Hemodynamic consequences of ketamine vs etomidate for endotracheal intubation in the air medical setting

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.

A systematic review and meta-analysis of the hemodynamic effects of etomidate versus other sedatives in patients undergoing rapid sequence intubation

INTRODUCTION

Rapid sequence intubation is an airway rescue and protection technique in which different sedatives are used to perform orotracheal intubation. Etomidate, due to its pharmacokinetic and pharmacodynamic qualities, particularly hemodynamic stability, is the most widely used sedative in this scenario. However, its superiority over other sedatives is controversial.

MATERIALS AND METHODS

We performed a meta-analysis using a pre-designed protocol and PRISMA guidelines to evaluate the mean difference between systolic blood pressure before and after administration of the sedative. We also analyzed the relative risks of hypotension.

RESULTS

Ten studies were included. The incidence of hypotension in patients receiving etomidate ranged from 6.4% to 75.2%, and between 24.0% and 65.9% in patients receiving other sedatives. No significant differences were found in the mean difference in systolic blood pressure during pre-intubation 0.01 mm Hg (95% CI: -0.90; 0.92) or in post-intubation 0.98 mmHg (95% CI: -0.24; 2.20). The relative risk analysis showed that the risk of hypotension is equal to an RR of 1.19 (95% CI: 0.92-1.54) between those who received etomidate and those who received the other sedatives.

CONCLUSIONS

The risk of hypotension after rapid intubation sequence with etomidate does not differ significantly compared to other sedatives. However, the studies included in this review were heterogeneous.

Ketamine is not associated with more post-intubation hypotension than etomidate in patients undergoing endotracheal intubation

INTRODUCTION

Emergency department (ED) patients undergoing emergent tracheal intubation often have multiple physiologic derangements putting them at risk for post-intubation hypotension. Prior work has shown that post-intubation hypotension is independently associated with increased morbidity and mortality. The choice of induction agent may be associated with post-intubation hypotension. Etomidate and ketamine are two of the most commonly used agents in the ED, however, there is controversy regarding whether either agent is superior in the setting of hemodynamic instability. The goal of this study is to determine whether there is a difference in the rate of post-intubation hypotension who received either ketamine or etomidate for induction. Additionally, we provide a subgroup analysis of patients at pre-existing risk of cardiovascular collapse (identified by pre-intubation shock index (SI) > 0.9) to determine if differences in rates of post-intubation hypotension exist as a function of sedative choice administered during tracheal intubation in these high-risk patients. We hypothesize that there is no difference in the incidence of post-intubation hypotension in patients who receive ketamine versus etomidate.

METHODS

A retrospective cohort study was conducted on a database of 469 patients having undergone emergent intubation with either etomidate or ketamine induction at a large academic health system. Patients were identified by automatic query of the electronic health records from 1/1/2016-6/30/2019. Exclusion criteria were patients <18-years-old, tracheal intubation performed outside of the ED, incomplete peri-intubation vital signs, or cardiac arrest prior to intubation. Patients at high risk for hemodynamic collapse in the post-intubation period were identified by a pre-intubation SI > 0.9. The primary outcome was the incidence of post-intubation hypotension (systolic blood pressure < 90 mmHg or mean arterial pressure < 65 mmHg). Secondary outcomes included post-intubation vasopressor use and mortality. These analyses were performed on the full cohort and an exploratory analysis in patients with SI > 0.9. We also report adjusted odds ratios (aOR) from a multivariable logistic regression model of the entire cohort controlling for plausible confounding variables to determine independent factors associated with post-intubation hypotension.

