Evaluation of gastric emptying using radionuclides: gastric lavage versus ipecac-induced emesis.

STUDY OBJECTIVES: To compare the efficacy of gastric lavage and ipecac-induced emesis by using a radionuclide marker in a simulated overdose and to determine the amount of material recoverable after lavage fluid appears clear. DESIGN: Case-control, prospective cross-over study. SETTING: Nuclear medicine department of Valley Medical Center, Fresno, California. TYPE OF PARTICIPANTS: Fourteen male and five nonpregnant female adult volunteers with no pre-existing gastrointestinal disease and no medication use. INTERVENTIONS AND MEASUREMENTS: In phase 1, each volunteer ingested 30 capsules labeled with a measured amount of Tc99m with 75 mL H2O followed in five minutes by ipecac-induced emesis. In phase 2, two to four weeks later, each subject was lavaged after ingesting 30 labeled capsules. After lavage appeared clear, a 1,000-mL supplemental lavage was done and analyzed separately. All emesis or gastric lavage fluid was collected and measured for tracer activity. RESULTS: All subjects in the ipecac group vomited with an average time from ipecac to emesis of 19 minutes. Two subjects withdrew from the study, refusing to complete lavage due to discomfort. Based on retrieved material, ipecac-induced emesis returned significantly more tracer (mean +/- SD, 54.1 +/- 21.3%) than lavage until clear (mean +/- SD, 30.3 +/- 17.4%) (P = .0021). Supplemental lavage returned 12.9% of the total recovered marker (SD, 11.6%). The total of initial and supplemental returns from lavage was 35.5% (SD, 21.0%). This return was significantly less than that returned by ipecac-induced emesis (P = .016). CONCLUSION: In this study, ipecac-induced emesis was significantly more effective than gastric lavage in emptying the stomach after simulated overdose. Significant amounts of ingested material are recoverable in gastric lavage return after it appears clear.

The effect of axial traction during orotracheal intubation of the trauma victim with an unstable cervical spine.

Axial (in-line) traction is recommended as a stabilizing maneuver during orotracheal intubation of a trauma victim with a potential cervical spine injury. There are no published data demonstrating the safety of this technique in trauma patients with an unstable cervical spine. In our study, 17 victims of blunt traumatic arrest had radiographic analysis of the cervical spine during orotracheal intubation, with and without axial traction. Four (24%) had unstable injuries, which included a C6-7 fracture dislocation, a Hangman's fracture, and two atlanto-occipital dislocations. Axial traction during oral intubation in these victims resulted in a mean distraction at the fracture site of 7.75 mm. Axial traction produced 4 mm of posterior subluxation in the C6-7 fracture dislocation, demonstrating that axial traction alone may result in subluxation, as well as distraction. This depends on the direction of the traction force and integrity of surrounding tissues. We recommend that trauma patients requiring intubation prior to a complete examination and radiographic analysis of the cervical spine be nasotracheally intubated without axial traction, and that the head and neck be stabilized in the neutral position. If a contraindication to nasotracheal intubation exists, a cricothyroidotomy should be performed.

Antishock trousers: a comparison of inflation techniques and inflation pressures.

Ten healthy male volunteers were studied to compare the effects of simultaneous versus sequential inflation of antishock trousers (AST) and simultaneous inflation pressures of 20, 40, and 100 mm Hg on blood volume displacement centrally. Radioisotope scans were used to determine the change in blood volume distribution with various inflation methods and inflation pressures of the AST. Our data suggest that the minimum inflation pressure that displaces blood centrally is 40 mm Hg, and that higher inflation pressures displace a greater percentage of the total blood volume to the central circulation than do lower pressures. The difference is small, however, and probably has no clinical effect. No difference was suggested between simultaneous and sequential inflation.

Blood volume distribution in the Trendelenburg position.

The Trendelenburg position is used frequently in treating hypotensive patients. It is believed that placing patients in the Trendelenburg position causes an autotransfusion of blood to the central circulation. No published studies document the volume of blood displaced centrally. In our study ten volunteers were placed in the Trendelenburg position. Blood volumes were determined from body surface area, and radionuclide scanning was used to determine blood volume distribution. Placing normovolemic volunteers in the Trendelenburg resulted in a 1.8% (median) displacement of the total volume centrally. The autotransfusion of blood produced by the Trendelenburg position is small and is unlikely to have an important clinical effect.

Blood volume displacement with inflation of antishock trousers.

Eleven healthy male volunteers were studied to determine the amount of blood displaced by the inflation of the antishock trousers (AST) at pressures of 40 and 100 mm Hg. Radioisotope scans were used to determine the blood volume distribution and the change in the volume of distribution with inflation of the AST. The volunteers were then phlebotomized approximately one liter of blood and the study was repeated. Less than 5% of the total blood volume was displaced with inflation of the AST. It is unlikely that the clinical improvement seen with inflation of the AST in hypovolemic shock is due to autotransfusion of blood alone.