Effect of Fluid Bolus Administration on Cardiovascular Collapse Among Critically Ill Patients Undergoing Tracheal Intubation: A Randomized Clinical Trial

Effect of esketamine on postinduction hypotension in elderly patients undergoing elective noncardiac surgery: a secondary analysis of a randomized clinical trial

Postinduction hypotension (PIH) increases the risk of perioperative adverse events. This study aimed to test if low-dose esketamine could significantly decrease the incidence of PIH in elderly patients undergoing elective noncardiac surgery. This was a post hoc analysis of a randomized clinical trial in university-affiliated academic tertiary hospital. Patients (65 to 85 years, ASA physical status classification II or III) randomly received esketamine (0.2 mg/kg) or normal saline intravenous injection before general anesthesia induction. The primary outcome was the incidence of PIH. The secondary outcomes were the profiles of induction and adverse events during postinduction period. Several different definitions of hypotension and postinduction period were prespecified as the sensitivity analysis. The baseline characteristics were comparable between esketamine group (n = 211) and normal saline group (n = 213). The incidence of PIH was significantly lower in esketamine group than that in normal saline group (44.1 vs. 64.8%, P < 0.01). Esketamine pretreatment significantly decreased the consumption of propofol (P < 0.01) and the rate of vasoconstrictor utilization (P = 0.02). There were no significant differences in the incidence of postinduction adverse events between two groups (all P > 0.05). And, no other severe adverse events were observed. The sensitivity analysis displayed the robustness of the conclusion, though the effect size was lower than 0.2 under certain definition of PIH. A low dose of esketamine treatment before general anesthesia induction for elderly patients undergoing noncardiac surgery could significantly reduce the risk of PIH.Trial registration: www.chictr.org.cn (ChiCTR2100051179); registered 15 September 2021. Date of enrolment of the first participant to the trial: 24 February 2022.

Incidence of post-induction hypotension following emergency rapid sequence induction with ketamine: a systematic review and meta-analysis

INTRODUCTION

Rapid sequence induction (RSI) is a potentially-life saving intervention in critically ill patients. An important adverse effect of this procedure is post-induction hypotension (PIH), which is associated with worsened patient outcomes. Choice of induction agent can affect incidence of PIH, although the optimal drug has yet to be determined. Ketamine is postulated to reduce PIH incidence in emergency RSI when used instead of alternative agents.

AIMS

This systematic review and meta-analysis aims to evaluate the effect on PIH incidence of inducing anaesthesia with ketamine during emergency RSI.

METHODS

A systematic search was conducted to identify a sample of studies fulfilling criteria for population (emergency RSI), intervention (ketamine), comparator (any alternative induction agent) and outcome (PIH). No single definition of PIH was required for eligibility. A random-effects model was used to produce a pooled effect size estimate from the extracted data. The study question was also tested in pre-specified subgroups, including by specific comparator induction agent and by indication for RSI (medical vs trauma).

RESULTS

27 studies, including 6 randomised controlled trials, were eligible for inclusion, with total n = 31,956. There was considerable methodological heterogeneity. The pooled estimate of odds ratio (OR) of PIH when ketamine is used for emergency RSI is 1.10, with 95% confidence interval 0.78-1.56. Excluding data from the 6 studies (1 randomised and 5 observational) at greater risk of bias, the pooled OR is 0.99 (0.69-1.43). There was no significant difference between ketamine and comparators in any subgroup, although significance was approached when comparing ketamine to etomidate, with OR 1.38 (0.99-1.94) and p = 0.058.

CONCLUSIONS

Choice of ketamine to carry out emergency RSI did not affect the incidence of PIH incidence in this diverse sample of studies. Given the breadth of inclusion criteria, applicability of this result is not necessarily universal. It is likely that optimal choice of induction agent varies according to specific circumstances in a manner as yet incompletely understood.

Peri-intubation adverse events and clinical outcomes in emergency department patients: the BARCO study

BACKGROUND

Emergency tracheal intubation in critically ill patients carries a high risk of complications, and practices vary substantially across different settings. Identifying risk factors and understanding how peri-intubation adverse events affect patient outcomes may guide standardization of care and improve survival.

METHODS

This prospective cohort study involved 18 emergency departments in Brazil (March 2022-April 2024). We included adults (≥ 18 years) undergoing emergency intubation and excluded patients intubated electively or for cardiac arrest. We defined major peri-intubation adverse events as severe hypoxemia, new hemodynamic instability, or cardiac arrest occurring within 30 min of initiating intubation. The primary outcome was 28-day mortality. Multivariable regression analyses assessed associations between adverse events and mortality, controlling for potential confounders.

RESULTS

Among 2846 patients, major adverse events occurred in 919 (32.3%) intubations, most frequently new hemodynamic instability (20.0%), followed by severe hypoxemia (12.5%) and cardiac arrest (3.5%). The overall 28-day mortality was 45.1%. Patients experiencing any major adverse event had a significantly higher 28-day mortality (57.6 vs 39.2%; aHR 1.43, 95% CI 1.26-1.62; p < 0.001). Sensitivity analyses confirmed these findings. Successful first-attempt intubation was associated with a reduced likelihood of major adverse events (aOR 0.52; 95% CI 0.41-0.65; p < 0.001).

CONCLUSION

One in three patients undergoing emergency intubation experienced a major peri-intubation adverse event, which was associated with higher 28-day mortality. These results underscore the importance of optimizing intubation strategies to reduce complications and potentially improve patient outcomes in critically ill patients.

Incidence and predisposing factors associated with peri-intubation cardiac arrest: A systematic review and meta-analysis

OBJECTIVES

Various studies have delved into its incidence and risk factors, but a comprehensive meta-analysis exploring this life-threatening complication during emergent endotracheal intubation has been lacking. This study quantitatively assesses the global incidence and associated risk factors of peri-intubation cardiac arrest (PICA).

METHODS

We conducted a systematic literature search on PubMed, Embase, Web of Science, and Cochrane Library from inception to October 28, 2024. Two independent authors searched, reviewed, and evaluated selected studies. Any peer-reviewed published studies reporting the incidence of PICA among adults (≥18 years) outside of the operating theater were included. Studies reporting incidence within heterogeneous populations or from overlapping groups were excluded. The primary outcome focused on determining the global incidence of PICA, while the secondary outcome addressed associated risk factors. A random-effects model was used to aggregate overall incidence rates. Subgroup analysis and meta-regression were conducted to examine PICA incidence in different locations and with the study's sample size. The publication bias was assessed via Egger's test and visualization of the funnel plot. The risk of bias was evaluated using the Joanna Briggs Institute Critical Appraisal Checklist.

RESULTS

Fifteen articles met the inclusion criteria for the meta-analysis. PICA incidence varied from 0.5% to 23.3%. The estimated pooled incidence was 2.7% (95% confidence interval [CI]: 1.9-3.6) across PICA in the emergency department (ED) (2.5%, 95% CI: 1.4-3.7) and outside of the ED (2.9%, 95% CI: 2.2-3.6). Egger's test yielded P = 0.009, indicating potential publication bias due to small-study effects, as suggested by the funnel plot. Meta-regression analysis revealed higher incidence in studies with smaller populations. Notably, preintubation hypotension, hypoxemia, and body mass index were found to be the most associated risk factors for PICA. Additionally, there was significant variability in PICA definitions, ranging from immediate to occurrences within 60 min after intubation.

CONCLUSION

PICA occurrences during emergent endotracheal intubation reached up to 3%, showing a similar rate both within and outside the ED. While limitations such as heterogeneity and potential bias exist, these findings underscore the imperative for prospective research. Prospective studies are warranted to further delineate this critical aspect of emergent intubation.

Interventions to Reduce Risk in the Physiologically Difficult Pediatric Airway: A Descriptive Study and Exploratory Analysis

Objectives

Patients with physiologically difficult airways are at high risk for peri-intubation cardiac arrest in the pediatric emergency department (PED). We sought to describe how preintubation interventions designed to improve physiologic status are used and if they are associated with a reduction in peri-intubation cardiac arrest.

