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

Importance: Hypotension is common during tracheal intubation of critically ill adults and increases the risk of cardiac arrest and death. Whether administering an intravenous fluid bolus to critically ill adults undergoing tracheal intubation prevents severe hypotension, cardiac arrest, or death remains uncertain. Objective: To determine the effect of fluid bolus administration on the incidence of severe hypotension, cardiac arrest, and death. Design, Setting, and Participants: This randomized clinical trial enrolled 1067 critically ill adults undergoing tracheal intubation with sedation and positive pressure ventilation at 11 intensive care units in the US between February 1, 2019, and May 24, 2021. The date of final follow-up was June 21, 2021. Interventions: Patients were randomly assigned to receive either a 500-mL intravenous fluid bolus (n = 538) or no fluid bolus (n = 527). Main Outcomes and Measures: The primary outcome was cardiovascular collapse (defined as new or increased receipt of vasopressors or a systolic blood pressure <65 mm Hg between induction of anesthesia and 2 minutes after tracheal intubation, or cardiac arrest or death between induction of anesthesia and 1 hour after tracheal intubation). The secondary outcome was the incidence of death prior to day 28, which was censored at hospital discharge. Results: Among 1067 patients randomized, 1065 (99.8%) completed the trial and were included in the primary analysis (median age, 62 years [IQR, 51-70 years]; 42.1% were women). Cardiovascular collapse occurred in 113 patients (21.0%) in the fluid bolus group and in 96 patients (18.2%) in the no fluid bolus group (absolute difference, 2.8% [95% CI, -2.2% to 7.7%]; P = .25). New or increased receipt of vasopressors occurred in 20.6% of patients in the fluid bolus group compared with 17.6% of patients in the no fluid bolus group, a systolic blood pressure of less than 65 mm Hg occurred in 3.9% vs 4.2%, respectively, cardiac arrest occurred in 1.7% vs 1.5%, and death occurred in 0.7% vs 0.6%. Death prior to day 28 (censored at hospital discharge) occurred in 218 patients (40.5%) in the fluid bolus group compared with 223 patients (42.3%) in the no fluid bolus group (absolute difference, -1.8% [95% CI, -7.9% to 4.3%]; P = .55). Conclusions and Relevance: Among critically ill adults undergoing tracheal intubation, administration of an intravenous fluid bolus compared with no fluid bolus did not significantly decrease the incidence of cardiovascular collapse. Trial Registration: ClinicalTrials.gov Identifier: NCT03787732.

Protocol and statistical analysis plan for the PREventing cardiovascular collaPse with Administration of fluid REsuscitation during Induction and Intubation (PREPARE II) randomised clinical trial.

INTRODUCTION: Cardiovascular collapse is a common complication during tracheal intubation of critically ill adults. Whether administration of an intravenous fluid bolus prevents cardiovascular collapse during tracheal intubation remains uncertain. A prior randomised trial found fluid bolus administration to be ineffective overall but suggested potential benefit for patients receiving positive pressure ventilation during tracheal intubation. METHODS AND ANALYSIS: The PREventing cardiovascular collaPse with Administration of fluid REsuscitation during Induction and Intubation (PREPARE II) trial is a prospective, multi-centre, non-blinded randomised trial being conducted in 13 academic intensive care units in the USA. The trial will randomise 1065 critically ill adults undergoing tracheal intubation with planned use of positive pressure ventilation (non-invasive ventilation or bag-mask ventilation) between induction and laryngoscopy to receive 500 mL of intravenous crystalloid or no intravenous fluid bolus. The primary outcome is cardiovascular collapse, defined as any of: systolic blood pressure <65 mm Hg, new or increased vasopressor administration between induction and 2 min after intubation, or cardiac arrest or death between induction and 1 hour after intubation. The primary analysis will be an unadjusted, intention-to-treat comparison of the primary outcome between patients randomised to fluid bolus administration and patients randomised to no fluid bolus administration using a χ2 test. The sole secondary outcome is 28-day in-hospital mortality. Enrolment began on 1 February 2019 and is expected to conclude in June 2020. ETHICS AND DISSEMINATION: The trial was approved by either the central institutional review board at Vanderbilt University Medical Center or the local institutional review board at each trial site. Results will be submitted for publication in a peer-reviewed journal and presented at scientific conferences. TRIAL REGISTRATION NUMBER: NCT03787732.

