Clinic
Case reports
Hardy et al. 1982: 2 Crotalus molossus molossus bites; identification: morphological.
Signs & symptoms
Local effects
Pain, extensive swelling, in one patient involving the thorax (haematothorax) and abdomen over a period of 72 h after the bite, with extensive ecchymosis, blistering (Hardy et al. 1982).
Haemostatic effects
See below, Laboratory and physical investigations.
Morbidity
After 22 months reduced fist grasp and dorsiflexion of the wrist (1/2). After 12 months mild swelling and stiffness of the finger in the morning (1/2).
Case fatality rate
0/2 (Hardy et al. 1982).
Laboratory and physical investigations
1. Haemostasis
Type of haemostatic defect
Primary, direct, i.e. not plasminogen-dependent, fibrin(ogen)olysis and platelet aggregation, weak coagulative activity (Hardy et al. 1982).
Haemostatic parameters
| Overview haemostasis | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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A
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A
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C
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H | CT | (FSP) | Tc | PT | aPTT | TT | I | FSP | D | II | V | VIII | X | XIII | PC | ATIII | PI | tPA | α2AP | |||||||||||||||||||||||||||||||||||||||||||
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D
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B
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Essential bed-side tests |
Tests for full clinical assessment | Tests for research purposes | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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| A | PT, thrombin time: increased; approx. 1 h after the bite PT >100 s (normal 11–13 s), thrombin time >100 s (normal 11–12 s) (Hardy et al. 1982). |
| B | Fibrinogen: approx. 1 h after the bite 60 mg/dl, minimum 12 mg/dl 12½ h after the bite, returned to normal after 28 h; 30 vials of polyvalent Wyeth (Crotalidae) antivenom were administered (Hardy et al. 1982). |
| C | FSP: 16 h after the bite, 40 μg/ml (normal <10 μg/ml), not determined prior to that (Hardy et al. 1982). |
| D | Platelets: approx. 1 h after the bite, 80,000/mm³, fluctuating for up to 40 h after the bite (1/2); 30 vials of polyvalent Wyeth (Crotalidae) antivenom were administered. Within the first hour after the bite 32,000/mm³, <150,000/mm³ up to and on the 4th day after the bite (fibrinogen was not decreased at any point in time) (1/2); 21 vials of polyvalent Wyeth (Crotalidae) antivenom were administered (Hardy et al. 1982). |
Treatment (symptomatic)
Fluid replacement i.v. (Hardy et al. 1982).
Treatment (specific)
1. Crotalidae Polyvalent Immune Fab Antivenom, ovine (immunized with Crotalus adamanteus, Crotalus atrox, Crotaus scutulatus ssp. and Agkistrodon piscivorus) / CroFab™, Savage Laboratories, Melville, New York
see Crotalus sp.
2. Wyeth antivenom (Crotalidae), polyvalent, Philadelphia, USA (no longer in use)
Studies
No controlled clinical studies available. Experience from observations of individual cases. Hardy et al. 1982: antivenom administration commenced 7.5 h after the bite: total dose 300 ml (= 30 vials) within 20 h (1/2); and 1.25 h after the bite: total dose 210 ml (= 21 vials) within 3 h (1/2).
Efficacy
- Effect on local cytotoxicity: no effect, drastic increase in local symptoms during and after antivenom administration. One patient received antivenom as early as 1.25 h after the bite. Apart from thrombopaenia (30,000/mm³), he did not show any haemostatic defect, but did develop massive swelling involving the right thorax (haematothorax) and abdomen within 72 h (Hardy et al. 1982).
- Effect on the haemostatic defect: clear effect on platelets, no significant effect on fibrinogen (Hardy et al. 1982).
Adverse reactions
Acute: skin rash, pruritus, rhonchi 1/2 (Hardy et al. 1982).
Delayed: on 6th day (210 ml of antivenom) 1/2 (Hardy et al. 1982).