Methods

We completed a secondary analysis of a multicenter, retrospective cohort of patients <21 years old requiring tracheal intubation in 8 academic PEDs. Included patients underwent rapid sequence intubation and met at least 1 of 6 criteria for a physiologically difficult airway. We examined administration rates of preintubation interventions (intravenous [IV] fluids, vasoactive medications, and sodium bicarbonate) overall and by high-risk criteria. In an exploratory analysis, we assessed the relationship of preintubation interventions with peri-intubation cardiac arrest using weighted propensity scores and generalized linear mixed models.

Results

Of 332 included patients, 264 patients (80%) received at least 1 intervention. A total of 257 (77%) patients received IV fluids, 87 (26%) received vasoactive medications, and 20 (6%) received sodium bicarbonate. Across sites, there were wide ranges of administration of IV fluids (59%-98%), vasoactive medications (10%-58%), and sodium bicarbonate (0%-36%). Preintubation interventions were not associated with peri-intubation cardiac arrest (odds ratio, 1.59; 95% CI 0.50 to 5.05).

Conclusion

In PED patients with physiologically difficult airways, there is wide variability in the use of preintubation interventions. Receiving preintubation interventions was not associated with peri-intubation cardiac arrest. Future video-based prospective studies are needed to further evaluate interventions designed to prevent peri-intubation cardiac arrest.

Evaluation of MACOCHA Score for Predicting Difficult Intubation in Critically Ill Cancer Patients: A Prospective Observational Study

Introduction

Tracheal intubation (TI) is often needed in the intensive care unit (ICU) but can have disastrous consequences. The MACOCHA score was developed for prediction of difficult intubation (DI) in critically ill.

Material and methods

After Institutional Ethics Committee approval, we conducted this prospective, single-center observational study. Evaluated the ability of MACOCHA score to predict difficult intubation in our ICU. We included 500 adults undergoing TI in our ICU. We collected the demographic data, details of ICU admission, and intubation-related data for calculating MACOCHA score. We used Statistical Package for the Social Sciences (version 21) for analysis. The accuracy of MACOCHA score for predicting DI was determined by area under the receiver operating characteristic (AUROC) curve. The Hosmer-Lemeshow goodness-of-fit statistics was used to determine calibration.

Results

Since complete dataset was available for 449/500 patients, we analyzed their data. Acute renal failure and shock were the most frequent reasons for TI. Ketamine and rocuronium were most commonly used drugs for TI. The incidence of DI was 13.5% (60/449). There were 30 patients whose Mallampati score was either III and IV, while 84 and 45 patients had severe hypoxemia and coma before TI, respectively. The AUROC curve for the MACOCHA score was 0.659 (confidence interval, 0.574-0.743), suggesting a moderate discrimination. The Hosmer-Lemeshow goodness-of-fit test showed moderate calibration (χ2 = 3.142, with p = 0.208). One hundred and seventy-one (26.5%) complications occurred in the entire cohort. Some patients had multiple complications.

Conclusion

The MACOCHA score showed moderate discrimination and calibration in predicting DI in our study.

How to cite this article

Kulkarni AP, Bhosale SJ, Kalvit KR, Cherian S, Shrivastava AM, Gorade MR. Evaluation of MACOCHA Score for predicting Difficult Intubation in Critically Ill Cancer Patients: A Prospective Observational Study. Indian J Crit Care Med 2025;29(3):208-214.

Protocol and Statistical Analysis Plan for the Randomized Trial of Sedative Choice for Intubation (RSI)

Background

Emergency tracheal intubation is a common and high-risk procedure. Ketamine and etomidate are sedative medicines commonly used to induce anesthesia for emergency tracheal intubation, but whether the induction medication used affects patient outcomes is uncertain.

Research Question

Does the use of ketamine for induction of anesthesia decrease the incidence of death among adults undergoing emergency tracheal intubation, compared to the use of etomidate?

Study Design and Methods

The Randomized trial of Sedative choice for Intubation (RSI) is a pragmatic, multicenter, unblinded, parallel-group, randomized trial being conducted in 14 sites (6 emergency departments and 8 intensive care units) in the United States. The trial compares ketamine vs etomidate for induction of anesthesia among 2,364 critically ill adults undergoing emergency tracheal intubation. The primary outcome is all-cause, 28-day in-hospital mortality. The secondary outcome is the incidence of cardiovascular collapse during intubation, a composite of hypotension, receipt of vasopressors, and cardiac arrest. Enrollment began on April 6, 2022, and is expected to conclude in 2025.

Interpretation

The RSI trial will provide important data on the effects of ketamine vs etomidate on death and other outcomes for critically ill adults undergoing emergency tracheal intubation. Specifying the protocol and statistical analysis plan before the conclusion of enrollment increases the rigor, reproducibility, and interpretability of the trial.

Trial Registry

ClinicalTrials.gov ; No.: NCT05277896 ; URL: www.clinicaltrials.gov.

Take-Home Points

Study Question: Does use of ketamine for induction of anesthesia during emergency tracheal intubation decrease the incidence of death, compared with use of etomidate?Results: This manuscript describes the protocol and statistical analysis plan for the Randomized trial of Sedative choice for Intubation (RSI) comparing ketamine vs etomidate for induction of anesthesia for emergency tracheal intubation.Interpretation: Prespecifying the full statistical analysis plan before completion of enrollment increases rigor, reproducibility, and transparency of the trial results.

Eligibility Criteria of Randomized Clinical Trials in Critical Care Medicine

Importance

Eligibility criteria for randomized clinical trials (RCTs) are designed to select clinically relevant patient populations. However, not all eligibility criteria are strongly justified, potentially excluding marginalized groups, and limiting the generalizability of trial findings.

Objective

To summarize and evaluate the justification of exclusion criteria in published RCTs in critical care medicine.

Evidence Review

A systematic sampling review of parallel-group RCTs published in the top 5 general internal medicine journals by impact factor (The Lancet, New England Journal of Medicine, Journal of the American Medical Association, British Medical Journal, and Annals of Internal Medicine) between January 1, 2018, and February 23, 2023, was conducted. RCTs enrolling adults in intensive care units (ICUs) and RCTs enrolling critically ill patients who required life-sustaining interventions typically initiated in the ICU were included. All study exclusion criteria were categorized as either poorly justified, potentially justified, or strongly justified, adapting previously established criteria, independently and in duplicate.

Findings

In total, 225 studies were identified, 75 of which were included. The median (IQR) number of exclusion criteria per trial was 19 (14-24), with 1455 total exclusion criteria. Common exclusion criteria were related to the risk of adverse reaction to interventions (302 criteria [20.8%]), followed by inability to obtain consent (120 criteria [8.2%]), and treatment limitation decisions (97 criteria [6.7%]). Most exclusion criteria were either strongly justified (1080 criteria [74.2%]) or potentially justified (297 criteria [20.4%]), whereas 5.4% (78 criteria) were poorly justified. Of the 78 poorly justified exclusion criteria, the most common were pregnancy (19 criteria [24.4%]), communication barriers (11 criteria [14.1%]), lactation (10 criteria [12.8%]), and lack of health insurance (10 criteria [12.8%]). Overall, 45 of 75 studies (60.0%) had at least 1 poorly justified exclusion criteria.

Conclusions and Relevance

Most exclusion criteria in critical care medicine RCTs were strongly justifiable. Across poorly justified criteria, the most common exclusions were pregnant or lactating persons, those with communication barriers, and individuals without health insurance. This highlights the need to carefully consider exclusion criteria when designing trials to minimize the inappropriate exclusion of participants and enhance generalizability.

Induction Agents for Tracheal Intubation in Critically Ill Patients

OBJECTIVES

Concise definitive review of the use of induction agents in critically ill patients undergoing tracheal intubation and their association with outcomes.

