Can psychological factors help us to determine adherence to CPAP? A prospective study.

The present study objective was to establish whether pretreatment social cognitive variables may contribute to the explanation of variance in adherence to continuous positive airway pressure (CPAP) treatment for patients with obstructive sleep apnoea/hypopnoea syndrome (OSAHS). A total of 119 of 180 consecutive OSAHS patients were recruited to the study prior to initial CPAP titration. Patients completed psychological measures of health value, health locus of control (incorporating internality, chance, powerful others) and self-efficacy prior to CPAP titration. Objective adherence data were measured by CPAP unit time clocks and collected at 3-month follow-up. Average nightly use was calculated over this period. Logistic regression of prospective predictors of adherence produced a model comprising psychological (health value, internality, powerful others), as well as clinical variables (Epworth score, body mass index, apnoea/hypopnoea index, CPAP pressure). This model explained 24% of the variance in CPAP use, and correctly identified 75% of adherers and 53% of nonadherers. Although the psychological variables explained only a small amount of the overall variance in adherence behaviour, this result provides further support for the hypothesis that psychological variables contribute, in part, to continuous positive airway pressure adherence. Future research should focus on highlighting discrete variables, which may helpfully inform psychologically based interventions aimed at improving the use of continuous positive airway pressure by patients with obstructive sleep apnoea/hypopnoea syndrome at risk of discontinuance.

Maintenance of anaesthesia with sevoflurane or isoflurane effects on adverse airway events in smokers.

Patients who smoke are at risk of coughing and other adverse airway events during induction of anaesthesia. We have studied the incidence of adverse airway events in smokers under isoflurane or sevoflurane anaesthesia after induction with propofol. Smokers inhaling isoflurane had a 45% incidence of adverse airway events compared to 10% in those inhaling sevoflurane (p = 0.013).

The provision of clinical psychology services within a general hospital: an analysis and interpretation of referral rates.

A semi-structured interview was administered to fifteen hospital based medical and surgical consultants. This aimed to assess the level of knowledge and understanding regarding the activities of clinical psychologists and to evaluate the perception of need for the clinical psychology service within a general hospital in Central Scotland. Differences between high/regular and occasional/non-referring departments were examined. Results indicated that high/regular referring departments displayed a greater level of knowledge and understanding of clinical psychology practice than occasional/non-referring departments. The occasional/non-referring departments demonstrated more cautious attitudes regarding psychological input to the care of patients than high/regular referring departments. This study suggests that lower referral rates were more likely to be a result of generally low levels of awareness and understanding of psychological issues rather than mistrust of psychological methods. This highlights the need for education about the role of clinical psychology in general hospitals and improved communication between the psychology service and other departments in the hospital.

Biosynthesis of triphosphoribosyl-dephospho-coenzyme A, the precursor of the prosthetic group of malonate decarboxylase.

Malonate decarboxylase from Klebsiella pneumoniae consists of four subunits MdcA, D, E, and C and catalyzes the cleavage of malonate to acetate and CO(2). The smallest subunit MdcC is an acyl carrier protein to which acetyl and malonyl thioester residues are bound via a 2'-(5' '-phosphoribosyl)-3'-dephospho-CoA prosthetic group and turn over during the catalytic mechanism. We report here on the biosynthesis of holo acyl carrier protein from the unmodified apoprotein. The prosthetic group biosynthesis starts with the MdcB-catalyzed condensation of dephospho-CoA with ATP to 2'-(5' '-triphosphoribosyl)-3'-dephospho-CoA. In this reaction, a new alpha (1' ' --> 2') glycosidic bond between the two ribosyl moieties is formed, and thereby, the adenine moiety of ATP is displaced. MdcB therefore is an ATP:dephospho-CoA 5'-triphosphoribosyl transferase. The second protein involved in holo ACP synthesis is MdcG. This enzyme forms a strong complex with the 2'-(5' '-triphosphoribosyl)-3'-dephospho-CoA prosthetic group precursor. This complex, called MdcG(i), is readily separated from free MdcG by native polyacrylamide gel electrophoresis. Upon incubation of MdcG(i) with apo acyl carrier protein, holo acyl carrier protein is synthesized by forming the phosphodiester bond between the 2'-(5' '-phosphoribosyl)-3'-dephospho-CoA prosthetic group and serine 25 of the protein. MdcG corresponds to a 2'-(5' '-triphosphoribosyl)-3'-dephospho-CoA:apo ACP 2'-(5' '-phosphoribosyl)-3'-dephospho-CoA transferase. In absence of the prosthetic group precursor, MdcG catalyzes at a low rate the adenylylation of apo acyl carrier protein using ATP as substrate. The adenylyl ACP thus formed is an unphysiological side product and is not involved in the biosynthesis of holo ACP. The 2'-(5' '-triphosphoribosyl)-3'-dephospho-CoA precursor of the prosthetic group has been purified and its identity confirmed by mass spectrometry and enzymatic analysis.

Pneumatic retinopexy: a survey of current practice patterns among the vitreous society members.

It was our purpose to assess the current practice patterns of vitreoretinal surgeons in the continental United States regarding the use of pneumatic retinopexy for the repair of rhegmatogenous retinal detachments. Preferences of vitreoretinal surgeons regarding the repair of rhegmatogenous retinal detachments were obtained via mail survey of all active members of the Vitreous Society residing in the continental United States as of December 1995. Forty-eight percent of those surveyed responded to the questionnaire. Scleral buckle was preferred over pneumatic retinopexy by more than 2 to 1 for repair of multiple superior tears within 3 clock hours, moderate myopia, small vitreous hemorrhage, detached macula, age greater than 65 years old, visually significant cataract, mild proliferative vitreoretinopathy, pseudophakia, and patient membership in an HMO. Pneumatic retinopexy was preferred in patients who were uninsured and in cases in which an operating room was not immediately available. Although the initial success rate of pneumatic retinopexy was felt to be lower than scleral buckling, the majority felt that there was no difference in the ultimate visual outcome. Among responding members of the Vitreous Society, scleral buckling continues to be the procedure of choice for the repair of the majority of primary retinal detachments.