Continuous positive airway pressure for treating hypoxemia due to pulmonary vein injury:A case report

BACKGROUND Vascular injury during thoracoscopic surgery for esophageal cancer is a rare but life-threatening complication that can lead to severe hypotension and hypoxemia.Anesthesiologists need to provide rapid and effective treatment to save patients'lives.CASE SUMMARY A 54-year-old male patient was scheduled to undergo a thoracoscopic-assisted radical resection of esophageal cancer through the upper abdomen and right chest.While dissociating the esophagus from the carina through the right chest,unexpected profuse bleeding occurred from a suspected pulmonary vascular hemorrhage.While the surgeon attempted to achieve hemostasis,the patient developed severe hypoxemia.The anesthesiologist implemented continuous positive airway pressure(CPAP)using a bronchial blocker(BB),which effectively improved the patient’s oxygenation and the operation was completed success-fully.CONCLUSION CPAP using a BB can resolve severe hypoxemia caused by accidental injury of the left inferior pulmonary vein during surgery.

Bi-level Nasal Positive Airway Pressure(BiPAP)versus Nasal Continuous Positive Airway Pressure(CPAP)for Preterm Infants with Birth Weight Less Than 1500g and Respiratory Distress Syndrome Following INSURE Treatment:A Two-center Randomized Controlled Trial

The present study aimed to examine the effectiveness of bi-level positive airway pressure(BiPAP)versus continuous positive airway pressure(CPAP)in preterm infants with birth weight less than 1500 g and respiratory distress syndrome(RDS)following intubation-surfactant-extubation(INSURE)treatment.A two-center randomized control trial was performed.The primary outcome was the reintubation rate of infants within 72 h of age after INSURE.Secondary outcomes included bronchopulmonary dysplasia(BPD),necrotizing enterocolitis(NEC),retinopathy of prematurity(ROP)and incidences of adverse events.Lung function at one year of corrected age was also compared between the two groups.There were 140 cases in the CPAP group and 144 in the BiPAP group.After INSURE,the reintubation rates of infants within 72 h of age were 15%and 11.1%in the CPAP group and the BiPAP group,respectively(P>0.05).Neonates in the BiPAP group was on positive airway pressure(PAP)therapy three days less than in the CPAP group(12.6 d and 15.3 d,respectively,P<0.05),and on oxygen six days less than in the CPAP group(20.6 d and 26.9 d,respectively,P<0.05).Other outcomes such as BPD,NEC,ROP and feeding intolerance were not significantly different between the two groups(P>0.05).There was no difference in lung function at one year of age between the two groups(P>0.05).In conclusion,after INSURE,the reintubation rate of infants within 72 h of age was comparable between the BiPAP group and the CPAP group.BiPAP was superior to CPAP in terms of shorter durations(days)on PAP support and oxygen supplementation.There were no differences in the incidences of BPD and ROP,and lung function at one year of age between the two ventilation methods.

Sildenafil versus continuous positive airway pressure for erectile dysfunction in men with obstructive sleep apnea： a comparat-ive study of their efficacy and safety and the patient＇s satisfaction with treatment

Aim： To assess the efficacy of sildenafil and continuous positive airway pressure （CPAP） in the treatment of concurrent erectile dysfunction （ED） with obstructive sleep apnea （OSA）, and to gauge the level of treatment satisfaction in patients and their partners. Methods： Forty men were treated for 12 weeks with sildenafil 100 mg （20 men） or CPAP during nighttime sleep （20 men）. Treatment efficacy was assessed by the rate of successful intercourse attempts, and satisfaction with treatment was assessed by patients＇ and partners＇ answers to question 1 of the Erectile Dysfunction Inventory of Treatment Satisfaction. Results： Under sildenafil, 128 of 249 （51.4%） intercourse attempts were successful; under CPAP, 51 of 193 （26.9%） attempts were successful （^cp 〈 0.001）. Erectile function was improved in both groups. After sildenafil and CPAP treatment, the mean International Index for Erectile Function domain scores were 14.3 and 10.8, respectively （^bp = 0.025）, compared to 7.8 and 7 at baseline, respectively. CPAP and sildenafil were well tolerated. Sporadic episodes of nasal dryness under CPAP and transient headache and flushing under sildenafil were not significant. Fifty percent of patients treated with sildenafil and 25% with CPAP were satisfied with the treatment, and their partners were equally satisfied. The satisfaction scores for both patients and partners under sildenafil were superior to those under CPAP （^cP 〈 0.002）. Conclusion： Both sildenafil 100 mg and CPAP, used separately, had positive therapeutic impact but sildenafil was superior. Patients and their partners were more satisfied with sildenafil for the treatment of ED. However, because of the high proportion of dissatisfied men and partners, new therapeutic agents or a combination of the two methods must be studied further.