DATA SOURCES

Original publications were retrieved through a PubMed search with search terms related to induction agents for tracheal intubation in critically ill patients.

STUDY SELECTION

We included randomized controlled trials and observational studies that reported patient outcomes.

DATA EXTRACTION

Data from included studies, including choice of induction agents and clinically relevant outcomes, were extracted.

DATA SYNTHESIS

Etomidate and ketamine have been the most studied induction agents in critical care during last years. Recent studies on etomidate investigated the clinical impact of its recognized adrenal suppression in terms of morbidity and mortality. Etomidate may carry a non-negligible mortality risk without definitive hemodynamic benefits compared with ketamine. Available data then support the use of ketamine over etomidate, since the difference in the hemodynamic profile seems to be of minor clinical relevance. No multicenter randomized studies are available comparing propofol to other induction agents but evidence from a large observational study identified an association of propofol with post-intubation cardiovascular instability in critically ill patients. Despite the observational nature of these findings cannot exclude the role of confounders, the association of propofol with post-induction cardiovascular instability is pharmacologically plausible, justifying its avoidance in favor of drugs with a better safety profile in critical care such as ketamine.

CONCLUSIONS

Although no definitive conclusions can be drawn based on the available evidence, recent evidence pointed out the potential negative effect of etomidate on survival and the association of propofol with cardiovascular instability. Ketamine may be considered the drug with a safer profile, widespread availability and low cost but future research should provide definitive data on optimal drug selection, its dosage in the context of critical illness and concomitant interventions to minimize the risk of peri-intubation complications.

Diabetes Mellitus Is Not a Risk Factor for Difficult Intubation Among Critically Ill Adults: A Secondary Analysis of Multicenter Trials

OBJECTIVES

Diabetes mellitus has been associated with greater difficulty of tracheal intubation in the operating room. This relationship has not been examined for tracheal intubation of critically ill adults. We examined whether diabetes mellitus was independently associated with the time from induction of anesthesia to intubation of the trachea among critically ill adults.

DESIGN

A secondary analysis of data from five randomized trials completed by the Pragmatic Critical Care Research Group (PCCRG).

SETTING

Emergency departments (EDs) or ICUs at 11 centers across the United States that enrolled in randomized trials of a pre-intubation checklist, fluid bolus administration, bag-mask ventilation between induction and laryngoscopy, and intubation using a bougie vs. stylet.

PATIENTS

Critically ill adults undergoing tracheal intubation with a laryngoscope in an ED or an ICU.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 2654 patients were included in this analysis, of whom 638 (24.0%) had diabetes mellitus. The mean time from induction of anesthesia to intubation of the trachea was 169 seconds (sd, 137s). Complications occurred during intubation in 1007 patients (37.9%). Diabetes mellitus was not associated with the time from induction of anesthesia to intubation of the trachea (-4.4 s compared with nondiabetes; 95% CI, -17.2 to 8.3 s; p = 0.50). Use of a video vs. direct laryngoscope did not modify the association between diabetes mellitus and the time from induction to intubation (p for interaction = 0.064). Diabetes mellitus was not associated with the probability of successful intubation on the first attempt (85.6% vs. 84.3%; p = 0.46) or complications during intubation (39.8% vs. 37.4%; p = 0.52).

CONCLUSIONS

Among 2654 critically ill patients undergoing tracheal intubation in an ED or an ICU, diabetes mellitus was not independently associated with the time from induction to intubation, the probability of successful intubation on the first attempt, or the rate of complications during intubation.

Association Between Neuromuscular Blocking Agents and Outcomes of Emergency Tracheal Intubation: A Secondary Analysis of Randomized Trials

STUDY OBJECTIVE

To examine the association between the neuromuscular blocking agent received (succinylcholine versus rocuronium) and the incidences of successful intubation on the first attempt and severe complications during tracheal intubation of critically ill adults in an emergency department (ED) or ICU.

METHODS

We performed a secondary analysis of data from 2 multicenter randomized trials in critically ill adults undergoing tracheal intubation in an ED or ICU. Using a generalized linear mixed-effects model with prespecified baseline covariates, we examined the association between the neuromuscular blocking agent received (succinylcholine versus rocuronium) and the incidences of successful intubation on the first attempt (primary outcome) and severe complications during tracheal intubation (secondary outcome).

RESULTS

Among the 2,440 patients in the trial data sets, 2,339 (95.9%) were included in the current analysis; 475 patients (20.3%) received succinylcholine and 1,864 patients (79.7%) received rocuronium. Successful intubation on the first attempt occurred in 375 patients (78.9%) who received succinylcholine and 1,510 patients (81.0%) who received rocuronium (an adjusted odds ratio of 0.87; 95% CI 0.65 to 1.15). Severe complications occurred in 67 patients (14.1%) who received succinylcholine and 456 patients (24.5%) who received rocuronium (adjusted odds ratio, 0.88; 95% CI 0.62 to 1.26).

CONCLUSION

Among critically ill adults undergoing tracheal intubation, the incidences of successful intubation on the first attempt and severe complications were not significantly different between patients who received succinylcholine and patients who received rocuronium.

Intubation of critically ill patients: A pilot study of minute-by-minute physiological changes within an Australian tertiary intensive care unit

BACKGROUND

There are no published minute-by-minute physiological assessment data for endotracheal intubation (ETT) performed in the intensive care unit (ICU). The majority of physiological data is available from Europe and North America where etomidate is the induction agent administered most commonly.

AIMS

The aim of this study was to describe the feasibility of obtaining minute-by-minute physiological and medication data surrounding ETT in an Australian tertiary ICU and to assess its associated outcomes.

METHODS

We performed a single-centre feasibility observational study. We obtained minute-by-minute data on physiological variables and medications for 15 min before and 30 min after ETT. We assessed feasibility as enrolled to screened patient ratio and completeness of data collection in enrolled patients. Severe hypotension (systolic blood pressure < 65 mmHg) and severe hypoxaemia (pulse oximetry saturation < 80%) were the secondary clinical outcomes.

RESULTS

We screened 43 patients and studied 30 patients. The median age was 58.5 (interquartile range: 49-70) years, and 18 (60%) were male. Near-complete (97%) physiological and medication data were obtained in all patients at all times. Overall, 15 (50%) ETTs occurred after hours (17:30-08:00) and 90% were by video laryngoscopy with a 90% first-pass success rate. Prophylactic vasopressors were used in 50% of ETTs. Fentanyl was used in all except one ETT at a median dose of 2.5 mcg/kg. Propofol (63%) or midazolam (50%) were used as adjuncts at low dose. Rocuronium was used in all but one patient. There were no episodes of severe hypotension and only one episode of short-lived severe hypoxaemia.

CONCLUSION

Minute-by-minute recording of ETT-associated physiological changes in the ICU was feasible but only fully available in two-thirds of the screened patients. ETT was based on fentanyl induction, low-dose adjunctive sedation, and frequent prophylactic vasopressor therapy and was associated with no severe hypotension and a single short-lived episode of severe hypoxaemia.

A Systematic Review and Meta-Analysis of Prophylactic Vasopressors for the Prevention of Peri-Intubation Hypotension

BACKGROUND/OBJECTIVES

Peri-intubation hypotension is a known complication of endotracheal intubation. In the hospital setting, peri-intubation hypotension has been shown to increase hospital mortality and length of stay. The use of prophylactic vasopressors at the time of sedation induction to prevent peri-intubation hypotension has been raised. This systematic review and meta-analysis aims to review the safety and efficacy of this practice.

METHODS

The study was fully registered with PROSPERO on 13 October 2022, and screening for eligibility was initiated on 20 September 2024. Randomized controlled trials, along with retrospective or prospective cohort studies, were included in the search. The terms "peri-intubation hypotension", "vasopressors", "intubation", and "anesthesia induced hypotension" were used to search the title/summary in PubMed, Cochrane Library, and Google Scholar databases. An assessment of bias for each study was conducted using the Newcastle-Ottawa Quality Assessment Scale. The primary outcome was the rate of hypotension peri-intubation. Any complications secondary to hypotension or vasopressors were the secondary outcome.

