Miguel Claudio Fernandez

Snakes and snakebite in Central America

This review treats the general biology, taxonomy, distribution and venom apparatus of the venomous snakes of Central America. Consideration has been given to the chemistry, pharmacology and immunology of the venom, and particular attention is dispensed to the clinical problem, including the treatment, of envenomations by these reptiles.

Successful treatment of valproic acid overdose with hemodialysis

A 43-year-old woman took a large amount of depakote (divalproex, a slow-release form of valproate), became comatose, and developed severe hypotension refractory to fluid resuscitation and high-dose vasopressors. The serum valproic acid (VPA) concentration on admission was 1,380 microgram/mL (therapeutic range, 50 to 100 microgram/mL). She also had metabolic acidosis, thrombocytopenia, and normal renal and liver functions. Hemodialysis was initiated 4 hours after presentation. After 6 hours of hemodialysis with a high-flux dialyzer, her serum VPA concentration decreased from 940 microgram/mL to 164 microgram/mL, coincident with improvement in clinical status. The half-life of VPA was reduced to 2.4 hours with hemodialysis, whereas it was 7.2 hours before the procedure. Hemodialysis could be a valuable therapeutic intervention in VPA toxicity.

Gabapentin, valproic acid, and ethanol intoxication : Elevated blood levels with mild clinical effects

CASE REPORT A suicidal, epileptic patient ingested ethanol, valproic acid, and gabapentin, a new antiepileptic drug. He did well clinically despite elevated blood gabapentin, valproic acid, and ethanol. CONCLUSIONS Preliminary data from this case and one previous report indicate relatively mild clinical signs and symptoms with gabapentin poisoning.

Hemodynamics after intraosseous administration of hydroxocobalamin or normal saline in a goat model.

STUDY OBJECTIVE Hydroxocobalamin may be lifesaving in cyanide (CN) poisoning, but personal protective equipment (PPE) wear, rescue, and decontamination may delay intravenous administration. Intraosseous (IO) lines may be rapidly placed even when wearing PPE. We assessed the hemodynamics of hydroxocobalamin (OHCo) and normal saline (NS) by the IO route. METHODS Twelve anesthetized Spanish goats underwent arterial line catheterization. Operators in PPE placed IO lines. After placement confirmation by fluoroscopy, animals randomly received hydroxocobalamin 75 mg/kg (3 mL/kg) (n = 6) or normal saline (NS) 3 mL/kg (n = 6) IO over approximately 7.5 minutes. Blood pressures and heart rates were monitored for 240 minutes after infusion initiation. RESULTS In the OHCo group, mean systolic and diastolic pressures peaked at 120 minutes, with mean increases of 14% and 17%, respectively, relative to infusion start, returning to near preinfusion values at 240 minutes. Heart rate changes were virtually nil. In the NS group, mean systolic pressures peaked at 60 minutes, with a mean increase of 36%, whereas diastolic pressures peaked at about 110 minutes, increasing 42%, returning to near preinfusion values at 240 minutes. Heart rate changes were minimal. CONCLUSION Hemodynamic effects of OHCo given by the IO route in non-CN-poisoned goats are mild and well tolerated. Increases in mean blood pressure at peak after baseline were greater in the NS group, but the mean values over time were not significantly different from those observed in the OHCo group. Hemodynamic effects would likely differ somewhat in a CN-poisoned goat. Intraosseous OHCo administration warrants additional investigation.

Intraosseous line placement for antidote injection by first responders and receivers wearing personal protective equipment.

STUDY OBJECTIVE Early antidotal therapy may be lifesaving in hazardous materials victims. Intravenous line placement is difficult while wearing personal protective equipment (PPE). We assessed the ability of protected, experienced first responders and limited-experience first receivers to place intraosseous (IO) lines for antidote administration. METHODS Six first responders donned 4 (A, B, C, and D) and 12 first receivers donned 2 (C and D) United States Environmental Protection Agency PPE levels in random order and then placed IO lines in 1 of 4 anatomical sites in 12 anesthetized Spanish goats. Observers timed interventions until bolus injection of isotonic sodium chloride solution. RESULTS First responders placed IO lines successfully in 100% of cases. The median (interquartile range) times to completion (in seconds) were as follows: level A, 43.5 (23.0); B, 45.0 (29.0); C, 40.0 (15.0); D, 30.0 (17.0). First receivers placed IO lines successfully in 91% of cases. The median (interquartile range) times to completion (in seconds) were as follows: level C, 42.0 (19.5); D, 37.0 (11.0). There were no significant differences in time to completion among PPE levels (overall or pairwise) or between operator groups. Two (4%) of 48 line placements resulted in recognized extravasation due to penetration of the opposite cortex. Infusions were completed successfully. CONCLUSION Hazardous materials first responders and receivers can effectively place IO lines in a goat while wearing PPE. Intraosseous lines may facilitate earlier administration of antidotes in hazardous materials victims.