Lack of controlled studies on snakebite prevention: a rapid review

Globally, snakebites cause an estimated 80 000-140 000 deaths annually. While there are evidence-based recommendations for managing snakebite victims, recommendations on the prevention of snakebites are limited to expert opinions. We conducted a rapid review to summarise evidence from human studies with a control group on preventing snakebites. Searching PubMed, Web of Science, Scopus, CINAHL and EMBASE with inclusive search terms without language or time limits only yielded three eligible studies (one case control study and two prospective controlled clinical studies), highlighting a knowledge gap. Two studies in Nepal by the same group showed that health education of stakeholders and sleeping under a bednet can significantly reduce snakebite incidence (p<0.05), but these observations are not confirmed elsewhere, and because of the high risk of bias the certainty of evidence was low. The third study from Sri Lanka, which assessed if sleeping above ground would prevent snakebites, had inconclusive results. This demonstrates an urgent need for studies with a control group to guide evidence-based recommendations for snakebite prevention. Potential interventions tested can range from low-cost measures such as wearing appropriate footwear in resource-limited settings to testing the efficacy of chemical, biological (e.g. rodent control) or device-based methods and community-supported platforms tracking snakebite sightings with real-time geolocation data in highly resourced settings.

The use of rotational thromboelastometry parameters in understanding the coagulopathy following hump-nosed viper (Hypnale spp) bites: a preliminary study

BACKGROUND

Hump-nosed vipers (HNV; Hypnale spp) are one of the medically important venomous snakes in Sri Lanka and South-Western regions of India. The haemostatic dysfunction due to HNV bites is poorly characterized by standard diagnostic tests performed to identify coagulopathy. We aimed to determine the usefulness of rotational thromboelastometry (ROTEM) parameters compared to 20-minute whole blood clotting test (WBCT20) and prothrombin time (PT) in understanding the coagulopathy of HNV bites.

METHODS

Twenty-three HNV snakebite patients in a prospective study of 127 consecutive snakebites were recruited. After recording details of the clinical presentation, PT/international normalized ratio (INR), WBCT20 and ROTEM delta were performed at presentation.

RESULTS

In this preliminary study, none of the patients had clinically apparent bleeding. Coagulopathy was detected by either WBCT20, INR or ROTEM in 13 HNV patients. Eleven had a coagulopathy detectable by ROTEM (either abnormal EXTEM-CT, INTEM-CT or FIBTEM-MCF) but with negative WBCT20. Of them, only two had prolonged INR values. Two patients had positive WBCT20 but with normal ROTEM and INR values. The remaining 10 patients did not show any coagulopathy either by INR, ROTEM or WBCT20.

CONCLUSION

In this preliminary study with small number of sample size, ROTEM parameters appeared to be more sensitive to subtle changes in coagulation compared to WBCT20. The clinical utility of detecting these changes and their usefulness in managing snakebite should be explored further in a larger study.

Knowledge on prevention, diagnosis and treatment of snakebite envenoming among doctors in snakebite-dense regions in Sri Lanka

BACKGROUND

Sri Lanka is one of the highest envenoming reporting countries globally with >80 000 snakebites per year. Among other factors, knowledge of snakebite among doctors predominantly determines patient outcomes.

METHODS

Using a pretested 72-item self-administered questionnaire, we assessed knowledge on identifying common snake species, signs of envenoming and management of venomous snakebites among 280 doctors working in eight state hospitals in regions where snakebite prevalence is highest in Sri Lanka.

RESULTS

Visually, 92.1% correctly identified a cobra and 74.3% identified a Russell's viper, but only 30% could identify a hump-nosed viper (HNV). Syndromic identification of snakes was best for the krait (71.8%) followed by the cobra (59.6%), but poor for the HNV (30%). The median knowledge scores of pictorial and syndromic snake identification, indoor preventive measures and indications of antivenom were <75% of the maximum score. Apart from 62.5% who expected the victim to bring the snake along to the hospital, most doctors selected the correct options of pre-hospital care. The duration of work experience did not influence the competency of syndromic identification. Utilisation of local guidelines was associated with better knowledge in antivenom usage (odds ratio 2.22 [95% confidence interval 1.04 to 5.36]; p=0.03).

