Complications of emergency tracheal intubation: hemodynamic alterations--part I

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.

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.

Propofol administration for induction is associated with peri-intubation instability in trauma critical care unit patients

INTRODUCTION

Peri-intubation hypotension is associated with increased hospital length of stay and morbidity. Propofol is associated with alterations in hemodynamics. We hypothesize that using propofol for induction leads to peri-intubation hypotension in trauma critical care patients.

METHODS

Patients that underwent unplanned intubation in the trauma intensive care unit (TICU) were prospectively enrolled. Peri-intubation vitals and medications were recorded to assess hypotension within 10 ​min of intubation. Patients were divided into propofol (PROP) or other medication (OTR) groups.

RESULTS

Data was complete for 69 patients; 31 PROP and 38 OTR. In OTR there was an 8.8-point (-21.1, 3.6) SBP decrease (p ​= ​0.159) and in PROP there was a 30.8-point (-45.6, -16.0) SBP decrease (p ​= ​0.0002) with significant increases in heart rate (HR) and shock index (SI) (HR p ​= ​0.001, SI p ​< ​0.0001).

CONCLUSION

In patients without hypotension prior to intubation, we observed a statistically significant drop in the patients' SBP with use of propofol. In trauma critical care unit patients, we recommend considering an induction medication for unplanned intubation other than propofol.

The use of vasopressors to reduce post-intubation hypotension in critically ill adult patients undergoing emergent endotracheal intubation: a scoping review

INTRODUCTION

Patients requiring emergent endotracheal intubation are at higher risk of post-intubation hypotension due to altered physiology in critical illness. Post-intubation hypotension increases mortality and hospital length of stay, however, the impact of vasopressors on its incidence and outcomes is not known. This scoping review identified studies reporting hemodynamic data in patients undergoing emergent intubation to provide a literature overview on post-intubation hypotension in cohorts that did and did not receive vasopressors.

METHODS

A systematic search of CINAHL, Cochrane, EMBASE and PubMed-Medline was performed from database inception until September 28, 2023. Two independent reviewers completed the title and abstract screen, full text review and data extraction per PRISMA guidelines. Studies including patients < 18 years or intubations during cardiac arrest were excluded. Primary outcome was the presence of hypotension within 30 min of emergent intubation. Secondary outcomes included mortality at 1 h and in-hospital.

RESULTS

The systematic search yielded 13,126 articles, with 61 selected for final inclusion. There were 24,547 patients with a mean age of 57.2 years and a slight male predominance (63.8%). Respiratory failure was the most common intubation indication. Across 18 studies reporting on vasopressor use prior to intubation, 1171/7085 patients received vasopressors pre-intubation. Post-intubation hypotension occurred in 22.2% of patients across all studies, and in 34.3% of patients in studies where vasopressor administration pre-intubation was specifically reported. One-hour mortality of patients across all studies and within the vasopressor use studies was 1.2% and 1.6%, respectively. In-hospital mortality across studies was 21.5%, and 13.1% in studies which reported on vasopressor use pre-intubation.

CONCLUSION

Patients requiring emergent intubation have a high rate of post-intubation hypotension and in-hospital mortality. While there is an intuitive rationale for the use of vasopressors during emergent intubation, current evidence is limited to support a definitive change in clinical practice at this time.

Ventilation strategies in cardiogenic shock: insights from the FRENSHOCK observational registry

BACKGROUND

Despite scarce data, invasive mechanical ventilation (MV) is widely suggested as first-line ventilatory support in cardiogenic shock (CS) patients. We assessed the real-life use of different ventilation strategies in CS and their influence on short and mid-term prognosis.

METHODS

FRENSHOCK was a prospective registry including 772 CS patients from 49 centers in France. Patients were categorized into three groups according to the ventilatory supports during hospitalization: no mechanical ventilation group (NV), non-invasive ventilation alone group (NIV), and invasive mechanical ventilation group (MV). We compared clinical characteristics, management, and occurrence of death and major adverse event (MAE) (death, heart transplantation or ventricular assist device) at 30 days and 1 year between the three groups.

RESULTS

Seven hundred sixty-eight patients were included in this analysis. Mean age was 66 years and 71% were men. Among them, 359 did not receive any ventilatory support (46.7%), 118 only NIV (15.4%), and 291 MV (37.9%). MV patients presented more severe CS with more skin mottling, higher lactate levels, and higher use of vasoactive drugs and mechanical circulatory support. MV was associated with higher mortality and MAE at 30 days (HR 1.41 [1.05-1.90] and 1.52 [1.16-1.99] vs NV). No difference in mortality (HR 0.79 [0.49-1.26]) or MAE (HR 0.83 [0.54-1.27]) was found between NIV patients and NV patients. Similar results were found at 1-year follow-up.

CONCLUSIONS

Our study suggests that using NIV is safe in selected patients with less profound CS and no other MV indication. NCT02703038.

Alfentanil versus fentanyl for emergency department rapid sequence induction with ketamine: A-FAKT, a pilot randomized trial

BACKGROUND

Fentanyl is often administered during rapid sequence induction of anesthesia (RSI) in the emergency department (ED) to ameliorate the hypertensive response that may occur. Due to its more rapid onset, the use of alfentanil may be more consistent with both the onset time of the sedative and the commencement of laryngoscopy. As such, we compared the effect of alfentanil and fentanyl on post-induction hemodynamic changes when administered as part of a standardized induction regimen including ketamine and rocuronium in ED RSI.

METHODS

This was a double-blind pilot randomized controlled trial of adult patients requiring RSI in the ED of three urban Australian hospitals. Patients were randomized to receive either alfentanil or fentanyl in addition to ketamine and rocuronium for RSI. Non-invasive blood pressure and heart rate were measured immediately before and at two, four, and six minutes after induction. The primary outcome was the occurrence of at least one post-induction systolic blood pressure outside the pre-specified range of 100-160mmHg (with adjustment for patients with baseline hypertension). Secondary outcomes included hypertension, hypotension, hypoxia, first-pass intubation success, 30-day mortality, and the pattern of hemodynamic changes.

RESULTS

A total of 61 patients were included in the final analysis (31 in the alfentanil group and 30 in the fentanyl group). The primary outcome was met in 58% of the alfentanil group and 50% of the fentanyl group (difference 8%, 95% confidence interval: -17% to 33%). The 30-day mortality rate, first-pass success rate, and incidences of hypertension, hypotension, and hypoxia were similar between the groups. There were no significant differences in systolic blood pressure or heart rate between the groups at any of the measured time-points.

CONCLUSION

Alfentanil and fentanyl produced comparable post-induction hemodynamic changes when used as adjuncts to ketamine in ED RSI. Future studies could consider comparing different dosages of these opioids.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

TRIAL REGISTRATION

ClinicalTrials.gov identifier - NCT02105415.

A Comparative Study Between Intravenous Esmolol and Oral Clonidine in Attenuating Hyperdynamic Cardiovascular Response to Laryngoscopy and Endotracheal Intubation

Background In today's era of anesthesia, balanced anesthesia is the main basis of patient care and pain management. Of all the medications given during general anesthesia, premedication, induction agents, and muscle relaxants play a major role in keeping the hemodynamics properly under control. When laryngoscopy is performed to intubate, a pain stimulus will be generated, leading to a rise in blood pressure and heart rate. This stimulus can be avoided without any complications if appropriate premedication is given to the patient at the appropriate dosage. In this research, we compare the influence of injection esmolol and oral clonidine during the time of induction as premedications to suppress the hemodynamic response. Material and methods In a prospective randomized controlled trial, 90 patients were divided into three groups: Group E (esmolol) received 2 mg/kg IV esmolol diluted in 0.9% NS two minutes pre-anesthesia; Group C (clonidine) received oral clonidine 4 mcg/kg 90 minutes pre-anesthesia; and Group P (placebo) received IV normal saline and oral water. Blood pressure, heart rate, and mean arterial pressure were measured at baseline and seven subsequent time points. Results The study compared systolic blood pressure (SBP), mean arterial pressure (MAP), and diastolic blood pressure (DBP) changes over seven minutes in three groups, clonidine (Group C), placebo (Group P), and esmolol (Group E). At one minute, Group E showed a consistent MAP decrease from 95.21 mmHg to 85.92 mmHg, while Group C and Group P exhibited fluctuating trends. DBP decreased across all groups, with Group P ending highest (77.7 mmHg) and Group C lowest (66.8 mmHg). Group E's SBP decreased steadily from 126.2 mmHg to 118.0 mmHg, Group C decreased from 128 mmHg to 116.1 mmHg, and Group P showed more erratic fluctuations in SBP, DBP, and MAP. Conclusion These findings suggest that intravenous esmolol shows a good hemodynamic response having superior control over heart rate and getting the pressure under control quickly without major drop compared with the clonidine and placebo groups.