Emulating a Novel Clinical Trial Using Existing Observational Data. Predicting Results of the PreVent Study.

Rationale: "Target trial emulation" has been proposed as an observational method to answer comparative effectiveness questions, but it has rarely been attempted concurrently with a randomized clinical trial (RCT).Objectives: We tested the hypothesis that blinded analysts applying target trial emulation to existing observational data could predict the results of an RCT.Methods: PreVent (Preventing Hypoxemia with Manual Ventilation during Endotracheal Intubation) was a multicenter RCT examining the effects of positive-pressure ventilation during tracheal intubation on oxygen saturation and severe hypoxemia. Analysts unaware of PreVent's results used patient-level data from three previous trials evaluating airway management interventions to emulate PreVent's eligibility criteria, randomization procedure, and statistical analysis. After PreVent's release, results of this blinded observational analysis were compared with those of the RCT. Difference-in-differences estimates for comparison of treatment effects between the observational analysis and the PreVent trial are reported on the absolute scale.Results: Using observational data, we were able to emulate PreVent's randomization procedure to produce balanced groups for comparison. The lowest oxygen saturation during intubation was higher in the positive-pressure ventilation group than the no positive-pressure ventilation group in the observational analysis (n = 360; mean difference = 1.8%; 95% confidence interval [CI] = -1.0 to 4.6) and in the PreVent trial (n = 401; mean difference = 3.9%; 95% CI = 1.4 to 6.4), though the observational analysis could not exclude no difference. Difference-in-differences estimates comparing treatment effects showed reasonable agreement for lowest oxygen saturation between the observational analysis and the PreVent trial (mean difference = -2.1%; 95% CI = -5.9 to 1.7). Positive-pressure ventilation resulted in lower rates of severe hypoxemia in both the observational analysis (risk ratio = 0.60; 95% CI = 0.38 to 0.93) and in the PreVent trial (risk ratio = 0.48; 95% CI = 0.30 to 0.77). The absolute reduction in the incidence of severe hypoxemia with positive-pressure ventilation was similar in the observational analysis (9.4%) and the PreVent trial (12.0%), though the difference between these estimates had wide CIs (mean difference = 2.5%; 95% CI = -8.0 to 13.6%).Conclusions: Applying target trial emulation methods to existing observational data for the evaluation of a novel intervention produced results similar to those of a randomized trial. These findings support the use of target trial emulation for comparative effectiveness research.

Utility and diagnostic accuracy of bedside lung ultrasonography during medical emergency team (MET) activations for respiratory deterioration.

PURPOSE: We investigated the feasibility and diagnostic accuracy of lung ultrasonography during medical emergency team (MET) activations for respiratory deterioration. MATERIAL AND METHODS: We performed a prospective study of inpatients requiring MET evaluation for respiratory decompensation. A blinded investigator recorded videos of lung and lower extremity ultrasonography. The videos were reviewed by blinded investigators to determine a ultrasonography diagnosis. The accuracy of MET diagnosis and ultrasonography diagnosis were compared to the final diagnosis determined by retrospective chart review. RESULTS: The ultrasound exam was completed in 49/50 (98%) patients enrolled in the study with a mean duration of 13±4min. When excluding six cases that were not amenable to diagnosis by our algorithm, we report a lung ultrasonography diagnostic accuracy of 84% (37/44) which is similar to the accuracy of the MET clinical diagnosis of 75% (33/44) (p=0.29). Furthermore, we report in 28/37 (76%) of cases where the lung ultrasonography diagnosis was correct, patients may have received inappropriate therapies. CONCLUSIONS: Lung ultrasonography can be rapidly performed in the majority of patients with MET activation for respiratory deterioration. As an independent diagnostic test, lung ultrasonography is non-inferior to the MET clinical assessment and may prevent unnecessary treatments if used simultaneously.

Independent lung ventilation in the management of ARDS and bronchopleural fistula.