CONCLUSIONS

Specific deficiencies of core knowledge in snakebite management exist among doctors working in snakebite prevalent regions.

Acute poisoning with acetamiprid: a case report

BACKGROUND

Acetamiprid is a potent new first-generation neonicotinoid insecticide in agricultural practices. It is well described that it has low toxicity among animals and is lethal if consumed in large amounts. However, toxicity in humans is rarely reported in literature. Here, we describe acetamiprid toxicity complicated with severe lactic acidosis, myocardial ischemia, refractory hypotension, and severe hypokalemia in a middle-aged man who presented with deliberate self-harming with acetamiprid poisoning in Sri Lanka.

CASE PRESENTATION

We describe a case of acute poisoning with an acetamiprid in a middle-aged Sri Lankan Tamil farmer for suicidal purposes following family conflicts with his wife. He presented with severe nausea, vomiting, and altered level of consciousness. He had electrocardiogram changes, hypoxia, and lactic acidosis. With intensive care management including ventilatory support, inotropic therapy along with intraarterial blood pressure monitoring, correction of acidosis, and administration of electrolytes, he made good clinical recovery. He was discharged without any further complications 6 days after ingestion of acetamiprid.

CONCLUSIONS

This case illustrates a rare, acute poisoning with acetamiprid in human, as well as its clinical manifestations and successful management with supportive therapy. This will be helpful for clinicians to identify clinical manifestations and to guide management of acute poisoning with acetamiprid in the future.

Adjunct treatment in snakebite envenoming: a systematic review of randomised controlled trials

Adjunct therapy in snakebite may be lifesaving if administered appropriately or can be harmful if non-judicious use leads to avoidable delays in administering antivenom. This systematic review analyses the evidence from randomised controlled trials (RCTs) on the efficacy of adjunct treatment administered with antivenom. PubMed, EMBASE, Scopus, Cochrane library and CINAHL were searched for RCTs enrolling patients with snakebite envenoming where a treatment other than antivenom has been assessed for its efficacy within the last 25 y. Fifteen studies met the inclusion criteria. The interventions assessed were categorised as adjunct therapies (heparin or fresh frozen plasma) to reverse haemotoxicity (three studies), antibiotics to prevent local infections (three studies), steroids to reduce local swelling (one study), premedication (adrenaline, steroids and antihistamines, either alone or in combination) to reduce hypersensitivity reactions to antivenom (five studies) and other interventions (three studies). Apart from a beneficial effect of low-dose adrenaline (1:1000, 0.25 ml administered subcutaneously) in preventing antivenom-induced hypersensitivities (OR: 0.54, 95% CI 0.32 to 0.93, two RCTs, 354 participants, moderate certainty evidence) in Sri Lanka, evidence for any other adjunct therapy is either non-existent or needs confirmation by larger better designed trials.

Comparison of rotational thromboelastometry parameters with 20-minute whole blood clotting test as a predictor of envenoming in Russell's viper bite patients

BACKGROUND

Coagulopathy is an important and common systemic clinical syndrome caused by snake envenoming. The major clinical effect of Russell's viper (RV) envenoming is haematotoxicity. The 20-min whole blood clotting test (WBCT20) is the standard test for identification of envenoming in resource-limited settings. However, its reliability as a diagnostic test has been questioned. Rotational thromboelastometry (ROTEM) assays different phases of clot formation from initiation to fibrinolysis. Our objective was to compare parameters of ROTEM with WBCT20 and the international normalized ratio (INR) as predictors of envenoming in RV bite patients.

