Venomous snakebite in Thailand. II: Clinical experience.

We reviewed a total of 2,525 snakebite patients in Bangkok. Of these, 1,415 were bitten by venomous snakes, 91 by neurotoxic snakes of genus Naja or Bungarus and 1,324 by snakes of family Viperidae or Crotalidae. Seventy-one percent of bites were on the lower extremity. There were two fatal cobra bites; both patients were dead on arrival at the hospital. Bites from vipers caused morbidity but no deaths. Species-specific antivenins are effective in reversing respiratory failure from cobra bites and coagulopathies from bites by Viperidae and Crotalidae snakes. However, early respiratory and wound care will save lives even in the absence of specific cobra and krait antivenin. Care of a snakebite victim should consist of immobilization and bandaging of the bitten limb with elastic bandages during transport to the hospital, early surgical debridement of necrotic tissue, appropriate infusion of antivenin, aggressive respiratory support, management of shock and infection, and peritoneal dialysis or hemodialysis. Incision of bite wounds, suctioning, application of ice, and tourniquets are of no proven value and may be dangerous. All snakebite victims in southeast Asia should survive if they receive early competent care.

Management of thai cobra bites with a single bolus of antivenin.

Between January 1981 and December 1991, 68 adults were treated at Chulalongkorn University for cobra bites. Respiratory failure developed in the bite victims even when an adequate genus-specific antivenin was administered at the onset of neuromuscular paralysis. The duration of time spent on a respirator was, however, significantly less in patients treated with an intravenous 100-ml antivenin bolus given at the onset of neurotoxic signs. We found that a bolus of 100 ml of purified equine antivenin produced by the Queen Saovabha Memorial Institute, Bangkok, from Naja kauthia venom was adequate and that increasing the dose did not lead to added benefits. Time spent on a respirator was approximately 10 h in antivenin-treated groups and 40 h if no antivenin or an inadequate dose was used. Competent respiratory and nursing care alone without antivenin will lead to eventual recovery and prevent death. Local bite site tissue necrosis and duration of hospitalization were not related to the dose of antivenin given. Hospitalization was prolonged in subjects who developed sepsis or who had severe tissue necrosis or other surgical or medical complications.

Renal dysfunction in glomerulonephropathy associated with rapid onset renal failure.

Eight patients between the ages of 5 and 26 years developed a rapid decline of renal function with a period of oliguria or anuria which ranged between 1 and 21 days. The initial assessment of renal function revealed a severe degree of glomerular, tubular, and vascular abnormalities. The magnitude of the renal dysfunction was quantified and expressed in terms of a clinical score. The degree of glomerular and tubular dysfunction was inversely proportional to the renal plasma flow and peritubular capillary blood flow, respectively. Similar findings have been observed in a variety of other glomerulonephropathies where a relationship exists between the reduction of peritubular capillary blood flow and the severity of the tubulointerstitial disease. Evidence to support the position that the reduction of peritubular capillary blood flow plays a primary role in inducing tubulointerstitial disease is as follows: (i) A reduction of peritubular capillary blood flow has been documented in mesangial proliferative nephrosis with steroid resistance prior to the detection of tubulointerstitial disease. (ii) Ischemic insults are capable of inducing tubulointerstitial disease in the experimental setting of renal artery occlusion in animals. (iii) As demonstrated in the present report, an improvement of tubular function can be achieved following an increase in peritubular capillary blood flow with therapy designed to enhance renal perfusion.

Spontaneous recovery from severe neurotoxic envenoming by a Malayan krait Bungarus candidus (Linnaeus) in Thailand.

A patient bitten by Bungarus candidus (Malayan krait) developed nausea, vomiting, weakness, and myalgia 30 minutes after being bitten. One hour later, ptosis and occulomotor palsies as well as tightness of his chest were noted. Respiratory failure requiring mechanical respiration appeared 8 hours after the bite and lasted for nearly 96 hours. The two bite sites were virtually painless and resulted in slight transient erythema and edema. No specific antivenin was available, and treatment consisted of respiratory support and management of aspiration pneumonitis. Recovery was complete.

Renal dysfunctions in glomerulonephropathy with rapidly declined renal failure.

