Influence of sleep position on respiratory function of patients with sleep apnea/hypopnea syndrome / 中国组织工程研究

BACKGROUND: In patients with obstructive sleep apnea(OSA),the degree of severity of OSA is mostly related to the sleep time spent in the supine position. According to the apnea-hypopnea index(AHI), positional and n onpositional OSA has been distinguished.OBJECTIVE: To compare the clinical characteristics of positional and nonpositional OSA and investigatethe relationship between sleep position and respiratory function of patients with OSA.DESIGN: A comparative clinica] observation based on the OSA patients.SETTING: Center of Sleep Disorders,Nanjing General Hospital of Nanjing Military Area Command of Chinese PLA.PARTICIPANTS: From October 1998 to May 2002,225 patients were examined with overnight polysomnography in the Center of Sleep Disorders,Department of Respiratory Disease, Nanjing General Hospital of Nanjing Command. According to the inclusion criteria of ① AHI≥10 times/hour;② Sleep time in supine and lateral positions≥30 minutes; ③ Over 20years of age; 225 patients were selected from the total of 415 consecutive patients,including 63 with positional and 162 with nonpositional OSA.METHODS: All patients received overnight monitoring with HMS-5500polysomnography system(Respironics Inc USA) in the sleep laboratory. Queries for a detailed case history and physical examination were performed with the pulmonary functions evaluated with body p lethysmography. The clinical data and results of polysomnographic and pulmonary function tests were compared between the two groups of patients and a multiple stepwise regression analysis was employed to evaluate the determinant factors for sleep position dependence of the patients' condition.MAIN OUTCOME MEASURES: Main outcome: Comparisons of the clinical data,polysomnographic result and pulmonary function between the two groups. Secondary outcome: Correlation between classification of OSA and the clinical data.RESULTS: Totally 63 (28%) of the 225 OSA patients were identified as the positional type,who had significantly greater body mass index (BMI)then the nonpositional type patients [(43.46 ± 16.43) kg/m2 vs (23.90 ± 12.36) kg/m2,t =3. 977,P<0.01]. Except for sleeping time in lateral and supine positions, minimal SatO2 and basic SatO2 before the matching for BMI,all the other factors in polysomnograms of the two groups were significant different(P<0.05 or P<0.01). After BMI matching,all the measurements were identical to those recorded for the primary grouping with the exception of nocturnal limb movement frequency,which differed but insignificant between the two groups. The pulmonary function in the two groups was no significant difference(P>0.05) . Multiple stepwise regression analysis indicated that AHI and BMI were the two determinant factors for positional dependence of OSA with a predictive power of 26. 2%. Linear correlation analysis showed correlation of AHI and SatO2 with BMI in the whole group and nonpositional group(P<0.05 or P<0.01),but not in the positional group (P>0.05).CONCLUSION: About one-third of the OSA patients shows sleep position dependence,who may respond favorably to sleep position training. Sufficient patency can be retained in the upper airway of these patients to relieve respiratory obstruction during sleep and improve the respiratory function.

Analysis of morbidity, diagnosis and treatment in 26 pulmonary infection patients after renal transplantation / 医学研究生学报

Objectives: To analyze the strategies of the diagnosis and treatment in patients with the pulmonary infection after renal transplantation. Methods: A retrospective analysis was made on 28 cases of pulmonary infections among 285 patients undergoing renal transplantation. Results: The morbidity of pulmonary infection was 9.82%(28/285). The majority pathogens of pulmonary infection in this study were pseudomonas, staphylococcus epidermidis, canadida and cytomegalovirus. Chest X ray was important in the diagnosis, but there was no specificity to determine the pathogens. The mortality in 28 pulmonary infection patients was 32.1%(9/28). Most of the patients suffered from pulmonary infection within 4 months after the operation, and the postoperative period from 2 months to 4 months was a high risk time window for death caused by pulmonary infections. Conclusions: The morbidity and mortality of pulmonary infections, especially severe pneumonia, in patients with renal transplantation, are higher than healthy people. Treatment following clinical epidemiology and strategy of microbiology play a very important role to reduce the mortality in those patients.

Assessment of polymerase chain reaction and serology for detection of chlamydia pneumoniae in patients with acute respiratory tract infection / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To study Chlamydia pneumoniae (C. pneumoniae) infection in 110 patients with respiratory tract infection admitted to our hospital from January to December 1995 in Nanjing.</p><p><b>METHODS</b>Sputum and throat swab specimens were taken and C. pneumoniae DNA was detected by using polymerase chain reaction (PCR) with the HM-1-HR-1 primer pair. At the same time, serum samples were taken and immunoglobulin G and M (IgG and IgM) fractions of antibodies to C. pneumoniae were studied by microimmunofluorescence test.</p><p><b>RESULTS</b>Prevalence of specific IgG was 70% in patients with respiratory tract infection. Seventeen patients (15.5%) were serologically diagnosed as having recent C. pneumoniae infections and 12 patients (10.9%) had positive PCR in sputum and/or swab specimens. The total positive rate was 22.7% (25/110) detected by PCR combined with serological tests. Acute infection of C. pneumoniae was common in patients with asthma (57.1%), pneumonia (35.0%), COPD (25.9%) and bronchitis (25.0%). Clinical features between C. pneumoniae infection and non-C. pneumonia infection showed no significant differences.</p><p><b>CONCLUSIONS</b>Chlamydia pneumoniae is an important pathogen that causes infection of the human respiratory tract and attention should be drawn to this special illness.</p>

