Paramedic orotracheal intubation: A feasibility study

Paramedic Orotracheal Intubation: A Feasibility DAVID A. GUSS, MD,* MARILYN In order to determine whether paramedics could be effectively trained in the skill of orotracheal intubation, 11 paramedics were entered into a pilot study. All paramedics received the same limited didactic, cadaver, and in viva clinical preparation. Over a six-month period, intubation was attempted on 33 patients in a variety of field situations. lntubation was successful in 28 cases with no reported complications. Subsequently, training has been expanded to a large number of paramedics, and the experience with intubation now includes a total of 128 patients and an overall success rate of 86%. It is concluded that paramedics can safely and effectively perform omtracheal intubation in a variety of adverse field conditions. (Am J Emerg Med 1984;2:399-401)

The optimal management of the compromised airway in the prehospital arena is controversial. The two invasive adjuncts used most often are the esophageal obturator airway (EOA) and the endotracheal tube (ET). The EOA has gained popularity because of its ease of use and minimal training requirements. The ET, while generally accepted as a more definitive airway adjunct, has not been universally supported for field use because of perceived difficulties in training and potential hazards of application of the device by paramedical personnel under a variety of adverse field conditions. Presented herein is the experience of San Diego County with the training and field application of the skill of endotracheal intubation by paramedics (EMT-P). METHODS

San Diego County has been served by EMT-Ps for seven years. There are several different provider agencies throughout the county, including private corporations and fire departments. To study the feasibility of intubation by EMT-Ps, a single fire department pro-

From the *Division of Emergency Medical Services, University of California Medical Center, San Diego, California, and the TEducation/Paramedic Department, Tri-City Hospital District, Oceanside, California. Manuscript received December 22, 1983; revision received ruary 10, 1964; revision accepted March 2, 1984.

Feb-

Address reprint requests to Dr. Guss: Emergency Medical Services, Mail Code H-665-A, UCSD Medical Center, 225 Dickinson Street, San Diego, CA 92103. Key Words: Airway medics.

maintenance,

orotracheal

intubation,

para-

POSLUSZNY,

Study RNt

vider agency from an incorporated community was selected to serve as a pilot group. The agency was chosen on the basis of its defined geographic area of response and the fact that it was controlled by, and delivered patients to, only one regional hospital. The pilot group, consisting of 11 experienced paramedics, included all of the active duty paramedics from that agency. Their training consisted of three hours of didactic classroom lecture, encompassing upper and lower airway anatomy, equipment, indications, contraindications, benefits, disadvantages, and complications, as well as formalized step-by-step protocol for orotracheal intubation. This was followed by a three- to four-hour session that included demonstration and practice of intubation on manikins and fresh cadavers. At the completion of this phase, each paramedic was given a written and practical examination. After successful testing, the paramedic advanced to the clinical sphere, which included intubation of live patients either in the base hospital emergency department or in the operating room, under supervision by an emergency department physician or an anesthesiologist, respectively. A previously agreed-upon standard required a minimum of two successful intubations, or more until proficiency was demonstrated. The supervising physician during this phase of training was charged with the responsibility of determining proficiency. The physician responsible for didactic and practical training was not the same physician responsible for the clinical phase or final certification. After all components of training were complete, the paramedics could begin orotracheal intubation in the field. Indications for intubation included nontraumatic instances of cardiopulmonary arrest, respiratory arrest, and agonal respiration without gag reflex. (Situations involving traumatic arrest were eliminated because of concerns about injury to the cervical spine.) In the field, the paramedics began airway resuscitation in the usual fashion with oral or nasopharyngeal airway and bag-valve-mask (BVM) ventilation. Before intubation was attempted, the patient was hyperventilated for 1 minute on high-flow oxygen. Thirty seconds were allotted for each attempt at intubation and a maximum of two attempts was permitted. Timing, done by the noninterventional paramedic member of the two-man team, began when ventilatory assistance ceased and ended when ventilation was resumed. If, after two attempts, intubation was unsuccessful, either 399

AMERICAN

JOURNAL

OF EMERGENCY

MEDICINE

TABLE 1. San Diego County EMS Indications Contraindications to Endotracheal lntubation Indications (Nontraumatic) Cardiopulmonary arrest Respiratory arrest Unconscious patient with gag reflex

agonal

H Volume

2, Number

for or

respirations

and no

Contraindications Patients with obvious or suspected C-spine injury Apneic patients known or suspected of narcotic overdose prior to trial of naloxone