Independent lung ventilation is a decades-old, but infrequently used technique for physiological separation in critically-ill patients with asymmetric lung disease. Here we present a case report of bilateral necrotizing pneumonia complicated by acute respiratory distress syndrome and bronchopleural fistula, which was successfully managed with independent lung ventilation. The use of independent lung ventilation allowed for adequate oxygenation with use of high positive end expiratory pressure in the "good lung" while simultaneously allowing for closure of the bronchopulmonary fistula in the contralateral lung by maintaining relatively low airway pressures.

Can We Trust Observational Studies Using Propensity Scores in the Critical Care Literature? A Systematic Comparison With Randomized Clinical Trials.

OBJECTIVE: To assess the degree of agreement between propensity score studies and randomized clinical trials in critical care research. DATA SOURCES: Propensity score studies published in highly cited critical care or general medicine journals or included in a previous systematic review; corresponding randomized clinical trials included in Cochrane Systematic Reviews or published in PubMed. STUDY SELECTION: We identified propensity score studies of the effects of therapeutic interventions on short- or long-term mortality. We systematically matched propensity score studies to randomized clinical trials based on patient selection criteria, interventions, and outcomes. DATA EXTRACTION: We appraised the methods of included studies and extracted treatment effect estimates to compare the results of propensity score studies and randomized clinical trials. When multiple studies were identified for the same topic, we performed meta-analyses to obtain summary treatment effect estimates. DATA SYNTHESIS: We matched 21 propensity score studies with 58 randomized clinical trials in 18 distinct comparisons (median, one propensity score study and two randomized clinical trials per comparison), for short- and long-term mortality. We found one statistically significant difference between designs (hyperoncotic albumin vs crystalloid fluids) among these 18 comparisons. Propensity score studies did not produce systematically higher (or lower) treatment effect estimates compared with randomized clinical trials, but estimates from the two designs differed by more than 30% in one third of the comparisons examined. Observational studies in critical care met widely accepted methodological standards for propensity score analyses. CONCLUSIONS: Across diverse critical care topics, propensity score studies published in high-impact journals produced results that were generally consistent with the findings of randomized clinical trials. However, caution is needed when interpreting propensity score studies because occasionally their results contradict those of randomized clinical trials and there is no reliable way to predict disagreements.

Left-sided superior vena cava and venous hyperoxia masquerading as inadvertent carotid artery catheterization.

BACKGROUND: A persistent left-sided superior vena cava (PLSVC) is a rare, often asymptomatic, venous anomaly that may be first diagnosed during central venous catheterization. During chest radiograph interpretation, a PLSVC can be confused with inadvertent arterial catheterization. CASE REPORT: We describe the presentation of a 45-year-old man with end-stage liver disease who required central venous catheterization for treatment of septic shock. An aberrantly placed catheter noted on chest radiograph and an elevated central venous oxygen saturation gave the appearance of inadvertent carotid artery catheterization. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: A persistent left-sided superior vena cava can masquerade as an inadvertent cannulation of the carotid artery during central line placement. It is important for emergency physicians to be aware of this possibility when evaluating a chest radiograph with an aberrantly placed catheter. Venous hyperoxia may further complicate attempts to differentiate between arterial and venous catheterization in patients with septic shock. After confirmatory tests, the emergency physician should consider removal of the catheter due to potential complications.

Resource utilization and end-of-life care in a US hospital following medical emergency team-implemented do not resuscitate orders.

BACKGROUND: Medical emergency teams frequently implement do not resuscitate orders, but little is known about end-of-life care in this population. OBJECTIVE: To examine resource utilization and end-of-life care following medical emergency team-implemented do not resuscitate orders. DESIGN: Retrospective review. SETTING: Single, tertiary care center. PATIENTS: Consecutive adult inpatients requiring a medical emergency team activation over 1 year. MEASUREMENTS: Changes to code status, time spent on medical emergency team activations, frequency of palliative care consultation, discharges with hospice care. INTERVENTIONS: None. RESULTS: We observed 1156 medical emergency team activations in 998 patients. Five percent (58/1156) resulted in do not resuscitate orders. The median time spent on activations with a change in code status was longer than activations without a change (66 vs 60 minutes, P = 0.05). Patients with a medical emergency team-implemented do not resuscitate order had a higher inpatient mortality (43 vs 27%, P = 0.04) and were less likely to be discharged with hospice at the end of life than patients with a preexisting do not resuscitate order (4 vs 29%, P = 0.01). There was no difference in palliative care consultation in patients with a preexisting do not resuscitate versus medical emergency team-implemented do not resuscitate order (20% vs 12%, P = 0.39). CONCLUSIONS: Despite high mortality, patients with medical emergency team-implemented do not resuscitate orders had a relatively low utilization of end-of-life resources, including palliative care consultation and home hospice services. Coordinated care between medical emergency teams and inpatient palliative care services may help to improve end-of-life care.

