Differential amnesic properties of benzodiazepines: a dose-response comparison of two drugs with similar elimination half-lives

The effects on memory and psychomotor functions of oxazepam (15, 30 mg) were compared with those of its chlorinated derivative lorazepam (1, 2 mg) and placebo. Forty five volunteers took part in a double-blind, independent groups design. Subjects completed a battery of tests before and 1.5 and 3 h after drug administration.Lorazepam and oxazepam had similar dose-related effects on tests of attention, manual motor speed and recoding skills and all active treatments produced similar levels of subjective sedation. Both drugs caused anterograde impairments of long-term verbal memory and had no effects on short-term verbal span or recency. Neither drug produced retrograde amnesia for material learned before drug administration nor affected retrieval from semantic memory. The high (2 mg) dose of lorazepam positively facilitated recall of pre-drug information. The magnitude of anterograde amnesia produced by the two benzodiazepines was not linearly dose-related in that the two low doses had similar effects whereas the high dose of lorazepam produced impairments many times greater than oxazepam 30 mg. We conclude that drugs with similar half-lives may have similar effects on some cognitive and mood factors but be completely different in terms of amnesic effects. Differing potencies of the two drugs may be a more important factor determining amnesic side-effects.     

Intracranial ependymomas in children

Between 1970 and 1988, 51 children with intracranial ependymal tumors (33-infratentorial, 18-supratentorial received initial treatment at the University of Pennsylvania. Therapy consisted of total or near total tumor resection in 15 patients and partial resection or biopsy in 36. Postoperative irradiation alone was given to 18, chemotherapy to 4, and a combination of these two modalities to 26. Patients have been followed for a median period of 7.75 years. The 5-year actuarial survival and progression-free survival (PFS) rates are 46% and 30%, respectively. Of the 30 patients who have progressed, 29 did so locally and one died before the site of failure could be determined. Six patients also had disease outside the primary site at relapse; three of them had received craniospinal irradiation. Local control was significantly better for patients whose tumor dose exceeded 4500 cGy (32% vs. 0%, p = .01) and for Caucasian patients (34% vs. 15%, p =.05). Survival was better for patients who were over 4 years of age at diagnosis (55% vs. 30%, p = .04), for patients who received local radiation doses above 4500 cGy (51% vs. 18%, p = .01), and for Caucasian patients (43% vs. 14%, p = .01). Extent of resection, histology, location, the use of cranial or craniospinal irradiation, and the use of chemotherapy did not significantly impact on survival. We conclude that the inability to control local disease remains the single most important factor leading to treatment failure. Older age, higher local radiation dose, and Caucasian race appear to be the only favorable prognostic factors.     

The impact of corporate culture on nurse retention

This article concerns the impact of the corporate culture of today's hospitals on the hospital's ability to attract and retain nurses. Several sources are used to illuminate recent sociohistoric changes that have had a profound impact on the business of health care and the professional world of staff nurses. Organizational characteristics that are associated with successful nurse retention strategies are offered.     

Emergency medicine in Sri Lanka: The inevitable evolution to a new specialty

Sri Lanka is a low‐income country with a relatively advanced, equitable and accessible health‐care system offered to its 20 million populations free of charge through a national pro‐poor health policy. Its weaknesses in emergency services, however, surfaced in 2004 when it faced the Tsunami, the worst natural disaster of the world of the 21st century. Since then, the local health community with the assistance of the government and foreign aid agencies have embarked on a path to establish emergency services, improve its preparedness for disaster management and establishment of emergency medicine training. The present article traces this path and how it is evolving in the country.     

Acute diarrhoea in adults: a prospective study

A prospective study of 74 adults with acute diarrhoea was carried out in Sydney in 1984-1985 to determine the infective agents that were involved and their relationship to clinical, epidemiological and laboratory features. Thirty-four potential pathogens were identified in 32 (43.2%) patients. These included, in order of frequency: Campylobacter spp., rotavirus, Clostridium difficile, Salmonella enteritidis, Aeromonas hydrophila, Vibrio parahaemolyticus, adenovirus, a small round virus and Giardia lamblia. A seasonal trend was noted; the majority of Campylobacter isolations occurred in summer. The patients with Cl. difficile infection formed a distinct group, and experienced a subacute onset of diarrhoea after antibiotic administration, with few systemic symptoms. Except in these patients, the clinical and epidemiological features, together with results of faecal microscopy, were not a reliable predictor of the nature of the pathogens that were identified. While most patients with diarrhoea can be treated supportively, stool culture is an important procedure in patients with severe or protracted illness when specific antimicrobial therapy is contemplated.     

