Effect of Bariatric Surgery on Obstructive Sleep Apnea and Hypopnea Syndrome, Electrocardiogram, and Pulmonary Arterial Pressure

Background: We evaluated the impact of surgically-induced weight loss on Obstructive Sleep Apnea/Hypopnea Syndrome (OSAHS), electrocardiographic changes, pulmonary arterial pressure and daytime sleepiness in morbidly obese patients. Methods: 16 women and 13 men (n=29) underwent bariatric surgery in a 3-year period. The following tests were performed before and 1 year after surgery: nocturnal polysomnography, daytime Multiple Sleep Latency Test (MSLT), and echocardiogram. Results: Mean age was 37.9±11 years (range 20-56). Preoperative body mass index was 56.5±12.3 kg/m² and it was 39.2±8.5 kg/m² at 13.7±6.6 months follow-up. Performed surgical procedures included: vertical banded gastroplasty in 6, Roux-en-Y gastric bypass in 12, and Distal Roux-en-Y gastric bypass in 11. Weight loss induced by surgery eliminated OSAHS in 46% of obese patients with an important improvement in oxygen saturation. Neck, thorax, waist and hip circumferences decreased significantly after surgical intervention but only neck circumference correlated significantly with the apnea/hypopnea index (Spearman rho=0.63, P <0.0001). Electrocardiographic abnormalities were present in 9 patients (31%) before surgery (sinus arrhythmia, ventricular arrhythmias, and sinus arrest). The number of electrocardiographic abnormalities decreased after surgery but new abnormalities appeared in some patients. Systolic pulmonary arterial pressure significantly decreased in the group of patients in whom OSAHS disappeared after surgery. Daytime sleepiness persisted after surgery in most patients. Conclusion: Bariatric surgery effectively reduces respiratory disturbances during sleep and improves pulmonary hypertension. Electro cardiographic abnormalities change after surgery. Daytime sleepiness appeared not to be related to respiratory disturbances during sleep.     

The use of pursed lips breathing in stable chronic obstructive pulmonary disease: a systematic review of the evidence

Abstract

Objective: A systematic review was carried out to determine the evidence for teaching pursed lips breathing (PLB) to patients with stable chronic obstructive pulmonary disease (COPD). Exertional dyspnoea is the single most important factor limiting function for people with COPD and PLB is commonly advocated for its management.

Method: A literature search of Medline, PEDro and CINAHL Plus was conducted. Articles were included if they studied the effects of PLB in stable COPD and excluded when proxy interventions or significant modifications of PLB were used. Where comparable data were available they were pooled using weighted means.

Results: Eleven studies involving 226 participants were included; four of the studies were of moderate quality according to the grading of recommendations assessments, development and evaluation (GRADE) system; the remaining studies were of low quality. Although no high quality evidence was identified, the direction of effect for PLB was consistently towards benefit, with the exception of one low quality study. Moderate quality evidence demonstrates that in stable COPD pursed lips breathing increases oxygen saturation and tidal volume, reduces respiratory rate at rest and reduces time taken to recover to pre-exercise breathlessness levels. One RCT showed reduction in exertional dyspnoea and improvement in functional performance at 3 months. Additionally, the evidence suggests that not all patients with COPD respond equally to PLB: those with moderate to severe COPD are most likely to benefit.

Conclusion: High quality studies are required to identify PLB responders from non-responders and to determine whether short-term effects translate into clinically significant benefit.     

Continuous Positive Airway Pressure (CPAP) Changes in Bariatric Surgery Patients Undergoing Rapid Weight Loss

Background: Obstructive sleep apnea (OSA) is a common condition in morbidly obese patients, with the reported prevalence ranging from 12-78%. There is increasing recognition of the need to diagnose and treat/manage OSA both preoperatively and postoperatively. Nasal CPAP is the preferred treatment of OSA; however, weight loss is associated with a reduction in required pressures. We evaluated the CPAP pressure requirements in a group of patients undergoing rapid weight loss following Roux-en-Y gastric bypass . Methods: 15 patients who had been diagnosed with OSA before surgery were retrospectively evaluated. All patients had demonstrated compliance on home CPAP therapy, were minimally 3 months post-surgery and had follow-up reports that their CPAP was less effective. We obtained data on age, sex, weight, BMI, and apnea/hypopnea index (AHI). Optimal CPAP pressure was obtained initially through attended in-laboratory complex polysomnography. Follow-up CPAP pressure was obtained using an auto-titrating PAP device at home. These data were used to evaluate the pressure changes that accompanied weight loss. Results: This group of patients had lost an average of 44.5 ± 19.4 kg. Four patients had achieved their goal weight. Their starting CPAP pressures averaged 11 ± 3.0 cm H₂O, with a range of 7-18 cm H₂O. Follow-up CPAP pressures averaged 9 ± 2.7 cm H₂O, with a range of 4-12 cm H₂O, representing an overall reduction of 18%. The subgroup of patients who had achieved goal weight had a pressure reduction of 22% (9 ± 2.0 to 7 ± 1.0 cm H₂O). Conclusion: CPAP pressure requirements change considerably in bariatric surgery patients undergoing rapid weight loss. Auto-titrating PAP devices have promise for facilitating the management of CPAP therapy during this time. Consideration should also be given to the use of autotitrating PAP units as the treatment of choice in these patients.     