Impact of continuous positive airway pressure therapy for nonalcoholic fatty liver disease in patients with obstructive sleep apnea

BACKGROUND Obstructive sleep apnea(OSA)has been suggested as an independent risk factor for nonalcoholic fatty liver disease(NAFLD),and continuous positive airway pressure(CPAP)is the first-line therapy for OSA.AIM To clarify the efficacy of effective CPAP therapy on NAFLD of OSA patients by serum markers and transient elastography(TE)using FibroScan®(Echosens,Paris,France).METHODS We prospectively enrolled 123 consecutive patients with OSA who met the indications for CPAP.Liver fibrosis and steatosis were assessed using TE.Before and after 6 mo of CPAP therapy,serum markers and TE were assessed for all patients.The mean usage rate of CPAP therapy for 6 mo was arbitrarily calculated in each patient and expressed as“mean compliance index”(m-CI).RESULTS In 50 OSA patients with NAFLD,both aspartate aminotransferase(AST)and alanine aminotransferase(ALT)levels were significantly decreased after 6 mo of CPAP therapy.Univariate analysis showed that decreased body weight(BW),decreased body mass index(BMI),decreased AST level,decreased hemoglobin A1c,and high m-CI were significantly related with improved ALT level.In multivariate regression model adjusted for quantities of BW change during 6 mo of CPAP therapy,high m-CI tended to improve ALT level(P=0.051).All 17 OSA patients with NAFLD,high m-CI and no BMI changes showed significant improvements in AST and ALT levels.Meanwhile,no significant changes in TE data or serum fibrosis markers were seen.CONCLUSION Some NAFLD could be associated with chronic intermittent hypoxia due to OSA independent of BW changes.In those cases,adequate reoxygenation from effective CPAP therapy may improve NAFLD.

Relationship between intubation rate and continuous positive airway pressure therapy in the prehospital setting

BACKGROUND: To determine whether the prehospital use of continuous positive airway pressure(CPAP) therapy is associated with a reduced rate of endotracheal intubation in patients with an acute respiratory disorder brought to the emergency department(ED).METHODS: We reviewed medical records of patients with acute respiratory distress who had been treated with CPAP in the Mobile Intensive Care Unit(MICU) from January 2010 to December 2011. These records were compared with those of patients who received standardized care without CPAP in the MICU from January 2004 to December 2004. Categorical variables were summarized as frequencies and compared between groups using Fisher's exact test or the Chi-square test. Continuous variables were summarized as medians(interquartile range), and comparison between the groups was made using Wilcoxon's rank-sum test. The relationship between CPAP and intubation rate was determined using multivariable logistic regression analysis of propensity scores. The results were presented as odds ratio(OR), 95% confidence interval(CI), and P value for test effect. The adequacy of the model was calibrated using Hosmer and Lemeshow's goodness-of-fit test. P<0.05 was considered statistically significant.RESULTS: The records of 785 patients were reviewed. Of the 215 patients treated with CPAP in the MICU, 13% were intubated after admission. In contrast, of the 570 patients who did not receive CPAP, 28% were intubated after ED admission. Unadjusted logistic regression analysis showed that patients who had been treated with CPAP were less likely to be intubated than those without CPAP treatment(OR=0.37, 95% CI, 0.24–0.57, P<0.0001). With propensity scores adjusted, multivariate logistic regression analysis showed that CPAP treatment was associated with a 62% reduction of intubation(OR=0.384, 95%CI, 0.25–0.60, P≤0.0001).CONCLUSIONS: In patients with acute respiratory disorder, there was a relationship between CPAP therapy and the decreased intubation rate. CPAP therapy was feasible in prehospital management of patients with respiratory distress.

