Nasal masks for domiciliary positive pressure ventilation: patient usage and complications.

BACKGROUND--Nasal mask discomfort is a major factor in compliance with treatment by nasal intermittent positive pressure ventilation (NIPPV) and nasal continuous positive airway pressure (CPAP). METHODS--A study of skin complications resulting from mask usage, with particular reference to predisposing factors, was carried out in 66 patients by means of a postal questionnaire. An effective means of managing ulceration at the nasal bridge while continuing therapy is described. RESULTS--Some disruption of treatment due solely to mask discomfort was experienced by 35 patients (53%), consisting of broken skin or open sores in 11 cases (17%). CONCLUSIONS-Although complications resulting from nasal mask usage are common, early identification of patients at risk of developing such complications and appropriate intervention will result in improved patient compliance.     

Antigenuria after immunization with Haemophilus influenzae oligosaccharide CRM197 conjugate (HbOC) vaccine

We tested the urine of 30 infants 6 weeks to 7 months of age after they received standard 10-micrograms (0.5-ml) doses of HbOC (HibTITER) Haemophilus influenzae b (Hib) conjugate vaccine for the presence of Hib antigenuria using a commercially available latex particle agglutination assay (Directigen). Urines were collected within 1 hour, from 1 to 3 hours, at 24 hours and at 3, 6 and 9 days after vaccine administration and reactions were quantitated from 0 to 3+. In contrast to previous studies in older children which showed little or no antigenuria following HbOC vaccination, our study shows that in infants intense Hib antigenuria is evident within 2 to 3 hours and persists 3 days after vaccine administration and that less intense antigenuria may be detected in some infants for several days. With efficacious vaccines now being used in 2- to 6-month-old infants, invasive Hib disease may soon be limited to infants of this age just before their seroconversion. It should be recognized that antigenuria occurs for several days after vaccination with Hib conjugate vaccines and that it could be erroneously interpreted as evidence of invasive Hib infection.     

The human major histocompatibility complex class Ib molecule HLA-E binds signal sequence-derived peptides with primary anchor residues at positions 2 and 9

Human histocompatibility leukocyte antigen E (HLA-E) and mouse major histocompatibility complex (MHC) class Ib antigen, Qa-1, share the same substitutions at two normally conserved positions 143 and 147, which are likely to affect binding of the C terminus of peptides. Qa-1 is able to bind a peptide derived from the leader sequence of H-2 D and H-2 L molecules. We developed a peptide binding assay in vitro to compare the binding specificity of HLA-E with the mouse MHC class Ib molecule Qa-1. We demonstrate that HLA-E binds, although poorly, the peptide which binds to Qa-1 and that it also binds nonamer signal sequence-derived peptides from human MHC class I molecules. Using alanine and glycine substitutions, we could define primary anchor residues at positions 2 and 9 and secondary anchor residues at position 7 and possibly 3.     

Reflex Cardiorespiratory Effects of Nociceptive Oesophageal Distension in the Decerebrate Rat

It is well established that painful distension of hollow viscera such as the oesophagus can evoke a reflex tachycardia and pressor response; however, the nature of the oesophageal afferent pathway(s) remains controversial. This study investigated the afferent arc which mediates these reflex cardiovascular changes in the decerebrate rat. In addition, the effect of oesophageal distension on the respiratory activity of the costal diaphragm was studied. Focal distension of the oesophagus (volume of 0.3 ml applied for 10 s) just above the diaphragmatic hiatus evoked a reproducible pressor response and tachycardia in the decerebrate rat. Respiration was transiently inhibited at the beginning of oesophageal distension and prior to the rise in blood pressure. Neuromuscular blockade with the nicotinic acetylcholine receptor blocker alpha-bungarotoxin (140 microg bolus) had no effect on the magnitude of the cardiovascular response. Therefore the efferent supply to the striated muscle of the rat oesophagus was not essential in mediating this reflex. Signal averaging of the mean blood pressure response showed that neither selective ablation of oesophageal spinal afferents nor bilateral vagotomy altered the early trajectory of the pressure response. Bilateral vagotomy reduced the peak magnitude of the response to sustained oesophageal distension. In contrast, selective removal of spinal afferents had no effect on the response. Ablation of both neural pathways was essential to abolish the reflex cardiovascular and respiratory responses. It can be concluded that both vagal and spinal afferent pathways are utilised in the reflex cardiorespiratory response to painful oesophageal distension. Although ablation of one neural pathway had no effect on the response it was still implicated in the reflex, since ablation of both pathways was necessary to prevent the cardiorespiratory changes. This study emphasises the need for caution when inferences are made concerning single selective ablations of multiply innervated organs.     