Human placental insulin binding in normal and well-controlled diabetic patients

Previous studies of insulin binding to placentas of both insulin-dependent and untreated gestational diabetic patients have described placentas from diabetics to contain fewer insulin receptors than placentas from nondiabetic gravidas. However, these studies were done using membrane fractions prepared from the placentas and at a time when adequacy of antepartum glycemic control in the diabetic patients was not routinely evaluated by self blood sugar measurement or hemoglobin A1 assay. The current study compares specific 125I-insulin binding in vitro to intact placental villi from 15 normal patients with insulin binding to intact villi obtained from 15 insulin-dependent diabetic mothers whose fasting and postprandial blood sugars and hemoglobin A1 levels were maintained in a range normal for term pregnancy. We demonstrate that insulin binding to intact placental villi is the same in this group of diabetic patients as in the nondiabetic patients.     

Sudden unexpected death in infancy: epidemiologically determined risk factors related to pathological classification

Infants that died suddenly and unexpectedly were studied as part of the European Concerted Action on sudden infant death syndrome (SIDS). Three paediatric pathologists, first independently of each other and later in a consensus meeting, classified 63 cases into 3 groups: SIDS (19 cases), borderline SIDS (30 cases) and non-SIDS (14 cases). The interobserver agreement among the pathologists before the consensus meeting was moderate (Kappa = 0.41) and jointly it was higher (Kappa = 0.83). The distribution of epidemiologically determined risk factors was studied over these three groups. Maternal smoking after birth, low socioeconomic status and thumb sucking were found more often in SIDS than in the other cases. Inexperienced prone sleeping was a determinant for SIDS, but not for non-SIDS. Previous hospital admission, low birthweight and/or short gestation were associated with borderline SIDS. Non-SIDS cases received more breastfeeding, the parents hardly smoked during pregnancy and after birth, a firm mattress had been used, and more often signs of illness had been reported by the parents, compared with the SIDS and borderline SIDS cases. Bedding factors and both primary and secondary prone sleeping were equally distributed over the three groups which supports the hypothesis that, in SIDS and borderline SIDS, as well as in non-SIDS cases, some similar external and preventable factors might influence the events leading to death. Research should therefore focus on all sudden unexpected deaths, after which subgroups such as SIDS cases can be separately analysed. The postmortem is an essential part of the whole work-up of each case and the results should be interpreted with all other available data to arrive at a sound evaluation of cases and thus form the basis for the prevention of all sudden unexpected infant death.     

An evaluation of Merocel and Series 5000 nasal packs in patients following nasal surgery: a prospective randomised trial.

OBJECTIVE: The primary objective of this study was to compare postoperative pain levels between Merocel and Series 5000 nasal packs. DESIGN: A prospective randomised, single blind, paired control trial. SETTING: A single consultant in two tertiary Otolaryngology units. PARTICIPANTS: Twenty-four adults, ASA 1, who underwent septoplasty, endoscopic sinus surgery or both, were considered after exclusion criteria were applied: bleeding abnormalities, patients taking anticoagulant medications and any significant co-morbidity requiring admission beyond 24-h postoperatively. Twenty-one patients were randomly assigned to have one side of their nose packed with Merocel pack and the other with Series 5000 overnight. MAIN OUTCOME MEASURES: The difference in pain levels, using a visual analogue scale, both with the pack in situ and on removal. RESULTS: In 20 patients, the mean pain scores while the packs were in situ were 3.78 for Merocel and 3.62 for Series 5000 and was not found to be significantly different (P = 0.65. 95% CI = -0.57-0.89). The mean pain score on removal of the Merocel pack was five and for the Series 5000 was 3.08. The Series 5000 pack was significantly less painful than Merocel on removal (P < 0.0001. 95% CI = 1.11-2.7). Both were equally effective in their stability and haemostatic effect. CONCLUSIONS: Both the Merocel and Series 5000 packs are effective packs regarding haemostasis and have equivalent pain levels while in situ. However, the Series 5000 pack was significantly less painful on removal of the pack.     

Abnormal patterns of pulmonary neuroendocrine cells in victims of sudden infant death syndrome

Ventilatory dysfunction has become the main focus of current research in sudden infant death syndrome (SIDS). This has been correlated with structural abnormalities in the carotid body and respiratory nuclei of the brainstem. In recent studies, the denervating effect of asphyxial brainstem dysfunction on the pulmonary neuroendocrine cells, which probably function as chemoreceptors, was demonstrated and prompted the following study. The pulmonary neuroendocrine system was evaluated in 25 victims of SIDS and 20 control infants, ranging in age from 3 weeks to 7 months and 1 to 12 months, respectively. The pulmonary neuroendocrine cells were stained by the Churukian-Schenk method and the neuroendocrine cell-positive airway values expressed as a percentage of the total number of airways. The range of positive airway values for victims of SIDS was 2% to 97% with a median of 73%. In contrast, the range for the control infants was 1% to 44% with a median of 25.5%. The SIDS victims' percentage was significantly greater than the control infants' percentage (P less than .0001). The number of pulmonary neuroendocrine cells in positive airway was also increased among SIDS victims compared with control infants. The altered pulmonary neuroendocrine cell pattern could be attributable to either brainstem dysfunction or chronic hypoxia. These explanations are not, however, mutually exclusive of one another; in fact, it is possible that both mechanisms may be operative.