RESULTS

A total of 358 patients were included (etomidate: 272; ketamine: 86). The mean pre-intubation SI was higher in the group that received ketamine than etomidate, (0.97 vs. 0.83, difference: -0.14 (95%, CI -0.2 to -0.1). The incidence of post-intubation hypotension was greater in the ketamine group prior to SI stratification (difference: -10%, 95% CI -20.9% to -0.1%). Emergency physicians were more likely to use ketamine in patients with SI > 0.9. In our multivariate logistic regression analysis, choice of induction agent was not associated with post-intubation hypotension (aOR 1.45, 95% CI 0.79 to 2.65). We found that pre-intubation shock index was the strongest predictor of post-intubation hypotension.

CONCLUSION

In our cohort of patients undergoing emergent tracheal intubation, ketamine was used more often for patients with an elevated shock index. We did not identify an association between the incidence of post-intubation hypotension and induction agent between ketamine and etomidate. Patients with an elevated shock index were at higher risk of cardiovascular collapse regardless of the choice of ketamine or etomidate.

Prehospital Drug Assisted Airway Management: An NAEMSP Position Statement and Resource Document

Airway management is a critical intervention for patients with airway compromise, respiratory failure, and cardiac arrest. Many EMS agencies use drug-assisted airway management (DAAM) - the administration of sedatives alone or in combination with neuromuscular blockers - to facilitate advanced airway placement in patients with airway compromise or impending respiratory failure who also have altered mental status, agitation, or intact protective airway reflexes. While DAAM provides several benefits including improving laryngoscopy and making insertion of endotracheal tubes and supraglottic airways easier, DAAM also carries important risks. NAEMSP recommends:DAAM is an appropriate tool for EMS clinicians in systems with clear guidelines, sufficient training, and close EMS physician oversight. DAAM should not be used in settings without adequate resources.EMS physicians should develop clinical guidelines informed by evidence and oversee the training and credentialing for safe and effective DAAM.DAAM programs should include best practices of airway management including patient selection, assessmenct and positioning, preoxygenation strategies including apneic oxygenation, monitoring and management of physiologic abnormalities, selection of medications, post-intubation analgesia and sedation, equipment selection, airway confirmation and monitoring, and rescue airway techniques.Post-DAAM airway placement must be confirmed and continually monitored with waveform capnography.EMS clinicians must have the necessary equipment and training to manage patients with failed DAAM, including bag mask ventilation, supraglottic airway devices and surgical airway approaches.Continuous quality improvement for DAAM must include assessment of individual and aggregate performance metrics. Where available for review, continuous physiologic recordings (vital signs, pulse oximetry, and capnography), audio and video recordings, and assessment of patient outcomes should be part of DAAM continuous quality improvement.

Etomidate versus ketamine for emergency endotracheal intubation: a randomized clinical trial

PURPOSE

Etomidate and ketamine are hemodynamically stable induction agents often used to sedate critically ill patients during emergency endotracheal intubation. In 2015, quality improvement data from our hospital suggested a survival benefit at Day 7 from avoidance of etomidate in critically ill patients during emergency intubation. In this clinical trial, we hypothesized that randomization to ketamine instead of etomidate would be associated with Day 7 survival after emergency endotracheal intubation.

METHODS

A prospective, randomized, open-label, parallel assignment, single-center clinical trial performed by an anesthesiology-based Airway Team under emergent circumstances at one high-volume medical center in the United States. 801 critically ill patients requiring emergency intubation were randomly assigned 1:1 by computer-generated, pre-randomized sealed envelopes to receive etomidate (0.2-0.3 mg/kg, n = 400) or ketamine (1-2 mg/kg, n = 401) for sedation prior to intubation. The pre-specified primary endpoint of the trial was Day 7 survival. Secondary endpoints included Day 28 survival.

RESULTS

Of the 801 enrolled patients, 396 were analyzed in the etomidate arm, and 395 in the ketamine arm. Day 7 survival was significantly lower in the etomidate arm than in the ketamine arm (77.3% versus 85.1%, difference - 7.8, 95% confidence interval - 13, - 2.4, p = 0.005). Day 28 survival rates for the two groups were not significantly different (etomidate 64.1%, ketamine 66.8%, difference - 2.7, 95% confidence interval - 9.3, 3.9, p = 0.294).

