Survival after massive hydroxychloroquine overdose.

Hydroxychloroquine overdose is infrequently reported and the majority of recommendations come from the greater experience with chloroquine poisoning. We report two cases of massive hydroxychloroquine poisoning (20 g in each case), both of which received advanced cardiac life support and a treatment regimen consisting of sodium bicarbonate, adrenaline and potassium. Both these patients survived beyond their initial rapid deterioration and cardiovascular collapse to be discharged from hospital without sequelae. These patients had the highest reported non-lethal serum concentrations (13.8 and 26.0 mg/l). They both demonstrated rapid recovery from a pre-arrest condition, following aggressive correction of electrolyte and pH disturbance and rapid distribution of the drug to peripheral tissues.

Correlation of paired plasma and saliva paracetamol levels following deliberate self-poisoning with paracetamol (the Salivary Paracetamol In Toxicology [SPIT] study).

AIM: To determine the correlation between plasma and saliva paracetamol levels following paracetamol deliberate self-poisoning. METHODS: Paired plasma and saliva paracetamol levels were measured. Saliva analysis was performed contemporaneously using a colorimetric method. RESULTS: 21 patients (76% female) mean age 28.3 +/- 12.9 years (range 15-55) were enrolled. Mean reported paracetamol ingestion was 10.3 g (range 2-20 g). Specimens were collected at a mean of 6.2 +/- 3.1 hours post-ingestion (range 4-13 hours) and mean plasma and saliva paracetamol levels were 48 mg/L and 62 mg/L respectively (mean difference 14; 95% CI 5-22; p < 0.004); Pearson's correlation r = 0.95 (p < 0.0001). No patient needing treatment would have been missed using saliva levels only. CONCLUSION: There is concordance between the indications for treatment of paracetamol deliberate self-poisoning based on plasma and saliva paracetamol levels. Saliva paracetamol levels are typically higher than plasma levels. Further studies involving larger numbers of patients, comparing plasma and saliva paracetamol levels in patients with potentially toxic plasma paracetamol concentrations, would be useful in determining the potential clinical value of this method.

Thrombotic microangiopathy from Australian brown snake (Pseudonaja) envenoming.

BACKGROUND: Australian brown snake (genus Pseudonaja) envenoming causes a venom-induced consumptive coagulopathy (VICC). A proportion of cases go on to develop thrombotic microangiopathy characterized by thrombocytopenia, microangiopathic haemolytic anaemia (MAHA) and acute renal failure (ARF). AIM: The aim of the study was to define better the natural history and empirical treatments for thrombotic microangiopathy in brown snake envenoming. METHODS: A review of brown snake bites recruited to the Australian Snakebite Project (ASP), a national multicentre study of snake envenoming was undertaken. Serial data are recorded on clinical effects and laboratory results, including measurement of venom concentrations. We describe cases of thrombotic microangiopathy and compare these to cases without thrombotic microangiopathy. RESULTS: From 32 cases of brown snake envenoming with severe VICC, four (13%) developed thrombotic microangiopathy, we also included two cases of thrombotic microangiopathy from prior to ASP. All six developed severe thrombocytopenia (<20 x 10(-9)/L), worst 3 days after the bite and resolving over a week, MAHA with fragmented red blood cells on the blood film and five developed anuric ARF requiring dialysis and lasting 2-8 weeks. All six received antivenom, which was delayed compared with other brown snake-envenoming cases. Four were treated with plasmapheresis. The severity and recovery of the thrombocytopenia, anaemia and renal function were similar with and without plasmapheresis. The median length of stay for MAHA cases was 14 days (interquartile range (IQR) 12-14) compared to 1.8 days (IQR 1.3-2) for all other cases. CONCLUSION: Thrombotic microangiopathy resulting from brown snake bite appears to have a good prognosis and management should focus on early antivenom therapy and supportive care including dialysis. The role of plasmapheresis is yet to be defined.

Toxicology case of the month: ingestion of two unidentified tablets by a toddler.

An asymptomatic 18 month old child presents to the emergency department of a small district hospital shortly after ingesting two unidentified tablets. A small number of pharmaceuticals and illicit drugs may produce life threatening toxicity in a small child if ingested even in one or two dose units and the onset of toxicity may be delayed for some agents. Following risk assessment, a rational management plan is devised and the child is carefully monitored. The patient is observed overnight and discharged home the following day.

Observational study of prehospital delays in patients with chest pain.

OBJECTIVE: To define and measure patient reported prehospital delay in presentation to the emergency department with chest pain and identify simple strategies that may reduce this delay. The authors investigated the null hypothesis that the patients choice of service to call for acute medical help has no effect on the timing of thrombolysis. METHOD: A prospective observational study of prehospital times and events was undertaken on a target population of patients presenting with acute chest pain attributable to an acute coronary syndrome over a three month period. RESULTS: Patients who decided to call the ambulance service were compared with patients who contacted any other service. Most patients who contact non-ambulance services are seen by general practitioners. The prehospital system time for 121 patients who chose to call the ambulance service first was significantly shorter than for 96 patients who chose to call another service (median 57 min v 107 min; p<0.001). Of the 42 patients thrombolysed in the emergency department, those who chose to call the ambulance service had significantly shorter prehospital system times (number 21 v 21; median 44 v 69 min; p<0.001). Overall time from pain onset to initiation of thrombolysis was significantly longer in the group of patients who called a non-ambulance service first (median 130 min v 248 min; p=0.005). CONCLUSIONS: Patient with acute ischaemic chest pain who call their general practice instead of the ambulance service are likely to have delayed thrombolysis. This is likely to result in increased mortality. The most beneficial current approach is for general practices to divert all patients with possible ischaemic chest pain onset within 12 hours direct to the ambulance service.