Influence of Obstructive Jaundice on Jejunal Absorption of Glucose, Electrolytes, and Vitamin A in Rats

Jejunal absorption of glucose, electrolytes, andvitamin A was investigated in rats. A Tyrode solutioncontaining glucose, sodium, and potassium inconcentrations two and four times higher than usual was infused through the jejunal loops of jaundicedand control rats during 40 min. The glucose values inthe influx and effluent were not different during theexperiment time. However, the concentrations of sodium and potassium of the effluent decreasedwith concentrations twice normal. The osmotic pressureof the effluent was directly related to the electrolyticconcentration. When the perfusate fluid was four times higher, the differences between shamand jaundiced groups remained unchanged. The osmoticpressure means of the jaundiced group decreased duringthe experimental time. The absorption of vitamin A increased during the 40-min experiment timein the control rats. On the other hand, vitamin Aconcentration in the perfused lumen of the jaundicedgroup did not change over the time. These data indicate that obstructive jaundice has little influenceon glucose and electrolytes absorption, while vitamin Ais impaired by this condition.     

Serum Amyloid A and Obstructive Sleep Apnea Syndrome before and after Surgically-Induced Weight Loss in Morbidly Obese Subjects

Background: Serum amyloid A (SAA) is an inflammatory marker associated with cardiovascular disease (CVD) and found to be increased in obesity. Obstructive sleep apnea (OSA) syndrome, a frequent complication of obesity also associated with CVD risk, is improved after surgically-induced weight loss. To explore the potential role of SAA in the relation between OSA and CVD, we investigated relationships between changes in SAA concentrations and nocturnal respiratory events in obese subjects undergoing bariatric surgery. Methods: We measured plasma SAA and used nocturnal respiratory polygraphy to assess the apneahypopnea index (AHI), the oxygen desaturation index (ODI) and the mean and lowest O₂ saturation (SaO₂ ) in 61 morbidly obese patients before either adjustable gastric banding or gastric bypass. For 35 subjects with OSA, the same data were obtained 1 year after the surgery. Results: Before surgery, SAA concentrations were significantly higher in patients with severe OSA (56.2±6.4 μg/ml) compared to subjects with moderate OSA (22.9±3.2 μg/ml) or without OSA (16.2±2.2 μg/ml). Plasma SAA correlated positively with AHI and ODI, and negatively with mean and lowest SaO₂. After surgery, plasma SAA decreased significantly by 41.7%, and changes in plasma SAA correlated with variations in OSA parameters. In multivariate analyses, AHI was a predictor of plasma SAA, independent of BMI, both at baseline and during weight loss. Conclusion: The improvement of OSA after bariatric surgery is associated with a decrease in SAA, independent of the change in BMI. SAA may represent a marker of the improvement in CVD risk profile after surgically-induced weight loss in patients with OSA.     

中医肺助心行血的实质与微循环关系的探讨

本文通过对51例气虚和46例血瘀的慢性阻塞性肺系疾病患者微循环多指标进行观察,发现中医肺助心行血与微循环之间有实质性联系。微循环系统的结构和功能及其与肺有关的某些调节因素,可以说是肺朝百脉,助心行血功能的重要物质基础,从而说明中医肺的实质可能包括了现代医学微循环系统的部分机能。对于肺系疾病的诊断,亦可借助微循环方法进行。     

