Cost-effectiveness of continuous positive airway pressure therapy in patients with obstructive sleep apnea-hypopnea in British Columbia

BACKGROUND:

Obstructive sleep apnea-hypopnea (OSAH) is a common disorder characterized by recurrent collapse of the upper airway during sleep. Patients experience a reduced quality of life and an increased risk of motor vehicle crashes (MVCs). Continuous positive airway pressure (CPAP), which is the first-line therapy for OSAH, improves sleepiness, vigilance and quality of life.

OBJECTIVE:

To assess the cost-effectiveness of CPAP therapy versus no treatment for OSAH patients who are drivers.

METHODS:

A Markov decision analytical model with a five-year time horizon was used. The study population consisted of male and female patients, between 30 and 59 years of age, who were newly diagnosed with moderate to severe OSAH. The model evaluated the cost-effectiveness of CPAP therapy in reducing rates of MVCs and improving quality of life. Utility values were obtained from previously published studies. Rates of MVCs under the CPAP and no CPAP scenarios were calculated from Insurance Corporation of British Columbia data and a systematic review of published studies. MVCs, equipment and physician costs were obtained from the British Columbia Medical Association, published cost-of-illness studies and the price lists of established vendors of CPAP equipment in British Columbia. Findings were examined from the perspectives of a third-party payer and society.

RESULTS:

From the third-party payer perspective, CPAP therapy was more effective but more costly than no CPAP (incremental cost-effectiveness ratio [ICER] of $3,626 per quality-adjusted life year). From the societal perspective, the ICER was similar ($2,979 per quality-adjusted life year). The ICER was most dependent on preference elicitation method used to obtain utility values, varying almost sixfold under alternative assumptions from the base-case analysis.

CONCLUSION:

After considering costs and impact on quality of life, as well as the risk of MVCs in individuals with OSAH, CPAP therapy for OSAH patients is a highly efficient use of health care resources. Provincial governments who do not provide funding for CPAP therapy should reconsider.     

Insulin-resistant diabetes during growth hormone therapy in a child with SHORT syndrome

We report the case of a 13-year-old boy with SHORT syndrome, including lipoatrophy and insulin resistance, who developed diabetes mellitus while receiving growth hormone therapy. The diabetes persisted after cessation of exogenous growth hormone but oral hypoglycaemic therapy was successful and could be discontinued eight months later.     

Successful treatment of epiglottitis with two doses of ceftriaxone

Epiglottitis in childhood is caused by Haemophilus influenzae type b. The usual antibiotic treatment at the Royal Children's Hospital, Parkville, Victoria is a five day course of chloramphenicol. Increasingly, third generation cephalosporins are being used to treat invasive H influenzae type b infections and preliminary data suggest that they can be used successfully for epiglottitis. In a prospective, randomised trial, the efficacy of a short course (two days) of ceftriaxone was compared with that of five days of chloramphenicol for the treatment of epiglottitis. The ability of these treatment regimens to eradicate H influenzae type b from the throat was also studied. Fifty five children were enrolled over an 18 month period. Epiglottitis was diagnosed clinically and confirmed on inspection of the epiglottis at direct laryngoscopy. Fifty three (96%) of 55 patients had H influenzae type b detected from at least one site: 44/52 (85%) from blood cultures, 41/47 (87%) from throat swab, and 6/8 (75%) as H influenzae type b urinary antigen. Children were randomised to receive either ceftriaxone 100 mg/kg intravenously followed by a single dose of 50 mg/kg 24 hours later (28 patients), or chloramphenicol 40 mg/kg intravenously, then 25 mg/kg eight hourly for five days, intravenously then by mouth (27 patients). All household contacts and patients receiving chloramphenicol received rifampicin 20 mg/kg daily for four days. Index patients randomised to ceftriaxone were not treated with rifampicin. There was no significant difference in outcome between the two groups with respect to the mean duration of fever, the duration of intubation, or the length of hospital admission. The proportion of patients colonised with H influenzae type b four weeks after discharge was not significantly different between the two groups: ceftriaxone 5/22 (23%) versus chloramphenicol and rifampicin 3/23 (13%). A short course of ceftriaxone was successful in treating all patients with no significant side effects and no relapses. A short course of ceftriaxone is a safe, efficacious, and economic alternative to the standard treatment in children with epiglottitis.     

Inhaled hypertonic saline increases sputum expectoration in cystic fibrosis

Objective : To determine whether inhalation of hypertonic saline (HS) increases sputum expectoration in patients with cystic fibrosis (CF).
Methodology : Ten adolescents with CF, who were receiving inpatient treatment for a pulmonary exacerbation, were enrolled in a controlled cross-over clinical trial. After inhalation of a beta adrenergic drug to prevent possible broncho-constriction, each patient inhaled for 10min either 0.9% isotonic saline (IS) or 6% HS prior to routine physiotherapy. The following day the patient received the alternative solution. Seven patients undertook a second block after 1-5 days. Outcome measures included weight of sputum, a visual analogue score to assess the subjective feeling of a cleared chest after physiotherapy, and spirometry.
Results : Sputum expectoration (median; Q1,Q3) from the beginning of the inhalation of HS or IS to the final spirometry measure 60min post-physiotherapy was significantly greater after HS than IS [17.2g (11.7, 34.8) vs 11.3g (6.5. 16,1); P — 0.006]. A clinical score of the patient's own judgement of a cleared chest was significantly better after HS than IS. Spirometry results did not change following either of the two inhalations.
Conclusions : These data show that the inhalation of 6% HS prior to physiotherapy can increase sputum expectoration in patients with CF and suggest that HS might be an effective, safe and cheap adjunct to regular physiotherapy in patients with CF.     

