Recurrent opioid toxicity after pre-hospital care of presumed heroin overdose patients.

BACKGROUND: In patients with presumed heroin overdose, the recommended time of observation after reversing heroin toxicity with naloxone varies widely. The aims of this study were to examine the incidence of recurrent opioid toxicity and the time interval in which it occurs after pre-hospital treatment in presumed heroin overdose patients. METHODS: We undertook a retrospective study in Helsinki (population, 560,000). Records were reviewed from 1 January 1995 to 31 December 2000. Patients included were treated by the emergency medical service (EMS) for a presumed heroin overdose. Patients with known polydrug/alcohol use or the use of opioids other than heroin were excluded. The EMS records were compared with the cardiac arrest database and the medical examiners' records. RESULTS: One hundred and forty-five patients were included. The median dose of pre-hospital administered naloxone was 0.4 mg. After pre-hospital care, 84 patients refused further care and were not transported to an emergency department (ED). Seventy-one received pre-hospital naloxone, and no life-threatening events were recorded during a 12-h follow-up period in these patients. After pre-hospital care, 61 patients were transported to an ED. Twelve patients received naloxone in the ED for respiratory depression. All had signs of heroin use-related adverse events within 1 h after receiving pre-hospital naloxone. CONCLUSIONS: Allowing presumed heroin overdose patients to sign out after pre-hospital care with naloxone is safe. If transported to an ED, a 1-h observation period after naloxone administration seems to be adequate for recurrent heroin toxicity.

Cardiovascular changes after naloxone administration in propofol-sedated piglets during opioid overdose.

BACKGROUND: Naloxone is an opioid receptor antagonist. Even when used in modest doses, it has been associated with serious cardiopulmonary side-effects. In this experimental porcine study, we examined the cardiac effects of naloxone during an opioid overdose. METHODS: Cardiac parameters, changes in the left ventricular compliance and the magnitude of catecholamine release were evaluated in eight spontaneously breathing piglets under propofol sedation. Cardiac parameters were recorded every 30 s and transthoracic echocardiography was used for the continuous assessment of cardiac performance. Respiratory arrest was induced by morphine (8 mg/kg). Ten minutes after morphine administration, naloxone (80 microg/kg) was injected intravenously. Every 5 min, arterial blood gases were measured and, every 10 min, a sample for the analysis of plasma catecholamines was drawn. RESULTS: There were no statistically significant changes in left ventricular ejection fraction and no signs of pulmonary hypertension. There was a statistically significant increase in the mean arterial pressure immediately after naloxone administration and in norepinephrine concentration before naloxone administration. After naloxone administration, the plasma catecholamine levels decreased in all but one animal. Two animals developed cardiac arrest (pulseless electrical activity and ventricular fibrillation) shortly after receiving naloxone. Although they were both administered naloxone prematurely due to hypoxic bradycardia, naloxone could have contributed to the development of ventricular fibrillation. CONCLUSION: Naloxone did not cause changes in ejection fraction or mean pulmonary artery pressure in hypoxic and hypercarbic conditions. After naloxone administration, the plasma catecholamine levels returned to baseline in all but one animal, and two animals developed cardiac arrest.

Outcome after heroin overdose and cardiopulmonary resuscitation.

BACKGROUND: The survival of heroin overdose patients resuscitated from cardiac arrest is reported to be poor. The aim of our study was to investigate the outcome and characteristics of survivors after cardiac arrest caused by heroin overdose. METHODS: This was a retrospective study in a medium-sized city (population, 560,000). Between 1 January 1997 and 31 December 2000, there were 94 combined cardiac arrests caused by acute drug poisonings. The main outcome measure was survival to discharge. RESULTS: Cardiopulmonary resuscitation was attempted in 19 heroin overdose patients (group A) and in 53 patients with cardiac arrest caused by other poisonings (group B). Three (16%) vs. six (11%) patients were discharged alive (group A vs. B, respectively). The survivors in group A had an Emergency Medical Service (EMS)-witnessed cardiac arrest or the Emergency Dispatching Centre was called before the arrest occurred. There was no statistically significant difference between the two groups in terms of survival. Survivors in both groups suffered from acute renal failure (two), hypoglycaemia (four) and hypothermia (three). CONCLUSION: Survival after cardiac arrest caused by heroin overdose is possible if the arrest is EMS witnessed or the Emergency Dispatching Centre is called before the cardiac arrest occurs. In comparison with cardiac arrests caused by other poisonings, there was no difference in survival. The incidence and mechanism of hypoglycaemia should be examined in further studies.