CONCLUSION

While the primary outcome of Day 7 survival was greater in patients randomized to ketamine, there was no significant difference in survival by Day 28.

Etomidate Compared to Ketamine for Induction during Rapid Sequence Intubation: A Systematic Review and Meta-analysis

AIMS AND OBJECTIVES

The objective of the study was to compare the safety and efficacy of etomidate and ketamine as induction agents for rapid sequence intubation (RSI) in acutely ill patients in emergency department and prehospital settings with respect to post-induction hypotension and first-pass intubation success during RSI.

MATERIALS AND METHODS

For this systematic review and meta-analysis, we searched PubMed, Embase, Cochrane, and ClinicalTrials.gov between database inception and June 1, 2021. Articles were included if they compared safety and efficacy of etomidate vs ketamine as induction agents, in patients undergoing RSI in emergency department and prehospital settings, without any restrictions on study design. The outcome measures were incidence of post-induction hypotension and first-pass intubation success. The dichotomous outcomes were assessed for odds ratio (OR) with 95% confidence interval (CI) using random-effects meta-analysis.

RESULTS

Of 87 records identified, 9 were eligible, all assessed as having a low to moderate risk of overall bias. Six studies, including 12,060 patients from prehospital emergency medical services, air medical transport, and emergency department settings, compared post-induction hypotension incidence between etomidate and ketamine groups. The meta-analysis showed that etomidate was associated with decreased risk of post-induction hypotension compared to ketamine (OR: 0.53; 95% CI: 0.31-0.91; I 2 = 68%). Seven studies, including 15,574 patients, reported on the rate of first-pass intubation success with etomidate vs ketamine. In the pooled analysis, no differences were seen in first-pass intubation success during RSI using etomidate vs ketamine as the induction agent (OR: 1.13; 95% CI: 0.95-1.36; I 2 = 16%).

CONCLUSION

The use of etomidate for induction during RSI is associated with a decreased risk of post-induction hypotension as compared to the use of ketamine, without an impact on the first-pass intubation success rate.

HOW TO CITE THIS ARTICLE

Sharda SC, Bhatia MS. Etomidate Compared to Ketamine for Induction during Rapid Sequence Intubation: A Systematic Review and Meta-analysis. Indian J Crit Care Med 2022;26(1):108-113.

The association of ketamine induction with blood pressure changes in paramedic rapid sequence intubation of out-of-hospital traumatic brain injury

INTRODUCTION

Rapid sequence intubation (RSI) is used to secure the airway of traumatic brain injury (TBI) patients, with ketamine frequently used for induction. Studies show that ketamine-induction RSI might cause lower blood pressures when compared to etomidate. It is not clear if the results from that research can be extrapolated to systems that use different dosing regimens for ketamine RSI. Ambulance Victoria authorized the use of 1.5 mg/kg ketamine in January 2015 for head injury RSI induction by road-based paramedics. This study aims to examine whether systolic blood pressure changed when ketamine was introduced for prehospital head injury RSI.

METHODS

This study was a retrospective analysis of out-of-hospital suspected TBI that received RSI by paramedics. Our analysis employs an interrupted time-series analysis (ITSA), which is a quasi-experimental method that tested whether hypotension and systolic blood pressures changed after the switch to ketamine induction in 2015. This ITSA utilized an ordinary least squares regression on complete observations using Newey-West standard errors.

RESULTS

During the study period, paramedics performed RSI in 8,613 patients, and 1,759 (20.4%) had a TBI. Ketamine usage increased by 52.7% in January 2015 (p < 0.001) after road-based paramedics were authorized to use ketamine induction. This analysis found significant 5% increase in post-RSI hypotension (p = 0.046) after the introduction of ketamine, and thereafter the incidence of post-RSI hypotension increased steadily by 0.5% every 3 months (p = 0.004). Concurrently, changes in systolic blood pressure, as measured by the interval just before induction to the last measured on scene, show an average decrease of 7.8 mm Hg (p = 0.04) at the start of 2015 with the ketamine rollout.

