasia (BPD) may be at risk of hypoxaemia at altitude, such as during air travel. We have performed preflight hypoxic challenge testing (HCT) since 2006, incorporating British Thoracic Society (BTS) guidance since 2011, to determine which children may require oxygen during air travel.

AIMS

We aimed to compare the outcome of HCTs in children with a history of BPD who met the 2011 BTS criteria and those who did not and, in addition to this, to interrogate the data for factors that may predict the outcome of HCT in this population.

METHODS

We performed a retrospective analysis of data from HCTs of children with a history of BPD referred 2006-2020. Cases were excluded if the patient had a respiratory comorbidity, was still on oxygen therapy, if the test was a repeat or if the clinical record was incomplete. Descriptive and univariate analysis of the data was performed, and a binary logistic regression model was fitted.

RESULTS

There were 79 HCTs, of which 24/79 (30%) did not meet BTS 2011 guidelines referral criteria. The analysis showed a greater proportion of desaturation in the group that did not meet criteria: 46% vs 27% (no statistical significance). Baseline oxygen saturations were higher in those who did not require oxygen during HCT and this variable was significant when adjusted for confounders.

CONCLUSIONS

This study found that the current criteria for referral for preflight testing may incorrectly identify those most at risk and highlights the need for further investigation to ensure those most at risk are being assessed prior to air travel.

The chief culprit of intractable hypoxemia: a case report of rare pulmonary arteriovenous fistula complicated with giant hemangioma

BACKGROUND

Pulmonary arteriovenous fistula (PAVF) is a rare disease, which can lead to the direct return of unoxidized venous blood to pulmonary veins and left heart, resulting in right-to-left shunt leading to hypoxia. Long term, the right-to-left shunt will cause severe pathophysiological changes in the patient's body and pulmonary circulation, and the prognosis will be poor if PAVF is not treated timely.

CASE PRESENTATION

Here, we report the case of a 71-year-old man who presented with chest tightness and shortness of breath. After a series of examinations, PAVF and giant hemangioma were diagnosed, which are difficult to operate.Transcatheter interventional therapy was initiated. The patient recovered on the third day after operation and was discharged smoothly. During the long-term follow-up of nearly 4 years after discharge, the general condition and quality of life of the patient basically returned to normal.

CONCLUSIONS

PAVF is rare but very important clinical problem. When the clinical manifestations of persistent unexplained hypoxia appear, it is necessary to fully consider the possibility of PAVF. Once the diagnosis of PAVF is clear, timely treatment is recommended to avoid deterioration of the disease and affecting the prognosis.

Platypnea-orthodeoxia syndrome (POS) in a patient who had undergone partial liver resection

A South Asian male in his early 60s presented with acute-onset dyspnoea on postoperative day 4 after undergoing middle hepatic vein sacrificing partial liver resection for epithelioid angiomyolipoma. The patient's SpO2 on presentation was 65% in standing position which improved to 90% in left lateral decubitus. He was suspected of having platypnea-orthodeoxia syndrome (POS) which was confirmed on echocardiogram with microbubble contrast showing a large intracardiac right-to-left shunt. The patient was taken up for transcatheter closure of patent foramen ovale (PFO). A 30 mm Amplatzer PFO Occluder was deployed across the PFO which reduced the intracardiac shunt resulting in an improved arterial saturation as well as immediate relief of patient's symptoms. This case illustrates the importance of suspecting and recognising POS clinically as well as the efficacy of transcatheter closure of PFO in such cases leading to resolution of hypoxaemia in a short span of time.

Adverse Tracheal Intubation Events in Critically Ill Underweight and Obese Children: Retrospective Study of the National Emergency Airway for Children Registry (2013-2020)

OBJECTIVES

Extremes of patient body mass index are associated with difficult intubation and increased morbidity in adults. We aimed to determine the association between being underweight or obese with adverse airway outcomes, including adverse tracheal intubation (TI)-associated events (TIAEs) and/or severe peri-intubation hypoxemia (pulse oximetry oxygen saturation < 80%) in critically ill children.

DESIGN/SETTING

Retrospective cohort using the National Emergency Airway for Children registry dataset of 2013-2020.