Effect of a high-fat-sucrose diet on in vivo insulin receptor kinase activation.

Insulin-stimulated glucose uptake into muscle is depressed by high-fat-sucrose (HFS) feeding of rats. To investigate the mechanism of this insulin resistance, the in vivo activation of the insulin receptor kinase in liver and muscle of control and HFS-fed rats was determined. Rats were injected with glucose and insulin and killed 0, 5, 15, and 30 min after injection. Insulin binding was not changed in partially purified receptors from muscle of HFS rats. In control rats insulin receptor kinase activity was maximally stimulated threefold in liver at 5 min and fourfold in muscle at 15 min after insulin-glucose injection. The insulin-stimulated tyrosine kinase activity of receptors isolated from the liver of rats fed the HFS diet was decreased by 30% in comparison with the controls. In contrast, receptors isolated from muscle did not show any difference in basal or insulin-stimulated kinase activity between HFS-fed and control rats. Decreased in vivo activation of the insulin receptor kinase may be at least partially responsible for insulin resistance in liver. Because insulin binding and insulin stimulation of receptor kinase were normal in muscle of HFS-fed animals, it is concluded that the insulin resistance of glucose uptake into muscle is caused by a defect distal to the insulin receptor.

The role of energy and fluid imbalance in weight changes found during field work in Antarctica.

1. The effect on body-weight of field work in Antarctica when travelling by mechanical transport has been studied. 2. A steady loss of weight (mean 6-2 kg) was found in field, and there was a slow gain on return to less arduous conditions. 3. Changes in skinfold thickness and hip girth suggested that the loss of weight was due to an energy deficit, and the gain was due to an excess of energy. 4. However, although weight was being lost the energy balance was calculated to be positive. This was probably because the expenditure was underestimated as the result of a failure to take into account: (a) the weight and restriction of heavy clothing, (b) the high-protein diet, (c) the difficulty imposed by the terrain, (d) the intensity of the subjects' response to the cold. 5. Daily weight changes were significantly related to climatic conditions. 6. Daily weight changes were significantly related to fluid intakes, but it was not possible to assess with certainty the contribution made by dehydration to the recorded weight loss. 7. Daily fluctuations in weight were greater than those previously found under more standard conditions.

A study of the obstetric performance of the adolescent Jamaican primigravida.

PIP: Obstetrical outcome of a series of 226 primigravid Jamaican teenagers, less than 16 years old, was evaluated. All of the study subjects delivered at the University Hospital, Kingston, Jamaica, and their obstetrical outcomes were compared with the outcomes of older primigravidas delivering at the same institution. Incidence of preeclampsia was lower among the teenagers (8.4%) vs. older patients (9.8%). Incidence of antepartum hemorrhage was .9% in the teenage group vs. 3% among the older women. Spontaneous premature rupture also occurred less frequently among the teenagers (1.8%) vs. the older women (2.4%). 15.5% of older women suffered from anemia and so did the same percentage of teenagers. Postpartum hemorrhage had a higher incidence among the teenagers (12.8%) compared with the older women (9.3%). A low operative delivery rate was associated with a low incidence of fetal distress and babies with good Apgar scores among the teenagers. This overall good obstetrical performance is attributed to better antenatal care among the teenage mothers.^ieng

Case history: adhesive vulvitis in childhood.

In a case of adhesive vulvitis or agglutination of the labia in a young female, treatment with local applications of estrogen cream to the area resulted in complete separation of the labia within a period of one month.Although the condition is not that common, it is easily detected, and simple office treatment of this kind is eminently effective. The parents' fear that a major plastic operative procedure on the vulva might be required can be allayed, and including the mother in the therapeutic regime helps considerably in managing the problem.