Biology Reference
In-Depth Information
(empirical and specific) recommended for treating potential secondary infections
associated with snakebites have included amoxicillin and clavulanic acid, or clinda-
mycin for penicillin-allergic patients (Weinstein and Keyler, 2009); levofloxacin plus
amoxicillin and clavulanic acid (Lam et al., 2010; Shek et al., 2009); and gentamycin
with benzyl penicillin (Theakston et al., 1990).
In a prospective series of cases, Weed (1993) reported absence of infection in 68
28
patients bitten by nonvenomous snakes including
T. sirtalis
,
L. getula
, and pythoniids,
and commented that although pathogenic bacteria are reported from the ophidian buc-
cal cavity, nonvenomous bites do not usually require prophylactic antibiotics. As there
is only a single well-documented non-front-fanged colubroid bite that included superfi-
cial necrotic effects (Knabe, 1939; see page 161), there is no evidence to support the use
of antibiotics in the absence of clinically recognizable infection. The unnecessary and
excessive use of prophylactic antibiotics (particularly for upper respiratory infections that
are most often of viral etiology) has resulted in global antibiotic resistance among many
common bacterial species. This very serious trend should be avoided whenever possible,
including in cases of non-front-fanged snakebites that very rarely include significant sec-
ondary infection. Colubroid bites are very unlikely to develop necrosis due to the action
of Duvernoy's secretion or venom components. However, the inappropriate and posi-
tively damaging use of tourniquets, wound incision, vacuum extraction, electric current,
etc. for treatment of any snakebite may lead to serious secondary infection and necrosis.
4.6.2.16 Cautions and Contraindications
In general, the following
are to be avoided
in these cases:
l
Do not
attempt to suture or surgically modify any bleeding wound, as this will likely result
in massive hematoma and/or uncontrolled bleeding.
l
Do not
give i.m. injections, such as updating tetanus immune status, until any coagulopa-
thy or bleeding tendency has resolved; pressure should always be applied to the i.m. injec-
tion site. Note that tetanus is a risk in snakebite, albeit small, so tetanus immune status
should be considered.
l
Be aware
of the risk of ongoing and uncontrolled bleeding from any site of trauma, which
includes any i.v. needle insertions.
Avoid
, unless no reasonable alternative exists, any i.v.
sampling or canulation of the subclavian, jugular, or femoral vessels (e.g., insertion of cen-
tral lines; if a central line is deemed essential, the femoral is the best option as hemostatic
pressure can be applied as necessary). Due to the serious risks of uncontrollable hemor-
rhage, continuous monitoring via an intra-arterial line is
contraindicated
in any case of
coagulopathic envenomation.
l
Do not
permit patient intake of any supplements, botanical remedies, or naturopathic/
homeopathic treatments (useless in management and may contain pro- or anticoagulant
components, e.g., gingkosides of gingko biloba).
l
Do not
provide antibiotics unless there is evidence of infection or necrotic tissue is evi-
dent, and/or there has been nonsterile interference with the wound.
l
Carefully review
any medications routinely taken by the patient. Some medications [i.e.,
warfarin, some antidepressants (some mixed reuptake inhibitors such as venlafaxine and
28
Weed (1993) included 72 patients in the study, but four patients had taken prophylactic antibiotics prior
to presentation and therefore are not included in the brief assessment here.