RESULTS

We identified 13 studies, which were all randomized controlled studies, to include in the final analysis. The risk ratio for preventing peri-intubation hypotension was 1.6 (95% CI, 1.2-2.14) with the use of prophylactic phenylephrine while giving propofol versus no prophylactic vasopressors and 1.28 (95% CI 1.03-1.60) with the use of ephedrine.

CONCLUSIONS

These findings suggest that in patients undergoing intubation in the operating room with propofol, prophylactic vasopressors given with induction for intubation decrease the odds of hypotension.

Association between metabolic acidosis and post-intubation hypotension in airway management performed in the emergency department

Introduction

Post-intubation hypotension (PIH) is a common complication of intubations performed in the emergency department (ED). Identification of patients at high-risk for PIH is a major challenge. We aimed to determine whether pre-intubation metabolic acidosis affects the incidence of PIH in the ED.

Methods

This was a single-center, retrospective, observational study of consecutive patients requiring emergent endotracheal intubation (ETI) from November 1, 2016 to March 31, 2022 at Hyogo Emergency Medical Center, an urban ED. The primary outcome was PIH, defined as a decreased systolic blood pressure (sBP) of <90 mmHg, required initiation of any vasopressor, or a decrease in sBP by ≥ 20 % within 30 min following intubation. Patients were divided into two groups: those with pre-intubation metabolic acidosis (metabolic acidosis group), defined as pH < 7.3 and base excess (BE) < -4 mmol/L on arterial blood gas analysis, and those with no metabolic acidosis (without-metabolic acidosis group). The association between PIH and pre-intubation metabolic acidosis was examined using multivariable logistic regression models. A receiver operating characteristic (ROC) curve was produced to assess the predictive value of pre-intubation BE for PIH.

Results

The study included 311 patients. PIH occurred in 65.5 % (74/113) of patients in the metabolic acidosis group and 29.3 % (58/198) of patients in the without-metabolic acidosis group. Multivariable logistic regression demonstrated that metabolic acidosis was associated with PIH (odds ratio 4.06, 95 % confidence interval 2.31-7.11). In the ROC analysis, the optimal cut-off point for BE was -4.1 (sensitivity = 71 %, specificity = 70 %), with the area under the ROC curve 0.74.

Conclusion

Pre-intubation metabolic acidosis was significantly associated with PIH. Physicians.

Fluid infusion prior to intubation or anesthesia: A meta-analysis of randomized controlled trials

BACKGROUND

The results of current randomized controlled trials (RCTs) vary regarding the effectiveness of rehydration prior to anesthesia induction. Our objective was to determine the effectiveness of pre-induction rehydration in patients undergoing tracheal intubation or surgical procedures.

METHODS

This meta-analysis followed PRISMA guidelines and was registered in the INPLASY database (registration number: INPLASY2022100099). Two reviewers independently searched PubMed, Embase, The Cochrane Database of Systematic Reviews, and Clinical Trials databases until October 2022, without any restrictions on date. Any randomized controlled trial investigating the administration of intravenous fluids to patients undergoing tracheal intubation or pre-surgical anesthesia induction was considered eligible. Exclusion criteria were applied to exclude certain literature. Data were analyzed using RevMan (5.4.1) software after independent extraction. The primary objective of this study was to determine if intravenous rehydration could reduce the occurrence of hypotensive events and the use of vasoactive drugs following anesthesia induction.

RESULTS

This meta-analysis included seven studies with a total of 2850 patients, including 1430 patients who received rehydration and 1420 control patients. Patients who received early rehydration had a lower incidence of hypotensive events compared to those who did not (RR 0.78, 95% CI 0.66-0.92, P = 0.004). No heterogeneity was observed (p = 0.31, I2 = 16%). However, subgroup analysis showed that rehydration before tracheal intubation did not reduce hypotensive events in critically ill patients (RR 0.99, 95% CI 0.61-1.60, P = 0.96). There were no significant differences in the use of vasoactive medications between the two study groups (RR 0.96, 95% CI 0.80-1.16, P = 0.69). No heterogeneity was observed (p = 0.26, I2 = 23%). The funnel plot indicated no evidence of publication bias.

CONCLUSIONS

Pre-induction rehydration can reduce the occurrence of hypotensive events, but only in pre-surgical patients, and does not decrease the use of vasoactive medications.

Comparing the hemodynamic effects of ketamine versus fentanyl bolus in patients with septic shock: a randomized controlled trial

BACKGROUND

Ketamine and fentanyl are commonly used for sedation and induction of anesthesia in critically ill patients. This study aimed to compare the hemodynamic effects of ketamine versus fentanyl bolus in patients with septic shock.

METHODS

This randomized controlled trial included mechanically ventilated adults with septic shock receiving sedation. Patients were randomized to receive either 1 mg/kg ketamine bolus or 1 mcg/kg fentanyl bolus. Cardiac output (CO), stroke volume (SV), heart rate (HR), and mean arterial pressure (MAP) were measured at the baseline, 3, 6, 10, and 15 min after the intervention. Delta CO was calculated as the change in CO at each time point in relation to baseline measurement. The primary outcome was delta CO 6 min after administration of the study drug. Other outcomes included CO, SV, HR, and MAP.

RESULTS

Eighty-six patients were analyzed. The median (quartiles) delta CO 6 min after drug injection was 71(37, 116)% in the ketamine group versus - 31(- 43, - 12)% in the fentanyl group, P value < 0.001. The CO, SV, HR, and MAP increased in the ketamine group and decreased in the fentanyl group in relation to the baseline reading; and all were higher in the ketamine group than the fentanyl group.

CONCLUSION

In patients with septic shock, ketamine bolus was associated with higher CO and SV compared to fentanyl bolus.

CLINICAL TRIAL REGISTRATION

Date of registration: 24/07/2023.

CLINICALTRIALS

gov Identifier: NCT05957302. URL: https://clinicaltrials.gov/study/NCT05957302 .

Tracheal intubation in critically ill adults with a physiologically difficult airway. An international Delphi study

PURPOSE

Our study aimed to provide consensus and expert clinical practice statements related to airway management in critically ill adults with a physiologically difficult airway (PDA).

METHODS

An international Steering Committee involving seven intensivists and one Delphi methodology expert was convened by the Society of Critical Care Anaesthesiologists (SOCCA) Physiologically Difficult Airway Task Force. The committee selected an international panel of 35 expert clinician-researchers with expertise in airway management in critically ill adults. A Delphi process based on an iterative approach was used to obtain the final consensus statements.

RESULTS

The Delphi process included seven survey rounds. A stable consensus was achieved for 53 (87%) out of 61 statements. The experts agreed that in addition to pathophysiological conditions, physiological alterations associated with pregnancy and obesity also constitute a physiologically difficult airway. They suggested having an intubation team consisting of at least three healthcare providers including two airway operators, implementing an appropriately designed checklist, and optimizing hemodynamics prior to tracheal intubation. Similarly, the experts agreed on the head elevated laryngoscopic position, routine use of videolaryngoscopy during the first attempt, preoxygenation with non-invasive ventilation, careful mask ventilation during the apneic phase, and attention to cardiorespiratory status for post-intubation care.

CONCLUSION

Using a Delphi method, agreement among a panel of international experts was reached for 53 statements providing guidance to clinicians worldwide on safe tracheal intubation practices in patients with a physiologically difficult airway to help improve patient outcomes. Well-designed studies are needed to assess the effects of these practice statements and address the remaining uncertainties.