BVM ventilation was resumed or an EOA was inserted. All patients upon whom orotracheal intubation was attempted were transported to the same base hospital. The on-duty physician was responsible for determining proper ET tube selection and placement, as well as noting any complications. ET tube placement was verified by either auscultation, direct visualization, or chest x-ray. RESULTS

Over a six-month period, orotracheal intubation was attempted on 33 patients who met the criteria (Table 1). Ten patients were female; 23 were male. The average age of the patients was 63 years, with a range of 1 to 87 years. Intubation attempts occurred with the patient on the ground outdoors or on the floor in an enclosure in 28 cases and either on a gurney or in the ambulance in the remaining five cases. Twenty-eight of the 33 patients were successfully intubated in the field by the paramedics (85%). Five cases required two attempts, whereas the remaining intubations were accomplished on the first attempt. Five patients could not be intubated in the field (15%) (Table 2). No particular personal or environmental circumstances characterized the intubation failures. In no instances was there evidence of dental trauma, esophageal intubation, or mainstem bronchus intubation. Of the 33 patients, four were successfully resuscitated; three of them were successfully intubated and one was not (Ns). In the four months since completion of the pilot study, identical training has been offered to paramedics in other provider agencies. During this time, intubation has been attempted on an additional 95 patients. The age and sex characteristics were similar to those of the pilot study group. Intubation was successful in 82 patients (86%) and unsuccessful in 13 patients (14%). Fourteen of the 82 patients successfully intubated required two attempts, and four of the patients who were not successfully intubated had only one attempt. 400

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There was one serious complication in this group: an unrecognized missed intubation. This patient was an IS-month-old drowning victim. The hospital report indicated the patient to be cyanotic without breath sounds upon arrival in the emergency department. Under direct visualization by the emergency physician, the ET was seen not to be in the trachea, although esophageal intubation was not confirmed. The patient could be intubated only with difficulty by an anesthesiologist. Three minor complications occurred in the successfully intubated group, including two cases of right mainstem intubation and one case in which the ET tube became dislodged during transfer and required reinsertion. There were 21 short-term survivors in this group of 95 patients, all of whom where in the group successfully intubated. Statistical analysis is not possible, however, because outcome data were incomplete in the unsuccessful intubation group. Causes of failure included secretions, bright outdoor sunlight, obesity, and nonvisualization due to blood. In five cases, the intubation was noted to be difficult by the physician evaluator, and ultimately required cricothyroidotomy in one case and the services of an anesthesiologist in another.

DISCUSSION

The ET is the primary airway adjunct used in hospitals of this country today. It is a relatively simple device that, when placed correctly, definitively secures and protects the lower airway. In addition, it affords access for pulmonary toilet and allows partially or totally assisted ventilation with varying airway pressures and partial pressures of oxygen. Despite the advantages of the ET, it has not been uniformly accepted as the preferred airway adjunct in the apneic patient in the prehospital arena. The primary reasons for nonacceptance are related to the perceived difficulty and expense in acquisition and maintenance of skills and the concern about complications of ET use in the field by paramedics. These factors have led to reliance OR the EOA and exclusion of the ET in the prehospital care systems of many counties of the United States. ’ The EOA has been favored by some for use by paramedics because of its simplicity of use, efficacy of protecting the airway from gastric contents, and low incidence of complications.2.3 Despite the enthusiasm in some EMS systems, a consensus on both the effectiveness and safety of the EOA has failed to emerge. While reports by Schofferman et ai4 and Meislin5 suggest a high degree of ventilatory utility with the EOA, other reports have suggested that adequate ventilation is not easily obtained in the field by paramedics or in the controlled hospital setting by physicians.6,7 The

GUSS AND POSLUSZNY

TABLE 2.