Prehospital SALAD Airway Technique in an Adolescent with Penetrating Trauma Case Report

We present a case of an adolescent patient with a penetrating gunshot wound to the mouth requiring endotracheal intubation via rapid sequence intubation in the prehospital setting. The team used video laryngoscopy (VL) to secure the airway; however, continuous bloody secretions increased the complexity of the procedure and required the application of the Suction-Assisted Laryngoscopy and Airway Decontamination (SALAD) method to facilitate intubation. By utilizing the SALAD procedure, the field of view on the VL camera remained unobscured, and the patient's airway remained clear, allowing for an uneventful intubation procedure. No episodes of hypoxia, hypotension, bradycardia, or obvious clinical signs of pulmonary aspiration occurred during the procedure. The patient was transported to a local Pediatric Level I trauma center, where he underwent emergent surgery to repair an esophageal laceration and was discharged to home 40 days later. This case highlights the importance of deliberate and proactive management of the contaminated airway in the prehospital setting. The SALAD technique replaces the Yankauer suction catheter with a larger bore suction catheter in conjunction with VL to perform gross decontamination of the mouth and airway before attempting intubation. This is followed by permanently placing the large bore suction catheter under constant suction in the posterior pharynx or esophagus to keep the VL camera unobscured by vomit or blood to facilitate intubation. After the intubation, the suction catheter may be removed unless ongoing suction is required. Keeping the VL camera unobscured during the procedure may improve first-pass intubation success rate.

The Clinical Usability Evaluation of an Attachable Video Laryngoscope in the Simulated Tracheal Intubation Scenario: A Manikin Study

The aim of this study was to assess the usefulness of an attachable video laryngoscope (AVL) by attaching a camera and a monitor to a conventional Macintosh laryngoscope (CML). Normal and tongue edema airway scenarios were simulated using a manikin. Twenty physicians performed tracheal intubations using CML, AVL, Pentax Airwayscope® (AWS), and McGrath MAC® (MAC) in each scenario. Ten physicians who had clinical experience in using tracheal intubation were designated as the skilled group, and another ten physicians who were affiliated with other departments and had little clinical experience using tracheal intubation were designated as the unskilled group. The time required for intubation and the success rate were recorded. The degree of difficulty of use and glottic view assessment were scored by participants. All 20 participants successfully completed the study. There was no difference in tracheal intubation success rate and intubation time in the normal airway scenario in both skilled and unskilled groups. In the experienced group, AWS had the highest success rate (100%) in the tongue edema airway scenario, followed by AVL (60%), MAC (60%), and CML (10%) (p = 0.001). The time required to intubate using AWS was significantly shorter than that with AVL (10.2 s vs. 19.2 s) or MAC (10.2 s vs. 20.4 s, p = 0.007). The difficulty of using AVL was significantly lower than that of CML (7.8 vs. 2.8; p < 0.001). For the experienced group, AVL was interpreted as being inferior to AWS but better than MAC. Similarly, in the unskilled group, AVL had a similar success rate and tracheal intubation time as MAC in the tongue edema scenario, but this was not statistically significant. The difficulty of using AVL was significantly lower than that of CML (8.8 vs. 3.3; p < 0.001). AVL may be an alternative for VL.

Risk factors for peri-intubation cardiac arrest: A systematic review and meta-analysis

BACKGROUND

Peri-intubation cardiac arrest (PICA) is an uncommon yet serious complication of intubation. Although some associated risk factors have been identified, the results have been inconsistent. The aim of this study was to systematically review the relevant research and examine the associated risk factors of PICA through meta-analysis.

METHODS

Studies examining the risk factors for PICA before 1 Nov. 2022 were identified through searches in MEDLINE (OvidSP) and EMBASE. The reported adjusted or unadjusted odds ratios (ORs) and risk ratios (RRs) were recorded. We calculated pooled ORs and created forest plots using a random-effects model to identify the statistically significant risk factors. We assessed the certainty of evidence for each risk factor.

RESULTS

Eight studies were included in the meta-analysis. Pre-intubation hypotension, with a pooled OR of 4.96 (95% confidence interval [C.I.]: 3.75-6.57), pre-intubation hypoxemia, with a pooled OR of 4.43 (95% C.I.: 1.24-15.81), and two or more intubation attempts, with a pooled OR of 1.88 (95% C.I.: 1.09-3.23) were associated with a significantly higher risk of PICA. The pooled incidence of PICA was 2.1% (95% C.I.: 1.5%-3.0%).

CONCLUSIONS

Pre-intubation hypotension, hypoxemia, and more intubation attempts are significant risk factors for PICA. The findings could help physicians identify patients at risk under the acute setting.

Validation of Difficult Airway Physiological Score (DAPS) in Critically Ill Adults Undergoing Endotracheal Intubation in the Emergency Department

Background

Critically ill patients have increased risk of cardiovascular collapse following endotracheal intubation due to physiological instability. This study aims to validate the Difficult Airway Physiological Score (DAPS) in adults to predict the risk of serious outcomes in the emergency department of a tertiary care private hospital.

Methods

This is a cohort study conducted in the emergency department (ED) from 2021 to 2022. Difficult Airway Physiological Score (DAPS) was derived from a sample of 1021 patients through a retrospective study. The variables in the score were age, gender, time of intubation, vitals and vomiting at presentation, pH <7.3, fever, physician's anticipation for patient decline, and agitation. The model performance was assessed prospectively on a separate dataset (n = 326) using train-test split method. Postintubation desaturation, hypotension, cardiac arrest, and mortality postintubation were the serious outcomes. ROC analysis, sensitivity, specificity, PPV, and NPV were used to assess score validity.

Results

Our study includes 326 patients, of which 123 (37.7%) were males and 203 (62.2%) were females. The sample was divided into high-risk (DAPS ≥10) group, n = 194 with mean age of 52 (SD = ±18) years, and low-risk (DAPS <10) group, n = 132 with mean age of 47.7 (SD = ±17.4) years. The shock index ≥0.9 was in 128 (66%), while it was <0.9 in low-risk n = 111 (84%), p value <0.001. Similarly, pH <7.3 was seen in 70 (36.1%) in high-risk group compared to 4 (3%) in low-risk group, p value <0.001. Cardiac arrest was observed in 56 (17.2%) patients, of which 45 (23.2%) were in high-risk and 11 (8.3%) in low-risk groups (p < 0.001). Hypotension was the primary outcome in the high-risk group 100 (51.5%) versus 32 (24.2%) in low-risk group (p < 0.001). The DAPS of 10 had an area under the curve of 0.865 (0.71-0.84). The sensitivity of DAPS was 78.5%, specificity 77.9%, and accuracy 78.2%.

Conclusion

The score can accurately predict serious outcomes in critically ill adult patients with physiologically difficult airway demonstrating good sensitivity and specificity.

