Biology Reference
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given taxa may provide fuel for concerns regarding unknown clinical potential. Also,
the majority of these bites occur during intentional contact with the snake. Therefore,
the inherent curiosity of many professional biologists and interested amateurs occa-
sionally results in a protracted bite due to interest in “what might happen” (e.g., see
Sections 4.5.1, 4.5.1.4, and 4.5.1.5 and Appendix A). This subjective experiment
projects uncertainty regarding possible effects and thus can generate anxiety regard-
ing an unforeseen response perceived as clinically significant.
4.6 Recommendations for Management of Medically
Significant “Colubrid” Bites
4.6.1 General
Most victims bitten by non-front-fanged colubroid snakes report mild, usually medi-
cally insignificant effects (
Table 4.1
; previous sections). However, as detailed in
Sections 4.3 and 4.4, bites by some taxa prove serious and occasionally cause fatal
envenomation. Therefore, as the majority of these diverse colubroids are of unknown
medical importance, specific management guidelines cannot be provided for most
species.
Table 4.3
assesses the medical risk of species for which sufficient informa-
tion is available to evaluate their potential hazard index.
Table 4.3
also summarizes
recommendations for management of medically significant bites inflicted by these
species. Significant envenomation from taxa assigned with a level 1 hazard index
require admission, extended observation, investigations/serial monitoring focused on
hemostatic and renal functions, supportive measures as indicated (see later), and spe-
cific antivenom as available (
Table 4.3
; Section 4.3). Although comprehensive coag-
ulation panels can help further characterize the nature of the hemorrhagic diathesis,
evidence suggests that a combination of the PT and aPTT is a sufficient and cost-
effective endpoint for treating venom-induced consumptive coagulopathy (Isbister
et al., 2006). Some patients bitten by hazard level 1 colubrids may exhibit gingi-
val bleeding as is observed in envenomings by front-fanged colubroids such as the
Malayan pit viper (
Calloselasma rhodostoma
; see
Plate 4.94
). As noted previously,
observations made during management of some life-threatening
R. tigrinus
enven-
omations have suggested that simple urine dipsticks may detect proteinuria and/
or hemoglobinuria, thereby providing an early indicator of systemic envenomation
(see later). In rural medical facilities without access to any instrumented testing, the
bedside 20-min whole blood clotting test provides a reasonably reliable guide to the
presence of coagulopathy (Warrell, 1995a, 1995b). Early discharge of these patients
is strongly discouraged.
Those with level 2 or 2/3 hazard indices often only require local wound care, but
occasional bites may produce systemic effects of unclear etiology, especially in pedi-
atric and, possibly, geriatric patients (see Sections 4.4.1 and 4.4.2 and
Tables 4.1 and
4.3
). Species with a level 3 hazard ranking commonly produce minor local effects,
but may produce moderate local effects (
Table 4.3
). Some may have the potential for