CONCLUSIONS

This ITSA shows that postinduction hypotension and also decreases in systolic blood pressures became evident after the introduction of ketamine. Further research to investigate the association between ketamine induction and survival is needed.

Hemodynamic Effects of Ketamine Versus Etomidate for Prehospital Rapid Sequence Intubation

OBJECTIVE

Rapid sequence intubation (RSI) is often required in managing critically ill patients in the prehospital setting. Although etomidate is a commonly used induction agent for RSI, ketamine has gained new interest in prehospital management with reported neutral hemodynamic effects. Limited data exist to support ketamine as an alternative to etomidate, particularly in the prehospital setting. The purpose of this study was to evaluate hemodynamic changes after the administration of ketamine versus etomidate in prehospital RSI.

METHODS

This retrospective study evaluated adult patients undergoing prehospital RSI over 13 months within a regional emergency transport medicine service. Hypotension was defined as a 20% decrease in systolic blood pressure (SBP) within 15 minutes of receiving ketamine or etomidate. Hemodynamic data were collected 15 minutes before and 15 minutes after administration or until additional sedative medications were given. Data were analyzed using SPSS software (Version 21; IBM Corp, Armonk, NY), with P < .05 considered significant.

RESULTS

One hundred thirteen patients met the inclusion criteria (ketamine, n = 33; etomidate, n = 80), with the primary reasons for intubation being respiratory failure and trauma. There was no difference between the incidence of patients who experienced a 20% decrease in SBP (16% etomidate vs. 18% ketamine, P = .79). There were no significant differences in SBP pre- to postadministration between ketamine and etomidate.

CONCLUSION

No hemodynamic differences occurred between patients who received ketamine versus etomidate for prehospital RSI. Neither drug was associated with an increased need for additional sedatives, and neither drug was associated with an increased first-pass intubation success rate. Larger, prospective, powered studies are required to identify patients who may benefit from either ketamine or etomidate.

Airway Management in the Critically Ill Patient

Purpose of Review

This paper will evaluate the recent literature and best practices in airway management in critically ill patients.

Recent Findings

Cardiac arrest remains a common complication of intubation in these high-risk patients. Patients with desaturation or peri-intubation hypotension are at high risk of cardiac arrest, and each of these complications have been reported in up to half of all intubations in critically ill patient populations.

Summary

There have been significant advances in preoxygenation and devices available for performing laryngoscopy and rescue oxygenation. However, the risk of cardiovascular collapse remains concerningly high with few studies to guide therapeutic maneuvers to reduce this risk.

Ketamine Versus Etomidate and Peri-intubation Hypotension: A National Emergency Airway Registry Study

BACKGROUND

The hemodynamic impact of induction agents is a critically important consideration in emergency intubations. We assessed the relationship between peri-intubation hypotension and the use of ketamine versus etomidate as an induction agent for emergency department (ED) intubation.

METHODS

We analyzed ED intubation data for patients aged >14 years from the National Emergency Airway Registry performed in 25 EDs during 2016 through 2018. We excluded patients with preintubation hypotension (systolic blood pressure <100 mm Hg) or cardiac arrest prior to intubation. The primary outcome was peri-intubation hypotension. Secondary outcomes included interventions for hypotension (e.g., intravenous fluids or vasopressors). We report adjusted odds ratios (aOR) from multivariable logistic regression models controlling for patient demographics, difficult airway characteristics, and intubation modality.