Changes in peak inspiratory flow rate and peak airway pressure with endotracheal tube size during chest compression

BACKGROUND:Adequate airway management plays an important role in high-quality cardiopulmonary resuscitation(CPR).Airway management is usually performed using an endotracheal tube(ETT)during CPR.However,no study has assessed the effect of ETT size on the fl ow rate and airway pressure during CPR.METHODS:We measured changes in peak inspiratory fl ow rate(PIFR),peak airway pressure(Ppeak),and mean airway pressure(Pmean)according to changes in ETT size(internal diameter 6.0,7.0,and 8.0 mm)and with or without CPR.A tidal volume of 500 mL was supplied at a rate of 10 times per minute using a mechanical ventilator.Chest compressions were maintained at a constant compression depth and speed using a mechanical chest compression device(LUCAS2,mode:active continuous,chest compression rate:102±2/minute,chest compression depth 2–2.5 inches).RESULTS:The median of several respiratory physiological parameters during CPR was significantly different according to the diameter of each ETT(6.0 vs.8.0 mm):PIFR(32.1 L/min[30.5–35.3]vs.28.9 L/min[27.5–30.8],P<0.001),Ppeak(48.84 cmH2O[27.46–52.11]vs.27.45 cmH2O[22.53–52.57],P<0.001),and Pmean(18.34 cmH2O[14.61–21.66]vs.13.66 cmH2O[8.41–19.24],P<0.001).CONCLUSION:The changes in PIFR,Ppeak,and Pmean were related to the internal diameter of ETT,and these values tended to decrease with an increase in ETT size.Higher airway pressures were measured in the CPR group than in the no CPR group.

Effect of Right Supine Tracheal Extubation on Respiratory Complications and Airway Pressure in the Waking Period of General Anesthesia in Pediatric Stomatology

Objective: The purpose of this study was to investigate the effect of right supine endotracheal intubation on respiratory complications and airway pressure of general anesthesia, and to provide guidance for clinical application. Methods: Seventy-two children who received oral treatment under general anesthesia from November 2020 to November 2021 in Yantai Stomatological Hospital were randomly divided into three groups, 24 cases in each group. All three groups of children entered the PACU after the surgery. The children in Group I were extubated in the supine position, the children in Group II were immediately changed to the right decubitus after extubation in the horizontal position, and the children in Group III were extubated in the right decubitus. HR, MAP and SpO2 of T1 (the time point at the beginning of surgery), T2 (the time point at 1 hour after surgery), T3 (the time point after extubation), T4 (the time point at 1 minute after extubation), T5 (the time point at 3 minutes after extubation) in the three groups were observed, t1 (operation time) and t2 (the time of leaving the PACU) were recorded. The airway pressure (P1) in the recumbent position and the airway pressure (P2) in the right decubitus position before extubation were recorded in Group III. The number of sputum suction and complications after extubation were counted. Results: The t2 in Group III was shorter than that in Groups I and II, and the number of sputum suction in Group III was less than that in Groups I and II (P < 0.05). The HR at T3, T4 and T5 in Group III was lower than that in Group I, and the HR at T4 and T5 was lower than that in Group II (P < 0.05). There were significant differences in the incidence of respiratory complications among the three groups (P < 0.05). The incidence of asphyxia, bucking and glossocoma postoperative agitation in Group III was significantly lower than that in Group I, and the incidence of asphyxia and choking was lower than that in Group II (P < 0.05). The incidence of glossoptosis in Group II was significantly lower than that in Group I (P < 0.05). In Group III, the airway pressure P2 in the right decubitus position during endotracheal intubation was higher than that of P1 in the supine position during endotracheal intubation (P < 0.05). The 95% Confidence Interval (CI) of airway pressure difference was 1.416 - 1.834 cmH2O. Conclusion: For children undergoing intraoral therapy under general anesthesia, tracheal extubation in the right decubitus position can improve the circulation fluctuation before and after extubation, reducing the number of sputum suction and respiratory tract-related complications, and can shorten the departure time. The body position change during the tracheal intubation will slightly increase the airway pressure, but the supine position after extubation can better ensure the smooth spontaneous breathing of children, which can provide the reference for clinical application.

