The Quarterly journal of medicine
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Randomized Controlled Trial Comparative Study Clinical Trial
Randomized comparative trial of three antivenoms in the treatment of envenoming by lance-headed vipers (Bothrops jararaca) in São Paulo, Brazil.
In São Paulo City, Brazil, 121 patients with moderately severe envenoming by Bothrops snakes (principally B. jararaca) were randomized for treatment with Brazilian polyspecific Bothrops antivenoms: Instituto Butantan (39 patients), Instituto Vital Brazil (41), Fundação Ezequiel Dias (FUNED) (41). The initial dose was four ampoules (40 ml) in 89 patients with less severe envenoming and eight ampoules (80 ml) in 32 patients with more severe envenoming. A second dose of four ampoules was required in 20 patients. ⋯ A possible explanation was the higher total protein content and percentage immunoglobulin of Butantan antivenom. The doses of antivenom recommended in Brazil and used in this study may be unnecessarily high, resulting in an unacceptably high incidence of reactions. Results of the study should prompt a critical re-evaluation of antivenom production techniques and dosage recommendations in Brazil.
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The pathophysiology of afterdrop of core temperature during rewarming in patients with induced or accidental hypothermia remains controversial. We studied the effect of cooling and rewarming in four female patients with acquired poikilothermia and in four normal females. Exposure to cold air (16.5 degrees C) induced shivering and adequate vasoconstriction in normal individuals, without a fall in rectal temperature (Tr; 36.3 +/- 0.2 degrees C [mean +/- SD]); subsequent heating (40 degrees C) induced a rise in Tr to 37.0 +/- 0.3 degrees C and generalized sweating. ⋯ The basal metabolic rate was decreased by 71-82% in all patients during steady-state hypothermia and remained lowered during normothermia in two patients. We conclude that during hypothermia three of the four patients showed severe disorders of peripheral vasomotor function and shivering response. These data provide evidence for thermal conduction as the major mechanism of afterdrop during hypothermia.
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Randomized Controlled Trial Clinical Trial
Phrenic nerve and diaphragm function following open heart surgery: a prospective study with and without topical hypothermia.
In a prospective study, 100 patients undergoing open heart surgery were randomly allocated to receive ice/slush topical hypothermia for myocardial protection (Group I, n = 56) or not (Group II, n = 44). Chest radiographs, diaphragm screening, lung function and phrenic nerve conduction time were assessed pre-operatively and at 1 week and 1 month post-operatively in all patients and subsequently at 3 months, 6 months, 1 year and 2 years in all patients with radiological evidence of diaphragm paralysis. The two groups were similar in terms of age, sex, diabetes and smoking habits. ⋯ Phrenic nerve conduction time was recorded in 98 per cent of patients pre-operatively, but was unrecordable on the appropriate side in all 20 patients with diaphragm paralysis 1 week post-operatively. Prolonged phrenic nerve conduction time on the left side was found in a further seven Group I patients 1 week post-operatively. There were no significant differences between the two groups in terms of post-operative arrhythmias, myocardial infarction or mortality.(ABSTRACT TRUNCATED AT 250 WORDS)