METHODS

Fifty-three patents with RV bite presenting to Anuradhapura Hospital, Sri Lanka were recruited. Epidemiological and clinical data were obtained. Venous blood samples were collected at admission for ROTEM, INR and WBCT20.

RESULTS

A total of 46 of 53 patients with RV bites received antivenom serum (AVS); 74% had a non-clottable WBCT20. All 46 had at least one abnormal ROTEM parameter and 93% had a prolonged EXTEM clotting time (EXTEM-CT). The sensitivity of a prolonged INR was only 55%.

CONCLUSIONS

EXTEM-CT is a better predictor of envenoming and the need for AVS than WBCT20 in RV bites (p=0.02). It provides a numerical value that can be used post-AVS to objectively assess the response and decide on further treatment.

Saw-scaled viper envenoming complicated with acute myocardial infarction

The saw-scaled viper (Echis carinatus) is considered to be a venomous snake which is especially seen in Northern Sri Lanka. Systemic manifestations are rare and reported complications include coagulopathy and renal impairment. The cardiac toxicity following snakebites is rare and cardiac involvement following the saw-scaled viper bites is extremely rare. Here, we describe a patient with acute myocardial infarction following systemic envenoming by saw-scaled viper in Northern Sri Lanka, which was successfully managed per ward protocol following national guidelines.

Prevalence, vulnerability and epidemiological characteristics of snakebite in agricultural settings in rural Sri Lanka: A population-based study from South Asia

Background

The burden of snakebite remains poorly characterised because of the paucity of population-based data. Further, factors determining the vulnerability of individuals within rural communities to snakebite have been rarely investigated. We undertook a population-based study to determine the prevalence, vulnerability and epidemiological characteristics of snakebite in rural Sri Lanka.

Methods and findings

A population-based cross-sectional study was conducted among 8707 current residents in the district of Ampara, representing typical rural Sri Lanka. The sample was recruited using multi-stage cluster sampling with probability proportionate-to-size. Snakebite victims were identified using the WHO criteria. Data were collected using a pre-tested interviewer-administered questionnaire.

Each household had on average 3.8 persons; mean age 28.3 years (SD = 18.2); 51.3% males. The one-year point prevalence of snakebites was 17.6 per 1000 residents (95% CI: 15–20.6) and 6.12 per 100 households (95% CI: 5.25–7.13), while the lifetime prevalence was 9.4 per 100 residents (95% CI: 8.8–10.0) and 30.5 per 100 households (95% CI: 28.6–32.2) with a case fatality ratio of 0.033. Venomous snakebites accounted for 28.1%; snakes were unidentified among 30.1%. Compared to the non-snakebite victims, being single, males, of Sinhala ethnicity, aged >19 years, low education and socioeconomic status, engaging in farming or unskilled outdoor occupations denoted vulnerability to snakebites. Outdoor bites (77.8%) were more common among males; during daytime; mostly while walking; within the rural terrains and home gardens; on lower limbs; mostly by hump-nosed and Russell viper. Indoor bites were more common among females; during night-time; while sleeping and barefooted; on lower limbs; mostly by hump-nosed vipers, kraits and non-venomous snakes.

Conclusions

The burden of snakebite is considerably high among rural populations. The concept of vulnerability can be useful in healthcare decision-making and resource allocation.

Thrombotic microangiopathy and acute kidney injury following Sri Lankan Daboia russelii and Hypnale species envenoming