Characteristics and Outcomes of Critically Ill Patients With Pulmonary Hypertension Who Undergo Endotracheal Intubation and Mechanical Ventilation

Background: Patients with pulmonary hypertension (PH) who undergo endotracheal intubation have an increased risk of adverse outcomes, but little is known regarding prognostic factors and there is limited evidence to guide management. We sought to define characteristics, prognostic factors, and outcomes of critically ill patients with PH who underwent intubation. Study Design: We performed a single-center retrospective cohort study of critically ill patients with group 1, 3 or 4 PH who underwent intubation. Results: Eighty-one patients were included. Patients had a median age of 56 years (interquartile range 44-65) and were predominantly female (n = 53, 65%) and Caucasian (n = 71, 88%). Forty-five (56%) had group 1 PH while 25 (31%) had group 3 PH and 11 (14%) had group 4 PH. Patients were admitted to the hospital for right ventricular failure (n = 21, 25.6%), sepsis (n = 18, 22.2%), and respiratory failure (n = 19, 23.1%). Hypoxemic respiratory failure (n = 54, 66.7%) was the most common indication for intubation. In-hospital mortality was 30.9% and 1-year mortality was 48.2%. All patients (11 of 11, 100%) intubated electively for intensive care unit procedures survived to hospital discharge while only 1 of 6 (16.7%) intubated in the setting of a cardiac arrest survived. After adjusting for right ventricular systolic pressure, pre-intubation PaO2 (odds ratio [OR] = 0.99, 95% confidence interval [CI] 0.97-1.00, P = .02) and postintubation PaO2 (OR = 0.97 per 1mm Hg, 95% CI 0.95 to 0.99, P = .003), pH (OR = 0.49 per 0.1 increase, 95% CI 0.29 to 0.80, P = .005) and PaCO2 (OR = 1.08 per 1mm Hg, 95% CI 1.02 to 1.14, P = .005) were significantly associated with in-hospital mortality. Results were similar when we excluded patients intubated electively or in the setting of cardiac arrest. Conclusions: Intubation in critically ill patients with PH is associated with significant in-hospital mortality and nearly 50% 1-year mortality. Potentially modifiable factors, such as peri-intubation gas exchange, are associated with an increased risk of death while other demographic and hemodynamic variables are not.

The Effect of Ketamine Versus Etomidate for Rapid Sequence Intubation on Maximum Sequential Organ Failure Assessment Score: A Randomized Clinical Trial

BACKGROUND

The use of induction agents for rapid sequence intubation (RSI) has been associated with hypotension in critically ill patients. Choice of induction agent may be important and the most commonly used agents are etomidate and ketamine.

OBJECTIVE

This study aimed to compare the effects of a single dose of ketamine vs. etomidate for RSI on maximum Sequential Organ Failure Assessment (SOFA) score and incidence of hypotension.

METHODS

This single-center, randomized, parallel-group trial compared the use of ketamine and etomidate for RSI in critically ill adult patients in the emergency department. The study was performed under Exception from Informed Consent. The primary outcome was the maximum SOFA score within 3 days of hospitalization.

RESULTS

A total of 143 patients were enrolled in the trial, 70 in the ketamine group and 73 in the etomidate group. Maximum median SOFA score for the ketamine group was 6.5 (interquartile range [IQR] 5-9) vs. 7 (IQR 5-9) for etomidate with no significant difference (-0.2; 95% CI -1.4 to 1.1; p = 0.79). The incidence of post-intubation hypotension was 28% in the ketamine group vs. 26% in the etomidate group (difference 2%; 95% CI -13% to 17%). There were no significant differences in intensive care unit outcomes. Thirty-day mortality rate for the ketamine group was 11% (8 deaths) and for the etomidate group was 21% (15 deaths), which was not statistically different.

CONCLUSIONS

There were no significant differences in maximum SOFA score or post-intubation hypotension between critically ill adults receiving ketamine vs. etomidate for RSI.

Pre-hospital tracheal intubation in severe traumatic brain injury: a systematic review and meta-analysis

BACKGROUND

Severe traumatic brain injury (TBI) continues to be a leading cause of death, particularly in young adults. Severe TBI contributes to significant socioeconomic burden secondary to the long-term disability, impacting the individual and their family, and wider society. The aim of this study was to determine whether establishing a pre-hospital definitive airway was beneficial to mortality and morbidity when compared with no pre-hospital airway.

METHODS

A literature search for all relevant studies was performed in Medline, Embase, Cochrane, EBSCO, and Emcare databases, with studies comparing effects of pre-hospital tracheal intubation vs noninvasive airway management on mortality in non-paediatric patients with severe TBI. There were 1025 studies that had abstracts screened from this search. This study was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

We identified 19 studies that met inclusion criteria. The included studies identified no significant difference in mortality between pre-hospital and no pre-hospital tracheal intubation, with an odds ratio of 1.07 (95% CI, 0.72-1.57; P<0.001). The meta-analysis identified a trend favouring pre-hospital tracheal intubation with respect to long-term morbidity, with an odds ratio of 0.92 (95% CI, 0.51-1.67; P<0.001).

CONCLUSIONS

Management of traumatic brain injuries is a constantly evolving field, with ever-changing target parameters regarding management. There is growing evidence, based on the RCTs and recent studies, that pre-hospital tracheal intubation in patients with severe TBI is beneficial if performed by well-trained, experienced practitioners in accordance with current TBI guidelines.

PROSPERO REGISTRATION

CRD42021234439.

Design, development, and face validation of an intubation simulation device using real-time force data feedback

Objectives

To develop a novel laryngoscope device capable of dynamically measuring force and torque measurements in real-time during intubation and to explore the efficacy of such a device through a face validation simulation.

Methods

The torque sensor laryngoscope is designed for use during intubation and is modeled after a standard, single-use plastic laryngoscope. After device calibration, a face validation study was performed with intubation experts in the field. Quantitative data (intubation force metrics) and qualitative data (expert feedback on the device) were collected from three intubations using a Mac blade and three intubations with the Miller blade.

Results

Three experts (two anesthesiologists and one otolaryngologist) participated in the study. The mean maximum force exerted with the Mac blade was 24.5 N (95% confidence interval [CI], 22.3-26.8). The average force exerted was 13.6 N (95% CI, 11.7-15.5). The average total suspension time was 13.1 s (95% CI, 10.4-15.8). The average total impulse was 164.6 N·s (95% CI, 147.9-181.4). The mean maximum force exerted with the Miller blade was 31.6 N (95% CI, 26.4-36.8). The average force exerted was 15.8 N (95% CI, 13.8-17.9). The average total suspension time was 11.3 s (95% CI, 9.9-12.6). The average total impulse was 216.2 N·s (95% CI, 186.5-245.9). The mean maximum force (p = .0265) and total impulse (p = .009) were significantly higher in the Miller blade trials than in the Mac blade trials. Survey results found that this device, while bulky, intubated similarly to standard-use models and has potential as an intubation teaching tool.

Conclusion

The torque sensor laryngoscope can measure and display real-time intubation force metrics for multiple laryngoscope blades. Initial validation studies showed a significantly lower maximum force and total impulse when intubating with the Mac blade than with the Miller blade. Face validation survey results were positive and suggested the potential for this device as a teaching tool.

Level of Evidence

Level 5.

Risk factors associated with peri-intubation cardiac arrest in the emergency department

BACKGROUND

Peri-intubation cardiac arrest is an uncommon, serious complication following endotracheal intubation in the emergency department. Although several risk factors have been previously identified, this study aimed to comprehensively identify risk factors associated with peri-intubation cardiac arrest.

METHODS

This retrospective, nested case-control study conducted from January 1, 2016 to December 31, 2020 analyzed variables including demographic characteristics, triage, and pre-intubation vital signs, medications, and laboratory data. Univariate analysis and multivariable logistic regression models were used to compare clinical factors between the patients with peri-intubation cardiac arrest and patients without cardiac arrest.

RESULTS

Of the 6983 patients intubated during the study period, 5130 patients met the inclusion criteria; 92 (1.8%) patients met the criteria for peri-intubation cardiac arrest and 276 were age- and sex-matched to the control group. Before intubation, systolic blood pressure and diastolic blood pressure were lower (104 vs. 136.5 mmHg, p < 0.01; 59.5 vs. 78 mmHg, p < 0.01 respectively) and the shock index was higher in the patients with peri-intubation cardiac arrest than the control group (0.97 vs. 0.83, p < 0.0001). Cardiogenic pulmonary edema as an indication for intubation (adjusted odds ratio [aOR]: 5.921, 95% confidence interval [CI]: 1.044-33.57, p = 0.04), systolic blood pressure < 90 mmHg before intubation (aOR: 5.217, 95% CI: 1.484-18.34, p = 0.01), and elevated lactate levels (aOR: 1.012, 95% CI: 1.002-1.022, p = 0.01) were independent risk factors of peri-intubation cardiac arrest.