Changes in Brachial and Central Blood Pressure after Short Term Continuous Positive Airway Pressure Treatment of Patients with Moderate-to-Severe Obstructive Sleep Apnoea and Impaired Renal Function

Background: Previous studies of continuous positive airway pressure (CPAP) treatment for obstructive sleep apnoea (OSA) have shown conflicting results on the effect on blood pressure (BP), and patients with chronic kidney disease (CKD) have not been included in these studies. As OSA is a frequent comorbidity in patients with CKD, it is of relevance to evaluate the effect of CPAP treatment on BP in this population. Aim: In this prospective follow-up study, we measured the effect of short term CPAP treatment of moderate-to-severe OSA on brachial and central BP, plasma level of syndecan-1 and vasoactive hormones, renal handling of sodium, subjective sleepiness, and quality of life in patients with impaired renal function. Methods: From December 2015 until March 2017, 25 patients were invited to participate in the study at the University Clinic in Nephrology and Hypertension, Aarhus University and Holstebro Hospital. At baseline and at follow-up after three to four months of CPAP treatment, we performed 24 h brachial and central ambulatory BP measurement, blood sampling measurements of plasma concentrations of syndecan-1, renin, angiotensin II, aldosterone, vasopressin, creatinine, haemoglobin A1c, and cholesterol, cardio respiratory monitoring, 24 h urine collection for measurement of urinary excretion of albumin, aquaporin-2, and epithelial sodium channel, Epworth Sleepiness Scale (ESS), and SF-36 (quality of life). Results: At follow-up, the 17 included patients with mean baseline estimated glomerular filtration rate 66 mL/min/1.73 m2 had a significant decrease in systolic office-, 24 h- and daytime-BP (13, 7, and 8 mmHg, respectively, p Conclusion: Short-term CPAP treatment of patients with moderate-to-severe OSA and reduced renal function decreased 24 h- and daytime-BP significantly and reduced urinary albumin excretion. Our results underline the importance of treatment of OSA in hypertensive patients with impaired renal function.

Effect of Continuous Positive Airway Pressure Therapy on Glycemic Excursions and Insulin Sensitivity in Patients with Obstructive Sleep Apnea-hypopnea Syndrome and Type 2 Diabetes

Background： For patients with obstructive sleep apnea-hypopnea syndrome （OSAHS） and type 2 diabetes mellitus （T2DM）, the night sleep interruption and intermittent hypoxia due to apnea or hypopnea may induce glycemic excursions and reduce insulin sensitivity. This study aimed to investigate the effect of continuous positive airway pressure （CPAP） therapy in patients with OSAHS and T2DM. Methods： Continuous glucose monitoring system （CGMS） was used in 40 patients with T2DM and newly diagnosed OSAHS. The measurements were repeated after 30 days of CPAP treatment. Subsequently, insulin sensitivity and glycohemoglobin （HbAlc） were measured and compared to the pretreatment data. Results： After CPAP therapy, the CGMS indicators showed that the 24-h mean blood glucose （MBG） and the night time MBG were significantly reduced （P 〈 0.05 and P = 0.03, respectively）. The mean ambulatory glucose excursions （MAGEs） and the mean of daily differences were also significantly reduced （P 〈 0.05 and P = 0.002, respectively） compared to pretreatment levels. During the night, MAGE also significantly decreased （P = 0.049）. The differences between the highest and lowest levels of blood glucose over 24 h and during the night were significantly lower than prior to CPAP treatment （P 〈 0.05 and P = 0.024, respectively）. The 24 h and night time durations of high blood glucose （〉7.8 mmol/L and 〉 11.1 mmol/L） decreased （P 〈 0.05 and P 〈 0.05, respectively） after the treatment. In addition, HbA 1 c levels were also lower than those before treatment （P 〈 0.05）, and the homeostasis model assessment index of insulin resistance was also significantly lower than before CPAP treatment （P = 0.034）. Conclusions： CPAP therapy may have a beneficial effect on improving not only blood glucose but also upon insulin sensitivity in T2DM patients with OSAHS. This suggests that CPAP may be an effective treatment for T2DM in addition to intensive diabetes management.