Context: Thrombotic microangiopathy (TMA) resulting in acute kidney injury (AKI) is an important complication of venomous snakebites. We aimed to describe TMA secondary to Russell's viper (Daboia russelli) and hump-nosed viper (Hypnale spp.) bites and assess the effect of different treatments.Materials and methods: We undertook a prospective observational study of patients with AKI secondary to snakebite over a two-year period. Data recorded included: demographic details, clinical and laboratory features, treatment, complications and outcomes, until hospital discharge and at three months post-discharge. TMA was defined as the development of microangiopathic hemolytic anemia and thrombocytopenia along with AKI. Treatment with therapeutic plasma exchange (TPE; also known as plasmapheresis) and/or fresh frozen plasma (FFP) was determined by the treating clinician. Antivenom was given to all patients with evidence of systemic envenoming following Russell's viper bites.Results: Fifty-nine patients were included in the analysis. Thirty-three (56%) were males and median age was 56 years. Forty-five (76%) developed TMA while a further 11 and two developed isolated thrombocytopenia and microangiopathic hemolytic anemia, respectively. Presence of TMA was associated with increased dialysis requirements (5 vs. 3) and longer hospital stay (18 vs. 12 days). Of the patients with TMA, nine received TPE with or without FFP infusions. The use of TPE was not associated with improved outcomes in patients with TMA based on requirement for blood transfusion, recovery of thrombocytopenia, requirement of dialysis and duration of hospital stay. Patients who did not receive TPE had better renal function at three months compared to patients who received this treatment.Conclusion: Presence of TMA in patients with Daboia and Hypnale bites was associated with a more prolonged course of AKI. Patients with TMA who were treated with TPE did not have improved early or late outcomes compared to patients who were not treated with TPE.

Thrombotic microangiopathy following hump-nosed viper 'Hypnale' envenomation

The hump-nosed vipers which compromise ‘Hypnale hypnale’, ‘H. zara’ and ‘H. nepa’ have been highly venomous snakes and ‘H. zara’ and ‘H. nepa’ are indigenous to Sri Lanka and ‘H. hypnale’ is endemic to Sri Lanka and India. The clinical presentations range from local swelling, blistering and necrosis at the site of bite with distinct fang marks to systemic envenomations such as coagulopathy, thrombotic microangiopathy, acute kidney injury and death in severe cases. Here, we report a case of thrombotic microangiopathy following hump-nosed viper ‘Hypnale’ bite.

Severe acute kidney injury following Sri Lankan Hypnale spp. envenoming is associated with thrombotic microangiopathy

CONTEXT

Acute kidney injury (AKI) is the most serious clinical manifestation of the Sri Lankan hump-nosed pit viper (Hypnale spp.) bites. Thrombotic microangiopathy (TMA) is increasingly recognized in association with AKI in cases of Hypnale spp envenomation. We investigated AKI in a cohort of cases of Hypnale envenomation, its association with TMA and the early diagnostic value of common biomarkers for AKI occurring.

MATERIALS AND METHODS

We conducted a prospective observational study of suspected viper bites and included 103 confirmed cases of Hypnale envenomation, based on venom specific enzyme immunoassay of blood. AKI was defined using the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Thrombotic microangiopathy was diagnosed based on thrombocytopenia (platelet count < 150,000 × 10³/μL) and microangiopathic haemolytic anaemia (MAHA). We investigated the diagnostic performance of creatinine, platelet count and INR for AKI within 4 h and 8 h post-bite by area under the receiver operator characteristic curve (AUC-ROC).

RESULTS

Ten patients developed AKI: seven AKI stage 1 and three AKI stage 3. Ten patients (10%) developed thrombocytopaenia while 11 (11%) had MAHA. All three AKI stage 3 had thrombocytopaenia and MAHA fulfilling the criteria for TMA. Two of them presented with oliguria/anuria and all three required haemodialysis. Serum creatinine within 4 h post-bite was the best predictor of AKI with AUC-ROC of 0.83 (95% CI: 0.67-0.99) and was no better within 8 h of the bite.

CONCLUSIONS

We found that AKI is uncommon in Hypnale spp. envenomation, but an important serious complication. Severe AKI was associated with TMA. A creatinine within 4 h post-bite was the best predictor of AKI.