CONCLUSIONS

Patients with hypotension before intubation have a higher risk of peri-intubation cardiac arrest in the emergency department. Future studies are needed to evaluate the influence of resuscitation before intubation and establish airway management strategies to avoid serious complications.

Optimizing Physiology During Prehospital Airway Management: An NAEMSP Position Statement and Resource Document

Airway management is a critical component of resuscitation but also carries the potential to disrupt perfusion, oxygenation, and ventilation as a consequence of airway insertion efforts, the use of medications, and the conversion to positive-pressure ventilation. NAEMSP recommends:Airway management should be approached as an organized system of care, incorporating principles of teamwork and operational awareness.EMS clinicians should prevent or correct hypoxemia and hypotension prior to advanced airway insertion attempts.Continuous physiological monitoring must be used during airway management to guide the timing of, limit the duration of, and inform decision making during advanced airway insertion attempts.Initial and ongoing confirmation of advanced airway placement must be performed using waveform capnography. Airway devices must be secured using a reliable method.Perfusion, oxygenation, and ventilation should be optimized before, during, and after advanced airway insertion.To mitigate aspiration after advanced airway insertion, EMS clinicians should consider placing a patient in a semi-upright position.When appropriate, patients undergoing advanced airway placement should receive suitable pharmacologic anxiolysis, amnesia, and analgesia. In select cases, the use of neuromuscular blocking agents may be appropriate.

A surgical needs assessment for airway rapid responses: A retrospective observational study

BACKGROUND

Airway rapid response (ARR) teams can be compiled of anesthesiologists, intensivists, otolaryngologists, general and thoracic surgeons, respiratory therapists, and nurses. The optimal composition of an ARR team is unknown but considered to be resource intensive. We sought to determine the type of technical procedures performed during an ARR activation to inform team composition.

METHODS

A large urban quaternary academic medical center retrospective review (2016-2019) of adult ARR patients was performed. Analysis included ARR demographics, patient characteristics, characteristics of preexisting tracheostomies, incidence of concomitant conditions, and procedures completed during an ARR event.

RESULTS

A total of 345 ARR patients with a median age of 60 years (interquartile range, 47-69 years) and a median time to ARR conclusion of 28 minutes (interquartile range, 14-47 minutes) were included. About 41.7% of the ARR had a preexisting tracheostomy. Overall, there were 130 procedures completed that can be performed by a general surgeon in addition to the 122 difficult intubations. These procedures included recannulation of a tracheostomy, operative intervention, new emergent tracheostomy or cricothyroidotomy, thoracostomy tube placement, initiation of extracorporeal membrane oxygenation, and pericardiocentesis.

CONCLUSION

Highly technical procedures are common during an ARR, including procedures related to tracheostomies. Surgeons possess a comprehensive skill set that is unique and comprehensive with respect to airway emergencies. This distinctive skill set creates an important role within the ARR team to perform these urgent technical procedures.

LEVEL OF EVIDENCE

Epidemiologic/prognostic, level III.

Introduction of a rapid sequence induction checklist and its effect on compliance to guidelines and complications

BACKGROUND

Current evidence for the conduct of rapid sequence induction (RSI) is weak. This increases the risk of clinicians modifying the RSI procedure according to personal preferences. Checklists may help increase compliance to best practice guidelines and reduce complication rates. Their value during RSI, a critical procedure in anaesthesia, is unknown. The aim of this study was to investigate compliance to local guidelines and frequency of RSI-related complications before and after introduction of an RSI checklist.

METHODS

This was a prospective, observational, pre- and post-intervention study conducted at two hospitals. There were two interventions: the first was a standardized educational lecture to all staff at both hospitals, consisting of an educational instruction of the checklist and general information about RSI, and the second intervention was the introduction of a RSI checklist. The checklist consisted of 16 items. Compliance to guidelines was categorized as high, moderate and low, and was assessed pre- and post-intervention. The frequency of RSI-related complications was also measured.

RESULTS

We registered 811 RSI procedures of which 412 were pre-intervention. After intervention, the proportion of procedures with high compliance to RSI guidelines increased from 49% to 70% (P < .001). The proportion with partial and low compliance decreased from 37% to 26% (P < .001) and 13% to 3.3% (P < .001) respectively. No change in RSI-related complication rates was detectable post-intervention (16.6%-16.7% P = .56).

CONCLUSION

The introduction of a structured RSI checklist significantly increased compliance to RSI guidelines. A change in RSI-related complications could not be detected due to the size of the study. A checklist may be a useful tool to reduce variance during the RSI procedure.

Emergency Airway Management Outside the Operating Room: Current Evidence and Management Strategies

Emergency airway management outside the operating room (OR) is often associated with an increased risk of airway related, as well as cardiopulmonary, complications which can impact morbidity and mortality. These emergent airways may take place in the intensive care unit (ICU), where patients are critically ill with minimal physiological reserve, or other areas of the hospital where advanced equipment and personnel are often unavailable. As such, emergency airway management outside the OR requires expertise at manipulation of not only the anatomically difficult airway but also the physiologically and situationally difficult airway. Adequate preparation and appropriate use of airway management techniques are important to prevent complications. Judicious utilization of pre- and apneic oxygenation is important as is the choice of medications to facilitate intubation in this at-risk population. Recent study in critically ill patients has shown that postintubation hemodynamic and respiratory compromise is common, independently associated with poor outcomes and can be impacted by the choice of drugs and techniques used. In addition to adequately preparing for a physiologically difficult airway, enhancing the ability to predict an anatomically difficult airway is essential in reducing complication rates. The use of artificial intelligence in the identification of difficult airways has shown promising results and could be of significant advantage in uncooperative patients as well as those with a questionable airway examination. Incorporating this technology and understanding the physiological, anatomical, and logistical challenges may help providers better prepare for managing such precarious airways and lead to successful outcomes. This review discusses the various challenges associated with airway management outside the OR, provides guidance on appropriate preparation, airway management skills, medication use, and highlights the role of a coordinated multidisciplinary approach to out-of-OR airway management.

Rapid Sequence Induction Strategies Among Critically Injured U.S. Military During the Afghanistan and Iraq Conflicts

INTRODUCTION

Rapid sequence intubation of patients experiencing traumatic hemorrhage represents a precarious phase of care, which can be marked by hemodynamic instability and pulseless arrest. Military combat trauma guidelines recommend reduced induction dose and early blood product resuscitation. Few studies have evaluated the role of induction dose and preintubation transfusion on hemodynamic outcomes. We compared rates of postintubation systolic blood pressure (SBP) of < 70 mm Hg, > 30% drop in SBP, pulseless arrest, and mortality at 24 hours and 30 days among patients who did and did not receive blood products before intubation and then examined if induction agent and dose influenced the same outcomes.

MATERIALS AND METHODS

A retrospective analysis was performed of battle-injured personnel presenting to surgical care facilities in Iraq and Afghanistan between 2004 and 2018. Those who received blood transfusions, underwent intubation, and had an Injury Severity Score of  ≥15 were included. Intubation for primary head, facial, or neck injury, burns, operative room intubations, or those with cardiopulmonary resuscitation in progress were excluded. Multivariable logistic regression was performed with unadjusted and adjusted odds ratios for the five study outcomes among patients who did and did not receive preintubation blood products. The same analysis was performed for patients who received full or excessive versus partial induction agent dose.

