A seven year experience of medical emergencies in the assessment unit.

AIMS: To analyse retrospectively all referrals to the assessment unit during a seven year period, to determine their sources and destination. METHODS: All referrals over the seven year period were analysed. Parental satisfaction was determined using a questionnaire in some of the patients. The disease pattern and the investigations performed were determined. The community nurses' working hours and type of work done were analysed. RESULTS AND CONCLUSIONS: A total of 43 496 children were seen in the unit. Over 65% of the patients were referred by the general practitioners; 13 517 (34.2%) of those referred to the unit were discharged directly from the unit. Respiratory disorders and gastrointestinal problems were commonly seen. The children discharged from the unit did not have significantly more tests done on them. Most of the parents whose children were discharged from the unit were happy to be managed at home. The community nurses attended many children who needed intravenous therapy and advice on fluid rehydration. Community nurses reduce admission to the wards by working with other members in the assessment unit. This in turn provides a single point of entry and bridges the gap between primary and secondary care. We suggest recommendations on setting up such a unit.     

Inhaled anesthetics have hyperalgesic effects at 0.1 minimum alveolar anesthetic concentration

We investigated the hyperalgesic (antianalgesic) effect of the inhaled anesthetics isoflurane, halothane, nitrous oxide, and diethyl ether, or the nonimmobilizer 1, 2-dichlorohexafluorocyclobutane at subanesthetic partial pressures (or, for the nonimmobilizer, subanesthetic partial pressures predicted from lipid solubility) in rats. Hyperalgesia was assessed as a decrease in the time to withdrawal of a rat hind paw exposed to heat. All four anesthetics, including nitrous oxide and diethyl ether, produced hyperalgesia at low partial pressures, with a maximal effect at 0.1 minimum alveolar anesthetic concentration (MAC) required to prevent response to movement in 50% of animals, and analgesia (an increased time to withdrawal of the hind paw) at 0. 4 to 0.8 MAC. The nonimmobilizer had neither analgesic nor hyperalgesia effects. We propose that inhaled anesthetics with a higher MAC-Awake (the MAC-fraction that suppresses appropriate responsiveness to command), such as nitrous oxide and diethyl ether, can be used as analgesics because patients are conscious at higher anesthetic partial pressures, including those which have analgesic effects, whereas anesthetics with a lower MAC-Awake do not produce analgesic effects at concentrations that permit consciousness. Implications: The inhaled anesthetics isoflurane, halothane, nitrous oxide, and diethyl ether produce antianalgesia at subanesthetic concentrations, with a maximal effect at approximately one-tenth the concentration required for anesthesia. This effect may enhance perception of pain when such small concentrations are reached during recovery from anesthesia.     

Naturally occurring variability in anesthetic potency among inbred mouse strains

We measured the naturally occurring variability in anesthetic potency, defined by the minimum alveolar anesthetic concentrations (MACs) of inhaled anesthetics required to produce immobility in response to noxious stimuli, in seven widely used laboratory mouse strains. To these data, we added similar data for eight other mouse strains. The average MAC values for each anesthetic for the 15 strains were normally distributed, with a coefficient of variation (ratio of SD to mean) of 0.1. The range of MAC values was 39% for desflurane, 44% for isoflurane, and 55% for halothane. MAC values were highly reliable, with approximately 1% of the variance in MAC measurements for the strains being explained by measurement error. One hundred forty-six statistically significant differences among the 15 strains were found for the three inhaled anesthetics (isoflurane, desflurane, and halothane). Our results suggest that multiple genes underlie the observed variability in anesthetic potency. IMPLICATIONS: Laboratory mouse strains differ significantly in susceptibility to anesthetics. These phenotypic differences may be exploited to help determine the genetic basis of anesthetic-induced immobility.     

Spontaneous resolution of a unilateral cataract in an infant.

We report a case of unilateral cataract with a posterior located central opacity greater than 3 mm in diameter, which resolved without surgical intervention in an otherwise healthy child.     

Fetal pleural effusions

The clinical course of primary fetal hydrothorax is unpredictable. Whereas smaller unilateral effusions might remain stable or even regress, this is rarely the case with larger collections. Bilateral effusions, hydrops, preterm delivery and the lack of antenatal therapy are all associated with poor outcome. Once structural and chromosomal anomalies have been excluded, optimal management depends on gestational age, rate of progression, the development of hydrops and associated maternal symptoms. For very large effusions with mediastinal shift, hydrops and/or hydramnios, or when there is rapid enlargement of the effusion, fetal intervention is warranted. Survival can be maximized by pleuroamniotic shunting, which can reverse hydrops and hydramnios and prevent pulmonary hypoplasia. Pleuroamniotic shunting can also be used for the treatment of other large cystic lung lesions, such as a macrocystic congenital cystic adenomatoid malformation or bronchopulmonary sequestration, especially when associated with hydrops.     

Cytogenetics and infertility in man. II. Testicular histology and meiosis.

Within a group of 207 subfertile men, selected for testicular biopsy, histological investigations were made successfully in 194 chromosomally normal and 7 chromosomally abnormal individuals. Fifty-two per cent of men with a normal karyotype showed normal testicular histology, 31% showed a general depression of spermatogenesis and 8% showed deficiency in the late stages. Ten per cent had only Sertoli cells in the testis. The range of testicular conditions seen in the chromosomally abnormal men was similar to that found in the chromosomally normal. Meiotic studies carried out on 118 chromosomally normal individuals gave a mean chiasma count of 48-9 per cell. There was a positive correlation between high numbers of cells at diakinesis/metaphase I showing X and Y univalents and low numbers of cells reaching metaphase II. Meiosis was studied in 3 translocation heterozygotes, one 47, XYY male, one 47, XY+mar individual and one patient with a ring Y chromosome.     

Antipodean forensics: a comment on ANZFSS’s response to PCAST

Recently, one of the world’s leading scientific and technical advisory groups, the U.S. President’s Council of Advisors on Science and Technology (or PCAST), published an assessment of the research supporting several forensic science procedures in regular use. PCAST was particularly interested in pattern recognition or comparison procedures, specifically: simple and mixed DNA profiles; bite marks; latent fingerprints; firearms; footwear; and hair analysis. In its report and recommendations PCAST emphasised the primacy of validation. In response, the Council of the Australian and New Zealand Forensic Science Society produced a short statement suggesting that the PCAST report has limited application to forensic science in Australia and New Zealand. This short commentary offers an alternative perspective.