Sri Lankan green pit viper (Trimeresurus trigonocephalus) bites in Deniyaya: A clinico-epidemiological study

Green pit viper (Trimeresurus trigonocephalus) is endemic to Sri Lanka and bites are reported from tropical rain forest and plantation areas. As scant data exists on clinico-epidemiological features of Sri Lankan green pit viper bite, objective of this study was to address this knowledge gap. A prospective observational study was conducted in Base Hospital Deniyaya from October 2013 to September 2015. Green pit viper as the offending snake was identified when the victims brought live or dead specimens. When the specimen was not available, green pit viper was identified by the victim pointing to preserved specimens and photographs of green pit viper and different similar appearing snakes. Clinical details were recorded during the hospital stay. Twenty four green pit viper bite patients (17-68 years) were studied. All cases were daytime bites despite green pit viper being a nocturnally active snake. Sixteen patients (67%) were bitten while they were working in tea plantation. Hands (42%), feet, (33%), forearms (8%), legs (8%), thighs (4%) and shoulders (4%) were the sites of bites. Thirteen (54%) had extensive limb swelling. Nine (38%) had local swelling and two had no swelling. Three (12.5%) developed haemorrhagic blisters. Four (17%) had regional lymphadenopathy. Two (8%) developed non clotting blood by the TWBCT. Green pit viper bites caused substantial morbidity. Risk factors included day time outdoor activities in bordering villages of tropical rain forests and occupation. Pain, extensive limb swelling and bite site swelling were prominent clinical features. However haemorrhagic blisters, regional lymphadenopathy and coagulopathy were reported. Nephrotoxicity and neurotoxicity were notably absent.

Determination of the sub-lethal nephrotoxic dose of Russell's viper (Daboia russelii) venom in Wistar rats

Wistar rats were administered increasing doses of Russell's viper venom (RVV; 0.025-0.4 mg/kg) intraperitoneally to investigate acute kidney injury (AKI) by measuring creatinine (1.5-fold increase in serum creatinine above baseline) and examining kidney histology. Approximately 50% of rats receiving 0.25-0.4 mg/kg venom died within 72 h. An increase in serum creatinine only occurred at a venom dose of 0.4 mg/kg, except in two rats. Acute tubular necrosis, glomerular necrosis, cortical necrosis and interstitial inflammation were observed at venom doses of ≥0.25 mg/kg in 12/36 rats. However, of those 12 rats only four survived to 48 h compared to the 24 rats not developing nephrotoxicity, in which 18 were alive at 48 h. There was poor correlation between histological nephrotoxicity and AKI based on creatinine measurement. The early death in rats with AKI makes this a poor model for studying RVV-induced AKI.

Long-term health complications following snake envenoming

Background

Snakebite is an important public health problem in tropical regions of the world. Although devastating effects of envenoming such as kidney failure, tissue necrosis, bleeding diathesis, and neurotoxicity are well known in the acute stage following a snakebite, the long-term effects of snake envenoming have not been adequately studied.

Materials and methods

A population-based study was conducted among 8707 residents in a rural district in Sri Lanka to assess the long-term sequelae following snakebite. Health-related complaints that snakebite victims had developed immediately or within 4 weeks of the bite and persisted for more than 3 months, were assessed by interviewer-administered questionnaire and in-depth interviews, and further evaluated by physical examination and relevant investigations.

Results

Of the 816 participants who were identified as ever snakebite victims, 112 (13.7%) presented with at least one snakebite-related long-term health complication. Among them, “migraine-like-syndrome” characterized by headache vertigo, and photosensitivity to sunlight was found in 46 (5.6%); musculoskeletal disorders such as pain, local swelling, muscle weakness, deformities, contractures, and amputations were found in 26 (3.2%); visual impairment in 21 (2.6%); acute kidney injury in 4 (0.5%); skin blisters at the bite site in 5 (0.6%); psychological distress in 2 (0.2%); hemiplegia in 1 (0.1%); right-side facial nerve palsy in 1 (0.1%); paresthesia over bite site in 1 (0.1%); generalized shivering in 1 (0.1%); and chronic nonhealing ulcer in 1 (0.1%). Interestingly, 31 (3.8%) reported nonspecific somatic symptoms such as abdominal colic, chest tightness, wheezing, receding gums, excessive hair loss, and lassitude with body aches following the bite. The average duration of symptoms since snakebite was 12.7 years (SD=11.7).

