No abstract

A pilot survey was designed to define incidence, rotation period, rotation direction and cycle of shiftwork plans in the production and service units in Kuwait. Preliminary results from the Ministry of Interior showed that four different shift plans are widely used. Forty policemen, ten from each shift plan, volunteered to fill in a diary for a period of two or more cycles. The diary was comprised of a set of questions planned to reveal disturbances in sleep duration, sleep quality, food intake and appetite. The daily questionnaire also covered psychosomatic complaints and subjective judgement of recovery. A control group, on permanent day work, volunteered to fill in the diary for the same period. The results indicated that one of the four shift plans was quite satisfactory and least harmful to the policemen. Two plans were associated with excessive strain during working days, but the number of free days was sufficient to achieve complete recovery. The fourth plan was associated with excessive strain during working days and recovery was not achieved after 24 h of rest at the end of the shift cycle.

1. Although heat stroke is a frequent cause of death in both humans and animals as a result of climatic or exercise-imposed stress, underlying mechanisms are understood poorly. In order to develop more effective strategies for prevention and treatment of this cause of death and suffering, controlled experiments were conducted on a small number of sheep to examine cardiovascular involvement in the thermoregulatory failure of heat stroke. 2. Sheep were studied in a hot environment at rest and then during exercise until collapse. 3. With exercise, mean arterial pressure (MAP) increased slightly, cardiac output (CO) increased markedly and total peripheral resistance (TPR) decreased slightly. As collapse was imminent, MAP increased but CO and TPR did not change significantly. On collapse, MAP and TPR increased markedly and CO decreased markedly. 4. Radioactive microsphere measurements demonstrated during exercise a redistribution of blood flow (BF) away from abdominal viscera and torso skin, to muscles involved in exercise, respiratory muscles, myocardium, fat, limb skin and nasobuccal tissues. With progressively increasing heat stress and exercise, BF increased in exercise muscles and decreased in limb skin and fat. As collapse was imminent, there were sharp increases in BF in exercise muscles, brain and spinal cord. On collapse, BF decreased markedly in exercise and respiratory muscles and fat. 5. It is concluded that collapse and ultimately heat stroke are not due primarily to cardiovascular 'failure' but, rather, to consequences of high body temperatures resulting from thermoregulatory failure attributable to demands for blood pressure regulation dominating requirements for body temperature regulation.

muscular 29 year old man, was admitted with a high body temperature, tachycardia, and peripheral circulatory failure with a metabolic acidosis. Over the next six hours the metabolic acidosis progressed and he developed widespread haemorrhages in muscle and in mucous membranes and skin. On further inquiry we note he was found to have hypertonicity of muscles and hyperreflexia. Also, just before the terminal cardiac arrest he was severely acidotic with a pH of 7 08 and a base excess of -19 7. The serum lactate concentration at that time was raised at 2 9 mmol/l (26-1 mg/100 ml) (normal 1-8 mmol/l (16 2 mg/100 ml)).We believe that malignant hyperpyrexia could explain the clinical findings. This diagnosis carries an important therapeutic implication, as dantrolene has been shown to be effective in treating this condition.We wish to acknowledge the help of Dr J A G Whitworth and Dr J M Bone, who furnished us with the further details mentioned.