Predicting outcome in acute organophosphorus poisoning with a poison severity score or the Glasgow coma scale

BACKGROUND

Organophosphorus (OP) pesticide poisoning kills around 200,000 people each year, principally due to self-poisoning in the Asia-Pacific region.

AIM

We wished to assess whether patients at high risk of death could be identified accurately using clinical parameters soon after hospital admission.

DESIGN

We evaluated the usefulness of the International Program on Chemical Safety Poison Severity Score (IPCS PSS) and the Glasgow Coma Score (GCS) prospectively for predicting death in patients poisoned by OP pesticides.

METHODS

Data were collected as part of a multicenter cohort study in Sri Lanka. Study doctors saw all patients on admission, collecting data on pulse, blood pressure, pupil size, need for intubation and GCS.

RESULTS

Of the patients, 1365 with a history of acute OP poisoning were included. Receiver operating characteristic (ROC) curves were calculated for the IPCS PSS and GCS on admission. The IPCS PSS and GCS had similar ROC area under the curves (AUC) and best cut points as determined by Youden's index (AUC/sensitivity/specificity 0.81/0.78/0.79 for IPCS PSS > or = grade 2 and 0.84/0.79/0.79 for GCS < or = 13). The predictive value varied with the pesticide ingested, being more accurate for dimethoate poisoning and less accurate for fenthion poisoning (GCS AUC 0.91 compared with 0.69).

CONCLUSION

GCS and the IPCS PSS were similarly effective at predicting outcome. Patients presenting with a GCS < or = 13 need intensive monitoring and treatment. However, the identity of the organophosphate must be taken into account, since the half of all patients who died from fenthion poisoning only had mild symptoms at presentation.

Myocardial infarction in young patients without coronary atherosclerosis: assume primary antiphospholipid syndrome until proved otherwise

The objective of this study was to highlight the need for investigation of antiphospholipid (aPL) antibodies in patients presenting with myocardial infarction (MI) and normal coronary arteries at angiography. We present five patients who were found to have had an MI without evidence of atherosclerosis. All had aPL antibodies and thus fulfilled the diagnosis of antiphospholipid syndrome (APS). Who did not have recurrent events on long-term anticoagulation maintaining an international normalised ratio of 3-4. This study suggests that APS is probably a major cause of MI in those with normal coronary arteries at angiography. It is an important diagnosis to make as they do not require anti-atherosclerotic treatment but appear, from this case series, to do well on high-dose warfarin. Further clinical studies are necessary to look at prevalence and best management in these patients.

Respiratory failure in acute organophosphorus pesticide self-poisoning

BACKGROUND

Acute organophosphorus (OP) pesticide poisoning is a major clinical problem in the developing world. Textbooks ascribe most deaths to respiratory failure occurring in one of two distinct clinical syndromes: acute cholinergic respiratory failure or the intermediate syndrome. Delayed failure appears to be due to respiratory muscle weakness, but its pathophysiology is unclear.

AIM

To describe the clinical patterns of OP-induced respiratory failure, and to determine whether the two syndromes are clinically distinct.

DESIGN

Prospective study of 376 patients with confirmed OP poisoning.

METHODS

Patients were observed throughout their admission to three Sri Lankan hospitals. Exposure was confirmed by butyrylcholinesterase and blood OP assays.

RESULTS

Ninety of 376 patients (24%) required intubation: 52 (58%) within 2 h of admission while unconscious with cholinergic features. Twenty-nine (32%) were well on admission but then required intubation after 24 h while conscious and without cholinergic features. These two syndromes were not clinically distinct and had much overlap. In particular, some patients who required intubation on arrival subsequently recovered consciousness but could not be extubated, requiring ventilation for up to 6 days.

DISCUSSION

Respiratory failure did not occur as two discrete clinical syndromes within distinct time frames. Instead, the pattern of failure was variable and overlapped in some patients. There seemed to be two underlying mechanisms (an early acute mixed central and peripheral respiratory failure, and a late peripheral respiratory failure) rather than two distinct clinical syndromes.