Concurrent review of the duration of antimicrobial prophylaxis in surgery.

The administration of prophylactic antibiotics in surgery is appropriate for many patients. Data have shown extending the duration of prophylaxis beyond 48 hours does not lower the rate of postoperative-infection. The purpose of this project was to concurrently assess the duration of prophylactic antibiotic use. A total of 95 patients were monitored over 3 weeks. Eighty patients (84.2%) received antimicrobial therapy. In 23 of these patients (28.75%) the duration of antibiotic administration was longer than 2 days without clinical or microbiological evidence of infection. In 5 other patients only postoperative antibiotics were prescribed. The cost difference between the actual duration of antibiotic administration and 2 days of the same regimen was +1,364.58. Extrapolating for one year, it can be estimated that antibiotic costs could be reduced about +23,600. Pharmacists can focus on the duration of antibiotic prophylaxis as a cost containment measure.     

The General Practice Research Club.

The General Practice Research Club was established in 1969, and now has 120 members. A meeting of the club is held twice a year, at which various papers, from research ideas through to completed, published studies are presented. A survey of 40 individuals who had presented papers at meetings during the period 1984-89 showed that almost half (18) had presented papers on clinical topics. As a result of the presentation, 29 individuals had modified their research, with 11 undertaking major alterations. The meeting was rated most highly by those offering ideas and plans for research. Most individuals responded positively to the meetings, commenting that they valued peer review, found the meetings encouraging, and useful for focusing ideas. Lack of criticism and feedback was commented upon. The club has an important role to play in encouraging research by service general practitioners.     

颈动脉内膜切除术的恰当应用

在颈动脉内膜切除术(CEA)首创的头30年里,一直没有明确的标准来确定哪些颈内动脉疾病患者适合这一手术.最近,从7项临床随机试验中得出了哪些有症状与无症状患者适合行CEA的结论.对于颈内动脉狭窄70%以上的患者,卒中的危险性最大,手术的益处也最大.在这些研究中,CEA对以下患者最有益半球短暂性脑缺血发作、颅内外联合病灶和无侧支循环且除此之外身体状况良好的老年患者.下列患者虽然能从手术中获益,但围手术期卒中和死亡的危险性较高广泛白质疏松、对侧颈内动脉闭塞和腔内有血栓者.狭窄50%～69%的患者较少获益,包括女性和仅有一过性单眼盲在内的一些患者行CEA甚至可能有害.腔隙性卒中和一侧颈内动脉接近闭塞的患者有手术指征,但益处不大;狭窄＜50%的患者不能从手术中获益.在最大的一项无症状患者随机试验中,围手术期卒中和死亡的危险性非常小(1.5%),但要在2年内防止1例卒中发生需要相当多的病例(83例)接受CEA治疗.以后的文献报道围手术期危险性较高(2.8%～5.6%).近一半无症状患者的卒中是心源性栓塞和小血管疾病所致.这些局限性抵消了任何潜在的益处.其他试验正在进行,并可能确认哪些无症状患者亚组可从手术中获益.同时,大多数无症状患者内科治疗效果也较好.     

CT evaluation of Crohn's disease: effect on patient management

CT scans from 80 consecutive patients with clinically symptomatic Crohn's disease were reviewed retrospectively to determine the effect of CT diagnosis on patient management. The initial clinical impression and any subsequent change in patient management because of the CT findings were noted. In 22 (28%) of the 80 patients, significant previously unsuspected findings led to a change in medical or surgical management. These included 12 patients with fistulae, four with abscess, two with avascular necrosis of the femoral head, two with sacral osteomyelitis, and single cases of pelvic inflammatory disease and femoral vein thrombosis.