Conclusion

This study highlights that a significant proportion of snakebite victims suffer disabling chronic health sequelae. There is a need to place systems to address these unmet health needs.

Management of scorpion envenoming: a systematic review and meta-analysis of controlled clinical trials

BACKGROUND

Scorpion stings cause an estimated 3000 deaths per annum worldwide. We conducted a systematic review of all controlled clinical trials related to scorpion sting management.

METHODS

We searched PubMed, EMBASE, Scopus, Web of Science and CINAHL and included controlled prospective clinical trials (randomized or non-randomized). The following interventions were assessed: adults and children with scorpion stings treated with (a) steroids vs. placebo, (b) different methods of pain relief, (c) antivenom vs. supportive treatment, (d) prazosin vs. supportive treatment, (e) antivenom vs. prazosin and (f) antivenom plus prazosin vs. prazosin alone. When trials had comparative outcomes, they were combined in a meta-analysis. Data was analysed with Review Manager 5. Dichotomous data were compared with relative risk (RR), and continuous data were compared with mean differences using a fixed effect model. There is no PROSPERO registration number for this study.

RESULTS

Antivenom against Centruroides sp. are effective in reversing the clinical syndrome faster than no antivenom treatment in children (RR, 0.02; 95% CI, 0.01 to 0.06; 322 participants; three trials). Antivenom (against Mesobuthus tamulus) and prazosin combination is better than prazosin alone for faster resolution of symptoms (mean difference, -12.59 h; 95% CI, -14.01 to -11.17; 173 participants; three trials).

CONCLUSIONS

The polyvalent antivenom against Centruroides sp. in USA/Mexico and the monovalent antivenom against M. tamulus in India are effective for rapid resolution of symptoms. Prazosin is useful as an add-on therapy for M. tamulus stings.

Prevention of krait bites by sleeping above ground: preliminary results from an observational pilot study

Introduction

Neurotoxic envenoming following the bites of kraits (Bungarus spp.) is a common cause of death in the dry zone of Sri Lanka and elsewhere in South Asia. Most of these bites occur at night and are inflicted on people sleeping on the ground. Thus we hypothesized that the simple measure of sleeping above ground would help to reduce the number of observed krait bites.

Methods

This study was conducted in two villages of the Kilinochchi district of Sri Lanka which had reported a high number of krait bites in the two years preceding the study. Most of the residents in these two villages slept on the ground. Residents in one area were given beds free of charge, using funds available from the study. Both villages received health education on the prevention of krait bites.

Results

Forty five beds were distributed to 45 families in one village. This enabled 115 individuals to sleep above ground level. 6 monthly follow up visits were conducted ensuring the proper utilization of beds. Follow up was continued for 30 months (September 2013–March 2016); during this time period no krait bites were reported in either area.

Conclusions

We observed a dramatic decline of krait bites in both villages. Better awareness with effective health education and clearing of vegetation could have led to the decline in the number of krait bites in both villages.

Chronic Musculoskeletal Disabilities following Snake Envenoming in Sri Lanka: A Population-Based Study

BACKGROUND

Snakebite is a major public health problem in agricultural communities in the tropics leading to acute local and systemic impairments with resultant disabilities. Snakebite related long-term musculoskeletal disabilities have been a neglected area of research. We conducted a population-based, cross-sectional study in an agricultural community to describe the chronic musculoskeletal disabilities of snake envenoming.

