Comparison of hyperbaric oxygen and dapsone therapy for loxosceles envenomation.

OBJECTIVE: To determine whether hyperbaric O2 (HBO), dapsone, or HBO plus dapsone affects lesion size in a swine model of Loxosceles envenomation. METHODS: In a randomized controlled animal laboratory experiment, 32 piglets were assigned to 1 of 4 equal groups. Each piglet received 15 microliters, of purified venom intradermally on day zero. Group 1 received no treatment; group 2 received HBO at 2 atm for 2 hours on days 1-3; group 3 received 50 mg of dapsone orally on days 1-3; and group 4 received dapsone 50 mg orally and HBO at 2 atm for 2 hours on days 1-3. On days 1-7, 14, and 21, an investigator blinded to the treatment groups measured necrosis and induration. Mean necrosis and induration rates were compared using analysis of variance for repeated measures. RESULTS: Comparing groups on any day, no significant difference was noted in necrosis, induration, reduction in necrosis from day 1, or rate of change in lesion size from days 1-7. A difference was seen in the reduction of induration between all 3 treatment groups and the control group on days 7 and 14 only. The sample size permitted a power of 0.8 to detect a 12-mm mean change in lesion size. CONCLUSION: Compared with the control, neither dapsone, HBO, nor the combination of dapsone and HBO reduced necrosis from Loxosceles envenomation on days 3-21. An increase was seen in the rate of reduction in induration between all 3 treatment groups and the control group on days 7-21. However, the magnitude of this effect was clinically insignificant. In this animal model, treatment with either dapsone or HBO or a combination offers little clinical benefit in Loxosceles envenomation.

Oral labetalol versus oral nifedipine in hypertensive urgencies in the ED.

Therapy in hypertensive urgencies is debated and complicated by the side effects of available agents. In a prospective, randomized, open labeled study, the use of oral labetalol, an alpha- and beta-adrenergic blocker, with oral nifedipine in hypertensive urgencies in the emergency department was compared. Patients with diastolic blood pressures (DBP) of more than 120 mm Hg without criteria for a hypertensive emergency were eligible. The drugs were given in a loading manner with doses and timing based on their respective pharmacokinetics until a DBP of 110 mm Hg or lower was obtained or 4 hours had passed. Either an initial labetalol dose of 200 mg and a repeat dose of 100 to 200 mg at 2 hours, depending on the DBP or nifedipine, 10-mg bite and swallow every hour up to a total dose of 20 mg were given. Ten patients were enrolled into each study group. A 100% response rate was defined as a DBP of 110 mm Hg or less was observed for nifedipine and an 80% response rate for labetalol (P > .2) was observed. The mean time to control was 67.5 minutes for labetalol and 60.0 minutes for nifedipine (P > .2). The pretreatment pressure for labetalol was 195/127 mm Hg and for nifedipine was 198/128 mm Hg (P > .2), which decreased to a posttreatment pressure for labetalol of 154/100 mm Hg and for nifedipine of 163/100 mm Hg (P > .2). The mean decrease in systolic (SBP)/DBP was 42.6/26.5 mm Hg with labetalol and 34.9/28.4 mm Hg for nifedipine (P > .2). No significant side effects occurred with either drug.(ABSTRACT TRUNCATED AT 250 WORDS)

Intranasal midazolam as a sedative for children during laceration repair.

We performed a retrospective chart review to determine the onset, duration, safety, and clinical sedative effects of 0.2 to 0.5 mg/kg intranasal midazolam in young children during laceration repair. Of 408 children treated for lacerations during an 8-month period, 42 (10%) received intranasal midazolam. Documentation was adequate for detailed analysis in 40 cases. Data are reported as mean +/- standard deviation and the frequency with 95% confidence limit (CL) estimates. The mean age of the study population was 32 +/- 9 months (range 12 months to 6 years), and the mean body mass was 14.5 +/- 3 kg. Topical or injected local anesthesia was used in 37 cases. Overall, 73% (CL 56% to 85%) of the children achieved adequate sedation. However, those receiving 0.2 to 0.29 mg/kg had adequate sedation in only 27% (CL 6% to 60%) of the cases compared with 80% (CL 52% to 95%) and 100% (CL 79% to 100%) when 0.3 to 0.39 and 0.4 to 0.5 mg/kg respectively were administered. When achieved, sedation occurred within 12 +/- 4 minutes, recovery occurred at 41 +/- 9 minutes, and discharge occurred at 56 +/- 11 minutes. No vomiting or clinically significant oxygen desaturation (defined as a drop of > 4% or to < 91%) was observed. We conclude that intranasal midazolam is a safe and effective sedative for laceration repair under local anesthesia in preschool-aged children. We recommend a dose of 0.3 to 0.5 mg/kg, with treatment failure less likely after 0.4 to 0.5 mg/kg compared with less than 0.3 mg/kg.