Changes of pulmonary malondialdehyde ,glutathione and total-antioxidation content in SD rat with nitrogen dioxide exposure / 医学研究生学报

Objectives:To evaluate lung injury mechanism in SD rat with nitrogen dioxide(NO2) exposure. 　Methods:In the test-control study, pulmonary malondialdehyde(MDA),glutathione(GSH) and total-antioxidant content(T-AOC) were determined in 10 SD rats with long-term NO2 exposure,10 SD rats with short-term NO2 exposure and 10 SD rats with fresh air as control. 　Results: Pulmonary MDA content was increased and T-AOC was decreased significantly in SD rat exposed to NO2. Pulmonary GSH was decreased significantly in long-term NO2 exposure group as compared with short-term NO2 exposure group and control group. 　Conclusions: Imbalance between oxidant and antioxidant was an important mechanism in the pathogenesis of oxidizing lung injury in SD rat with NO2 exposure.

Compensatory Head Posture Changes in Patients with Obstructive Sleep Apnea / 华中科技大学学报（医学）（英德文版）

The upper airway narrowing and changes in head posture and their relationship with apnea severity in patients with obstructive sleep apnea (OSA) were investigated. In 86 male OSA patients and 37 healthy men, one-night polysomnographic examination was performed and a lateral cephalogram by digital image processing system was taken in each subject. Fifteen variables concerning the upper airway dimensions, area and head postures were measured by using a computer software (NIH Image). The results showed that upper airway dimensions in the OSA group at all levels were significantly smaller than those in the control group and the results hold true when the age and body mass index were well controlled in these two groups. Significant forward inclination of the cervical column was found in the patients with an apnea index (AI) greater than 35episodes/h. And changes in the head posture variables in the whole study group were significantly correlated with AI and airway dimensions at various levels. It was suggested that there exist significant and extensive upper airway narrowing in OSA patients even in upright position and awake state; And as the apnea severity progresses, patients may assume certain compensatory head postures in an attempt to maintain an adequate airway patency.

Compensatory Head Posture Changes in Patients with Obstructive Sleep Apnea / 华中科技大学学报（医学）（英德文版）

The upper airway narrowing and changes in head posture and their relationship with apnea severity in patients with obstructive sleep apnea (OSA) were investigated. In 86 male OSA patients and 37 healthy men, one-night polysomnographic examination was performed and a lateral cephalogram by digital image processing system was taken in each subject. Fifteen variables concerning the upper airway dimensions, area and head postures were measured by using a computer software (NIH Image). The results showed that upper airway dimensions in the OSA group at all levels were significantly smaller than those in the control group and the results hold true when the age and body mass index were well controlled in these two groups. Significant forward inclination of the cervical column was found in the patients with an apnea index (AI) greater than 35episodes/h. And changes in the head posture variables in the whole study group were significantly correlated with AI and airway dimensions at various levels. It was suggested that there exist significant and extensive upper airway narrowing in OSA patients even in upright position and awake state; And as the apnea severity progresses, patients may assume certain compensatory head postures in an attempt to maintain an adequate airway patency.

Craniofacial morphological changes induced by a mandibular repositioning oral appliance and their significance / 医学研究生学报

Objectives: To identify any craniofacial morphological changes induced by a mandibular-repositioning oral appliance (MRA) and to explore the possibility of predicting the treatment response to MRA by cephalometric analysis in patients with obstructive sleep apnea (OSA). Methods: Seventy OSA patients [male/female: 63/7; age: (50.5±11.6) years; BMI: (27.6±4.6) kg/m2; AI: (34.9±21.3) episodes/hour; and oxygen saturation nadir: (66.3±16.5) %] were enrolled. MRA was fabricated individually for each patient after the consultation by a dentist. Polysomnographic (PSG) examination was repeated with MRA in place 3 months after the initiation of the MRA therapy. For cephalometric analysis, a pair of cephalograms of each patient was obtained, one with and another without MRA. Results and Conclusions: After 3 months' treatment, AI was (156±19.2) episodes/hour, significantly reduced compared with the pre-treatment average AI (34.9±21.3 episodes/hour,P<0.000 1). Oxygen saturation nadir improved from (66.3±16.5)% (pre-treatment) to (74.1±15.5)% (with MRA) (P<0.001). A reduction of AI≥50% was achieved in 42 patients. Insertion of MRA led to anterior shift of the mandible, increase in upper airway width and area and decrease in upper airway length. Those with evident retrognathia and longer anterior upper facial height were more likely to benefit from the MRA management.