PATIENTS

Critically ill children, 0 to 17 years old, undergoing TI in PICUs.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Registry data from 24,342 patients who underwent TI between 2013 and 2020 were analyzed. Patients were categorized using the Centers for Disease Control and Prevention weight-for-age chart: normal weight (5th-84th percentile) 57.1%, underweight (< 5th percentile) 27.5%, overweight (85th to < 95th percentile) 7.2%, and obese (≥ 95th percentile) 8.2%. Underweight was most common in infants (34%); obesity was most common in children older than 8 years old (15.1%). Underweight patients more often had oxygenation and ventilation failure (34.0%, 36.2%, respectively) as the indication for TI and a history of difficult airway (16.7%). Apneic oxygenation was used more often in overweight and obese patients (19.1%, 19.6%) than in underweight or normal weight patients (14.1%, 17.1%; p < 0.001). TIAEs and/or hypoxemia occurred more often in underweight (27.1%) and obese (24.3%) patients ( p < 0.001). TI in underweight children was associated with greater odds of adverse airway outcome compared with normal weight children after adjusting for potential confounders (underweight: adjusted odds ratio [aOR], 1.09; 95% CI, 1.01-1.18; p = 0.016). Both underweight and obesity were associated with hypoxemia after adjusting for covariates and site clustering (underweight: aOR, 1.11; 95% CI, 1.02-1.21; p = 0.01 and obesity: aOR, 1.22; 95% CI, 1.07-1.39; p = 0.002).

CONCLUSIONS

In underweight and obese children compared with normal weight children, procedures around the timing of TI are associated with greater odds of adverse airway events.

Apnoeic oxygenation during paediatric tracheal intubation: a systematic review and meta-analysis

BACKGROUND

Supplemental oxygen administration by apnoeic oxygenation during laryngoscopy for tracheal intubation is intended to prolong safe apnoea time, reduce the risk of hypoxaemia, and increase the success rate of first-attempt tracheal intubation under general anaesthesia. This systematic review examined the efficacy and effectiveness of apnoeic oxygenation during tracheal intubation in children.

METHODS

This systematic review and meta-analysis included randomised controlled trials and non-randomised studies in paediatric patients requiring tracheal intubation, evaluating apnoeic oxygenation by any method compared with patients without apnoeic oxygenation. Searched databases were MEDLINE, Embase, Cochrane Library, CINAHL, ClinicalTrials.gov, International Clinical Trials Registry Platform (ICTRP), Scopus, and Web of Science from inception to March 22, 2023. Data extraction and risk of bias assessment followed the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) recommendation.

RESULTS

After initial selection of 40 708 articles, 15 studies summarising 9802 children were included (10 randomised controlled trials, four pre-post studies, one prospective observational study) published between 1988 and 2023. Eight randomised controlled trials were included for meta-analysis (n=1070 children; 803 from operating theatres, 267 from neonatal intensive care units). Apnoeic oxygenation increased intubation first-pass success with no physiological instability (risk ratio [RR] 1.27, 95% confidence interval [CI] 1.03-1.57, P=0.04, I2=0), higher oxygen saturation during intubation (mean difference 3.6%, 95% CI 0.8-6.5%, P=0.02, I2=63%), and decreased incidence of hypoxaemia (RR 0.24, 95% CI 0.17-0.33, P<0.01, I2=51%) compared with no supplementary oxygen administration.

CONCLUSION

This systematic review with meta-analysis confirms that apnoeic oxygenation during tracheal intubation of children significantly increases first-pass intubation success rate. Furthermore, apnoeic oxygenation enables stable physiological conditions by maintaining oxygen saturation within the normal range.

CLINICAL TRIAL REGISTRATION

Protocol registered prospectively on PROSPERO (registration number: CRD42022369000) on December 2, 2022.

Nocturnal oxygen saturation is associated with all-cause mortality: a community-based study

STUDY OBJECTIVES

Observational studies have demonstrated the association between the single-point measurement of oxygen saturation (SpO2) level and mortality in the general population. This study aimed to evaluate whether nocturnal SpO2 level could predict all-cause mortality in a community-based population.

METHODS

The study samples were obtained from the Sleep Heart Health Study, which included 2,280 men and 2,606 women (mean age, 63.8 ± 11.1 years). A pulse oximeter based on overnight in-home polysomnography was used to monitor SpO2 levels during total sleep time (SpO2-TOTAL). Multivariable Cox proportional hazards analysis was performed to examine the association between nocturnal SpO2 and all-cause mortality.

RESULTS

During the follow-up period of 10.7 ± 3.0 years, 1,110 (22.7%) people died. After adjusting for confounding factors, multivariable Cox regression analysis showed that the average SpO2-TOTAL (hazard ratio [HR] 0.93; 95% confidence interval [CI] 0.90-0.96, P < .001) was associated with all-cause mortality. These findings remained stable in individuals with low and high apnea-hypopnea index levels. Additionally, maximum SpO2-TOTAL (HR, 0.91; 95% CI, 0.87-0.96; P = .001) and minimum SpO2-TOTAL (HR, 0.98; 95% CI, 0.97-0.99; P = .001) could predict all-cause mortality. A significant association between nocturnal hypoxemia and all-cause mortality was also observed.