Effects of Biofeedback Therapy on Anorectal Function in Obstructive Defecation

Biofeedback therapy improves symptoms inpatients with constipation and obstructive defecation.Whether it also improves anorectal function is unclear.Our purpose was to investigate prospectively the effects of biofeedback therapy on subjective andobjective parameters of anorectal function in 25consecutive patients with obstructive defecation.Biofeedback therapy consisted of pelvic floor relaxationexercises (phase I) and neuromuscular conditioning ofrectal sensation and rectoanal coordination, with asolid state manometry system and simulated defecationmaneuvers (phase II). The number of sessions wascustomized for each patient. Clinical improvement wasassessed from the changes in anorectal manometry,balloon (50 cc) expulsion test, and the symptom andstool diaries. The number of therapy sessions varied[mean (range) = 6 (2-10)]. After therapy, whenstraining as if to defecate, the percentage analrelaxation, intrarectal pressure, and defecation indexincreased (P < 0.001). The balloon expulsion time,laxative consumption, and straining effort decreased (P< 0.001). Before therapy, 16/25 (64%) patients hadimpaired rectal sensation, and after therapy thisimproved (P < 0.001). After therapy, 15/25 (60%) patients reported 75% satisfaction with bowelhabit and 8/25 (32%) reported 50% satisfaction (P< 0.001); 15/16 (94%) patients discontinued digitaldisimpaction. Biofeedback therapy not only improves subjective but also objective parameters ofanorectal function in at least 76% of patients byrectifying the underlying pathophysiologicdisturbance(s). Sensory conditioning and customizing thenumber of sessions may offer additionalbenefits.     

Anxiety in Chronic Obstructive Pulmonary Disease: The Role of Illness Specific Catastrophic Thoughts

The development of a self-report measuredesigned to assess illness-specific catastrophicthoughts in chronic obstructive pulmonary disease (COPD)is described. The measure is then used to testhypotheses about the relationship between catastrophicthoughts and anxiety in COPD. Preliminary findingssuggest that the measure, the Interpretation ofBreathing Problems Questionnaire (IBPQ), has goodpsychometric properties. Tests of specific hypothesesindicated that more severe catastrophic thoughts wereassociated with higher levels of anxiety. Catastrophicthoughts and anxiety were also more severe in unsafe than in safe situations. Severity ofcatastrophic thoughts was a significant predictor ofanxiety, particularly of situation specific (IBPQ)anxiety. Satisfaction with social support, but not age,duration, or severity of illness, was also important,particularly in safe situations. Implications for acognitive model of anxiety in COPD, and for treatment ofanxiety in this disorder, are briefly discussed. Limitations of the study are noted. Suggestionsare made for further research.     

Role of Endothelin in Obstructive Jaundice

Mediators responsible for renal changes inobstructive jaundice are not specified. This study isdesigned to study the role of endothelin-1 (ET-1) inobstructive jaundice in rats. Animals were randomly placed into five experimental groups. Group 1(N = 3) was the sham-operated group. Group 2 (N = 8)after common bile duct (CBD) ligation, receivedbosentan, which is a nonselective endothelin receptorblocker, 50 mg/kg/day for seven days. Group 3 (N = 7)received 1 g/kg/day captopril. Group 4 (N = 7) wasgiven both drugs orally for seven days. Group 5 (N = 6)after CBD ligation, received Arabic gum as the vehicle. Blood was drawn from the infrahepaticvena cava for the determination of ET-1, bilirubin,creatinine, protein oxidation products, hyaluronic acid,and -N-acetyl-hexosaminase. Liver tissue samples were obtained to determine glutathionelevels. ET-1, protein oxidation products, hyaluronicacid, bilirubin, and creatinine levels increasedsignificantly in the control group when compared with sham. Bosentan effectively prevented ET-1elevation but could not reverse creatinine or bilirubinelevation. Captopril with or without bosentan wascytoprotective but did not reverse increased creatinine levels. It is concluded that increased ET-1 inobstructive jaundice may be one of the contributingfactors of renal damage.     

The Shape of the Epiglottis Reflects Improvement in Upper Airway Obstruction after Weight Loss

Obstructive sleep apnea (OSA) is a sleep disorder characterized by recurrent episodes of closure of the upper airway during sleep, and is highly prevalent among overweight individuals. A significant percentage of patients with OSA remain undiagnosed. This condition creates chronic nighttime hypoxemia that can result in significant complications including systemic and pulmonary hypertension, cor pulmonale, and stroke. Polysomnography is still the most widely used method for diagnosing OSA. Studies have shown that in the majority of patients with OSA the airway obstruction involves the retroglossal region. Upon performing esophagogastroduodenoscopy on patients with a wide range of body mass indices (from 21 to 63), we noticed a gradual increase in the concavity of the posterior epiglottal surface as the BMI increases. Upon following some of the patients who underwent laparoscopic gastric banding and lost significant weight, we noticed a dramatic change in the shape of the epiglottis. This reflects a relief in the pressure on the epiglottis created by the collapsing airways in periods of apnea. Thus, the deformity in the shape of the epiglottis reflects the chronic airway collapse in obese patients, and improvement in this deformity after weight loss indicates a relief of the chronic upper airway obstruction.