Uncompensated metabolic acidosis: an underrecognized risk factor for subsequent intubation requirement.

BACKGROUND: There are no published reports identifying an inadequate ventilatory response to metabolic acidosis as a predictor of impending respiratory failure. Metabolic acidosis should induce a respiratory alkalosis in which the partial pressure of carbon dioxide (Paco2) is (1.5 [HCO3-] + 8) +/- 2. This study examined the relation between inadequate ventilatory compensation and intubation among trauma patients. METHODS: A retrospective chart review was performed for trauma patients admitted between January 1999 and December 2000. Age, gender, Injury Severity Score and combined Trauma and Injury Severity Score, chest injury, history of cardiac or pulmonary disease, partial pressure of oxygen (Pao2), Paco2, Glasgow Coma Score, respiratory rate, systolic blood pressure, base deficit, and ability to compensate were analyzed with respect to intubation and need for ventilator support. RESULTS: Of 140 patients with metabolic acidosis, 45 ultimately were intubated. The mean Paco2 for the unintubated patients was 34 +/- 7 mm Hg, as compared with 41 +/- 11 mm Hg for the intubated patients (p < 0.001). Only injury severity and ability to compensate for metabolic acidosis were independent predictors of intubation. Patients with inadequate compensation were 4.2 times more likely to require intubation when control was used for the Injury Severity Score (95% confidence interval, 1.8-9.7; p < 0.001). CONCLUSIONS: Inability to mount an adequate hyperventilatory response to metabolic acidosis is associated with an increased likelihood of respiratory failure and a need for ventilatory support. Recognition of this relation should lead to closer monitoring of patients with this condition, and could help to avert unforeseen crisis intubations. This observation needs to be validated in a prospective study.

Toll of methamphetamine on the trauma system.

HYPOTHESIS: Methamphetamine use affects length of hospital stay in the minimally injured patient. DESIGN: Case series. SETTING: The only tertiary trauma center serving Hawaii. PATIENTS: Trauma patients examined during a 12-month period with an Injury Severity Score of 1 to 5 and an age of 18 to 55 years undergoing urine toxicology screen for suspected suicide attempt or altered sensorium. MAIN OUTCOME MEASURES: Presence or absence of amphetamine or methamphetamine on urine toxicology screen, intention of injury, hospital admission rate, length of stay, and hospital charges. RESULTS: During the study period, 1650 trauma patients were examined, with 544 meeting study criteria. Urine toxicology screens were performed in 212 patients, with 57 positive and 155 negative for amphetamine or methamphetamine. There was no difference in sex (77% vs 73% male; P =.53), Injury Severity Score (3.2 for both groups), or total number of computed tomographic scans performed (mean +/- SEM, 3.0 +/- 0.3 vs 4.0 +/- 0.3; P =.07). Patients in the positive group were more likely to have intentional self-inflicted injury or intentional assaults than patients in the negative group (37% vs 22%; P =.04). The positive group was older than the negative group (33.6 +/- 1.3 vs 29.9 +/- 0.8 years; P =.02), had a significantly longer hospital stay (2.7 +/- 0.4 vs 1.7 +/- 0.1 days; P =.003), had significantly higher hospital charges (15 617 dollars +/- 1866 dollars vs 11 600 dollars +/- 648 dollars; P =.01), and was more likely admitted to the hospital (91% vs 70%; P =.001) despite the low Injury Severity Score. CONCLUSION: Methamphetamine use results in trauma center resource utilization out of proportion to injury severity.

etapi and eta'pi spectra and interpretation of possible exotic JPC=1-+ mesons.

We discuss a coupled channel analysis of the etapi and eta'pi systems produced in pi(-)p interactions at 18 GeV/c. We show that known Q(-)Q resonances, together with residual soft meson-meson rescattering, saturate the spectra including the exotic J(PC)=1(-+) channel. The possibility of a narrow exotic resonance at a mass near 1.6 GeV/c(2) cannot, however, be ruled out.