Inspiratory valve malfunction in a circle system: pitfalls in capnography

Capnography is a useful technique in monitoring the integrity of anaesthetic equipment such as the malfunctioning of unidirectional valves in circle system. However, the lack of a precise mechanism in existing capnographs to identify the start of inspiration and the beginning of expiration in the capnograms, makes the analysis of the carbon dioxide waveforms during inspiration difficult and thus results in inaccurate assessement of rebreathing. We report a case where, during the malfunction of the inspiratory unidirectional valve in the circle system, the capnograph failed to detect the presence of substantial rebreathing. Critical analysis of the capnogram recorded during the malfunction revealed that there was substantial rebreathing which was underestimated by the capnograph as it reports only the lowest CO2 concentration rebreathed during inspiration in such abnormal situations.(AU)

Modified plasma exchange in life-threatening Guillain-Barre syndrome - abstract

Modified plasma exchange (MPE), a simpler procedure than a conventional plasmapheresis which uses automated equipment and expensive replacement fluids, has recently been recommended for use in hospitals with limited resources in the management of patients with Guillain-Barre Syndrome (GBS). We have performed MPE in 7 patients with life-threatening respiratory failure due to GBS, using fresh frozen plasma as replacement fluid. In 5 out of 6 patients, in whom MPE was started at the onset of mechanical ventilation, rapid improvement inconsistent with the natural history of the disease was noted. In 2 of these patients, due to severity of illness, more plasma per day than previously recommended was safely removed. In one patient, MPE was started with a peak expiration flow rate of 2.2 litres per minute and assisted ventilation was unnecessary due to rapid improvement. Death occurred in one patient from respiratory complications and was not directly due to MPE. Our study confirms the safety and efficacy of MPE and suggests that more plasma can be safely exhanged by this method than previously recommended (AU)

Malathion poisoning: A report of 2 cases

Two cases of malathion poisoning are described. Serum chlinesterase levels for the duration of their stay in the Intensive Care Unit were followed. Supportive ventilation in these patients could be discontinued before normal levels of cholinesterase activity in the serum were reached. Although the levels of serum cholinesterase activity rose steadily as the patients improved, clinical assessment provided a more important prognostic index than the actual cholinesterase values (AU)

Epidemic of suicide by malathion poisoning in Guyana

Malathion, an organic phosphate insecticide, has become the agent most commonly used for suicides attempts in Guyana. The clinical characteristics of 264 cases are described. As with other types of organic phosphate poisoning, atropine is the mainstay of therapy after exposure to the toxin is terminated. The value of oximes in the treatment of malathion poisoning is not clear. The increase in malathion suicides is related to sociocultural factors.(Summary)