Treatment outcome and incidence of psychiatric disorders in dermatological out-patients

OBJECTIVE: Epidemiological studies have shown that the prevalence of psychiatric disorders among dermatological patients is high. We aimed at estimating the short-term incidence of psychiatric disorders among patients with skin disease. METHODS: The 12-item General Health Questionnaire (GHQ-12) was used to identify subjects free from psychiatric morbidity at their first dermatological visit. The GHQ-12 was administered again after 1 month during a computer-assisted telephone interview. RESULTS: A total of 277 subjects was included in the study. At the follow-up interview, 21 (7.6%) were found to have significant psychiatric morbidity. Only lack of improvement was associated with increased incidence of psychiatric morbidity (13.6%), with an odds ratio of 3.1 (95% confidence interval 1.2-7.8), after adjustment for gender, age, educational level and clinical severity. CONCLUSIONS: Physicians should devote special attention to the risk of psychiatric complications in patients who have not improved with treatment.     

犬自体肺组织瓣修补食管壁部分缺损的可行性

目的:分析犬自体肺组织瓣修补食管壁部分缺损的可行性。方法:实验于2003-01/2004-11在中国医科大学附属第二医院动物实验室完成。选用健康成年杂种犬20只,按随机数字表法分为2组,即支架组和无支架组,每组10只。20只实验犬经右胸第5肋间进胸,于胸内中段食管处胸内食管侧壁制成长4cm,环1/2~2/3周径全层缺损。于相应部位选择适当的肺组织,制成带蒂类舌状肺组织瓣。两组均将肺组织瓣覆盖并缝合固定于食管缺损处,支架组于食管缺损内衬自扩性记忆合金支架(管腔直径2.0cm、长6.0cm)并固定。术后抗炎及营养支持治疗。观察实验犬术后情况,并于术后2,4,6,8,10和12周定期处死实验犬行组织学观察。结果:无支架组实验犬存活7只,其中1只犬存活>24个月;支架组存活6只。①实验犬术后一般情况:存活犬于术后均能正常经口进食,早期有进食后呕吐,再吃下呕吐食物的现象,以支架组明显。②组织学观察结果:术后2周,无支架组均可见替代物表面有胶原及炎性渗出物,边缘见1~2层鳞状上皮细胞;支架组除有无支架组基本表现外,可见支架固定良好,光镜下见网架压迫处有较多中性粒细胞浸润。4~6周,两组均可见替代物表面有新生的3~5层复层鳞状上皮细胞;支架组见支架已基本陷入黏膜层内。8~10周,两组均可见管腔表面有6~8层新生复层鳞状上皮细胞;支架组网架边缘瘢痕组织增生,支架完全被包裹,炎症较重的局部有细胞爬行中断现象或新生细胞层数较薄,多为一两层。结论:应用自体肺组织瓣修补食管壁部分缺损是可行的,但支架组支架对食管修补处组织刺激大,炎性反应重,瘢痕重,因此如何选择合适的支撑物是今后替代节段性食管缺损面临的重要问题。     

Tumor cell anti-oxidant defenses. Inhibition of the glutathione redox cycle enhances macrophage-mediated cytolysis

The basis of resistance to oxidative injury was studied in six murine tumor cell lines that differed 54-fold in their resistance to enzymatically generated H(2)0(2). The tumors varied 56.7-fold in their specific activity of catalase, 5.3-fold in glutathione peroxidase (GPO), 3.3-fold in glutathione reductase (GR), and 2.7-fold in glutathione. There was no correlation among the levels of the three enzymes, and tumor cell resistance to lysis by H(2)0(2). However, the logarithm of the flux of H(2)0(2) necessary to cause 50 percent lysis of the tumor cells correlated with their content of glutathione (r = 0.91). The protective role of glutathione was analyzed by blocking GR and GPO, the catalysts of the glutathione redox cycle. This was facilitated by the demonstration that the anti-neoplastic agent 1,3-bis-(2- chloroethyl)-l-nitrosourea (BCNU) was a potent inhibitor of GR in intact tumor cells. BCNU inactivated tumor cell GR with a 50 percent inhibitory dose of 11 μM and a t(l/2) of inhibition of 30 s. Complete inhibition of GR was attained with no effect on GPO or catalase. Tumor cells whose GR was inactivated by BCNU could be lysed by fluxes of H(2)0(2) to which they were otherwise completely resistant. They could be killed by phorbol myristate acetate (PMA)-stimulated, bacilli Calmette-Guerin-activated macrophages in numbers which were otherwise insufficient, and by nonactivated macrophages, which otherwise were ineffective. BCNU-treated target cells were also much more sensitive to antibody-dependent, macrophage-mediated cytolysis. However, such tumor cells were no more sensitive than controls to lysis by alloreactive T cells or by antibody plus complement. Next, we deprived tumor cells of selenium by passage in selenium-deficient mice. GPO was inhibited 85 percent in such cells, with no effect on GR or catalase. Tumor cells with reduced GPO activity were markedly sensitized to lysis by small fluxes of H(2)0(2) or by PMA-stimulated macrophages or granulocytes. In contrast, inhibition of catalase with aminotriazole had no effect on the sensitivity of three tumors to peroxide-mediated lysis, and had modest effects with two others. Thus, the oxidation-reduction cycle of glutathione serves as one of the major defense mechanisms of tumor cells against three related forms of oxidant injury: lysis by fluxes of H(2)0(2), by PMA-triggered macrophages, and by macrophages in the presence of anti-tumor antibody.