METHODOLOGY/PRINCIPAL FINDINGS

A sample representative of residents of a single district in a region of high incidence of snake envenoming was recruited to identify ever snakebite victims. They were evaluated for chronic musculoskeletal disabilities that had developed immediately or within four weeks after the snakebite and persisted over three months. In-depth interviews, validated musculoskeletal functional assessment criteria and specialists' examinations were utilised. Among the 816 victims, 26 (3.2%, 95% confidence interval: 2.2-4.6%) had musculoskeletal disabilities, persisting on average for 13.4 years (SD = 14.4). The disabilities were mostly in lower limbs (61.5%) and ranged from swelling (34.6%), muscle wasting (46.1%), reduced motion (61.5%), reduced muscle power (50%), impaired balance (26.9%), chronic non-healing ulcers (3.85%), abnormal gait (3.85%), fixed deformities (19.2%) to amputations (15.4%). Based on disability patterns, six snakebite-related musculoskeletal syndromes were recognised. The offending snakes causing disabilities were cobra (30.8%), Russell's viper (26.9%) and hump-nosed viper (7.7%). Cobra bites manifested muscle wasting (87.5%), reduced muscle power (87.5%), joint stiffness (62.5%) and deformities (37.5%) while viper bites manifested impaired balance (42.8%), pain (71.4%) and swelling (71.4%).

CONCLUSIONS/SIGNIFICANCE

Snakebite envenoming is associated with considerable long-term musculoskeletal disabilities. Facilities for specialized care and rehabilitation need to be established in high risk areas.

Pulmonary effects and complications of snakebites

This review is on the pulmonary complications of snakebites, which can have fatal consequences. We identified three common themes as reported in the literature regarding envenomation: generalized neuromuscular paralysis affecting airway and respiratory muscles, pulmonary edema, and pulmonary hemorrhages or thrombosis due to coagulopathy. Respiratory paralysis and pulmonary edema can be due to either elapid or viper bites, whereas pulmonary complications of coagulopathy are exclusively reported with viper bites. The evidence for each complication, timeline of appearance, response to treatment, and details of pathophysiology are discussed.

Exchange transfusion can be life-saving in severe propanil poisoning: a case report

BACKGROUND

Propanil is an important cause of herbicide poisoning in Sri Lanka, accounting for about 2% of all cases of self-poisoning. The outcome is extremely poor when the poisoning is severe and current medical care is of limited efficacy. Death usually occurs due to the severe and prolonged methaemoglobinaemia. We describe a case of severe Propanil poisoning, successfully treated by exchange transfusion at a tertiary care hospital in Sri Lanka.

CASE PRESENTATION

A 17-year old Sri Lankan male (body weight--42 kg), presented to a local hospital 1 hour after self-ingestion of nearly 500 ml (4.3 g/kg) of liquid Propanil (concentration--360 g/l). On admission he had dizziness and peripheral cyanosis. He was given intravenous methylene blue (1 mg/kg) within one hour of admission, which was repeated subsequently due to minimal response. The next day morning, (18 hours after poisoning) the patient was transferred to the National Hospital of Sri Lanka (NHSL) for further management. On admission to NHSL, he was drowsy and confused, had a shallow respiratory effort and marked central and peripheral cyanosis. Respiratory rate was 20/min, with a pulse-oximetry of 77% on room air. The arterial blood gas analysis was as follows; pH--7.24, HCO3(-)--12 mmol/l, pCO2--28 mmHg, pO2--239 mmHg and O2 saturation--100%. Exchange transfusion was commenced within two hours of admission to NHSL. A dramatic improvement in oxygen saturation was observed immediately afterwards, with the saturation in pulse-oximetry rising to >95%. The level of consciousness and respiratory effort also improved. He was discharged subsequently 8 days after the initial poisoning.

CONCLUSION

Propanil has potential to produce severe life threatening clinical manifestations, despite categorization as a herbicide with low toxicity. In cases of severe poisoning, exchange transfusion may be life saving. Since methylene blue, intensive care and exchange transfusion facilities are also not readily available in local hospitals, which frequently encounter cases of severe Propanil poisoning, early transfer of patients to tertiary care hospitals should be considered. Exchange transfusion may be helpful even in late stages in patients with severe poisoning.

