High coherence between mean arterial blood pressure and tissue-oxygenation index indicates impaired cerebral autoregulation in clinically sick preterm infants and is strongly associated with subsequent mortality. Cross-spectral analysis of mean arterial blood pressure and tissue-oxygenation index has the potential to provide continuous bedside assessment of cerebral autoregulation and to guide therapeutic interventions.

Objectives To compare "hospital at home" and hospital care as an inpatient in acute exacerbations of chronic obstructive pulmonary disease. Design Prospective randomised controlled trial with three months' follow up. Setting University teaching hospital offering secondary care service to 350 000 patients. Patients Selected patients with an exacerbation of chronic obstructive pulmonary disease where hospital admission had been recommended after medical assessment. Interventions Nurse administered home care was provided as an alternative to inpatient admission. Main outcome measures Readmission rates at two weeks and three months, changes in forced expiratory volume in one second (FEV 1 ) from baseline at these times and mortality. Results 583 patients with chronic obstructive pulmonary disease referred for admission were assessed. 192 met the criteria for home care, and 42 refused to enter the trial. 100 were randomised to home care and 50 to hospital care. On admission, FEV 1 after use of a bronchodilator was 36.1% (95% confidence interval 2.4% to 69.8%) predicted in home care and 35.1% (6.3% to 63.9%) predicted in hospital care. No significant difference was found in FEV 1 after use of a bronchodilator at two weeks (42.6%, 3.4% to 81.8% versus 42.1%, 5.1% to 79.1%) or three months (41.5%, 8.2% to 74.8% versus 41.9%, 6.2% to 77.6%) between the groups. 37% of patients receiving home care and 34% receiving hospital care were readmitted at three months. No significant difference was found in mortality between the groups at three months (9% versus 8%). Conclusions Hospital at home care is a practical alternative to emergency admission in selected patients with exacerbations of chronic obstructive pulmonary disease.

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A small percentage of women have attacks only occurring at the time of menstruation, which can be defined as true "menstrual" migraine. This group is most likely to respond to hormonal treatment. The group of 34.5% who have an increased number of attacks at the time of menstruation in addition to attacks at other times of the month could be defined as having "menstrually related" migraine and might well respond to hormonal therapy. The 32.7% who have attacks throughout the menstrual cycle without an increase at menstruation are unlikely to respond to hormonal therapy. The 25.5% who do not have attacks related to menstruation almost certainly will not respond to hormonal therapy.

This study aimed to examine the performance characteristics of four high-frequency oscillatory-type ventilators, using an in vitro model of the intubated neonatal respiratory system. Each ventilator was examined across its operative range of settings and at varying model lung compliance (C) and resistance. The oscillatory pressure waveform was measured at the airway opening (Pao). Tidal volume (VT) and flow were determined from pressure changes within the model lung (DeltaPA). The spectral content of the Pao waveform differed between ventilators. The maximum ventilator VT ranged from 3.7 to 11.1 ml at 15 Hz and a mean airway pressure (Paw) of 12 cm H(2)O to oscillate a model lung (C = 0.4 ml/cm H(2)O) through a 3.0-mm internal diameter (i.d.) endotracheal tube (ETT). A small drop in C was associated with a decrease in VT and marked increase in DeltaPA from 0.1 to 0.8 ml/cm H(2)O. The influence of C on VT and DeltaPA and the pressure cost of ventilation (DeltaPA/f.VT(2)) was dependent on the oscillatory frequency, ETT inner diameter, and the specific ventilator used. Substantive differences exist between oscillatory ventilators that need to be considered in their clinical application. The rapid establishment of optimal lung volume and oscillatory frequency is important in minimizing barotrauma during high-frequency oscillatory ventilation.

Rapid arterial O2 desaturation during apnea in the preterm infant has obvious clinical implications but to date no adequate explanation for why it exists. Understanding the factors influencing the rate of arterial O2 desaturation during apnea () is complicated by the non-linear O2 dissociation curve, falling pulmonary O2 uptake, and by the fact that O2 desaturation is biphasic, exhibiting a rapid phase (stage 1) followed by a slower phase when severe desaturation develops (stage 2). Using a mathematical model incorporating pulmonary uptake dynamics, we found that elevated metabolic O2 consumption accelerates throughout the entire desaturation process. By contrast, the remaining factors have a restricted temporal influence: low pre-apneic alveolar causes an early onset of desaturation, but thereafter has little impact; reduced lung volume, hemoglobin content or cardiac output, accelerates during stage 1, and finally, total blood O2 capacity (blood volume and hemoglobin content) alone determines during stage 2. Preterm infants with elevated metabolic rate, respiratory depression, low lung volume, impaired cardiac reserve, anemia, or hypovolemia, are at risk for rapid and profound apneic hypoxemia. Our insights provide a basic physiological framework that may guide clinical interpretation and design of interventions for preventing sudden apneic hypoxemia.

SummaryThe reproductive histories of 777 women suffering from migraine were compared with 182 non-migrainous women. The incidence of miscarriage, stillbirth and toxaemia of pregnancy was very similar in both groups and there was no increase in the number of congenital malformations in the children born to women who suffered from migraine compared with the control group or with the national average. It was concluded that women suffering from migraine did not have an increased risk of giving birth to children with deformity and it was unlikely that drugs most commonly used in the treatment of migraine were teratogenic.

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