Intubation and Mechanical Ventilation in Patients with Acute Pulmonary Embolism: A Scoping Review

OBJECTIVES

High-risk acute pulmonary embolism (PE) is associated with significant mortality and may require emergency endotracheal intubation and mechanical ventilation. Intubation and ventilation are thought to exacerbate cardiorespiratory instability. Our purpose was to conduct a systematic literature review to identify studies investigating peri-intubation events in acute PE.

METHODS

A systematic search of Medline, Embase, Web of Science, Cumulative Index to Nursing and Allied Health Literature, and Cochrane Library was performed. Results were screened by two independent observers. Studies reporting on intubation and positive pressure ventilation in acute PE patients were included. The primary outcome was adverse events during the peri-intubation period. Data was synthesized and an assessment of risk of bias was conducted. The review was registered on PROSPERO (CRD42023444483).

RESULTS

4100 unique articles were screened. Three retrospective studies comprising 104 patients with acute PE met criteria and were included. Peri-intubation, hemodynamic collapse was observed in 19%-28% of cases. Patients with hemodynamic collapse exhibited higher rates of echocardiographic RV dysfunction.

CONCLUSIONS

Peri-intubation adverse events are common in patients with acute PE. Current evidence is limited and highlights the need for further research to optimize management of respiratory failure in acute PE and patient selection for intubation to improve patient outcomes.

Hemodynamic Collapse After Intubation in Critical Care Transport

OBJECTIVES

The aim of this study was to describe the incidence of and modifiable risk factors for post intubation hemodynamic collapse in prehospital and interfacility critical care transport.

METHODS

Single center retrospective chart review of adult patients (≥18 years) intubated by a critical care transport team between January 2017 and May 2023. The primary outcome was incidence of hemodynamic collapse (systolic blood pressure <90 mmHg for greater than 30 min, new vasopressor requirement, vasopressor dose increase, fluid bolus of >15 mL/kg, systolic blood pressure <65 mmHg at least once, or cardiac arrest). Secondary outcomes included post intubation hypoxia, as well as association of hemodynamic collapse with potentially modifiable risk factors including pre intubation shock index, pre intubation heart rate, pre intubation systolic blood pressure, and induction agent.

RESULTS

Three hundred and thirty-three patients were included. Ninety-seven (29.1%) patients experienced hemodynamic collapse and 36 (10.8%) of patients experienced life threatening hemodynamic collapse. Pre intubation shock index >1 (OR 3.18, 95% CI 1.15-8.74) was associated with post intubation hemodynamic collapse. Choice of induction agent, fluid bolus prior to intubation, location of intubation, presence of traumatic injury, and age were not correlated with risk of hemodynamic collapse. The number of intubation attempts and methods of intubation were similar between groups.

CONCLUSIONS

Hemodynamic collapse and life-threatening hemodynamic collapse after intubation occurred frequently in this critical care transport cohort. Shock index greater than one was associated with significantly higher risk of hemodynamic collapse and life-threatening hemodynamic collapse.

Toward Precision in Critical Care Research: Methods for Observational and Interventional Studies

Critical care trials evaluate the effect of interventions in patients with diverse personal histories and causes of illness, often under the umbrella of heterogeneous clinical syndromes, such as sepsis or acute respiratory distress syndrome. Given this variation, it is reasonable to expect that the effect of treatment on outcomes may differ for individuals with variable characteristics. However, in randomized controlled trials, efficacy is typically assessed by the average treatment effect (ATE), which quantifies the average effect of the intervention on the outcome in the study population. Importantly, the ATE may hide variations of the treatment's effect on a clinical outcome across levels of patient characteristics, which may erroneously lead to the conclusion that an intervention does not work overall when it may in fact benefit certain patients. In this review, we describe methodological approaches for assessing heterogeneity of treatment effect (HTE), including expert-derived subgrouping, data-driven subgrouping, baseline risk modeling, treatment effect modeling, and individual treatment rule estimation. Next, we outline how insights from HTE analyses can be incorporated into the design of clinical trials. Finally, we propose a research agenda for advancing the field and bringing HTE approaches to the bedside.

Peri-Intubation Push-Dose Vasopressors in Critical Care Transport

OBJECTIVE

Push-dose vasopressors are commonly administered to attenuate peri-intubation hypotension. The aim of this study was to describe the current use of push-dose vasopressors in critical care transport.

METHODS

This was a retrospective chart review of adult patients (≥ 18 years) intubated between January 2017 and May 2023 who received push-dose vasopressors. The outcomes were incidence of push-dose vasopressor administration and the frequency of initiation or an increase in continuous vasopressor infusion.

RESULTS

Of the 334 patients intubated during this period, 49 (14.7%) received push-dose vasopressors in the peri-intubation period. The mean preintubation shock index was 1.1 ± 0.5. Of those who received push-dose vasopressors, 34 (69.4%) received multiple push doses; the mean number of administrations was 2.5 ± 1.9. Most patients had persistent or recurrent hypotension (n = 39, 79.6%). Fifteen (30.6%) were started on a continuous vasopressor infusion, and 3 (11.1%) had an increase in an existing infusion postintubation.

CONCLUSION

Although push-dose vasopressors are convenient and appropriate in many settings, they inadequately address hypotension in critically ill patients with underlying shock. Further investigation is required to better elucidate the role of peri-intubation push-dose and continuous vasopressors in the critical care transport setting.

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.

Effect of Fluid Therapy in Early Morning on the Incidence of Post-Induction Hypotension During Non-Cardiac Surgery After Noon: A Single-Center Retrospective Study

Purpose

Post-induction hypotension (PIH) is a common clinical phenomenon linked to increased morbidity and mortality in various non-cardiac surgeries. Patients with surgery in the afternoon may have preoperative hypovolemia caused by prolonged fasting and dehydration, which increases the risk of hypotension during the induction period. However, studies on the fluid therapy in early morning combating PIH remain inadequate. Therefore, we aimed to investigate the influence of prophylactic high-volume fluid in the early morning of the operation day on the incidence of PIH during non-cardiac surgery after noon.

Patients and Methods

We reviewed the medical records of patients who underwent non-cardiac surgery after noon between October 2021 and October 2022. The patients were divided into two groups based on whether they received a substantial volume of intravenous fluid (high-volume group) or not (low-volume group) in the early morning of the surgery day. We investigated the incidence of PIH and intraoperative hypotension (IOH) as well as the accumulated duration of PIH in the first 15 minutes. In total, 550 patients were included in the analysis.

Results

After propensity score matching, the incidence of PIH was 39.7% in the high-volume group and 54.1% in the low-volume group. Multivariate logistic regression analysis showed that patients in the high-volume group had lower incidence of hypotension after induction compared with the low-volume group (odds ratio, 0.55; 95% CI, 0.34-0.89; p = 0.016). The high-volume fluid infusion in the preoperative morning was significantly correlated with the decreased duration of PIH (p = 0.013), but no statistical difference was observed for the occurrence of IOH between the two groups (p = 0.075).

Conclusion

The fluid therapy of more than or equal to 1000 mL in the early morning of the surgery day was associated with a decreased incidence of PIH compared with the low-volume group in patients undergoing non-cardiac surgery after noon.

Diagnosis and Management of Acute Respiratory Failure

Acute hypoxemic respiratory failure is defined by Pao2 less than 60 mm Hg or SaO2 less than 88% and may result from V/Q mismatch, shunt, hypoventilation, diffusion limitation, or low inspired oxygen tension. Acute hypercapnic respiratory failure is defined by Paco2 ≥ 45 mm Hg and pH less than 7.35 and may result from alveolar hypoventilation, increased fraction of dead space, or increased production of carbon dioxide. Early diagnostic maneuvers, such as measurement of SpO2 and arterial blood gas, can differentiate the type of respiratory failure and guide next steps in evaluation and management.