Eight patients aged between 5 and 26 years developed rapid deterioration of renal function and became oliguric/anuric with duration ranging from 1 to 21 days. The initial functional assessment revealed severe degree of glomerular, tubular, and vascular dysfunctions. The magnitude of renal dysfunction was quantified and expressed in terms of a clinical score. The degree of glomerular and tubular dysfunctions were inversely proportional to the renal plasma flow and peritubular capillary blood flow (PTCB), respectively. Similar findings have been observed in a variety of severe glomerulonephropathies. In this aspect, it is likely that the reduction of peritubular capillary blood flow and tubulointerstitial disease are interrelated. Further evidence to support the primary role of reduction of PTCB in inducing tubulointerstitial disease is provided by the following: (a) Reduction of PTCB is documented in mesangial proliferative nephrosis with steroid resistance prior to the detection of tubulointerstitial disease. (b) Ischemic insult can induce tubulointerstitial disease in experimental setting of renal artery occlusion in animal, (c) Improved tubular function can be achieved following the increase in PTCB with the enhanced renal perfusion therapy.

Management of cobra bite by artificial respiration and supportive therapy.

During the period when the hospital ran out of cobra antivenom, 4 patients bitten by cobra with neuromuscular symptoms and respiratory depression were treated with artificial respiration. Complete recovery was noted within 36 to 72 hours. The data are interpreted to indicate the reversible binding of the venom to receptors. Artificial ventilation appears to be another alternative to specific antivenom treatment and may be used when the antivenom is not available or if there is antivenom hypersensitivity.

Intrarenal hemodynamic abnormality in severe form of glomerulonephritis: therapeutic benefit with vasodilators.

Intrarenal hemodynamic and tubular function has been assessed in 16 patients who presented clinically with hypertension, hematuria and severe renal functional impairment. Twelve of these 16 patients had histopathologic classification as DPGN (3 cases), MPGN (3 cases) and FSGS (6 cases). The initial assessment of intrarenal hemodynamics in 11 patients revealed strikingly increased afferent (RA) and efferent arterioles (RE), filtration fraction (FF), intraglomerular capillary hydrostatic pressure (PG), whereas, there was marked reduction in renal plasma flow (RPF), in ultrafiltration coefficient (KFG) and in glomerular filtration rate (GFR). Tubular transporting defect as being reflected by enhanced fractional excretions of solutes was also observed. Both enhanced TXB2 production and diminished PGI2 may be in part responsible for the marked reduction of RPF and elevated intrarenal resistance. In light of the preceding intrarenal hemodynamics alteration, therapeutic intervention with vasodilators consisting of dipyridamole, calcium channel blocker and angiotensin convertase inhibitor has been accomplished with clinical improvement in glomerular and tubular functions following the improvement in intrarenal hemodynamics. Thus, this abnormal intrarenal hemodynamics renders a supportive view of the hemodynamically mediated glomerulo-tubulo-interstitial injury to be central to the pathogenetic mechanism.

Effects of acute arginine loading on renal and systemic hemodynamics in dogs.

Effects of L-arginine (ARG) infusion on renal and systemic hemodynamics were studied in 12 anesthetized dogs. The experiment was performed in two groups of dogs. The dogs of group 1 (n = 6) received intravenous ARG at 2.5 mmol/kg followed by indomethacin (IND) injection (10 mg/kg) and were rechallenged with ARG at the same amount. The dogs of group 2 (n = 6) received intravenous ARG at 5 mmol/kg followed by IND injection (10 mg/kg) and were later infused with ARG at the same dose. In group 1, the first ARG infusion caused no significant changes in renal and systemic hemodynamics. During the second ARG infusion, glomerular filtration rate (GFR) and renal plasma flow (RPF) were significantly increased when compared with the IND-treated period. In group 2, the first ARG infusion increased cardiac output (CO) and decreased total peripheral resistance (TPR) without significant changes in GFR and RPF. The second ARG infusion induced acute rise of both GFR and RPF approximately twofold, compared with the IND-treated period. CO was also increased significantly. Plasma glucagon levels determined in 2 dogs showed an increase following both ARG infusions. These results indicate that an acute ARG loading induces renal and systemic vasodilatation in a dose-dependent manner despite IND effect, and would indicate that increased renal hemodynamics are not prostaglandin-mediated.

The use of oral essential amino acids in hemodialysis patients.

Fifteen patients with chronic renal failure, stabilized on twice weekly hemodialysis, received oral essential amino acid therapy (6.3 g/day) over a period of 12.3 months. Clinical and laboratory improvement was observed with respect to body weight, tricep skin fold thickness, mid upper arm circumference serum albumin, C3 and plasma essential amino acids. Serum triglyceride was decreased. The patients felt well with increased appetite. Essential amino acids were well tolerated without side effects.

Acute interstitial nephritis in snake bite.

Acute renal failure with prolonged oliguria was observed in a patient following the bite of a Russell's viper (Vipera russellii siamensis). Renal biopsy revealed interstitial nephritis in addition to tubular necrosis and mesangial proliferation usually noted. There was no deposition of immunoglobulins. The finding expands the spectrum of renal changes in snake bite.