CONCLUSIONS

Our findings highlight the importance of monitoring nocturnal SpO2 level and improving hypoxemia in the general populations.

CITATION

Yan B, Gao Y, Zhang Z, Shi T, Chen Q. Nocturnal oxygen saturation is associated with all-cause mortality: a community-based study. J Clin Sleep Med. 2024;20(2):229-235.

Extracorporeal membrane oxygenation circuits in parallel for refractory hypoxemia in patients with COVID-19

OBJECTIVES

Refractory hypoxemia can occur in patients with acute respiratory distress syndrome from COVID-19 despite support with venovenous (VV) extracorporeal membrane oxygenation (ECMO). Parallel ECMO circuits can be used to increase physiologic support. We report our clinical experience using ECMO circuits in parallel for select patients with persistent severe hypoxemia despite the use of a single ECMO circuit.

METHODS

We performed a retrospective cohort study of all patients with COVID-19-related acute respiratory distress syndrome who received VV-ECMO with an additional circuit in parallel at Vanderbilt University Medical Center between March 1, 2020, and March 1, 2022. We report demographic characteristics and clinical characteristics including ECMO settings, mechanical ventilator settings, use of adjunctive therapies, and arterial blood gas results after initial cannulation, before and after receipt of a second ECMO circuit in parallel, and before removal of the circuit in parallel, and outcomes.

RESULTS

Of 84 patients with COVID-19 who received VV-ECMO during the study period, 22 patients (26.2%) received a circuit in parallel. The median duration of ECMO was 40.0 days (interquartile range, 31.6-53.1 days), of which 19.0 days (interquartile range, 13.0-33.0 days) were spent with a circuit in parallel. Of the 22 patients who received a circuit in parallel, 16 (72.7%) survived to hospital discharge and 6 (27.3%) died before discharge.

CONCLUSIONS

In select patients, the additional use of an ECMO circuit in parallel can increase ECMO blood flow and improve oxygenation while allowing for lung-protective mechanical ventilation and excellent outcomes.

High-Flow Nasal Cannula versus Bag Valve Mask for Preoxygenation during Rapid Sequence Intubation in the Emergency Department: A Single-Center, Prospective, Randomized Controlled Trial

OBJECTIVE

Hypoxia is a frequently reported complication during the intubation procedure in the emergency department (ED) and may cause bad outcomes. Therefore, oxygenation plays an important role in emergency airway management. The efficacy of oxygenation with high-flow nasal cannula (HFNC) in the ED has been studied, though the evidence is limited. The study aim was to compare two methods of preoxygenation in patients undergoing rapid sequence intubation (RSI) in the ED: (1) HFNC and (2) bag-valve mask (BVM) oxygenation.

METHODS

This is a single-center, prospective, randomized controlled trial (RCT) in adult ED patients requiring RSI. Patients were randomized to receive preoxygenation with either HFNC or BVM. While HFNC therapy was continued during the intubation procedure, BVM oxygenation was interrupted for laryngoscopy. The primary outcome was the lowest peripheral oxygen saturation (SpO2) level during intubation. Secondary outcomes were incidence of desaturation (SpO2<90%) and severe hypoxemia (SpO2<80%) throughout the procedure, intubation time, rate of failed intubation, and 30-day survival rates.

RESULTS

A total of 135 patients were randomized into two groups (HFNC n = 68; BVM n = 67). The median lowest SpO2 value measured during intubation was 96% (88.8%-99.0%) in the HFNC group and 92% (86.0%-97.5%) in the BVM group (P = .161). During the intubation procedure, severe hypoxemia occurred in 13.2% (n = 9) of patients in the HFNC group and 8.9% (n = 6) in the BVM group, while mild hypoxemia was observed in 35.8% (n = 24) of the BVM group and 26.5% (n = 18) of the HFNC group. However, there was no statistically significant difference between the groups in terms of hypoxemia development (P = .429 and P = .241, respectively). No significant difference was reported in the rate of failed intubation between the groups. Thirty-day mortality was observed in 73.1% of the BVM group and 57.4% of the HFNC group, with a borderline statistically significant difference (difference 15.7; 95% CI of the difference: -0.4 to 30.7; P = .054).

CONCLUSION

The use of HFNC for preoxygenation, when compared to standard care with BVM oxygenation, did not improve the lowest SpO2 levels during intubation. Also, the use of HFNC during intubation did not provide benefits in reducing the incidence of severe hypoxemia. However, the 30-day survival rates were slightly better in the HFNC group compared to the BVM group.

