Impact of Emergency Medicine Faculty and an Airway Protocol on Airway Management

Transcription

1 1452 Jones et al. EM FACULTY AND AIRWAY SUCCESS RATES Impact of Emergency Medicine Faculty and an Airway Protocol on Airway Management James H. Jones, MD, Christopher S. Weaver, MD, Daniel E. Rusyniak, MD, Edward J. Brizendine, MS, Roland B. McGrath, MD Abstract Objective: To determine the impact of emergency medicine (EM) faculty presence and an airway management protocol on success rates of tracheal intubation in the emergency department (ED). Methods: A retrospective observational study of prospectively collected data on rates of successful intubations between June 1997 and December 2001 in the ED of a large urban teaching hospital. The authors compared success rates of the first attempt at intubation and times to intubation prior to and after EM faculty presence and the institution of an airway management protocol. Results: Prior to EM faculty presence and the airway management protocol, tracheal intubation was achieved on the first attempt 46% of the time; more than six attempts were required 2.9% of the time. The mean time to intubation was 9.2 minutes ( 13.2 SD). Following EM faculty presence and the airway protocol, the success rate on the first attempt was 62%, more than six attempts were required 1.1% of the time, and the mean time to intubation was 4.6 minutes ( 6.2 SD). Conclusions: First-attempt intubation success rates and decreased mean time to successful intubation improved following EM faculty presence and the introduction of an airway management protocol. Key words: airway; education; rapid-sequence intubation; emergency medicine faculty. ACADEMIC EMERGENCY MEDICINE 2002; 9: The importance of airway management in emergency medicine (EM) is underscored by Advanced Cardiac Life Support and Advanced Trauma Life Support algorithms and the expectations of EM residency training programs. 1 4 Numerous studies support the use of rapid-sequence intubation (RSI) in the management of severely sick or injured patients outside of the operating room Omert et al. 13 reported the tracheal intubation success rates at a Level I trauma center after airway management was under the auspices of EM rather than anesthesiology. The overall success rates were 97.0% for EM residents and 98.0% for anesthesiology residents. They concluded that EM residents and staff can safely manage the airway of trauma patients. We are unaware of any studies that have evaluated the tracheal intubation success rates of EM faculty-supervised tracheal intubations in combination with an airway management protocol. We therefore conducted a study to determine the success rates of tracheal intubation in the emergency department (ED) before and after the introduction of EM faculty supervision and the implementation of an airway From the Department of Emergency Medicine (JHJ, CSW, DER, RBM) and the Division of Biostatistics (EJB), Indiana University School of Medicine, Indianapolis, IN. Received April 24, 2002; revision revised July 23, 2002; accepted July 29, Address for correspondence and reprints: James H. Jones, MD, Wishard Memorial Hospital, 1050 Wishard Boulevard, Room R2200, Indianapolis, IN Fax: ; management protocol. We hypothesized that the presence of EM faculty in combination with an airway management protocol would be associated with an improved rate of successful tracheal intubation. METHODS Study Design. This was a retrospective observational study of success at airway management using prospectively collected data on intubations in the ED of a large urban teaching hospital. Data were collected between June 1997 and December 2001 both prior to and after the presence of EM faculty and an airway management protocol. The university investigational review board approved the study and waived the informed consent requirement. Study Setting and Population. The study was conducted at a central-city public hospital (Wishard Memorial Hospital) on the Indiana University Medical Center campus in Indianapolis, Indiana. The annual ED census at the time of the study was 105,000. Data were collected on all tracheal intubations performed in the ED. Study Protocol. Indiana University recently developed an academic Department of Emergency Medicine. This resulted in the transition of Wishard Wishard Memorial Hospital from a specialty-based