RESULTS

A total of 153 patients had a mean age of 24.9 (SD 4.5), Injury Severity Score 29.7 (SD 11.2), heart rate 122.8 (SD 24), SBP 108.2 (SD 26.6). Eighty-one (53%) patients received preintubation blood products and had similar characteristics to those who did not receive transfusions. Adjusted multivariate analysis found odds ratios as follows: 30% SBP decrease 9.4 (95% CI 2.3-38.0), SBP < 70 13.0 (95% CI 3.3-51.6), pulseless arrest 18.5 (95% CI 1.2-279.3), 24-hour mortality 3.8 (95% CI 0.7-21.5), and 30-day mortality 1.3 (0.4-4.7). In analysis of induction agent choice and comparison of induction agent dose, no statistically significant benefit was seen.

CONCLUSION

Within the context of this historical cohort, the early use of blood products conferred a statistically significant benefit in reducing postintubation hypotension and pulseless arrest among combat trauma victims exposed to traumatic hemorrhage. Induction agent choice and dose did not significantly influence the hemodynamic or mortality outcomes.

Utility of a Modified Oropharyngeal Airway for Performing Tracheal Intubation Using a Fiberoptic Bronchoscope and Video Stylet: A Randomized Crossover Trial Using a Manikin

Purpose

The purpose of this study was to assess if a modified airway (MA), developed by the authors, would act as a guide and improve the performance of intubation when used with a video stylet (VS) or fiberoptic bronchoscope (FOB) for endotracheal intubation.

Methods

This randomized crossover simulation study using manikins was conducted with 36 novice operators. Time to complete intubation, time to see the glottis, and success rate of intubation of each device were measured and compared with or without use of MA.

Results

For intubation using FOB with MA, the median time to complete intubation significantly reduced from 46 to 31 seconds with a medium effect size (p=0.004, r = 0.483), and the median time to see the glottis significantly reduced from 7 to 5 seconds with a medium effect size (p=0.032, r = 0.357). The overall success rate was not statistically different between FOB with MA (33/36, 91.7%) and FOB alone (31/36, 86.1%); however, the cumulative success rate over time for FOB with MA was higher than that for FOB alone (p=0.333). For intubation using VS, there were no differences in the time to see the glottis and time to complete intubation between VS with MA and VS alone (p=0.065 and p=0.926, respectively), and the cumulative success rate was not statistically significant (p=0.594).

Conclusion

Adjunct use of MA helped reduce time to complete intubation in FOB, but not in VS. If an inexperienced operator uses FOB, it would be helpful to use MA as an adjunct device.

Comparison of drugs used for intubation of pediatric trauma patients

PURPOSE

Rapid sequence intubation (RSI) drugs, such as propofol, affect clinical outcomes, but this has not been examined in the pediatric population. This descriptive study compares the outcomes associated with intubation drugs used in pediatric traumatic brain injury (TBI) patients.

METHODS

A retrospective chart review and descriptive analysis of intubated TBI patients, ages 0-17, admitted to Children's Hospital London Health Sciences Centre (LHSC) from January 2006-December 2016 was performed.

RESULTS

Out of 259 patients intubated, complete data was available for 107 cases. Average injury severity score was 28; 46 were intubated at LHSC, 55 at primary care site, and 6 on scene. Intubation attempts were recorded in 87 of 107 paper charts. First-pass intubation success rate was 88.5%. Propofol (n = 21), midazolam (n = 31), etomidate (n = 13), and ketamine (n = 7) were the most commonly used intubation drugs. Paralytics were used in 50% of patients. Following use of propofol, Pediatric Adjusted Shock Index was increased as a result of worsening hypotension. Mean total hospital length of stay was 21 days with 7.5 days in ICU. Survival was 87%.

CONCLUSION

Great variability exists in the use of induction agents and paralytics for RSI. Propofol was commonly used and is potentially associated with poorer clinical outcomes.

TYPE OF STUDY

Retrospective.

LEVEL OF EVIDENCE

IV.

The High-Risk Airway

The high-risk airway is a common presentation and a frequent cause of anxiety for emergency physicians. Preparation and planning are essential to ensure that these challenging situations are managed successfully. Difficult airways typically present as either physiologic or anatomic, each type requiring a specialized approach. Primary physiologic considerations are oxygenation, hemodynamics, and acid-base, whereas anatomic difficulty is overcome using proper positioning and skilled laryngoscopy to ensure success. It is essential to be comfortable performing alternative techniques to address varying presentations. Ultimately, competence in airway management hinges on consistent training, deliberate practice, and a dedication to excellence.

Simulation Training for Critical Care Airway Management: Assessing Translation to Clinical Practice Using a Small Video-Recording Device

BACKGROUND

Critical care airway management (CCAM) is a key skill for critical care physicians. Simulation-based training (SBT) may be an effective modality in training intensivists in CCAM.

RESEARCH QUESTION

Is SBT of critical care fellows an effective means of providing training in CCAM, in particular in urgent endotracheal intubation?

STUDY DESIGN AND METHODS

Thirteen first-year pulmonary critical care medicine (PCCM) fellows at an academic training program underwent SBT with a computerized patient simulator (CPS) in their first month of fellowship training. At the end of the training period, the fellows underwent video-based scoring using a 46-item checklist (of which 40 points could be scored) while performing a complete CCAM sequence on the CPS. They were then tested, using video-based scoring on their first real-life CCAM. Maintenance of skill at CCAM was assessed during the fellows' second and third year of training, using the same scoring method.

RESULTS

For the first-year fellows, the score on the CPS was 38.3 ± 0.75 SD out of a maximum score of 40. The score on their first real-life patient CCAM was 39.0 ± 0.81 SD (P = .003 for equivalence; 95% CI for difference between real-life patient CCAM and CPS scores, 0.011-1.373). Sixteen second- and third-year fellows were tested at a real-life CCAM event later in their fellowship to examine for maintenance of skill. The mean maintenance of skill score of this group was 38.7 ± 1.14 SD.

INTERPRETATION

Skill acquired through SBT of critical care fellows for CCAM transfers effectively to the real-life patient care arena. Second- and third-year fellows who had initially received SBT maintained skill at CCAM.

High-flow nasal cannula therapy as apneic oxygenation during endotracheal intubation in critically ill patients in the intensive care unit: a systematic review and meta-analysis

We conducted a systematic review and meta-analysis to assess the clinical efficacy of high-flow nasal cannula (HFNC) therapy as apneic oxygenation in critically ill patients who require endotracheal intubation in the intensive care unit (ICU). This systematic review and meta-analysis included six randomized controlled trials and a prospective study identified in PubMed, Embase, Cochrane Library, and the Web of Science until August 18, 2019. In this meta-analysis including 956 participants, HFNC was noninferior to standard of care during endotracheal intubation regarding incidence of severe hypoxemia, mean lowest oxygen saturation, and in-hospital mortality. HFNC significantly shortened the ICU stay by a mean of 1.8 days. In linear meta-regression interaction analysis, the risk ratio of severe hypoxemia decreased with increasing baseline partial oxygen pressure (PaO2) to fraction of inspired oxygen (FiO2) ratio. In subgroup analysis, HFNC significantly reduced the incidence of severe hypoxemia during endotracheal intubation in patients with mild hypoxemia (PaO2/FiO2> 200 mmHg; risk difference, -0.06; 95% confidence interval, -0.12 to -0.01; number needed to treat = 16.7). In conclusion, HFNC was noninferior to standard of care for oxygen delivery during endotracheal intubation and was associated with a significantly shorter ICU stay. The beneficial effect of HFNC in reducing the incidence of severe hypoxemia was observed in patients with mild hypoxemia.

Examining the Learning Practice of Emergency Airway Management Within an Academic Medical Center: Implications for Training and Improving Outcomes

Emergency airway management (EAM) is a "high stakes" clinical practice, associated with a significant risk of procedure-related complications and patient mortality. Learning within the EAM team practice is complex and challenging for trainees. Increasing concern for patient safety and changes in the structure of medical education have resulted in educational challenges and opportunities for improvement within the EAM team practice. This paper is divided into 3 sections that describe the past, present, and future of the EAM team learning practice within a large academic institution. Section 1 provides a brief overview of the evolution of the existing practice of EAM. Key features, goals, and challenges of the practice are outlined and a recently performed needs analysis to identify areas for improvement is described. Section 2 examines the underlying assumptions regarding learning within the existing practice and explores how these assumptions fit into major theories of learning. Section 3 proposes an idealized learning practice for the EAM team which includes the assumptions regarding learners, design of the learning environment, use of technology to enhance learning, and the means of assessment and measuring success. It is hoped that through this systematic exploration of the EAM team practice, learning efficacy and efficiency will be improved and remain adaptable for challenges in the future.

