1996 OPEN FORUM Abstracts
COMPARISON OF SELF INFLATING BULB AND EXPIRED CO2 TO CONFIRM ENDOTRACHEAL PLACEMENT AFTER EMERGENCY INTUBATION.
CL Kasper, RRT, MS Benson, BS RRT, S Deem, MD, Harborview Medical Center, Seattle, WA.
Introduction: Failure to detect esophageal intubation may lead to irreversible brain damage or death. In the operating room (OR) the "gold standard" for confirming correct placement of the endotracheal tube (ETT) is the detection of expired CO2. Outside of the OR, a portable infrared device is available along with two other portable devices: 1) the portable colormetric analyzer and 2) the self-inflating bulb or syringe technique. These two devices appear to be reliable in the OR, however, there is little information to support their use outside of the OR in an emergency or intensive care (ICU) setting. We compared the colorimetric CO2 analyzer and bulb syringe with infrared CO2 analysis during emergent intubation to test their efficacy outside the OR. Methods: 300 consecutive patients (219 male, 81 female, mean age 49.7 19) undergoing endotracheal intubation in the Emergency Trauma Center (ETC), the ICU, and general wards had their ETT position tested. All intubations were done in the ETC (35%), ICU (56%) or elsewhere (9%) by an anesthesiologist. Immediately post-intubation but prior to ETT cuff inflation, the following sequence was strictly adhered to : 1) the self inflating bulb (Tube Chek B, Ambu Inc.) was compressed and connected to the ETT and released. A 10 second period was allowed for bulb reinflation. 2) The ETT cuff was inflated. 3) A colorimetric CO2 analyzer (Easi-Cap, Nellcor, Inc.) was attached to the ETT and 5 manual breaths were delivered via a self-inflating bag; 4) an infrared CO2 analyzer (Stat-Cap, Nellcor, Inc.) was attached to the ETT and 5 manual breaths were delivered. The final decision on ETT position was made from the findings of the three tests along with clinical evaluation by the RCP and Anesthesiologist. Results: 300 consecutive patients underwent 326 attempts at tracheal intubation. 145/300 (48%) were intubated for acute respiratory failure; 123 (41%) for airway protection or to facilitate pulmonary toilet. The remaining 32 (11%) were intubated for various diagnostic procedures. 42 (14%) had known COPD; 31 (10%) had pulmonary edema; 55 (18%) were obese and 104 (35%) had copious secretions; 9 (0.3%) had ARDS. There were 19 esophageal intubations (6% incidence), 2 patients required surgical airways for failed intubation (0.6% incidence). 269 pts (90%) had all 3 methods tested. All pts had at least 2 methods tested. The bulb was not available during 3 intubation attempts; the colorimetric device during 2 attempts the infrared detector was unavailable during 32 attempts due to mechanical problems or battery failure (10% failure rate). All 3 devices had a 100% sensitivity detection esophageal intubations. The 3 devices had 99% specificity detecting tracheal placements. The 3 false negatives obtained with the bulb occurred during 1 case each of COPD, copious secretions and obesity. The 2 false negatives with the CO2 analyzers occurred during CPR. Conclusion: All devices had 100% sensitivity detecting esophageal intubations. However the portable infrared device is not sufficiently reliable in emergency settings due to mechanical and battery failure. The cost of this device makes it prohibitive to stock in all areas or on all crash carts. The bulb and the colorimetric device provide equally reliable techniques for confirming ETT position in the emergency settings providing a rigid protocol for their use is followed. Practitioners need to be aware that secretions, obesity, COPD and ongoing CPR may affect the reliability of these devices and other clinical evaluations should be taken into account. The cost of the bulb is considerably less than that of the colormetric device, which along with its reliability and portability make it an attractive alternative for confirming ETT position in the emergency setting.