Invasive Mechanical Ventilation

Invasive mechanical ventilation allows clinicians to support gas exchange and work of breathing in patients with respiratory failure. However, there is also potential for iatrogenesis. By understanding the benefits and limitations of different modes of ventilation and goals for gas exchange, clinicians can choose a strategy that provides appropriate support while minimizing harm. The ventilator can also provide crucial diagnostic information in the form of respiratory mechanics. These, and the mechanical ventilation strategy, should be regularly reassessed.

Spanish Society of Anesthesiology, Reanimation and Pain Therapy (SEDAR), Spanish Society of Emergency and Emergency Medicine (SEMES) and Spanish Society of Otolaryngology, Head and Neck Surgery (SEORL-CCC) Guideline for difficult airway management. Part I

The Airway Management section of the Spanish Society of Anesthesiology, Resuscitation, and Pain Therapy (SEDAR), the Spanish Society of Emergency Medicine (SEMES), and the Spanish Society of Otorhinolaryngology and Head and Neck Surgery (SEORL-CCC) present the Guide for the comprehensive management of difficult airway in adult patients. Its principles are focused on the human factors, cognitive processes for decision-making in critical situations, and optimization in the progression of strategies application to preserve adequate alveolar oxygenation in order to enhance safety and the quality of care. The document provides evidence-based recommendations, theoretical-educational tools, and implementation tools, mainly cognitive aids, applicable to airway management in the fields of anesthesiology, critical care, emergencies, and prehospital medicine. For this purpose, an extensive literature search was conducted following PRISMA-R guidelines and was analyzed using the GRADE methodology. Recommendations were formulated according to the GRADE methodology. Recommendations for sections with low-quality evidence were based on expert opinion through consensus reached via a Delphi questionnaire.

Laryngoscopy and Tracheal Intubation: Does Use of a Video Laryngoscope Facilitate Both Steps of the Procedure?

STUDY OBJECTIVE

To compare the effect of the use of a video laryngoscope versus a direct laryngoscope on each step of emergency intubation: laryngoscopy (step 1) and intubation of the trachea (step 2).

METHODS

In a secondary observational analysis of data from 2 multicenter, randomized trials that enrolled critically ill adults undergoing tracheal intubation but did not control for laryngoscope type (video laryngoscope vs direct laryngoscope), we fit mixed-effects logistic regression models examining the 1) the association between laryngoscope type (video laryngoscope vs direct laryngoscope) and the Cormack-Lehane grade of view and 2) the interaction between grade of view, laryngoscope type (video laryngoscope vs direct laryngoscope), and the incidence of successful intubation on the first attempt.

RESULTS

We analyzed 1,786 patients: 467 (26.2%) in the direct laryngoscope group and 1,319 (73.9%) in the video laryngoscope group. The use of a video laryngoscope was associated with an improved grade of view as compared with a direct laryngoscope (adjusted odds ratio for increasingly favorable grade of view 3.14, 95% confidence interval [CI] 2.47 to 3.99). Successful intubation on the first attempt occurred in 83.2% of patients in the video laryngoscope group and 72.2% of patients in the direct laryngoscope group (absolute difference 11.1%, 95% CI 6.5% to 15.6%). Video laryngoscope use modified the association between grade of view and successful intubation on the first attempt such that intubation on the first attempt was similar between video laryngoscope and direct laryngoscope at a grade 1 view and higher for video laryngoscope than direct laryngoscope at grade 2 to 4 views (P<.001 for interaction term).

CONCLUSIONS

Among critically ill adults undergoing tracheal intubation, the use of a video laryngoscope was associated both with a better view of the vocal cords and with a higher probability of successfully intubating the trachea when the view of the vocal cords was incomplete in this observational analysis. However, a multicenter, randomized trial directly comparing the effect of a video laryngoscope with a direct laryngoscope on the grade of view, success, and complications is needed.

Effects of Etomidate on Postintubation Hypotension, Inflammatory Markers, and Mortality in Critically Ill Patients with COVID-19: An International, Multicenter, Retrospective Study

OBJECTIVE

To evaluate the association of etomidate with postintubation hypotension, inflammation, and mortality in critically ill patients with COVID-19.

DESIGN

International, multicenter, retrospective study.

PARTICIPANTS

Critically ill patients hospitalized specifically for COVID-19 from three major academic institutions in the US and Europe.

MAIN OUTCOME AND MEASURES

Patients were allocated into the etomidate (ET) group or another induction agent (OA) group. The primary outcome was postintubation hypotension. Secondary outcomes included postintubation inflammatory status, in-hospital mortality, and mortality at 30 days.

RESULTS

171 patients with a median age of 68 (IQR 58-73) years were included (ET, n  =  98; OA, n  =  73). Etomidate was associated with lower postintubation mean arterial pressure [74.33 (64-85) mm Hg versus 81.84 (69.75-94.25) mm Hg, p  =  0.005] compared to other agents. No statistically significant differences were generally observed in inflammatory markers between the two groups at 7- and 14-days after admission to the intensive care unit. In-hospital mortality [77 (79%) versus 41 (56%), p  =  0.003] and mortality at 30-days [78 (80%) versus 43 (59%), p  =  0.006] were higher in the ET group. In multivariate logistic regression analysis, only etomidate (p  =  0.009) and postintubation mean arterial pressure (p < 0.001) had a statistically significant effect on mortality, in contrast to stress-dose steroids (p  =  0.301), after adjusting for creatinine (p  =  0.695), blood urea nitrogen (p  =  0.153), age (p  =  0.055), oxygen saturation of hemoglobin (SpO2) (p  =  0.941), and fraction of inspired oxygen (FiO2) (p  =  0.712).

CONCLUSIONS

Administration of a single-bolus dose of etomidate in critically ill patients with COVID-19 is associated with lower postintubation mean arterial pressure and higher in-hospital and 30-day mortality compared to other induction agents.

Defining Successful Intubation on the First Attempt Using Both Laryngoscope and Endotracheal Tube Insertions: A Secondary Analysis of Clinical Trial Data

STUDY OBJECTIVES

Successful intubation on the first attempt has historically been defined as successful placement of an endotracheal tube (ETT) using a single laryngoscope insertion. More recent studies have defined successful placement of an ETT using a single laryngoscope insertion followed by a single ETT insertion. We sought to estimate the prevalence of first-attempt success using these 2 definitions and estimate their associations with the duration of intubation and serious complications.

METHODS

We performed a secondary analysis of data from 2 multicenter randomized trials of critically ill adults being intubated in the emergency department or ICU. We calculated the percent difference in successful intubations on the first attempt, median difference in the duration of intubation, and percent difference in the development of serious complications by definition.

RESULTS

The study population included 1,863 patients. Successful intubation on the first attempt decreased by 4.9% (95% confidence interval 2.5% to 7.3%) when defined as 1 laryngoscope insertion followed by 1 ETT insertion (81.2%) compared with when defined as only 1 laryngoscope insertion (86.0%). When successful intubation with 1 laryngoscope and 1 ETT insertion was compared with 1 laryngoscope and multiple ETT insertions, the median duration of intubation decreased by 35.0 seconds (95% confidence interval 8.9 to 61.1 seconds).

CONCLUSION

Defining successful intubation on the first attempt as placement of an ETT in the trachea using 1 laryngoscope and 1 ETT insertion identifies attempts with the shortest apneic time.

Society of Critical Care Medicine Clinical Practice Guidelines for Rapid Sequence Intubation in the Critically Ill Adult Patient

RATIONALE

Controversies and practice variations exist related to the pharmacologic and nonpharmacologic management of the airway during rapid sequence intubation (RSI).

OBJECTIVES

To develop evidence-based recommendations on pharmacologic and nonpharmacologic topics related to RSI.

DESIGN

A guideline panel of 20 Society of Critical Care Medicine members with experience with RSI and emergency airway management met virtually at least monthly from the panel's inception in 2018 through 2020 and face-to-face at the 2020 Critical Care Congress. The guideline panel included pharmacists, physicians, a nurse practitioner, and a respiratory therapist with experience in emergency medicine, critical care medicine, anesthesiology, and prehospital medicine; consultation with a methodologist and librarian was available. A formal conflict of interest policy was followed and enforced throughout the guidelines-development process.