Noninvasive ventilation support during fiberoptic bronchoscopy-guided nasotracheal intubation effectively prevents severe hypoxemia

Purpose

This study investigated the feasibility and efficacy of continuous noninvasive ventilation (NIV) support with 100% oxygen using a specially designed face mask, for reducing desaturation during fiberoptic bronchoscopy (FOB)-guided intubation in critically ill patients with respiratory failure.

Materials and methods

This was a single-center prospective randomized study. All patients undergoing FOB-guided nasal tracheal intubation were randomized to bag-valve-mask ventilation or NIV for preoxygenation followed by intubation. The NIV group were intubated through a sealed hole in a specially designed face mask during continuous NIV support with 100% oxygen. Control patients were intubated with removal of the mask and no ventilatory support.

Results

We enrolled 106 patients, including 53 in each group. Pulse oxygen saturation (SpO₂) after preoxygenation (99% (96%–100%) vs. 96% (90%–99%), p = .001) and minimum SpO₂ during intubation (95% (87%–100%) vs. 83% (74%–91%), p < .01) were both significantly higher in the NIV compared with the control group. Severe hypoxemic events (SpO₂ < 80%) occurred less frequently in the NIV group than in controls (7.4% vs. 37.7%, respectively; p < .01).

Conclusions

Continuous NIV support during FOB-guided nasal intubation can prevent severe desaturation during intubation in critically ill patients with respiratory failure.

Trial registration: ClinicalTrials.gov, NCT02462668. Registered on 25 May 2015, https://www.clinicaltrials.gov/ct2/results?term=NCT02462668.

•

Our study is the first to evaluate NIV during FOB-guided nasotracheal intubation.

•

NIV support during FOB-guided nasotracheal intubation was effectively prevented severe desaturation during intubation.

•

We used a specially-designed intubation face mask to ensure that there was no interruption of NIV support during intubation.

Multiple intubation attempts in the emergency department and in-hospital mortality: A retrospective observational study

OBJECTIVES

Multiple intubation attempts in the Emergency Department (ED) have been associated with adverse events, but no study examined the influence of multiple intubation attempts on survival during hospitalization. Our aim was to compare one or more intubation attempts in the ED with risk of morbidity and mortality during hospitalization.

METHODS

We conducted a single center retrospective analysis of all patients undergoing emergency intubation in the ED and then admission to the hospital, during September 2010 to April 2016. The primary exposure was multiple intubation attempts. The primary outcome was mortality during hospitalization after intubation in the ED.

RESULTS

Of 181 patients, 63 (35%) required two or more attempts. We found no significant difference in mortality (p = 0.11), discharge from the hospital (p = 0.45), length of stay in hospital (p = 0.34), intensive care unit (ICU) (p = 0.32), ED (p = 0.81) or intubation period (p = 0.64), between one or more intubation attempts. After adjustment for the number of intubation trials, age, sex, intubation methods, first intubator training level and diagnostic category, use of medications during intubation was the only independent prognostic variable for hospital death (adjusted OR 0.21, 95%CI 0.1-0.45, p < 0.01). Number of trials to achieve successful intubation was not associated with discharge disposition (OR 0.77 95%CI 0.24-2.46, p = 0.66). Age (OR 0.95, 95%CI 0.93-0.98, p < 0.01) and brain injury as a diagnostic category (OR 0.15 95%CI 0.04-0.56, p < 0.01) were independent prognostic variables.

CONCLUSIONS

We found multiple intubation attempts were not associated with increased mortality and morbidity during hospitalization.

Alternatives to Rapid Sequence Intubation: Contemporary Airway Management with Ketamine

Endotracheal intubation (ETI) is a high-risk procedure commonly performed in emergency medicine, critical care, and the prehospital setting. Traditional rapid sequence intubation (RSI), the simultaneous administration of an induction agent and muscle relaxant, is more likely to harm patients who do not allow appropriate preparation and preoxygenation, have concerning airway anatomy, or severe hypoxia, acidemia, or hypotension. Ketamine, a dissociative anesthetic, can be used to facilitate two alternatives to RSI to augment airway safety in these scenarios: delayed sequence intubation - the use of ketamine to allow airway preparation and preoxygenation in the agitated patient; and ketamine-only breathing intubation, in which ketamine is used without a paralytic to facilitate ETI as the patient continues to breathe spontaneously. Ketamine may also provide hemodynamic benefits during standard RSI and is a valuable agent for post-intubation analgesia and sedation. When RSI is not an optimal airway management strategy, ketamine's unique pharmacology can be harnessed to facilitate alternative approaches that may increase patient safety.

Evaluation of the laryngoscopy view using the modified Cormack-Lehane scale during tracheal intubation in an intensive care unit. A prospective observational study

BACKGROUND AND OBJECTVIES

Tracheal intubation in the Intensive Care Unit is associated with a high incidence of difficult intubation and complications. This may be due to a poor view of the glottis during direct laryngoscopy. The aim of this study is to determine if there is a relationship between laryngoscopy view using the modified Cormack-Lehane scale with the incidence of difficult intubation and complications.

METHODS

All patients who were subjected to tracheal intubated with direct laryngoscopy in the Intensive Care Unit over a 45 month period were included in the study. In all patients, an evaluation was made of the laryngoscopy view using the modified Cormack-Lehane scale, as well as the technical difficulty (number of intubations at first attempt, operator-reported difficulty, need for a Frova introducer), and the incidence of complications (hypotension, hypoxia, oesophageal intubation).

RESULTS

A total of 360 patients were included. When the grade of the modified Cormack-Lehane scale was increased from 1 to 4, the incidence of first success rate intubation decreased (1: 97%, 2a: 94%, 2b: 80%, 3: 60%, 4: 0%, p<.001), the incidence of moderate and severe difficulty intubation increased (1: 2%, 2a: 4%, 2b: 36%, 3: 77%, 4: 100%, p<.001.), as well as the need for a Frova guide (1: 7%, 2a: 8%, 2b: 45%, 3: 60%, 4: 100%, p<.001). When the grade of the modified Cormack-Lehane scale increased from 1 to 4, the incidence of hypoxia<90% increased (1: 20%, 2a: 20%, 2b: 28%, 3: 47%, 4: 100%, p=.0073), as well as hypoxia<80% (1: 11%, 2a: 10%, 2b: 12%, 3: 27%, 4: 100%, p=.00398). No relationship was observed between the incidence of hypotension and the grade of the modified Cormack-Lehane scale (p=ns).

CONCLUSIONS

During tracheal intubation in the Intensive Care Unit a close relationship was found between a poor laryngoscopy view using the modified Cormack-Lehane scale and a higher difficulty technique of intubation. A relationship was found between the incidence of hypoxia with a higher grade in the modified Cormack-Lehane scale. No relationship was found between hypotension and the modified Cormack-Lehane scale.

The incidence of post-intubation hypertension and association with repeated intubation attempts in the emergency department

BACKGROUND

Studies in the non-emergency department (ED) settings have reported the relationships of post-intubation hypertension with poor patient outcomes. While ED-based studies have examined post-intubation hypotension and its sequelae, little is known about, post-intubation hypertension and its risk factors in the ED settings. In this context, we aimed to identify the incidence of post-intubation hypertension in the ED, and to test the hypothesis that repeated intubation attempts are associated with an increased risk of post-intubation hypertension.

