Rapid-Sequence Intubation in Adults: Indications and Concerns:

Association between Etomidate Use for Rapid Sequence Intubation and Adrenal Insufficiency in Sepsis

Background The risk of adrenal insufficiency (AI) in using single-dose etomidate for intubation among patients with sepsis remains controversial. Our aim was to assess the prevalence of AI and characterize the risk factors in patients who received etomidate for rapid sequence intubation (RSI). Methods This is a retrospective study of prospectively-acquired data evaluating surgical intensive care unit (SICU) patients who developed respiratory failure undergoing RSI. Results Of the 44 adult SICU patients who developed respiratory failure, 34 patients received etomidate. The average age for the total cohort, for the patients that received etomidate and for those who did not, was 70.91 ± 14.92, 72.82 ± 13.61 years and 64.40 ± 15.93, respectively. Twenty-four patients of the total cohort (54.55%) developed AI; 26 had septic shock (59.09%), and 16 patients had AI and septic shock (36.36%). There was no statistical significance between the incidence of AI in patients who received etomidate (47%) and those who did not (80%). However, in the subset of patients who received etomidate for RSI, there was a non-significant trend toward increased incidence of AI in those who were septic compared to those who were not (p = 0.06). Conclusion A single dose of etomidate used for RSI in SICU patients is not associated with the development of AI or mortality. However, a trend was shown, although not statistically significant, towards the development of AI in septic patients. High-quality and adequately powered randomized control trials (RCTs) are warranted.

Effectiveness and risks of cricoid pressure during rapid sequence induction for endotracheal intubation

BACKGROUND

Rapid sequence induction (RSI) for endotracheal intubation is a technique widely used in anaesthesia, emergency and intensive care medicine to secure an airway in patients deemed at risk of pulmonary aspiration. Cricoid pressure is conceptually used to reduce the risk of aspiration by compressing the oesophagus.

OBJECTIVES

To identify and evaluate all randomized controlled trials (RCTs) involving participants undergoing elective or emergency airway management via RSI and compare participants who have cricoid pressure administered with participants who do not have cricoid pressure administered.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL 2015, Issue 4), MEDLINE via OvidSP (1946 to May 2015), EMBASE via OvidSP (1980 to May 2015), ISI Web of Science (from 1940 to May 2015) and CINAHL via EBSCOhost (1982 to May 2015).

SELECTION CRITERIA

We included all RCTs comparing people undergoing RSI who have cricoid pressure applied, either intermittently or continuously, with people undergoing RSI who do not have cricoid pressure applied in the context of endotracheal intubation using a direct laryngoscopic technique. We included both elective and emergency cases. We included studies of blinded and unblinded participants. Participants (male or female) were involved in any type of procedure where general anaesthetic utilizing RSI or emergency airway management utilizing RSI and endotracheal intubation was undertaken. We expected the control arm to be the absence of cricoid pressure at any stage during RSI. The primary outcome of interest was the reported event rate or prevalence of aspiration determined by a) documented gastric aspiration determined by visual inspection of aspirated stomach contents on laryngoscopy; b) pepsin detection in tracheal aspirate using the Ufberg method; c) post-anaesthetic radiographic changes suggestive of aspiration pneumonitis or d) any combination of a to c. Secondary outcomes of interest included documented impaired visualization of the airway by a treating laryngoscopist, force applied during cricoid pressure, the direction of application of force of applied cricoid pressure, independent risk factors for aspiration and whether the person applying cricoid pressure had previously done so in an emergency airway context.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the titles and abstracts of all the studies obtained from the search using recognition of words such as 'cricoid pressure', 'rapid sequence intubation', 'emergency airway management' and 'aspiration'. Two authors independently determined the study inclusion by using a study eligibility form that we developed for the purpose of this review. We also reported the decisions regarding inclusion and exclusion in accordance with the preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement. We assumed that studies that did not describe the use of RSI in their title, abstract or methodology used an alternative method of anaesthetic induction or emergency airway management and thus we excluded them. Data extracted from included studies comprised study characteristics, participant demographics, intervention and comparison details plus outcome measures and results. We contacted primary authors of studies with missing or unreported but potentially relevant data to obtain missing data.