METHODS

Panelists created Population, Intervention, Comparison, and Outcome (PICO) questions and voted to select the most clinically relevant questions for inclusion in the guideline. Each question was assigned to a pair of panelists, who refined the PICO wording and reviewed the best available evidence using predetermined search terms. The Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) framework was used throughout and recommendations of "strong" or "conditional" were made for each PICO question based on quality of evidence and panel consensus. Recommendations were provided when evidence was actionable; suggestions, when evidence was equivocal; and best practice statements, when the benefits of the intervention outweighed the risks, but direct evidence to support the intervention did not exist.

RESULTS

From the original 35 proposed PICO questions, 10 were selected. The RSI guideline panel issued one recommendation (strong, low-quality evidence), seven suggestions (all conditional recommendations with moderate-, low-, or very low-quality evidence), and two best practice statements. The panel made two suggestions for a single PICO question and did not make any suggestions for one PICO question due to lack of evidence.

CONCLUSIONS

Using GRADE principles, the interdisciplinary panel found substantial agreement with respect to the evidence supporting recommendations for RSI. The panel also identified literature gaps that might be addressed by future research.

Heart-Lung Interactions

The pulmonary and cardiovascular systems have profound effects on each other. Overall cardiac function is determined by heart rate, preload, contractility, and afterload. Changes in lung volume, intrathoracic pressure (ITP), and hypoxemia can simultaneously change all of these four hemodynamic determinants for both ventricles and can even lead to cardiovascular collapse. Intubation using sedation depresses vasomotor tone. Also, the interdependence between right and left ventricles can be affected by lung volume-induced changes in pulmonary vascular resistance and the rise in ITP. An increase in venous return due to negative ITP during spontaneous inspiration can shift the septum to the left and cause a decrease in left ventricle compliance. During positive pressure ventilation, the increase in ITP causes a decrease in venous return (preload), minimizing ventricular interdependence and will decrease left ventricle afterload augmenting cardiac output. Thus, positive pressure ventilation is beneficial in acute heart failure patients and detrimental in hypovolemic patients where it can cause a significant decrease in venous return and cardiac output. Recently, this phenomenon has been used to assess patient's volume responsiveness to fluid by measuring pulse pressure variation and stroke volume variation. Heart-lung interaction is very dynamic and changes in lung volume, ITP, and oxygen level can have various effects on the cardiovascular system depending on preexisting cardiovascular function and volume status. Heart failure and either hypo or hypervolemia predispose to greater effects of ventilation of cardiovascular function and gas exchange. This review is an overview of the basics of heart-lung interaction.

Video versus Direct Laryngoscopy for Tracheal Intubation of Critically Ill Adults

BACKGROUND

Whether video laryngoscopy as compared with direct laryngoscopy increases the likelihood of successful tracheal intubation on the first attempt among critically ill adults is uncertain.

METHODS

In a multicenter, randomized trial conducted at 17 emergency departments and intensive care units (ICUs), we randomly assigned critically ill adults undergoing tracheal intubation to the video-laryngoscope group or the direct-laryngoscope group. The primary outcome was successful intubation on the first attempt. The secondary outcome was the occurrence of severe complications during intubation; severe complications were defined as severe hypoxemia, severe hypotension, new or increased vasopressor use, cardiac arrest, or death.

RESULTS

The trial was stopped for efficacy at the time of the single preplanned interim analysis. Among 1417 patients who were included in the final analysis (91.5% of whom underwent intubation that was performed by an emergency medicine resident or a critical care fellow), successful intubation on the first attempt occurred in 600 of the 705 patients (85.1%) in the video-laryngoscope group and in 504 of the 712 patients (70.8%) in the direct-laryngoscope group (absolute risk difference, 14.3 percentage points; 95% confidence interval [CI], 9.9 to 18.7; P<0.001). A total of 151 patients (21.4%) in the video-laryngoscope group and 149 patients (20.9%) in the direct-laryngoscope group had a severe complication during intubation (absolute risk difference, 0.5 percentage points; 95% CI, -3.9 to 4.9). Safety outcomes, including esophageal intubation, injury to the teeth, and aspiration, were similar in the two groups.

CONCLUSIONS

Among critically ill adults undergoing tracheal intubation in an emergency department or ICU, the use of a video laryngoscope resulted in a higher incidence of successful intubation on the first attempt than the use of a direct laryngoscope. (Funded by the U.S. Department of Defense; DEVICE ClinicalTrials.gov number, NCT05239195.).

Prophylactic Administration of Vasopressors Prior to Emergency Intubation in Critically Ill Patients: A Secondary Analysis of Two Multicenter Clinical Trials

Hypotension affects approximately 40% of critically ill patients undergoing emergency intubation and is associated with an increased risk of death. The objective of this study was to examine the association between prophylactic vasopressor administration and the incidence of peri-intubation hypotension and other clinical outcomes.

DESIGN

A secondary analysis of two multicenter randomized clinical trials. The clinical effect of prophylactic vasopressor administration was estimated using a one-to-one propensity-matched cohort of patients with and without prophylactic vasopressors.

SETTING

Seven emergency departments and 17 ICUs across the United States.

PATIENTS

One thousand seven hundred ninety-eight critically ill patients who underwent emergency intubation at the study sites between February 1, 2019, and May 24, 2021.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was peri-intubation hypotension defined as a systolic blood pressure less than 90 mm Hg occurring between induction and 2 minutes after tracheal intubation. A total of 187 patients (10%) received prophylactic vasopressors prior to intubation. Compared with patients who did not receive prophylactic vasopressors, those who did were older, had higher Acute Physiology and Chronic Health Evaluation II scores, were more likely to have a diagnosis of sepsis, had lower pre-induction systolic blood pressures, and were more likely to be on continuous vasopressor infusions prior to intubation. In our propensity-matched cohort, prophylactic vasopressor administration was not associated with reduced risk of peri-intubation hypotension (41% vs 32%; p = 0.08) or change in systolic blood pressure from baseline (-12 vs -11 mm Hg; p = 0.66).

CONCLUSIONS

The administration of prophylactic vasopressors was not associated with a lower incidence of peri-intubation hypotension in our propensity-matched analysis. To address potential residual confounding, randomized clinical trials should examine the effect of prophylactic vasopressor administration on peri-intubation outcomes.

Role of Point-of-Care Ultrasound in Emergency Airway Management Outside the Operating Room

Tracheal intubation is one of the most frequently performed procedures in critically ill patients, and is associated with significant morbidity and mortality. Hemodynamic instability and cardiovascular collapse are common complications associated with the procedure, and are likely in patients with a physiologically difficult airway. Bedside point-of-care ultrasound (POCUS) can help identify patients with high risk of cardiovascular collapse, provide opportunity for hemodynamic and respiratory optimization, and help tailor airway management plans to meet individual patient needs. This review discusses the role of POCUS in emergency airway management, provides an algorithm to facilitate its incorporation into existing practice, and provides a framework for future studies.

General Critical Care, Temperature Control, and End-of-Life Decision Making in Patients Resuscitated from Cardiac Arrest

Cardiac arrest affects millions of people per year worldwide. Although advances in cardiopulmonary resuscitation and intensive care have improved outcomes over time, neurologic impairment and multiple organ dysfunction continue to be associated with a high mortality rate. The pathophysiologic mechanisms underlying the post-resuscitation disease are complex, and a coordinated, evidence-based approach to post-resuscitation care has significant potential to improve survival. Critical care management of patients resuscitated from cardiac arrest focuses on the identification and treatment of the underlying cause(s), hemodynamic and respiratory support, organ protection, and active temperature control. This review provides a state-of-the-art appraisal of critical care management of the post-cardiac arrest patient.