METHODS

This study is a secondary analysis of the data from a multicenter prospective observational study of emergency intubations in 15 EDs from 2012 through 2016. The analytic cohort comprised all adult non-cardiac-arrest patients undergoing orotracheal intubation without pre-intubation hypotension. The primary exposure was the repeated intubation attempts, defined as ≥2 laryngoscopic attempts. The outcome was post-intubation hypertension defined as an increase in systolic blood pressure (sBP) of >20% along with a post-intubation sBP of >160 mmHg. To investigate the association of repeated intubation attempts with the risk of post-intubation hypertension, we fit multivariable logistic regression models adjusting for ten potential confounders and patient clustering within the EDs.

RESULTS

Of 3,097 patients, the median age was 69 years, 1,977 (64.0%) were men, and 991 (32.0%) underwent repeated intubation attempts. Post-intubation hypertension was observed in 276 (8.9%). In the unadjusted model, the incidence of post-intubation hypertension did not differ between the patients with single intubation attempt and those with repeated attempts (8.5% versus 9.8%, unadjusted P = 0.24). By contrast, after adjusting for potential confounders and patient clustering in the random-effects model, the patients who underwent repeated intubation attempts had a significantly higher risk of post-intubation hypertension (OR, 1.56; 95% CI, 1.11-2.18; adjusted P = 0.01).

CONCLUSIONS

We found that 8.9% of patients developed post-intubation hypertension, and that repeated intubation attempts were significantly associated with a significantly higher risk of post-intubation hypertension in the ED.

Sedative dose and patient variable impacts on postintubation hypotension in emergency airway management

PURPOSE

Postintubation hypotension (PIH) is an adverse event associated with poor outcomes in emergency department (ED) endotracheal intubation. This study aimed to evaluate the association between sedative dose adjustment and PIH during emergency airway management. We also investigated the impact of patient and procedural factors on the incidence of PIH.

MATERIALS AND METHODS

This was a single-center, retrospective study that used a prospectively collected registry of airway management performed at the ED from April 2014 to February 2017. Adult patients who received emergency endotracheal intubation were included. Multivariable logistic regression models were used to evaluate the association of PIH with sedative dose, patient variables, and procedural variables.

RESULTS

Overall, 689 patients were included, and 233 (33.8%) patients developed PIH. In the patients overall, multivariable logistic regression demonstrated that age > 70 years, shock index >0.8, arterial acidosis (pH < 7.2), intubation indication, and use of non-depolarizing neuromuscular blocking agent were significantly related to PIH. In patients overall, the sedative dose was not related to PIH (overdose; OR: 1.09, 95%CI: 0.57-2.06), (reduction; OR: 0.93, 95%CI: 0.61-1.42), (none used; OR: 1.28, 95%CI: 0.64-2.53). In subgroup analysis, ketamine dose was not related to PIH (overdose; OR: 0.81, 95%CI: 0.27-2.38, reduction; OR: 1.41, 95%CI: 0.78-2.54). Reduction of etomidate dose was significantly associated with decreased PIH (reduction; OR: 0.46, 95%CI: 0.22-0.98, overdose; OR: 1.77, 95%CI: 0.79-3.93).

CONCLUSIONS

PIH was mainly related to predisposing patient-related factors. Only adjustment of etomidate dose was associated with the incidence of PIH.

Propofol Versus Thiopental for Rapid-Sequence Induction in Isolated Systolic Hypertensive Patients: A Factorial Randomized Double-Blind Clinical Trial

Objective

We investigated the effects of four different anaesthesia induction protocols on the haemodynamic response to laryngoscopy and tracheal intubation during rapid-sequence induction (RSI) in systolic hypertensive patients.

Methods

One hundred and twenty hypertensive adult patients (systolic pressure >140 mmHg and diastolic pressure <90 mmHg), classified according to the American Association of Anesthesiologists as Class II and III were randomized into four groups. After pre-oxygenation for 3 minutes, induction and tracheal intubation were performed by blinded investigators, who also scored the intubation. Study groups composed of 30 patients each received lidocaine 1 mg kg^-1+thiopental 5 mg kg^-1 or remifentanil 1 μg kg^-1+thiopental 5 mg kg^-1 or lidocaine 1 mg kg^-1+propofol 2 mg kg^-1 or remifentanil 1 μg kg^-1+propofol 2 mg kg^-1. Succinylcholine was the muscle relaxant. Haemodynamic data were obtained before (baseline) and after induction, at intubation, and at 1, 3, 5 and 10 minutes after intubation. A rise or drop in the arterial blood pressure and heart rate >20% were considered to be significant.

Results

Patients receiving remifentanil+propofol had a reduction in the systolic and mean blood pressure >20% when compared to patients receiving remifentanil and thiopental: systolic values were 125±27 mmHg in the remifentanil+propofol group versus 153±35 mmHg in the remifentanil+thiopental group 1 minute after intubation (p<0.01); the mean arterial pressure values were 87±18 mmHg in the remifentanil+propofol group versus 105±25 mmHg in the remifentanil+thiopental group 1 minute after intubation (p<0.05).

Conclusion

Propofol was not superior to thiopental for the attenuation of the response to laryngoscopy and intubation during RSI in systolic hypertensive patients, whereas propofol+remifentanil combination appears to be so in terms of the heart rate stability.

Therapeutic measures in a moving ambulance: Qualitative study of professional opinions regarding prehospital emergencies

Background:

current organization of the prehospital emergency teams, decreasing the prehospital times, given the possibility of working during the patient’s transport and, therefore, the consequences that may result from the same improving the prognostic.

Objectives:

To explore the opinion of professional healthcare experts regarding prehospital emergencies arising when forced to assist a critical patient in a moving vehicle, based on a high-fidelity clinical simulation, as well as the factors influencing them.

Methods:

An exploratory study of content analysis with qualitative methodology, via semi-structured questionnaires that are self-completed anonymously, before and after the clinical simulation intervention in which participants intubate a mannequin in a moving ambulance. The sample consisted of 36 experts in prehospital emergencies from the province of Alicante (Spain). Codification and assessment of the data obtained was carried out via triangulation, respecting the language and literal expressions of the participants.

Results:

Thirty-two pre- and post-intervention questionnaires were completed. Four different units of meaning or categories emerged which were organized based on two thematic structures, from the perspective of professional and patient needs. Twenty-three participants had never previously intubated in a moving vehicle.

Discussion:

Working in a moving vehicle may be yet another aspect to consider in the specialized teaching–learning process of prehospital emergency medicine.

Conclusion:

Based on the need to decrease prehospital assistance times, a new paradigm has been opened in prehospital emergencies with the possibility of being able to safely assist our patients during their transport on a moving ambulance or helicopter. It will be necessary further research in the future.

Evaluation of Physiologic Alterations during Prehospital Paramedic-Performed Rapid Sequence Intubation

OBJECTIVE

Physiologic alterations during rapid sequence intubation (RSI) have been studied in several emergency airway management settings, but few data exist to describe physiologic alterations during prehospital RSI performed by ground-based paramedics. To address this evidence gap and provide guidance for future quality improvement initiatives in our EMS system, we collected electronic monitoring data to evaluate peri-intubation vital signs changes occurring during prehospital RSI.

METHODS

Electronic patient monitor data files from cases in which paramedic RSI was attempted were prospectively collected over a 15-month study period to supplement the standard EMS patient care documentation. Cases were analyzed to identify peri-intubation changes in oxygen saturation, heart rate, and blood pressure.

RESULTS

Data from 134 RSI cases were available for analysis. Paramedic-assigned prehospital diagnostic impression categories included neurologic (42%), respiratory (26%), toxicologic (22%), trauma (9%), and cardiac (1%). The overall intubation success rate (95%) and first-attempt success rate (82%) did not differ across diagnostic impression categories. Peri-intubation desaturation (SpO₂ decrease to below 90%) occurred in 43% of cases, and 70% of desaturation episodes occurred on first-attempt success. The incidence of desaturation varied among patient categories, with a respiratory diagnostic impression associated with more frequent, more severe, and more prolonged desaturations, as well as a higher incidence of accompanying cardiovascular instability. Bradycardia (HR decrease to below 60 bpm) occurred in 13% of cases, and 60% of bradycardia episodes occurred on first-attempt success. Hypotension (systolic blood pressure decrease to below 90 mmHg) occurred in 7% of cases, and 63% of hypotension episodes occurred on first-attempt success. Peri-intubation cardiac arrest occurred in 2 cases, one of which was on first-attempt success. Only 11% of desaturations and no instances of bradycardia were reflected in the standard EMS patient care documentation.