MAIN RESULTS

Of 493 records that we identified from databases as a result of the search (excluding duplicates), we regarded 70 abstracts/titles as potentially relevant studies. Independent scrutiny of these 70 titles and abstracts identified 29 potentially relevant studies. Of the 29 potentially relevant studies, one study met the criteria for inclusion. This study was a RCT that compared participants undergoing RSI and endotracheal intubation in the context of elective surgery requiring a general anaesthetic. Forty participants were recruited, 20 of whom had cricoid pressure applied and 20 of whom had cricoid pressure simulated. The main outcomes reported were systolic arterial pressure and heart rate after laryngoscopy and tracheal intubation. We did not consider these outcomes relevant for the purposes of this systematic review. The search also identified one study that could potentially be included in an updated systematic review in the future, but was at the time of the search a proposal for a trial only and had no reported outcomes at this time.

AUTHORS' CONCLUSIONS

There is currently no information available from published RCTs on clinically relevant outcome measures with respect to the application of cricoid pressure during RSI in the context of endotracheal intubation. On the basis of the findings of non-RCT literature, however, cricoid pressure may not be necessary to undertake RSI safely, and therefore well-designed and conducted RCTs should nonetheless be encouraged to properly assess the safety and effectiveness of cricoid pressure.

Etomidate for rapid sequence intubation in the emergency department: Is adrenal suppression a concern?

Etomidate has become one of the most commonly used induction agents in the United States during emergency department (ED) endotracheal intubation. While etomidate may be popular, concerns have been raised about possible adrenal suppression and subsequent adverse effects. In this paper we critically evaluate the recent literature and perspectives regarding the effect of etomidate on the adrenocortical system.

A review of etomidate for rapid sequence intubation in the emergency department

Etomidate is a sedative-hypnotic chemically unrelated to other induction agents. The pharmacological and safety profile of etomidate offers many advantages for induction during rapid sequence intubation (RSI) in the emergency department (ED). Its onset of action is within 5 to 15 seconds, and its duration of action is 5 to 15 minutes. Unlike thiopental, propofol, midazolam and, to a lesser extent, ketamine, etomidate has minimal respiratory or cardiovascular effects and can be safely used in patients with hemodynamic instability or cardiac ischemia. Etomidate is cerebroprotective, with the ability to decrease intracranial pressure and maintain cerebral perfusion, making it an ideal agent for patients with head injuries. Of the currently available induction agents, etomidate offers the most favourable safety profile and is the least likely to produce adverse effects in patients with unknown or untreated medical conditions. Etomidate may cause pain on injection, myoclonic movements on induction, hiccups, nausea and vomiting. Transient adrenal suppression has been reported, but not to a clinically significant degree, after single induction doses for ED RSI. Etomidate has been well studied in the ED and should be adopted for RSI in specific ED patient groups.

Cricoid Pressure in Emergency Department Rapid Sequence Tracheal Intubations: A Risk-Benefit Analysis

Cricoid pressure is considered an integral part of patient safety in rapid sequence tracheal intubation and emergency airway management. Cricoid pressure is applied to prevent the regurgitation of gastric contents into the pharynx and subsequent aspiration into the pulmonary tree. This review analyzes the published evidence supporting cricoid pressure, along with potential problems, including increased difficulty with tracheal intubation and ventilation. According to the evidence available, the universal and continuous application of cricoid pressure during emergency airway management is questioned. An awareness of the benefits and potential problems with technique allows the practitioner to better judge when cricoid pressure should be used and instances in which it should be removed.

Intubating conditions and hemodynamic effects of etomidate for rapid sequence intubation in the emergency department: an observational cohort study

OBJECTIVES

To describe and analyze the intubating conditions and hemodynamic effects of etomidate in patients undergoing rapid sequence intubation (RSI) in the emergency department.

METHODS

The authors conducted a prospective observational study of all patients who received etomidate for induction of RSI over a 42-month period in a large tertiary care teaching hospital. Intubating conditions were determined by the emergency physician for both sedation and paralysis and for technical difficulty using a five-point Likert scale. Hemodynamic effects were evaluated before, after, and every five minutes for 15 minutes following administration of etomidate.