2 ACAD EMERG MED December 2002, Vol. 9, No triage scheme (predominantly internal medicine and surgery) to EM. Prior to this transition, faculty consisted of physicians from the Department of Internal Medicine. Internal medicine faculty physicians were present 24 hours each day with responsibility for oversight of medicine patient care and medicine resident education. On July 1, 2000, the faculty responsibility in the training site transitioned to academic emergency physicians. In addition to the transition of faculty, an airway management protocol (Fig. 1) was implemented in the spring of This protocol was developed by one of the EM faculty and subsequently edited and endorsed by the Departments of Anesthesia, Pediatrics, Pulmonary/Critical Care, and Surgery/ Trauma. In 1997 the Department of Respiratory Therapy began prospectively collecting data on tracheal intubations as part of a Critical Care Multidisciplinary Quality Assurance Subcommittee audit tool. Data were collected by respiratory therapists following all tracheal intubations in the ED. Collected data elements included success on the first attempt, total number of attempts, and time to successful intubation. An attempt was defined as insertion of the laryngoscope blade. Time to successful intubation was measured from insertion of the laryngoscope blade to clinical and/or end-tidal carbon dioxide confirmation of tracheal placement. Measures. The main study outcomes were time to successful intubation, proportion successful on the first attempt, and proportion of intubations taking more than six attempts to achieve proper placement. Data Analysis. A weighted mean of the monthly average intubation time was calculated for the preand post-intervention periods. The weight used was the number of cases seen in the month. A weighted Student s t-test was used to compare intervention means and a weighted 95% confidence interval for the difference in mean average monthly intubation times was determined. Proportions were compared between the pre- and post-intervention periods using the Pearson chi-square statistic. A 95% confidence interval for the difference in proportions was also calculated. Statistical analyses Figure 1. The airway management protocol.

3 1454 Jones et al. EM FACULTY AND AIRWAY SUCCESS RATES TABLE 1. Main Study Results Pre and Post Institution of Emergency Medicine Faculty and an Airway Management Protocol Pre-intervention (n = 627) Post-intervention (n = 368) Difference (Post Pre) 95% CI for Difference p-value First-attempt success rate 288 (45.9%) 228 (61.9%) 16.0% 9.7%, 22.3% <0.10 More than 6 attempts 18 (2.9%) 4 (1%) 1.8% 3.5%, 0.1% 0.06 Mean ( SD) time to intubation (min) 9.2 ( 13.2) 4.6 ( 6.2) , 3.0 <0.01 were preformed using the statistical software package SAS version 8.2 (SAS Institute, Cary, NC). RESULTS The pre-intervention period consisted of 31 months between June 1, 1997, and December 31, 1999, of which 26 months of data were available. The postintervention period consisted of 12 months of consecutively collected data from January 1 through December 31, Prior to the presence of EM faculty, there were 627 intubations (average 24 per month) performed in the ED by the residents of several services. After EM faculty presence, there were 368 intubations (average 31 per month) also performed by residents of these various services, under the supervision of the EM faculty. Following introduction of an EM faculty presence in the ED and promulgation of an airway management protocol, tracheal intubation was achieved in less time, was achieved more frequently on the first attempt, and less often required more than six attempts. In addition, the mean time to intubation was significantly reduced. The main results of the study are presented in Table 1. DISCUSSION The formation of a university academic Department of Emergency Medicine, with the addition of a second training site at Wishard Memorial Hospital, allowed us to conduct a study of tracheal intubation success rates before and after introduction of emergency physician coverage and the initiation of an airway management protocol. Our study demonstrated a significant decrease in time to intubation and first-time success rates following EM faculty presence and the institution of an airway management protocol. The published success rates for tracheal intubation are dependent upon the route of tracheal intubation, the use of neuromuscular-blocking agents, and the venue. Blind nasotracheal intubation success rates are reported to be from 60% to 65%. 5,11 Orotracheal intubation success rates, without neuromuscular blockade, range from 73% to 89%. 11,14 Series reporting success rates with neuromuscular blockade include the following: flight emergency medical technicians paramedics, 97 98%, 12,16,17,20 flight registered nurses (RNs), 96 98%, 19 physician/rn flight crew, 95 97%, 21 academic medical centers, %, 5,10,11,15 pediatric center, 100%, 8 and community hospital, 100%. 6 In our study, intubations were orotracheal before and after EM presence. Data on the use of neuromuscular-blockade intubation prior to EM faculty were not collected, but, in general, neuromuscular blockade was at the physician s discretion. After EM faculty presence and an airway management protocol, all patients without contraindications received RSI. In reviewing literature on first-pass success rates, there is often a discrepancy as to the definition of an attempt. Some authors considered it to be insertion of the laryngoscope, 6,15,17 19 while others considered it to be only attempted tube placement. 10,20 Using the audit tool available for this study, an attempt was defined as insertion of the laryngoscope blade. The published first-pass success rates vary from 43% to 90% depending on clinical setting and use of neuromuscular blockade. 5 9,11,13,16 19 The lowest reported success rates occur in teaching and out-of-hospital venues where the EM faculty role is primarily teaching and oversight. In studies of community EDs where EM faculty perform the intubations, success rates are higher. 9 In our study, the EM faculty role was primarily teaching and oversight, with EM faculty performing intubations only after failure by rotating residents. Our data show a first-pass success rate similar to those of other county hospitals, 10 but lower than reported success rates by EM residents (74 80%) in other academic departments. 13,22 This may reflect a difference in those primarily performing intubations. In our study, first attempts were predominantly performed by non-em residents pre- and post-intervention. There is surprisingly little literature that would advocate the use of an airway protocol unless RSI can be viewed as a protocol. Rose et al. 14 demonstrated that the introduction of RSI in an aeromedical transport service improved success rates from 73% to 96%, while Dronen et al. reported an improvement in both success rates, from 65% to 100%,