CONCLUSIONS

In this study, the majority of peri-intubation physiologic alterations occurred on first-attempt success, highlighting that first-attempt success is an incomplete and potentially deceptive measure of intubation quality. Supplementing the standard patient care documentation with electronic monitoring data can identify unrecognized physiologic instability during prehospital RSI and provide valuable guidance for quality improvement interventions.

The pressure exerted on the tongue during intubation with simultaneous cervical spine immobilisation: a comparison between four videolaryngoscopes and the Macintosh laryngoscope-a manikin study

Excessive pressures exerted on the tongue during intubation may be associated with serious complications and may make intubation more difficult. The aim of this study was to evaluate five different intubating devices in the hands of experienced anaesthetists during simulated conditions of reduced cervical spine mobility. Forty senior anaesthetists participated in the study (female = 18, male = 22). The mean pressure exerted on the tongue during intubation was recorded with a standard manometer. The overall intubation success rate as well as the difference in exerted pressures between female and male anaesthetists were also assessed. The five studied devices were used by each participant and they were randomly chosen. Each anaesthetists participating in the study had over 15 years of clinical anaesthetic practice. The mean pressure exerted on the tongue during intubation was significantly lower when the videolaryngoscopes (VLs) were used (p < 0.0001 for each of the studied VL). There were failed intubation attempts with all of the studied devices, the highest failure rate was in the Airtraq® group, 10 in 40 (25%). Female anaesthetists exerted lower pressures during intubation with all studied devices (except the Airtraq®). However, the difference was only significant for the Macintosh laryngoscope (p = 0.0083). The blades of VLs exerted lower pressures on the tongue during intubation than the Macintosh laryngoscope blade. Their use may be associated with less complications. Furthermore, male anaesthetists exerted higher pressures on the soft tissues although this was neither statistically nor clinically significant. There was higher failed intubation rate in the male anaesthetist group.

Mechanically Ventilating the Severe Asthmatic

The management of the critically ill patients with asthma can be rather challenging. Potentially devastating complications relating to this presentation include hypoxemia, worsening bronchospasm, pulmonary aspiration, tension pneumothorax, dynamic hyperinflation, hypotension, dysrhythmias, and seizures. In contrast to various other pathologies requiring mechanical ventilation, acute asthma is generally associated with better outcomes. This review serves as a practical guide to the physician managing patients with severe acute asthma requiring mechanical ventilation. In addition to specifics relating to endotracheal intubation, we also discuss the interpretation of ventilator graphics, the recommended mode of ventilation, dynamic hyperinflation, permissive hypercapnia, as well as the role of extracorporeal membrane oxygenation and noninvasive mechanical ventilation.

Factors and outcomes associated with inpatient cardiac arrest following emergent endotracheal intubation

BACKGROUND

Inpatient peri-intubation cardiac arrest (PICA) following emergent endotracheal intubation (ETI) is an uncommon but potentially preventable type of cardiac arrest (CA). Limited published data exist describing factors associated with inpatient PICA and patient outcomes. This study identifies risk factors associated with PICA among hospitalized patients emergently intubated out of the operating room and compares PICA to other types of inpatient CA.

METHODS

Retrospective case-control study of patients at our institution over a five-year period. Cases were defined as inpatients emergently intubated outside of the operating room that experienced cardiac arrest within 20min after ETI. The control group consisted of inpatients emergently intubated out of the operating room without CA. Predictors of PICA were identified through univariate and multivariate analysis. Clinical outcomes were compared between PICA and other inpatient CAs, identified through a prospectively enrolled CA registry at our institution.

RESULTS

29 episodes of PICA occurred over 5 years, accounting for 5% of all inpatient arrests. Shock index ≥1.0, intubation within one hour of nursing shift change, and use of succinylcholine were independently associated with PICA. Sustained ROSC, survival to discharge, and neurocognitive outcome did not differ significantly between groups.

CONCLUSION

Patients outcomes following PICA were comparable to other causes of inpatient CA. Potentially modifiable factors were associated with PICA. Hemodynamic resuscitation, optimized staffing strategies, and possible avoidance of succinylcholine were associated with decreased risk of PICA. Clinical trials testing targeted strategies to optimize peri-intubation care are needed to identify effective interventions to prevent this potentially avoidable type of CA.

Increased mortality in trauma patients who develop postintubation hypotension

BACKGROUND

Postintubation hypotension (PIH) is common and associated with poor outcomes in critically ill patient populations requiring emergency endotracheal intubation (ETI). The importance of PIH in the trauma population remains unclear. The objective of this study was to determine the prevalence of PIH in trauma patients and assess the association of PIH with patient outcomes.

METHODS

Retrospective case series of adult (≥16 years) patients who were intubated on arrival at a tertiary trauma center in Halifax, Nova Scotia, Canada, between 2000 and 2015. Data were collected from the Nova Scotia Trauma Registry and patient chart, and included demographics, comorbidities, trauma characteristics, intubation time, as well as all fluids, medications, adverse events, interventions, and vital signs during the 15 minutes before/after ETI. We evaluated the prevalence of PIH and created a logistic regression model to determine likelihood of mortality in the PIH and non-PIH groups after controlling for patient and provider characteristics.

RESULTS

Overall, 477 patients required ETI on assessment by the trauma service, of which 444 patients met eligibility criteria and were included in the analysis. The prevalence of PIH was 36.3% (161 of 444) in our study population. In-hospital mortality occurred in 29.8% (48 of 161) of patients in the PIH group, compared with 15.9% (45 of 283) of patients in the non-PIH group (p = 0.001). Development of PIH was associated with increased mortality in the emergency department (adjusted odds ratio, 3.45; 95% confidence interval, 1.42-8.36) and in-hospital (adjusted odds ratio, 1.83; 95% confidence interval, 1.01-3.31).

CONCLUSION

In our study of trauma patients requiring ETI, development of PIH was common (36.3%) and associated with increased mortality. Intubation practices in critically ill trauma patients is an important patient safety issue that requires further investigation.

LEVEL OF EVIDENCE

Prognostic and epidemiological, level III; Level IV, Therapeutic.

Assessing anesthesiology residents' out-of-the-operating-room (OOOR) emergent airway management

BACKGROUND

At many academic institutions, anesthesiology residents are responsible for managing emergent intubations outside of the operating room (OOOR), with complications estimated to be as high as 39%. In order to create an OOOR training curriculum, we evaluated residents' familiarity with the content and correct adherence to the American Society of Anesthesiologists' Difficult Airway Algorithm (ASA DAA).

METHODS

Residents completed a pre-simulation multiple-choice survey measuring their understanding and use of the DAA. Residents then managed an emergent, difficult OOOR intubation in the simulation center, where two trained reviewers assessed performance using checklists. Post-simulation, the residents completed a survey rating their behaviors during the simulation. The primary outcome was comprehension and adherence to the DAA as assessed by survey responses and behavior in the simulation.

RESULTS

Sixty-three residents completed both surveys and the simulation. Post-survey responses indicated a shift toward decreased self-perceived familiarity with the DAA content compared to pre-survey responses. During the simulation, 22 (35%) residents were unsuccessful with intubation. Of these, 46% placed an LMA and 46% prepared for cricothyroidotomy. Nineteen residents did not attempt intubation. Of these, only 31% considered LMA placement, and 26% initiated cricothyroidotomy.

CONCLUSIONS

Many anesthesiology residency training programs permit resident autonomy in managing emergent intubations OOOR. Residents self-reported familiarity with the content of and adherence to the DAA was higher than that observed during the simulation. Curriculum focused on comprehension of the DAA, as well as improving communication with higher-level physicians and specialists, may improve outcomes during OOORs.