Management of difficult airways in the field

Fatal deep neck infection and respiratory arrest

Despite the wide availability of antibiotics and medical care, deep neck infections requiring hospitalization are associated with significant morbidity and mortality. Thus, early recognition and aggressive treatment are key in preventing unfavorable outcomes. We present the case of a patient who rapidly progressed from nonspecific upper respiratory symptoms to obstructive airway loss and death due to a swiftly worsening deep neck infection.

Reliability of Ultrasonography in Confirming Endotracheal Tube Placement in an Emergency Setting

Background and Objectives:

Over the past few years, ultrasonography is increasingly being used to confirm the correct placement of endotracheal tube (ETT). In our study, we aimed to compare it with the traditional clinical methods and the gold standard quantitative waveform capnography. Two primary outcomes were measured in our study. First was the sensitivity and specificity of ultrasonography against the other two methods to confirm endotracheal intubation. The second primary outcome assessed was the time taken for each method to confirm tube placement in an emergency setting.

Methods:

This is a single-centered, prospective cohort study conducted in an emergency department of a tertiary care hospital. We included 100 patients with indication of emergency intubation by convenient sampling. The intubation was performed as per standard hospital protocol. As part of the study protocol, ultrasonography was used to identify ETT placement simultaneously with the intubation procedure along with quantitative waveform capnography (end-tidal carbon dioxide) and clinical methods. Confirmation of tube placement and time taken for the same were noted by three separate health-care staffs.

Results and Discussion:

Out of the 100 intubation attempts, five (5%) had esophageal intubations. The sensitivity and specificity of diagnosis using ultrasonography were 97.89% and 100%, respectively. This was statistically comparable with the other two modalities. The time taken to confirm tube placement with ultrasonography was 8.27 ± 1.54 s compared to waveform capnography and clinical methods which were 18.06 ± 2.58 and 20.72 ± 3.21 s, respectively. The time taken by ultrasonography was significantly less.

Conclusions:

Ultrasonography confirmed tube placement with comparable sensitivity and specificity to quantitative waveform capnography and clinical methods. But then, it yielded results considerably faster than the other two modalities.

A Follow-Up Analysis of Factors Associated with Head-Injury Mortality After Paramedic Rapid Sequence Intubation

BACKGROUND

The San Diego Paramedic Rapid Sequence Intubation (RSI) Trial documented an increase in mortality after paramedic RSI, with hyperventilation identified as a contributing factor in a small subgroup analysis. Here we explore factors affecting outcome in the entire cohort of patients undergoing paramedic RSI to confirm previous findings. This also represents a synthesis of findings from previous analyses

METHODS

Adult trauma patients with severe head injury (Glasgow Coma Scale score, 3-8) who could not be intubated without RSI were prospectively enrolled in the trial. This analysis excluded patients without traumatic brain injury (head/neck abbreviated injury score <2 or failure to meet Major Trauma Outcome Study criteria) or death in the field or within 30 minutes of arrival. Each remaining trial patient was matched to two nonintubated historical controls from the county trauma registry based on: age, sex, mechanism, abbreviated injury scores for each body system, and Injury Severity Score. Logistic regression, cohort analysis, mean least squares regression, and discordant group analysis were used to explore the impact of various factors on outcome.

RESULTS

Of the 426 trial patients, 352 met inclusion criteria for this analysis and were hand-matched to 704 controls. Trial patients and controls were identical with regard to all matching variables. Mortality was increased in RSI patients versus matched controls (31.8 versus 23.7%; odds ration, 1.5; 95% confidence interval, 1.1-2.0; p < 0.01). Hyperventilation was associated with an increase in mortality, whereas transport by aeromedical crews after paramedic RSI was associated with improved outcomes. The reported incidence of aspiration pneumonia was higher for the RSI patients.

CONCLUSION

Paramedic RSI was associated with an increase in mortality compared with matched historical controls. The association between hyperventilation and mortality was confirmed. In addition, patients transported by helicopter after paramedic RSI had improved outcomes. Paramedic RSI did not seem to prevent aspiration pneumonia.

Factors associated with the use of pharmacologic agents to facilitate out-of-hospital endotracheal intubation

OBJECTIVE

To identify a set of clinical factors most strongly associated with the use of drug-facilitated intubation (DFI) in the out-of-hospital setting.

METHOD

The authors used data from a prospective, multicentered endotracheal intubation (ETI) observational cohort trial, including patients from 45 emergency medical services in Pennsylvania. Providers reported clinical, physiologic, and anatomic factors associated with each ETI effort. The authors included only data from the 23 services using DFI. They identified all non-arrest (presence of a pulse) adult patients. They included both successful and failed ETIs. They defined DFI cases as patients who received a sedative or neuromuscular-blocking agent to facilitate ETI. The authors also classified patients who underwent nasotracheal intubation as DFI. They defined control subjects as patients undergoing conventional oral ETI. They performed multivariate logistic regression to identify the clinical, physiologic, and anatomic factors characteristic of DFI. They examined alternate forms of the final prediction model.

RESULTS

The authors analyzed data from 208 nonarrest patients, including 92 DFIs and 116 control subjects. Of 34 factors potentially related to DFI, 17 were excluded on univariate analysis (likelihood ratio p>0.25). Multivariate logistic regression revealed the following as positively associated with DFI: presence of clenched jaw/trismus (odds ratio [OR], 2.33; 95% confidence interval [CI], 1.10-4.95; p=0.026); increased verbal Glasgow Coma Scale score (OR, 1.71; 95% CI, 1.29-2.26; p<0.001); use of cervical spine precautions (OR, 2.30; 95% CI, 1.15-4.62; p=0.018). Anterior vocal cords (OR, 0.27; 95% CI, 0.10-0.71; p=0.004) and laryngospasm (OR, 0.14; 95% CI, 0.02-1.17; p=0.025) were negatively associated with DFI. The model showed good fit (Hosmer-Lemeshow p=0.75) and discrimination (area under the curve=0.76).