Presumptive thrombotic thrombocytopenic purpura following a hump-nosed viper (Hypnale hypnale) bite: a case report

Hump-nosed viper bites are frequent in southern India and Sri Lanka. However, the published literature on this snakebite is limited and its venom composition is not well characterized. In this case, we report a patient with thrombotic thrombocytopenic purpura-like syndrome following envenoming which, to the best of our knowledge, has not been reported in the literature before. A 55-year-old woman from southern Sri Lanka presented to the local hospital 12 hours after a hump-nosed viper (Hypnale hypnale) bite. Five days later, she developed a syndrome that was characteristic of thrombotic thrombocytopenic purpura with fever, thrombocytopenia, microangiopathic hemolysis, renal impairment and neurological dysfunction in the form of confusion and coma. Her clinical syndrome and relevant laboratory parameters improved after she was treated with therapeutic plasma exchange. We compared our observations on this patient with the current literature and concluded that thrombotic thrombocytopenic purpura is a theoretically plausible yet unreported manifestation of hump-nosed viper bite up to this moment. This study also provides an important message for clinicians to look out for this complication in hump-nosed viper bites since timely treatment can be lifesaving.

Saw-scaled viper bites in Sri Lanka: is it a different subspecies? Clinical evidence from an authenticated case series

The saw-scaled viper (SSV) (Echis carinatus) is considered to be a highly venomous snake in Sri Lanka despite any published clinical justification. Being a rarity, the clinical profile of SSV bites is not well established in Sri Lanka. We report a series of 48 (n-48) SSV bites from the Northern Province of Sri Lanka. The majority (65%) of victims had evidence of local envenoming at the site of the bite; however, 29% showed spontaneous bleeding and 71% had coagulopathy. There were no deaths in the series. The envenoming was mild in contrast to the mortality and significant morbidity associated with SSV bites in West Africa and some parts of India. These observations need to be further explored with laboratory studies to identify the venom components, study of morphological characteristics, and genetic profiling of the Sri Lankan SSV to see if it is different from the subspecies found elsewhere.

Complications and management of acute copper sulphate poisoning; a case discussion

Copper sulphate ingestion (accidental or deliberate) is a rare form of poisoning usually limited to the Indian subcontinent. Though the rates are on the decline, it is essential that physicians are aware of its lethal complications and management strategies. The main complications of copper sulphate ingestion include intravascular haemolysis, methaemoglobinaemia, acute kidney injury and rhabdomyolysis. The lethal dose can be as small as 10 grams. We have explored the complications of acute copper sulphate poisoning with examples from two case presentations. We also recommend measures for prevention of such events.

Hypothyroidism causing paralytic ileus and acute kidney injury - case report

We present a patient with severe hypothyroidism complicated by paralytic ileus and acute kidney injury. A 65 year old male patient, diagnosed with hypothyroidism one year ago was transferred to our unit in a state of drowsiness and confusion. He was severely hypothyroid and had paralytic ileus and impaired renal function at the time of transfer. Hypokalaemia was present, and was likely to have contributed to the paralytic ileus and this together with dehydration was likely to have contributed to renal injury. Nonetheless, hypothyroidism is very likely to have been the principal precipitant of both these complications, and both paralytic ileus and acute kidney injury improved with thyroxine replacement. Unfortunately, the patient died unexpectedly eight days after admission to the unit.

Hypothyroidism may induce de novo acute kidney injury or it may exacerbate ongoing chronic kidney disease. This rare complication is assumed to be due to the hypodynamic circulatory state created by thyroid hormone deficiency. Paralytic ileus is an even rarer fatal manifestation of hypothyroidism and is thought to be due to an autonomic neuropathy affecting the intestines that is reversible with thyroxine replacement. To our knowledge, both these complications have not been observed in a single patient so far.

It is important that clinicians are aware of these rare manifestations of hypothyroidism as in most occasions, thyroxine deficiency may be missed, and treatment can reverse the complications.