4 ACAD EMERG MED December 2002, Vol. 9, No and time to intubation. 5 Slater et al. compared preflight intubation with en-route intubation. 19 Firstattempt success rates (59% and 63%) and overall success rates (96 and 98%) were comparable. In our study, the use of an airway management protocol (Fig. 1) involved not only RSI but also pre-intubation preparation and post-intubation care and likely contributed to the success of post-em faculty presence. LIMITATIONS There are several limitations to our study. First, we retrospectively analyzed data collected for quality assurance purposes rather than for a clinical study. Thus, our study results are subject to the biases inherent in all retrospective studies, most notably potential confounders. However, since the only major changes that occurred in the clinical setting studied pre- and post-intervention were the implementation of an airway management protocol and the presence of EM faculty, we feel confident that other potential confounders have a negligible contribution. Second, in accessing the data from respiratory therapy, there were five months in which no data were available. In researching this, we are unable to determine whether data were either not collected or not put into the audit database. Since there was no known implemented change in airway management during this time frame and the monthly rates of intubations pre- and post-study periods are similar, we believe it is unlikely that the missing data would have significantly changed outcomes. Third, interrater reliability of the respiratory therapy data audit tool could not be assessed. Because of the retrospective nature of this protocol and the number of respiratory therapists involved, it was impossible to calculate kappa values for the study data. The use of the audit tool itself can be subjective and vary among individuals. Although the definitions of pass and time were consistent throughout the study periods, it is conceivable that these were not always adhered to. Departures from the convention were probably sporadic rather than systematic, thereby likely preserving the validity of the data. Finally, since both EM faculty presence and an airway protocol were introduced simultaneously, it is impossible to tell the relative impact that either of them had on airway success rates by itself. CONCLUSIONS Our study demonstrated an increase in the success rate of tracheal intubation and a decrease in intubation time following the institution of academic EM faculty supervision and the implementation of an airway management protocol. Our study adds to the growing number of studies supporting the supervision of resident physicians by academic EM faculty during tracheal intubation in the ED as well as the benefits of implementation of an airway management protocol. The authors acknowledge the assistance of William H. Cordell, MD, in preparing the manuscript and Edward Bartkus, MD, for the initial development of the airway management protocol. References 1. American College of Emergency Physicians. Core content for emergency medicine. Ann Emerg Med. 1991; 20: Residency Review Committee Emergency Medicine: Special Requirements for Residency Training in Emergency Medicine. Chicago, IL: Accreditation Council for Graduate Medical Education, Mar Advanced Trauma Life Support. American College of Surgeons Committee on Trauma American Heart Association. Guidelines 2000 for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Dallas, TX: AHA, Dronen SC, Merigian KS, Hedges JR, Hoekstra JW, Borron SW. 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