Supraglottic Jet Oxygenation and Ventilation to Minimize Hypoxia in Patients Receiving Flexible Bronchoscopy Under Deep Sedation: A 3-Arm Randomized Controlled Trial

BACKGROUND

Hypoxia often occurs due to shared airway and anesthetic sedation-induced hypoventilation in patients receiving flexible bronchoscopy (FB) under deep sedation. Previous evidence has shown that supraglottic jet oxygenation and ventilation (SJOV) via Wei nasal jet tube (WNJ) reduces the incidence of hypoxia during FB. This study aimed to investigate the extent to which SJOV via WNJ could decrease the incidence of hypoxia in patients under deep sedation as compared to oxygen supplementation via WNJ alone or nasal catheter (NC) for oxygen supplementation during FB.

METHODS

This was a single-center 3-arm randomized controlled trial (RCT). Adult patients scheduled to undergo FB were randomly assigned to 3 groups: NC (oxygen supplementation via NC), low-pressure low-flow (LPLF) (low-pressure oxygen supplementation via WNJ alone), or SJOV (high-pressure oxygen supplementation via WNJ). The primary outcome was hypoxia (defined as peripheral saturation of oxygen [Sp o2 ] <90% lasting more than 5 seconds) during FB. Secondary outcomes included subclinical respiratory depression or severe hypoxia, and rescue interventions specifically performed for hypoxia treatment. Other evaluated outcomes were sore throat, xerostomia, nasal bleeding, and SJOV-related barotraumatic events.

RESULTS

One hundred and thirty-two randomized patients were included in 3 interventions (n = 44 in each), and all were included in the final analysis under intention to treat. Hypoxia occurred in 4 of 44 patients (9.1%) allocated to SJOV, compared to 38 of 44 patients (86%) allocated to NC, with a relative risk (RR) for hypoxia, 0.11; 98% confidence interval (CI), 0.02-0.51; P < .001; or to 27 of 44 patients (61%) allocated to LPLF, with RR for hypoxia, 0.15; 95% CI, 0.04-0.61; P < .001, respectively. The percentage of subclinical respiratory depression was also significantly diminished in patients with SJOV (39%) compared with patients with NC (100%) or patients with LPLF (96%), both P < .001. In SJOV, no severe hypoxia event occurred. More remedial interventions for hypoxia were needed in the patients with NC. Higher risk of xerostomia was observed in patients with SJOV. No severe adverse event was observed throughout the study.

CONCLUSIONS

SJOV via WNJ effectively reduces the incidence of hypoxia during FB under deep sedation.

Causes of Hypoxemia in COVID-19 Acute Respiratory Distress Syndrome: A Combined Multiple Inert Gas Elimination Technique and Dual-energy Computed Tomography Study

BACKGROUND

Despite the fervent scientific effort, a state-of-the art assessment of the different causes of hypoxemia (shunt, ventilation-perfusion mismatch, and diffusion limitation) in COVID-19 acute respiratory distress syndrome (ARDS) is currently lacking. In this study, the authors hypothesized a multifactorial genesis of hypoxemia and aimed to measure the relative contribution of each of the different mechanism and their relationship with the distribution of tissue and blood within the lung.

METHODS

In this cross-sectional study, the authors prospectively enrolled 10 patients with COVID-19 ARDS who had been intubated for less than 7 days. The multiple inert gas elimination technique (MIGET) and a dual-energy computed tomography (DECT) were performed and quantitatively analyzed for both tissue and blood volume. Variables related to the respiratory mechanics and invasive hemodynamics (PiCCO [Getinge, Sweden]) were also recorded.

RESULTS

The sample (51 ± 15 yr; Pao2/Fio2, 172 ± 86 mmHg) had a mortality of 50%. The MIGET showed a shunt of 25 ± 16% and a dead space of 53 ± 11%. Ventilation and perfusion were mismatched (LogSD, Q, 0.86 ± 0.33). Unexpectedly, evidence of diffusion limitation or postpulmonary shunting was also found. In the well aerated regions, the blood volume was in excess compared to the tissue, while the opposite happened in the atelectasis. Shunt was proportional to the blood volume of the atelectasis (R2 = 0.70, P = 0.003). V˙A/Q˙T mismatch was correlated with the blood volume of the poorly aerated tissue (R2 = 0.54, P = 0.016). The overperfusion coefficient was related to Pao2/Fio2 (R2 = 0.66, P = 0.002), excess tissue mass (R2 = 0.84, P < 0.001), and Etco2/Paco2 (R2 = 0.63, P = 0.004).

CONCLUSIONS

These data support the hypothesis of a highly multifactorial genesis of hypoxemia. Moreover, recent evidence from post-mortem studies (i.e., opening of intrapulmonary bronchopulmonary anastomosis) may explain the findings regarding the postpulmonary shunting. The hyperperfusion might be related to the disease severity.

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