CONCLUSIONS

The authors identified a set of predictors strongly associated with DFI. These data offer insight into the current use of DFI and support the development of consensus-based guidelines for this procedure.

Capnometry for noninvasive continuous monitoring of metabolic status in pediatric diabetic ketoacidosis*

OBJECTIVE

To determine the utility of continuous noninvasive capnometry for monitoring pediatric patients with diabetic ketoacidosis as assessed by the agreement between end-tidal carbon dioxide (PetCO2) and PCO2

DESIGN

Clinical, prospective, observational study.

SETTING

University affiliated children's hospital.

INTERVENTIONS

Patients with diabetic ketoacidosis were monitored with an oral/nasal carbon dioxide (CO2) sampling cannula while in the emergency department. Laboratory studies were ordered per protocol. PetCO2 values were correlated with respiratory rate, PCO2, and pH.

MEASUREMENTS AND MAIN RESULTS

One hundred twenty-one patients were monitored for 5.9 +/- 0.32 hrs. The average (mean +/- sd) initial values for pH were 7.08 +/- 0.18; respiratory rate, 35.1 +/- 9.1 breaths/min; PetCO2, 18.6 +/- 10.8 torr; and venous PCO2, 20.2 +/- 10.6 torr. At the conclusion of the observation period, averages were pH, 7.29 +/- 0.05; respiratory rate, 22.4 +/- 3.7 breaths/min; PetCO2, 35.3 +/- 5.8 torr; and venous PCO2, 36.8 +/- 5.3 torr. For all 592 observations, the correlations between PetCO2 and venous PCO2 (r =.92, p =.0001), PetCO2 and pH (r =.88, p =.0001), Petco2 and respiratory rate (r = -.79, p =.0001), and respiratory rate and pH (r = -.80, p =.0001) were statistically significant and the correlations with respiratory rate were inversely related to pH and PetCO2. The difference scores were not related to the average scores for initial readings (r = -.073, p =.43), final readings (r = -.124, p =.18), and overall readings (r =.057, p =.17). Limits of agreement between the two methods were established with PetCO2 lower than venous PCO2 with 95% limits of agreement 0.8 +/- 8.3 (2 sd) torr.

CONCLUSIONS

PetCO2 monitoring of patients with diabetic ketoacidosis provides an accurate estimate of PCO2. Noninvasive PetCO2 sampling may be useful in patients with diabetic ketoacidosis to allow for continuous monitoring of patients.

Procedures performed by pediatric transport nurses: how "advanced" is the practice?

INTRODUCTION

Pediatric interfacility transport teams often rely on advanced practice nurses as primary care providers. These individuals may be required to transport patients without the presence of a physician. There is, however, little information in the medical literature regarding how frequently advanced practice transport nurses perform advanced procedures, how often these procedures are successfully performed, and the rate of complications associated with nurse-performed procedures.

PURPOSE

The purpose of this study was to determine how frequently advanced practice transport nurses were called on to perform advanced procedures and to determine the nurses' procedural success and complication rates.

DESIGN

Prospective convenience sample of consecutive pediatric interfacility transports.

METHODS

Transport nurses collected data on 336 pediatric interfacility transports that were performed during a 4-month period beginning in May 1997. All patient transports occurring during the study period were included. Data regarding procedures were recorded on data collection sheets. This data included the type of procedure performed, the outcome of the procedure, and the complications associated with the procedure. The number of attempts required to successfully complete the procedure was not recorded. During or after the patient's hospitalization, the medical record was reviewed to identify potential complications related to the transport that may not have been recorded on the data collection sheet.

RESULTS

Nurses performed 95.2% of transports without the presence of a physician. Twenty-six patients (8.8%) required advanced procedures. Nurses performed eight tracheal intubations. Personnel at the referring hospital performed the remaining procedures. All tracheal intubations by transport nurses were successful. There were no complications related to these procedures. All patients were transported to the receiving hospital without incident.

CONCLUSIONS

Although they had considerable training for advanced procedures, the transport nurses rarely used these skills. All tracheal intubations performed by transport nurses were successful, and there were no adverse consequences related to intubation by a transport nurse.

Guidelines based on the principle 'First, do no harm'. New guidelines on tracheal tube confirmation and prevention of dislodgment

In summary, this editorial and the one on pulse check point out another area in which a total reliance on evidence-based guidelines amy do our patients a disservice. The debate over dropping the pulse check hinged less on the strength of the evidence and more on the widespread clinical principle of fear of false-negative errors. The discussion of secondary confirmation of tracheal tube placement also lacks a strong base of evidence that identifies the one best technique of tube confirmation for patients with a pulse versus those without a pulse. The principles of the zero-risk intervention and first, do no harm come into play in this situation. We must deal with the growing awareness of the fact that tracheal intubation is not only a potentially lethal intervention but now is also a confirmed lethal intervention, and at a much higher death rate than has ever been suspected. Factors that contribute to the transformation of the tracheal tube from a life-saving to a death-causing intervention are being identified by honest and open researchers. National societies in emergency medicine are responding appropriately. We strongly recommend shifting from making an evidence-based recommendation to instead making a principle-based recommendation--killing our patients is unacceptable; we must act on the widespread concept regarding errors in medicine. We must adopt zero-risk interventions in all possible situations.