Effect of continuous positive airway pressure treatment on serum adiponectin level and mean arterial pressure in male patients with obstructive sleep apnea syndrome

Background Recent research suggested that obstructive sleep apnea syndrome （OSAS） might be independently associated with hypoadiponectinemia, which was linked to some complications of OSAS, such as hypertension, diabetes etc. This study was conducted to investigate the effect of continuous positive airway pressure （CPAP） treatment on changes of both serum adiponectin levels and mean arterial pressure and their possible links in male OSAS patients. Methods Twenty-three adult male patients with moderate-to-severe OSAS but without obesity, coronary heart disease and diabetes were recruited. Their blood samples were collected and morning mean arterial pressure （MAP） was measured before CPAP treatment and on day 3, 7, 14 of CPAP treatment respectively. The serum adiponectin concentration was tested with radioimmunoassay. Results Compared with the serum adiponectin level before CPAP treatment, no significant change was found in OSAS patients on day 3 and day 7 of CPAP treatment （P〉0.05）. It was not until day 14 of CPAP treatment did a significant elevation in serum adiponectin level occur （P〈0.01）. Meanwhile, the MAP showed no statistically significant difference among its levels before CPAP, on day 3 and day 7 of CPAP treatment （P〉0.05）. However, on day 14 of CPAP treatment, a significantly lower MAP than that obtained before treatment was observed （P〈0.05）. Conclusions CPAP treatment can gradually reverse hypoadiponectinemia and reduce MAP in OSAS patients. Hypoadiponectinemia might be involved in the pathogenesis of OSAS-mediated hypertension.

Physiological Correlation of Airway Pressure and Transpulmonary Pressure Stress Index on Respiratory Mechanics in Acute Respiratory Failure

Background： Stress index at post-recruitment maneuvers could be a method of positive end-expiratory pressure （PEEP） titration in acute respiratory distress syndrome （ARDS） patients. However, airway pressure （P_aw） stress index may not reflect lung mechanics in the patients with high chest wall elastance. This study was to evaluate the P stress index on lung mechanics and the correlation between P stress index and transpulmonary pressure （P_L） stress index in acute respiratory failure （ARF） patients. Methods： Twenty-four ARF patients with mechanical ventilation （MV） were consecutively recruited from July 2011 to April 2013 in Zhongda Hospital, Nanjing, China and Ospedale S. Giovanni Battista-Molinette Hospital, Turin, Italy. All patients underwent MV with volume control （tidal volume 6 ml/kg） for 20 rain. PEEP was set according to the ARDSnet study protocol. The patients were divided into two groups according to the chest wall elastance/respiratory system elastance ratio. The high elastance group （H group, n = 14） had a ratio _〉30%, and the low elastance group （L group, n = 10） had a ratio 〈30%. Respiratory elastance, gas-exchange, P stress index, and Pt stress index were measured. Student＇s t-test, regression analysis, and Bland-Altman analysis were used for statistical analysis. Results： Pneumonia was the major cause of respiratory failure （71.0%）. Compared with the L group, PEEP was lower in the H group （5.7 ± 1.7 cmH,O vs. 9.0 ± 2.3 cmH2O, P 〈 0.01 ）. Compared with the H group, lung elastance was higher （20.0 ± 7.8 cmH20/L vs. 11.6 ± 3.6 cmH,O/L, P 〈 0.01）, and stress was higher in the L group （7.0 ±1.9 vs. 4.9 ± 1.9, P = 0.02）. A linear relationship was observed between the P stress index and the P stress index in H group （x2 = 0.56, P 〈 0.01 ） and L group （x2 = 0.85, P 〈 0.01）. Conclusion： In the ARF patients with MV, P,w stress index can substitute for PL to guide ventilator settings.

