Biology Reference
In-Depth Information
Table 4.3
and include i.v. access and fluid resuscitation as needed, wound evaluation,
and management as noted previously, and attention to case-specific requirements (e.g.,
nasal cannula and oxygen). Need for insertion of central lines and/or repeated veni-
puncture must be cautiously considered in any case suggestive of possible coagulopa-
thy due to the risk of uncontrollable bleeding (see
Tables 4.1 and 4.3
and Section 4.3).
Arterial puncture and/or lines are contraindicated.
Patients with comorbidities such as ischemic heart disease may require admission
to a cardiac telemetry unit, as the anxiety/elevated catecholamine stimulation may
exacerbate cardiac symptoms (e.g., angina, dyspnea). Similarly, patients with psychi-
atric disorders (particularly generalized anxiety disorder or psychotic illnesses) may
require reinforced reassurance and mild sedation. Supportive management is deter-
mined on a case-by-case basis due to individual levels of anxiety, the nature of the
bite and its effects, and the extent of comorbid pathology.
4.6.2.7 Antivenom
The only antivenoms available for non-front-fanged colubroid snakes are prepared
against two hazard level 1 species (
D. typus
and
R. tigrinus
;
Table 4.3
). As noted,
there are no commercial antivenoms against any species of
Thelotornis
, and antive-
nom against
D. typus
venom does not cross-react with or paraspecifically neutralize
Thelotornis
venoms (Atkinson et al., 1980; Du Toit, 1980; Visser and Chapman, 1978).
Antivenom Against
D. typus
Effective antivenom against
D. typus
was first documented by Grasset and Shaafsma
(1940). These investigators also reported lack of efficacy of South African Institute for
Medical Research (SAIMR; now, South African Vaccine Producers, SAVP) polyvalent
antivenom for
D. typus
envenoming (Grasset and Shaafsma, 1940). Anti-
D. typus
anti-
venom has been used in a significant number of serious envenoming cases, and it clearly
reverses the life-threatening coagulopathy that characterizes the venom disease from this
species (
Table 4.1
). For example, Lakier and Fritz (1969) administered four ampoules of
anti-
D. typus
antivenom to a patient with life-threatening coagulopathy. The antivenom
effectively reversed the patient's consumptive coagulopathy and DIC. It is important to
note that this patient still received dialysis due to probable microangiopathic hemolytic
anemia (MAHA) with concomitant AKI due to hemoglobinuric nephropathy (Lakier
and Fritz, 1969). A thromboelastographic analysis indicated reversal of an evolving con-
sumptive coagulopathy following administration of two ampoules of
D. typus
antivenom
in a 10-year-old patient envenomed by a
D. typus
(Aitchison, 1990). A similarly rapid
reversal was noted in a delayed presentation after a life-threatening
D. typus
envenoming.
The patient presented 60 h after a bite from a snake tentatively identified as either a “bird-
snake or a boomslang” (Du Toit, 1980). It is noteworthy that the patient, a native “snake
charmer,” incorrectly identified the snake as a green mamba (Eastern green mamba,
Dendroaspis angusticeps
; although these snakes look significantly different, a casual
or excited observer could mistake their identities; see
Plate 4.95A and B
, and compare
with Plate 4.20A-C). The patient was semicomatose on arrival and exhibited marked
anemia and consumptive coagulopathy (Du Toit, 1980). Two vials of anti-
D. typus
