No abstract

Dopamine is a naturally occurring catecholamine with actions in the central nervous system and endocrine systems, including inhibition of prolactin release from the pituitary gland. Prolactin secretion has been shown to be increased in response to physiological stress, while hypoprolactinaemia is associated with a reduction in the cellular immune response. We have investigated the effects of low-dose infusion of dopamine 2.5 micrograms kg-1 min-1 on serum concentrations of prolactin in critically ill patients. Six hours after commencing the dopamine infusion, mean serum prolactin concentration had decreased from 746.95 to 128.9 mu. litre-1 (normal range 84-488 mu. litre-1). This represented a mean reduction of 79.2%, with 35% of patients exhibiting a subnormal concentration while receiving dopamine. This reduction was reversed after cessation of dopamine and reproducible on re-institution. This suppression of the release of dopamine may be a detrimental side effect of low-dose dopamine infusion in critically ill patients.

A prospective open randomized controlled study was performed to assess the ability of Euromedical ILM endotracheal tube cuff (silicone cuff) to prevent pulmonary aspiration The inflation characteristics of this silicone cuff enables the control of tracheal wall pressure. The silicone cuffed tube was shortened and an adjustable flange was used to convert it to a cuffed tracheostomy tube. Twelve patients requiring a tracheostomy on a four-bed intensive care unit (ICU) in a district general hospital received either a silicone or a Shiley cuffed tracheostomy tube. Tracheal wall pressures of both cuffs were maintained at 30 cm H 2 O with a constant pressure inflation device. Blue food dye was instilled once daily into the subglottic space through a fine catheter above the cuff. There were six patients in the Shiley group and six patients in the silicone cuff group. Dye leaked to the trachea in six (100%) of the Shiley group compared with none (0%) of the silicone cuff group (P=0.001). This study confirms the effectiveness of this silicone cuff at preventing aspiration and the high incidence of leakage with the conventional high-volume low-pressure tracheostomy tube cuff.

Reports and guidelines concerning intensive care practice have been issued recently. However, the introduction of such centrally issued recommendations may be difficult because of marked heterogeneity between intensive care units. This study examined the facilities (number of beds, consultant sessions, nursing establishment), annual workload (number and types of patients admitted) and outcome (intensive care unit mortality) in the (old) Anglia Region. There were significant differences in the distribution of patients' ages, severities of illness, diagnoses, durations of admission and outcomes. Such heterogeneity may make multicentre trials more difficult to conduct and create problems when uniform measures designed to improve intensive care services are being planned.

Thirty patients were randomly allocated to receive either atracurium or pancuronium for neuromuscular blockade during surgery. At the end of the operation residual paralysis was antagonized with neostigmine. Voluntary strength was assessed at intervals after the antagonism, by observing grip strength, maximum inspiratory and expiratory force, 5-s head lift and the presence or absence of double vision. Grip strength and maximum expiratory force recovered significantly more quickly in the atracurium group over the 2-h measurement period. Double vision was significantly more frequent at up to 1 h when pancuronium had been used. At no time was there any significant difference between the two groups in respect of the 5-s head lift or, after 30 min, in the measurement of inspiratory force.