Results

of lntubation

Successful Unsuccessful l

Excluding

INTUBATION

by Paramedics Pilot Group

Result

n OROTRACHEAL

First Attempt

Second Attempt

23 10

5 5

Expanded Total (“Y)

Experience*

First Attempt

Second Attempt

Total (%)

68 27

14 13

a2 (86) 13 (14)

28 (85) 5 (15)

data from pilot group.

statement that the EOA is easy to use is challenged by Smith et aZ’ in a review of 158 field resuscitations by trained prehospital technicians (EMT-11s). In this report, the EOA could not be placed in 18% of cases and required more than four minutes to place in 47% of patients. The supposed safety of the EOA is eclipsed by a growing number of reported cases of tracheal intubation and esophageal rupture.8-‘3 While the case against the EOA grows, an increasingly favorable experience with paramedic intubation is emerging. In 1973, DeLeo14 reported an 88% success rate for field intubation by paramedics. More recently, Jacobs ef alI5 reported a paramedic intubation success rate of 96% in 178 patients in the Boston area. Our study substantiates the high rate of success and reaffirms the safety of the procedure under adverse conditions. In addition, our training program suggests that a limited classroom and in vitro experience, augmented by several live, supervised intubations, can adequately prepare paramedics for performing orotracheal intubation in the field. It is believed that strict adherence to protocol-allowing only two attempts at intubation and never exceeding 30 seconds of apnea per attempt-should obviate adverse consequences of intubation, even in patients who are ultimately not successfully intubated. Analysis of survival statistics was not possible because of incomplete outcome data in the patients in whom intubation was unsuccessful. Even if the difference suggested by the incomplete data was substantiated, it would not be possible, given the limited population characteristics, to assign this difference to airway management alone. The one potential deficiency in our training program is a limited clinical experience with pediatric patients. Pediatric cadavers and hospitalized patients were not available for intubation, and training in this area was limited to lecture and manikin practice. Although the numbers are too small for meaningful analysis, both pediatric patients in our study, ages 1 year and 18 months, could not be intubated in the field. In addition, the one serious complication in the study, an unrecognized missed intubation, occurred in one of the pediatric patients. Currently, we do not have a solution to this potentially significant training deficit and will be monitoring the situation carefully. This problem is of particular concern because of the inadequacy of the alternative airway adjuncts for pediatric patients.

CONCLUSION Endotracheal intubation, generally accepted as the preferred technique for management of the compromised airway, can be effectively and safely performed in the field by well-trained paramedics. Reliance on the EOA to the exclusion of the ET tube in the prehospital setting should no longer be supported. The EOA should be reserved for use in patients in whom orotracheal intubation either is contraindicated or cannot be performed in a timely fashion.

REFERENCES 1. Grigsby

2. 3.

4.

5. 6.

7.

8.

9.

JW, Rottman SJ. Prehospital airway management: Esophageal obturator airway or endotracheal intubation? Top Emerg Med 1981 ;July:25-29. Don Micheal TA. Esophageal obturator airway. Med lnstrum 1977;11:331-333. Don Michael TA, Gordon AS. The oesophageal obturator airway: A new device in emergency cardiopulmonary resuscitation. Br Med J 1980;281 :1,531-l ,534. Schofferman J, Oill P, Lewis AJ. The esophageal obturator airway: A clinical evaluation. Chest 1976;69:67-71. Meislin HW. The esophageal obturator airway: A study of respiratory effectiveness. Ann Emerg Med 1960;9:54-58. Bryson TK, Benumof JL, Ward CF. The esophageal obturator airway: A clinical comparison to ventilation with a mask and oropharyngeal airway. Chest 1978;74:537-539. Smith JP, Bodai BI, Aubourg R, et al. A field evaluation of the esophageal obturator airway. J Trauma 1983;23:317321. Donen N, Tweed WA, Dashfsky S, et al. The esophageal obturator airway: An appraisal. Can Anaesth Sot J i983;30:194-200. Carlson WJ, Hunter SW, Bonnabeau RC. Esophageal perforation with obturator airway. JAMA 1979;241 :11541155.

10. Yancey W, Wears R, Kamajian G, et al. Unrecognized cheal intubation: A complication of the esophageal turator airway. Ann Emerg Med 1980;9:18-20. 11. Strate RG, Fischer RP: Midesophageal esophageal obturator airways. J Trauma

traob-

perforations by 1976;6:503-509.

12. Pilcher DB, Demeules JE. Esophageal perforation following use of the esophageal airway. Chest 1976;69:377-380. 13. Harrison EE, Nord HJ, Beeman RW. Esophageal perforation following use of the esophageal obturator airway. Ann Emerg Med 1980;9:21-25. 14. DeLeo BC. Endotracheal intubation sonnel. Heart Lung 1977;6:851-854. 15. Jacobs

LM, Berrizbeitia

intubation

LD, Bennett

in the prehospital

phase

by rescue

squad

per-

B, et al. Endotracheal medical

of emergency

care. JAMA 1983:250:2175-2177. 401