RESULTS

There were 738 encounters with ketamine and 6,068 with etomidate. Patients receiving ketamine were more likely to have difficult airway characteristics (effect size difference = 8.8%, 95% confidence interval [CI] = 5.3% to 12.4%) and to undergo intubation with video laryngoscopy (8.1%, 95% CI = 4.4% to 12.0%). Peri-intubation hypotension incidence was 18.3% among patients receiving ketamine and 12.4% among patients receiving etomidate (effect size difference = 5.9%, 95% CI = 2.9% to 8.8%). Patients receiving ketamine were more likely to receive treatment for peri-intubation hypotension (effect size difference = 6.5%, 95% CI = 3.9% to 9.3%). In logistic regression analyses, patients receiving ketamine remained at higher risk for peri-intubation hypotension (aOR = 1.4, 95% CI = 1.2 to 1.7) and treatment for hypotension (aOR = 1.8, 95% CI = 1.4 to 2.0). There was no difference in the aOR of hypotension between patients receiving ketamine at doses ≤1.0 mg/kg versus >1.0 mg/kg or patients receiving etomidate at doses ≤0.3 mg/kg versus >0.3 mg/kg.

CONCLUSIONS

Pending additional data, our results suggest that clinicians should not necessarily prioritize ketamine over etomidate based on concern for hemodynamic compromise among ED patients undergoing intubation.

High-Risk Airway Management in the Emergency Department: Diseases and Approaches, Part II

BACKGROUND

Successful airway management is critical to the practice of emergency medicine. Thus, emergency physicians must be ready to optimize and prepare for airway management in critically ill patients with a wide range of physiologic challenges. Challenges in airway management commonly encountered in the emergency department are discussed using a pearl and pitfall discussion in this second part of a 2-part series.

OBJECTIVE

This narrative review presents an evidence-based approach to airway and patient management during endotracheal intubation in challenging cases commonly encountered in the emergency department.

DISCUSSION

Adverse events during emergent airway management are common with postintubation cardiac arrest, reported in as many as 1 in 25 intubations. Many of these adverse events can be avoided by proper identification and understanding the underlying physiology, preparation, and postintubation management. Those with high-risk features including trauma, elevated intracranial pressure, upper gastrointestinal bleed, cardiac tamponade, aortic stenosis, morbid obesity, and pregnancy must be managed with airway expertise.

CONCLUSIONS

This narrative review discusses the pearls and pitfalls of commonly encountered physiologic high-risk intubations with a focus on the emergency clinician.

Out-of-hospital ketamine: review of a growing trend in patient care

Ketamine is a unique medication with a long history of use in the emergency department. Out-of-hospital indications for ketamine have been explored and are currently expanding in some systems. This article provides background on ketamine history and pharmacology, its use in the hospital environment and possible applications for emergency medical services usage of this medication. Contraindications and adverse reactions are discussed to provide education on the nuances of ketamine administration and mitigation strategies. Out-of-hospital indications for ketamine are discussed including airway management, rapid sequence induction, analgesia, sedation, and treatment of excited delirium.

Prehospital Airway Management in Severe Traumatic Brain Injury

OBJECTIVE

Traumatic brain injury (TBI) is a leading cause of death and disability among trauma patients. The final outcome of TBI results from a complex interaction between primary and secondary mechanisms of injury that begin immediately after the traumatic event. The aim of this review was to evaluate the latest evidence regarding the impact of prehospital airway management and the outcome after traumatic brain injury.

METHODS

PubMed, Embase, and Cochrane searches were conducted using the MeSH database. Airway management, traumatic brain injury, pneumonia, and the subheadings of these Medical Subject Headings were combined.

RESULTS

The review is structured into 4 major topics: airway management devices, prehospital pharmacologic management, mortality and neurologic outcomes, and early respiratory infections. The available literature shows a shift toward a more comprehensive view of prehospital airway management, taking into account not only the location where airway management is attempted but also the drugs administered, the airway management devices used, and the skills of the main professional figures attending the scene.

CONCLUSIONS

Literature about this topic is still inconclusive; however, new evidence taking into consideration more complex aspects of airway management rather than orotracheal intubation per se shows improved outcomes with aggressive prehospital airway management.