Effects of Continuous Positive Airway Pressure on Cognitive Deficits in Middle-aged Patients with Obstructive Sleep Apnea Syndrome： A Meta-analysis of Randomized Controlled Trials

Background： Current views on continuous positive airway pressure （CPAP） treatment to improve the cognitive deficits of patients with obstructive sleep apnea syndrome （OSAS） are controversial, so we performed a meta-analysis. Methods： A comprehensive literature search was undertaken in PubMed, CINAHL, Medline, Psyclnfo, EMBASE, Cochrane Library, CNKI, WanFang, VIP, and CBMdisc for studies published from June 1971 to July 2014. The outcome measures included neuropsychological tests of the 7 cognitive domains detailed below. Results： After screening the titles and abstracts and thoroughly reading the fuU text, we obtained 13 studies with little risk of bias that incorporated 1744 middle-aged obese participants with mild to severe OSAS. The studies were published from 1994 to 2012. Treatment durations varied from 1 to 24 weeks. The effect sizes of attention, vigilance, processing speed, working memory, memory, verbal fluency, and visuoconstructive skills domains were -0.10 （P = 0.24）, -0.12 （P = 0.04）, -0.08 （P = 0.16）, 0.00 （P = 0.95）, -0.04 （P = 0.30）, -0.06 （P = 0.34）, and -0.01 （P = 0.92）, respectively. Conclusions： Cognition partially improved in patients with OSAS after CPAP treatment. The only domain with significant improvement was vigilance. Rigorous randomized controlled trials need to be performed to obtain clear results.

Significance of depression in obstructive sleep apnea patients and the relationship between the comorbidity and continuous positive airway pressure treatment

Obstructive sleep apnea （OSA）, which is the most common sleep-related breathing disorder and characterized by recurrent collapse of the upper airway, causes repeated arousals from sleep, decreased oxygen saturation of the blood, and excessive daytime sleepiness. Patients with OSA are at increased risk of cardiovascular and cerebrovascular disease,

Effect of continuous positive airway pressure treatment on elderly Chinese patients with obstructive sleep apnea in the prethrombotic state

Objectives To characterize the prethrombotic state ( PTS) in elderly Chinese patients with obstructive sleep apnea hypopnea syndrome (OSAHS) and the effect of nasal continuous positive airway pressure (nCPAP) ventilation on their PTS.Methods Forty-one elderly patients with moderate and severe OSAHS were enrolled into the OSAHS group and underwent nCPAP treatment. Their blood samples were drawn at 6:00 am and 4:00 pm before and during nCPAP treatment, respectively, to test hemocrit, platelet aggregation (PAG), whole blood viscosity (WBV), plasma fibrinogen (fng), prothrombin time (PT) and activated partial thromboplastin time (APTT). All blood factors were also tested in a control group consisting of 32 healthy elderly Chinese with neither OSAHS nor cerebrocardiac vascular disease.Results In the OSAHS group there was a significantly higher hemocrit, WBV, fng, and a significantly shorter PT and APTT at 6:00 am compared to 4:00 pm before nCPAP treatment, while there was no significant difference among all blood test factors between 6:00 am and 4:00 pm on day 30 of the nCPAP treatment. In the OSAHS group, the hemocrit, WBV, PAG and plasma fng were significantly lower and the PT and APTT were significantly longer at 6:00 am on day 30 of the nCPAP treatment compared to 6:00 am before the nCPAP treatment. A significantly lower hemocrit, but a much longer PT and APTT were observed at 4:00 pm on day 30 of the treatment, compared with 4:00 pm before the treatment. No significant difference among the blood test factors was found between 6:00 am and 4:00 pm blood in the control group or between the control and OSAHS groups after 30 days of nCPAP treatment.Conclusion In elderly Chinese OSAHS patients, PTS could be effectively eliminated by nCPAP treatment.