RESULTS

Etomidate was used for induction of RSI in 522 patients, all of whom were included in the final efficacy analysis, while 491 were included in the analysis of hemodynamics. Lidocaine and fentanyl were used as pretreatment in 65.1% and 26.1% of patients, respectively, while succinylcholine was the paralytic in 94.3% of intubations. Sedation and paralysis were rated as excellent or good in 88.1% and 8.8% of patients, respectively, while technical difficulty was very easy or easy in 60.7% and 19.0% of patients, respectively. Mean (+/- SD) baseline systolic blood pressure (sBP), diastolic blood pressure (dBP), and heart rate were found to be 132.7 (+/- 35.4) mm Hg, 69.5 (+/- 21.2) mm Hg, and 96.1 (+/- 26.2) bpm, respectively. Overall, there was a clinically insignificant elevation in sBP (p < 0.0001), dBP (p = 0.0002), and heart rate (p < 0.0001) immediately postintubation. Elevations in sBP persisted at five minutes (p = 0.0230) and ten minutes (p = 0.0254) postintubation. Diastolic blood pressure and heart rate returned to baseline at five minutes after intubation and remained stable throughout the 15-minute postintubation assessment period. In the subgroup of 80 patients with a preintubation sBP < 100 mm Hg, there was a 12.1-mm Hg elevation in sBP (p < 0.0001) and a 7.3-mm Hg elevation in dBP (p = 0.0001) immediately postintubation. This elevation persisted throughout the 15-minute postintubation assessment period.

CONCLUSIONS

Etomidate appears to provide appropriate intubating conditions in a heterogeneous group of patients undergoing RSI in the emergency department. Hemodynamic stability appears to be present following administration of this agent, even in patients with low pre-RSI blood pressure. This attribute must be weighed against potential adverse effects of this agent, including adrenal suppression.

Cricoid pressure decreases ease of tracheal intubation using fibreoptic laryngoscopy (WuScope System

PURPOSE

Cricoid pressure is commonly used during rapid sequence induction and intubation to minimize the risk of aspiration. The objective of the study was to evaluate the ease of fibreoptic (WuScope System(TM)) intubation in anesthetized adults receiving cricoid pressure.

METHODS

The intubation difficulty scale (IDS) was used to measure tracheal intubation difficulties in 33 patients undergoing elective surgery with general anesthesia and complete neuromuscular blockade. Each patient had their trachea intubated under two conditions: with and without cricoid pressure. The order of conditions was determined randomly. Cricoid pressure was applied by an experienced anesthesia provider.

MAIN RESULTS

An IDS value of 0 (ideal intubation, that is one performed by the first operator on the first attempt, using the first technique with full visualization of the glottis and no vocal cord compression) occurred in 30 of 33 patients (91%) without cricoid pressure and in 22 of 33 patients (67%) with cricoid pressure (P < 0.05). Cricoid pressure compressed the vocal cords in nine patients (27%) and impeded tracheal tube placement in five (15%). In three patients (9%), pressure had to be released in order to successfully intubate.

CONCLUSION

Cricoid pressure may impede or even prevent fibreoptic laryngoscopic intubation with the WuScope System(TM).

Prehospital tracheal intubating conditions during rapid sequence intubation: rocuronium versus vecuronium

INTRODUCTION

The study purpose was to evaluate tracheal intubating conditions and cardiovascular effects of rocuronium (roc) and vecuronium (vec) in the transport setting.

METHODS

A prospective blinded study of adult patients requiring emergency rapid sequence oral tracheal intubation using direct laryngoscopy. Patients received equipotent doses of roc 1.0 mg/kg (n = 44) or vec 0.15 mg/kg (n = 56) on an alternate day basis.

RESULTS

Intubation was successful in 95% of patients in the vec group and 100% in the roc group. The percentage of patients having good or excellent jaw relaxation and vocal cord exposure was similar between groups (vec/79%, roc/77%). Eleven patients (vec/7, roc/4) had difficult intubation as evidenced by Grade III or IV view and more than three attempts. Five patients in the vec group had inadequate neuromuscular blockade versus 1 patient in the roc group (P = 0.17). No cardiovascular differences occurred between groups after intubation.

CONCLUSION

Tracheal intubating conditions and clinical evidence of complete neuromuscular blockade tended to be better after roc than after vec.