The impacts of medication shortages on patient outcomes: A scoping review

Background

In recent years, medication shortages have become a growing worldwide issue. This scoping review aimed to systematically synthesise the literature to report on the economic, clinical, and humanistic impacts of medication shortages on patient outcomes.

Methods

Medline, Embase, Global Health, PsycINFO and International Pharmaceutical Abstracts were searched using the two key concepts of medicine shortage and patient outcomes. Articles were limited to the English language, human studies and there were no limits to the year of publication. Manuscripts included contained information regarding the shortage of a scheduled medication and had gathered data regarding the economic, clinical, and/or humanistic outcomes of drug shortages on human patients.

Findings

We found that drug shortages were predominantly reported to have adverse economic, clinical and humanistic outcomes to patients. Patients were more commonly reported to have increased out of pocket costs, rates of drug errors, adverse events, mortality, and complaints during times of shortage. There were also reports of equivalent and improved patient outcomes in some cases.

Conclusions

The results of this review provide valuable insights into the impact drug shortages have on patient outcomes. The majority of studies reported medication shortages resulted in negative patient clinical, economic and humanistic outcomes.

Does the addition of fentanyl to ketamine improve haemodynamics, intubating conditions or mortality in emergency department intubation: A systematic review

BACKGROUND

Ketamine is an induction agent frequently used for general anaesthesia in emergency medicine. Generally regarded as haemodynamically stable, it can cause hypertension and tachycardia and may cause or worsen shock. The effects of ketamine may be improved by the addition of fentanyl to the induction regime. We conducted a systematic review to identify evidence with regard to the effect of adding fentanyl to an induction regime of ketamine and a paralysing agent on post-induction haemodynamics, intubating conditions and mortality.

METHODS

We conducted a search of the Cochrane library, EMBASE, MEDLINE, PROQUEST, OpenGrey and clinical trial registries. Prominent authors were contacted in order to identify additional literature pertinent to the research question. Studies were included if they pertained to intubation of adult patients in the prehospital or emergency department environments and included an induction regime of ketamine and a paralysing agent, with at least one outcome measure of haemodynamics, intubating conditions or mortality. Search results were reviewed by two investigators independently, adjudicated by a third investigator where disagreement occurred.

RESULTS

One observational study was identified that partially answered the research question.

DISCUSSION

Only one observational study was identified that partially answered the research question. This paper demonstrated that the use of fentanyl as a pretreatment increases the incidence of post-induction hypotension, a phenomenon that was seen with propofol, midazolam and ketamine. The difference in hypotension between these agents was not statistically significant. The impact of this on patient-orientated outcomes is unclear.

Airway and ventilator management in trauma patients

PURPOSE OF REVIEW

Securing the airway to provide sufficient oxygenation and ventilation is of paramount importance in the management of all types of emergency patients. Particularly in severely injured patients, strategies should be adapted according to useful recent literature findings.

RECENT FINDINGS

The role of out-of-hospital endotracheal intubation in patients with severe traumatic brain injury as prevention of hypoxia still persists, and the ideal neuromuscular blocking agent will be a target of research. Standardized monitoring, including capnography and the use of standardized medication protocols without etomidate, can reduce further complications. Prophylactic noninvasive ventilation may be useful for patients with blunt chest trauma without respiratory insufficiency.

SUMMARY

An algorithm-based approach to airway management can prevent complications due to inadequate oxygenation or procedural difficulties in trauma patients; therefore, advanced equipment for handling a difficult airway is needed. After securing the airway, ventilation must be monitored by capnography, and normoventilation involving the early use of protective ventilation with low-tidal volume and moderate positive end-expiratory pressure must be the target. After early identification of patients with blunt chest trauma at risk for respiratory failure, noninvasive ventilation might be a treatment strategy, which should be evaluated in future research.