The effect of body mass index on intubation success rates and complications during emergency airway management.

We evaluated the effect of body mass index (BMI) on intubation success rates and complications during emergency airway management. We retrospectively analyzed an airway registry at an academic medical center. The primary outcomes were the incidence of difficult intubation and complication rates, stratified by BMI. We captured 1,075 (98 %, 1,075/1,102; 95 % CI 97-99) intubations. Four hundred twenty-six patients (40 %) had a normal BMI, 289 (27 %) were overweight, 261 (25 %) were obese, and 77 (7 %) were morbidly obese. In a multivariate analysis, obesity (OR 1.90; 95 % CI 1.04-3.45; p = 0.04), but not morbid obesity (OR 2.18; 95 % CI 0.95-4.99; p = 0.07), predicted difficult intubation. BMI was not predictive of post-intubation complications. Airway management in the morbidly obese differed when compared with lean patients, with less use of rapid sequence intubation and increased use of fiberoptic bronchoscopy in the former. During emergency airway management, difficult intubation is more common in obese patients, and morbidly obese patients are more commonly treated as potentially difficult airways.

Ruptured abdominal aortic aneurysm presenting as painless testicular ecchymosis: the scrotal sign of Bryant revisited.

The diagnosis of ruptured abdominal aortic aneurysm (AAA) is often missed as a result of an atypical presentation, resulting in increased mortality. Here we present an unusual case of painless scrotal ecchymosis as a presentation of ruptured AAA. We review the origin of the scrotal sign of Bryant and emphasize the importance of this uncommon finding as a diagnostic aid in atypical cases of ruptured AAA.

Ultrasonography-guided peripheral intravenous catheter survival in ED patients with difficult access.

OBJECTIVES: We determined the survival and complications of ultrasonography-guided peripheral intravenous (IV) catheters in emergency department (ED) patients with difficult peripheral access. METHODS: This was a prospective, observational study conducted in an academic hospital from April to July of 2007. We included consecutive adult ED patients with difficult access who had ultrasonography-guided peripheral IVs placed. Operators completed data sheets and researchers examined admitted patients daily to assess outcomes. The primary outcome was IV survival >96 hours. As a secondary outcome, we recorded IV complications, including central line placement. We used descriptive statistics, univariate survival analysis with Kaplan Meier, and log-rank tests for data analysis. RESULTS: Seventy-five patients were enrolled. The average age was 52 years. Fifty-three percent were male, 21% obese, and 13% had a history of injection drug use. The overall IV survival rate was 56% (95% confidence interval, 44%-67%) with a median survival of 26 hours (interquartile range [IQR], 8-61). Forty-seven percent of IVs failed within 24 hours, most commonly due to infiltration. Although 47 (63%) operators reported that a central line would have been required if peripheral access was unobtainable, only 5 (7%; 95% confidence interval, 2%-15%) patients underwent central venous catheterization. Only 1 central line was placed as a result of ultrasonography-guided IV failure. We observed no infectious or thrombotic complications. CONCLUSION: Despite a high premature failure rate, ultrasonography-guided peripheral IVs appear to be an effective alternative to central line placement in ED patients with difficult access.

The painful eye.

Emergency physicians are required to diagnose and treat patients who have a painful eye on a regular basis. This article focuses on ophthalmologic emergencies that range in presentation from mild to severe symptomatology and include vision and eye-threatening ailments. The etiology, pathophysiology, physical examination, and treatment of the following conditions are discussed: acute angle closure glaucoma, scleritis, anterior uveitis, optic neuritis, keratitis, and corneal abrasion. This article should provide the necessary information to allow for rapid diagnosis and initiation of appropriate treatment of the painful eye.