Effect of continuous positive airway pressure treatment on vascular endothelial function in patients with obstructive sleep apnea hypopnea syndrome and coronary artery disease

Background Continuous positive airway pressure (CPAP) treatment has been proven to be effective in improving the symptoms of coexisting coronary heart disease (CHD) in patients with obstructive sleep apnea hypopnea syndrome (OSAHS). However,it is still unclear whether such improvements are linked to changes in vascular endothelial function. This research was carried out to investigate the effects of CPAP treatment on vascular endothelial function in patients with OSAHS and CHD.Methods Thirty-six patients with moderate or severe OSAHS and CHD undergoing three months of CPAP treatment were recruited for this study. The changes in their morning plasma nitric oxide (NO) and endothelin (ET) levels,NO/ET ratio,total ischemic burden (TIB) of the myocardium,apnea hypopnea index (AHI),and minimal and mean pulse oxygen saturation (SpO_2) were compared and analyzed before and during CPAP treatment. Results Compared with the plasma levels of ET [(51.39±11.69) ng/L] and NO [(36.67±11.86) μmol/L],NO/ET (0.71±0.14),AHI (32.4±7.9),minimal SpO_2 [(68.9±11.4)%],and myocardial TIB [(66.29±16.37) mm·min] before treatment,there were significant decreases in ET [(33.41±10.03) ng/L] ( P <0.05),increases in NO [(59.89±10.26) μmol/L] and NO/ET (1.79±0.38) ( P <0.01),decreases in AHI (1.9±0.5),and increases in minimal SpO_2 [(90.6±1.8) %] (all P <0.01) and myocardial TIB [(36.42±10.87) mm·min] ( P <0.05) after three months of CPAP treatment.Conclusion CPAP treatment may play an important role in the improvement and protection of vascular endothelial dysfunction and myocardial ischemia in OSAHS patients with CHD.

Effects of nasal continuous positive airway pressure treatment on insulin resistance and ghrelin levels in non-diabetic apnoeic patients with coronary heart disease

Background Obesity is a common risk factor for several diseases. Obesity related hormone and increased insulin resistance （IR） may contribute to the effects of obstructive sleep apnoea on cardiovascular consequences. We investigated ghrelin and IR in non-diabetic apnoeic patients with stable coronary heart disease and assessed the effects of continuous positive airway pressure （CPAP）. Methods Plasma ghrelin, glucose and insulin were measured in 22 patients with CPAP and 22 matched controls without CPAP at baseline and three months. Indexes including homeostasis model assessment IR （HOMA IR）, HOMA S and HOMA β were calculated for the assessment of IR, insulin sensitivity and pancreatic β cell function. Results At three months follow-up, plasma ghrelin levels and HOMA IR in CPAP group were significantly decreased （P=0.002 and 0.046, respectively） while those in control group increased significantly （P=0.012 and 0.009, respectively）. Significant moderate correlations were found between ghrelin vs. HOMA IR and ghrelin vs. HOMA S after CPAP, however, for those without CPAP, no significant associations were observed. Conclusions Short-term effective continuous positive airway pressure had a significant effect on lowering plasma ghrelin levels and IR, but not body fat. Further large scale and longer term studies are warranted to corroborate these findings.

Safety of restarting continuous positive airway pressure (CPAP) therapy following endoscopic endonasal skull base surgery

Objectives:Patients with obstructive sleep apnea(OSA)are at increased risk of perioperative and postoperative morbidity.The use of continuous positive airway pressure(CPAP)in the perioperative period may be of potential benefit.However,among patients who have undergone endonasal skull base surgery,many surgeons avoid prompt re-initiation of CPAP therapy due to the theoretical increased risk of epistaxis,excessive dryness,pneumocephalus,repair migration,intracranial introduction of bacteria,and cerebrospinal fluid(CSF)leak.The objective of this article is to review the most up-to-date literature regarding when it is safe to resume CPAP usage in the patient undergoing endonasal skull base surgery.Data Sources and Methods:This review combines the most recent literature as queried through PubMed regarding the safety of CPAP resumption following endonasal skull base surgery.Results:Recent surveys of skull base surgeons demonstrate little consensus regarding the post-operative management of OSA.Recent cadaveric studies suggest that approximately 85%of delivered CPAP pressures are transmitted to the sphenoid sinus.Further,at frequently prescribed CPAP pressure settings,common sellar reconstruction techniques maintain their integrity while preventing very little transmission of pressure into the sella.In small retrospective case series,patients with OSA who received CPAP immediately following transsphenoidal pituitary surgery had similar rates of surgical complications as OSA patients who did not receive CPAP in the immediate post-operative period.Concerns of reinitiating CPAP too early,such as the development of pneumocephalus,rarely develop.Conclusions:There remains a paucity of objective data regarding when it is safe to resume CPAP following endonasal skull base surgery.Recent cadaveric studies and small retrospective case series suggest that it may be safe to resume CPAP earlier than is often practiced following endonasal skull base surgery.