Protocol and statistical analysis plan for the PREOXI trial of preoxygenation with noninvasive ventilation vs oxygen mask

Background

Hypoxemia is a common and life-threatening complication during emergency tracheal intubation of critically ill adults. The administration of supplemental oxygen prior to the procedure ("preoxygenation") decreases the risk of hypoxemia during intubation.

Research Question

Whether preoxygenation with noninvasive ventilation prevents hypoxemia during tracheal intubation of critically ill adults, compared to preoxygenation with oxygen mask, remains uncertain.

Study Design and Methods

The PRagmatic trial Examining OXygenation prior to Intubation (PREOXI) is a prospective, multicenter, non-blinded randomized comparative effectiveness trial being conducted in 7 emergency departments and 17 intensive care units across the United States. The trial compares preoxygenation with noninvasive ventilation versus oxygen mask among 1300 critically ill adults undergoing emergency tracheal intubation. Eligible patients are randomized in a 1:1 ratio to receive either noninvasive ventilation or an oxygen mask prior to induction. The primary outcome is the incidence of hypoxemia, defined as a peripheral oxygen saturation <85% between induction and 2 minutes after intubation. The secondary outcome is the lowest oxygen saturation between induction and 2 minutes after intubation. Enrollment began on 10 March 2022 and is expected to conclude in 2023.

Interpretation

The PREOXI trial will provide important data on the effectiveness of noninvasive ventilation and oxygen mask preoxygenation for the prevention of hypoxemia during emergency tracheal intubation. Specifying the protocol and statistical analysis plan prior to the conclusion of enrollment increases the rigor, reproducibility, and interpretability of the trial.

Clinical trial registration number

NCT05267652.

Managing the Physiologically Difficult Airway in Critically Ill Adults

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2023. Other selected articles can be found online at https://www.biomedcentral.com/collections/annualupdate2023 . Further information about the Annual Update in Intensive Care and Emergency Medicine is available from  https://link.springer.com/bookseries/8901 .

Individualizing Fluid Management in Patients with Acute Respiratory Distress Syndrome and with Reduced Lung Tissue Due to Surgery—A Narrative Review

Fluids are the cornerstone of therapy in all critically ill patients. During the last decades, we have made many steps to get fluid therapy personalized and based on individual needs. In patients with lung involvement—acute respiratory distress syndrome—finding the right amount of fluids after lung surgery may be extremely important because lung tissue is one of the most vulnerable to fluid accumulation. In the current narrative review, we focus on the actual perspectives of fluid therapy with the aim of showing the possibilities to tailor the treatment to a patient’s individual needs using fluid responsiveness parameters and other therapeutic modalities.

Effect of Laryngoscope Blade Size on First Pass Success of Tracheal Intubation in Critically Ill Adults

Tracheal intubation (TI) is a common procedure in critical care, often performed with a Macintosh curved blade used for direct laryngoscopy (DL). Minimal evidence informs the choice between Macintosh blade sizes during TI. We hypothesized that Macintosh 4 blade would have higher first-attempt success than Macintosh 3 blade during DL.

DESIGN

Retrospective analysis using a propensity score and inverse probability weighting of data from six prior multicenter randomized trials.

SETTING AND PARTICIPANTS

Adult patients who underwent nonelective TI at participating emergency departments and ICUs. We compared the first-pass success of TI with DL in subjects intubated with a size 4 Macintosh blade on the first TI attempt to subjects with a size 3 Macintosh blade on the first TI attempt.

MAIN RESULTS

Among 979 subjects, 592 (60.5%) had TI using DL with a Macintosh blade, of whom 362 (37%) were intubated with a size 4 blade and 222 (22.7%) with a size 3 blade. We used inverse probability weighting with a propensity score for analyzing data. We found that patients intubated with a size 4 blade had a worse (higher) Cormack-Lehane grade of glottic view than patients intubated with a size 3 blade (adjusted odds ratio [aOR], 1.458; 95% CI, 1.064-2.003; p = 0.02). Patients intubated with a size 4 blade had a lower first pass success than those with a size 3 blade (71.1% vs 81.2%; aOR, 0.566; 95% CI, 0.372-0.850; p = 0.01).

CONCLUSIONS AND RELEVANCE

In critically ill adults undergoing TI using DL with a Macintosh blade, patients intubated using a size 4 blade on first attempt had a worse glottic view and a lower first pass success than patients intubated with a size 3 Macintosh blade. Further prospective studies are needed to examine the optimal approach to selecting laryngoscope blade size during TI of critically ill adults.

Recall of Awareness During Paralysis Among ED Patients Undergoing Tracheal Intubation

BACKGROUND

Critically ill patients sometimes remember periods of neuromuscular blockade.

RESEARCH QUESTION

What is the prevalence of recalled awareness during paralysis in patients who underwent emergency tracheal intubation and mechanical ventilation, and what clinical variables are associated with this outcome?

STUDY DESIGN AND METHODS

This study analyzed data from a prospectively collected continuous quality improvement database of emergency tracheal intubation in an urban, county hospital. Patients who received a neuromuscular blocking agent to facilitate emergency tracheal intubation in the ED were included. The database contained details of intubation management, including medications received and patient mental status prior to intubation. Patient recall of awareness of paralysis was assessed by trained staff during an in-person interview following extubation using a modified Brice questionnaire. For this analysis, three expert reviewers used these data to adjudicate whether patients may have had awareness of paralysis, the primary outcome. A logistic regression model was constructed to determine whether clinical variables were associated with the primary outcome.

RESULTS

A total of 886 patients were analyzed. There were 66 patients (7.4%; 95% CI, 5.8-9.4) determined to possibly (61 patients) or definitely (5 patients) have experienced and recalled awareness of paralysis. A logistic regression model revealed that a decreased level of consciousness prior to intubation was associated with lower odds of awareness (adjusted OR, 0.39; 95% CI, 0.22-0.69), whereas the class of neuromuscular blocking agent used, sedative used, preintubation shock index, and postintubation sedation were not significantly associated with recall of this outcome.

INTERPRETATION

Among patients intubated emergently using a neuromuscular blocking agent, 7.4% of patients recalled awareness without being able to move, which was more likely when patients had a normal level of consciousness prior to intubation.

DirEct versus VIdeo LaryngosCopE (DEVICE): protocol and statistical analysis plan for a randomised clinical trial in critically ill adults undergoing emergency tracheal intubation

INTRODUCTION

Among critically ill patients undergoing orotracheal intubation in the emergency department (ED) or intensive care unit (ICU), failure to visualise the vocal cords and intubate the trachea on the first attempt is associated with an increased risk of complications. Two types of laryngoscopes are commonly available: direct laryngoscopes and video laryngoscopes. For critically ill adults undergoing emergency tracheal intubation, it remains uncertain whether the use of a video laryngoscope increases the incidence of successful intubation on the first attempt compared with the use of a direct laryngoscope.

METHODS AND ANALYSIS

The DirEct versus VIdeo LaryngosCopE (DEVICE) trial is a prospective, multicentre, non-blinded, randomised trial being conducted in 7 EDs and 10 ICUs in the USA. The trial plans to enrol up to 2000 critically ill adults undergoing orotracheal intubation with a laryngoscope. Eligible patients are randomised 1:1 to the use of a video laryngoscope or a direct laryngoscope for the first intubation attempt. The primary outcome is successful intubation on the first attempt. The secondary outcome is the incidence of severe complications between induction and 2 min after intubation, defined as the occurrence of one or more of the following: severe hypoxaemia (lowest oxygen saturation <80%); severe hypotension (systolic blood pressure <65 mm Hg or new or increased vasopressor administration); cardiac arrest or death. Enrolment began on 19 March 2022 and is expected to be completed in 2023.

ETHICS AND DISSEMINATION

The trial protocol was approved with waiver of informed consent by the single institutional review board at Vanderbilt University Medical Center and the Human Research Protection Office of the Department of Defense. The results will be presented at scientific conferences and submitted for publication in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT05239195).