Alterations in renal function in patients with obstructive sleep apnea syndrome and effects of continuous positive airway pressure

Objective To assess renal function in patients with obstructive sleep apnea syndrome (OSAS) during two nights when they were untreated and treated with continuous positive airway pressure (CPAP). Methods Tubular function was estimated on the basis of the renal lithium clearance and its derived formulae, urinary osmolality, osmolal clearance and free water clearance; while glomerular function was evaluated by endogenous creatinine clearance. Twenty patients with OSAS and sixteen normal controls were studied. Results The untreated patients with OSAS had significantly lower fractional proximal tubular sodium reabsorption (59.1%±7.1%,P<0.001 vs controls), lower fractional distal tubular sodium reabsorption (93.8%±1.7%, P<0.05 vs controls) and urinary osmolality (573.0±107.9 mosm·kg 1 , P<0.05 vs controls). The absolute distal tubular reabsorption rate of sodium and osmolal clearance in the untreated patients were higher 47.0±26.0 mmol·L 1 and 25.0±4.1 ml·L 1 ; P< 0.01 and P<0.05 respectively vs controls). During CPAP treated nights all abnormal renal function indexes in the OSAS patients restored to normal control values (P>0.05). Conclusions The natriuresis and diuresis of OSAS patients were due to the decrease in proximal and distal tubular sodium reabsorption and in tubular concentration ability during their nocturnal sleep and were returned to normal by CPAP therapy.

Mean airway pressure has the potential to become the core pressure indicator of mechanical ventilation: Raising to the front from behind the clinical scenes

Mean airway pressure(Pmean)is a common pressure monitoring parameter of mechanical ventilators that is closely correlated with mean alveolar pressure and represents stresses applied to the lung parenchyma during ventilation.Pmean is determined by the peak inspiratory pressure,positive end-expiratory pressure(PEEP),and inspiratory-to-expiratory time ratio with dynamic and real-time characteristics,which represents mechanical power affected by the ventilator mode.Additionally,Pmean is an important parameter that affects hemodynamics.Tidal forces and PEEP increase pulmonary vascular resistance(PVR)in direct proportion to their effects on Pmean.Therefore,Pmean is increasingly considered to be related to the prognosis of patients on mechanical ventilation.We propose a 3P strategy(Pmean,central venous pressure[CVP],and perfusion index[PI])which is indicated to achieve circulation protection mechanical ventilation with flow priority.Titrating the appropriate CVP and meeting PI to ensure tissue perfusion with a lower Pmean are the core purposes.Pmean links the circulatory and respiratory systems and is expected to become a potential parameter for intelligent ventilation.

Weaning preterm infants from continuous positive airway pressure: evidence for best practice

Background:Nasal continuous positive airway pressure(NCPAP)is frequently used in preterm infants.However,there is no consensus on when and how to wean them from NCPAP.Data sources:Based on recent publications,we have reviewed the criteria of readiness-to-wean and factors affecting weaning success.A special focus is placed on the methods of weaning from NCPAP in preterm infants.Results:Practical points of when and how to wean from NCPAP in preterm infants are explained.Preterm infants are ready to be weaned from NCPAP when they are stable on a low NCPAP pressure with no(or minimal)oxygen requirement.Methods used to wean from NCPAP include:sudden weaning of NCPAP,gradual decrease of NCPAP pressure,graded-time-off NCPAP(cycling),weaning to high or low flow nasal cannula,and a combination of these methods.The best strategy for weaning is yet to be determined.Cycling-off NCPAP increases the duration of NCPAP and length of hospital stay without beneficial effect on success of weaning.Gradual decrease of NCPAP pressure is more physiological and better tolerated than cycling-off NCPAP.Conclusion:Further studies are needed to reach a consensus regarding the optimal timing and the best method for weaning from NCPAP in preterm infants.