ObjectiveTo systematically evaluate the risk factors for hypoxemia after coronary artery bypass grafting (CABG).MethodsEight electronic databases including PubMed, EMbase, CENTRAL, Web of Science, CNKI, CBM, VIP and Wanfang data were searched by computer to collect cochort and case-control studies about CABG and hypoxemia published from inception to March 2020. Two authors independently assessed the quality using the Newcastle-Ottawa Scale (NOS), and a meta-analysis was performed by RevMan 5.3 software.ResultsA total of 15 studies involving 4 277 patients were included in this study and among them 1 273 patients suffered hypoxemia. Meta-analysis showed that age (OR=1.55, 95%CI 1.22 to 1.96, P=0.000 3), smoking (OR=3.22, 95%CI 2.48 to 4.17, P<0.000 01), preoperative chronic pulmonary diseases (OR=4.75, 95%CI 3.28 to 6.86, P<0.000 01), diabetes (OR=2.49, 95%CI 1.86 to 3.33,P<0.000 01), left ventricular ejection fraction (OR=3.15, 95%CI 2.19 to 4.52, P<0.000 01), number of coronary artery lesions (OR=2.20, 95%CI 1.63 to 2.97, P<0.000 1) were independent risk factors for hypoxemia after CABG; body mass index (OR=1.31, 95%CI 0.97 to 1.77, P=0.08) and cardiopulmonary bypass time (OR=3.40, 95%CI 0.72 to 15.94, P=0.12) were not associated with hypoxemia.ConclusionCurrent evidence shows that age, preoperative chronic pulmonary diseases, smoking, diabetes, left ventricular ejection fraction, number of coronary artery are risk factors for hypoxemia after CABG, which can be used to identify high-risk patients and provide guidance for medical staff to develop perioperative preventive strategies to reduce the incidence of hypoxemia. The results should be validated by large-scale standard studies in the future.
Objective To observe the effects of peritoneal ventilation with pure oxygen in the rabbits with hypoxaemia and hypercapnia induced by mechanical controlled hypoventilation. Methods Sixteen rabbits were invasively ventilated after trachea incision. Hypoxaemia and hypercapnia were induced by hypoventilation which was implemented both by degrading ventilation parameters and respiratory depression induced by intravenous infusion of muscle relaxant. Then pure oxygen was insufflated into the peritoneal cavity and arterial blood gases were measured every 30 minutes for two hours. Results The PaO2 was ( 52. 50 ±3. 46) mmHg at baseline and increased to ( 76. 46 ±7. 79) mm Hg, ( 79. 62 ±9. 53) mm Hg,( 78. 54 ±7. 18) mmHg, and ( 81. 1 ±8. 3) mm Hg, respectively at 30, 60, 90, and 120 minutes after the peritoneal ventilation with pure oxgen( all P lt; 0. 05) . Meanwhile PaCO2 was ( 63. 84 ±9. 09) mm Hg at baseline and ( 59. 84 ±14. 22) mmHg, ( 59. 16 ±15. 5) mmHg, ( 60. 02 ±7. 07) mmHg, and ( 61. 38 ±6. 56) mm Hg, respectively at 30, 60, 90, and 120 minutes after the peritoneal ventilation with pure oxgen with no significant change( P gt;0. 05) . Conclusion Peritoneal ventilation can obviously improve hypoxaemia induced by mechanical controlled hypoventilation, whereas hypercapnia remains unchanged.
在过去二十年间，麻醉技术和手术技术的改进使肺部恶性肿瘤患者的手术死亡率大大降低，但术后并发症仍是主要问题。肺切除术后的常见并发症是肺部并发症[1]，主要表现是低氧血症，尤其在肺功能减退的肺切除患者中发病率更高[2]。目前国内对低氧血症的诊断缺乏统一的诊断标准，一些作者采用Russell等[3]提出的标准，吸空气氧的情况下，患者动脉血氧饱和度（SpO2）≤92%，大于30 s就可诊断为术后低氧血症。也有作者建议[4]将一次或以上血气检查PaO2lt;8 kPa或PaO2/FiO2lt;300 mm Hg（1 mm Hg=0.133 kPa）作为诊断低氧血症的标准。30%~50%的术后患者可发生低氧血症，一般认为这样的低氧血症是一过性的，对大多数患者是无害的[5]。但如果合并心脑或其他器官动脉硬化或其他原因的血管阻塞，这种低氧血症就是很危险的[6]。常见低氧血症的原因是肺萎陷不张和误吸、心源性肺水肿、静脉输入液体过量、通气血流比例失调和急性肺损伤/急性呼吸窘迫综合征（ALI/ARDS）[7]，其中ALI/ARDS是肺切除术后患者死亡的主要原因[8-10]。
Objective To explore the daytime variables which are predictive to nocturnal hyoxemia among COPD patients unqualified for long-term oxygen therapy ( LTOT) . Methods Forty-eight stable COPD patients with SaO2≥90% were enrolled in this study and regarded as patients unqualified for LTOT. All patients underwent lung function examination during daytime. Their nocturnal oxygen saturation was monitored with overnight pulse oximetry ( OPO) . ResultsDaytime oxygen saturation was positively correlated with nocturnal mean SaO2 ( r =0. 79, P lt;0. 0001) , and negatively correlated with time spend with saturation below 90% ( TB90) ( r = - 0. 75, P lt; 0. 0001) . No significant relationship was found between lung function parameters and nocturnal SaO2 . The patients with daytime oxygen saturation between 90% and 95% were more likely to have lower nocturnal oxygen saturation and longer TB90 ( P lt;0. 05) .Conclusions Daytime oxygen saturation may effectively predict the occurrence of nocturnal hyoxemia in stable COPD patients unqualified for LTOT. To reduce COPD complications and improve prognosis, we suggest a relative indication of LTOT for patients with daytime oxygen saturation between 90% and 95% and with nocturnal hyoxemia.
ObjectiveTo summarize the experience and lessons of right ventricular decompression in children with pulmonary atresia and intact ventricular septum (PA/IVS) and to reflect on the strategies of right ventricular decompression.MethodsThe clinical data of 12 children with PA/IVS who underwent right ventricular decompression in our hospital from March 2015 to December 2019 were reviewed retrospectively. There were 10 males and 2 females with a median age at the time of surgery was 5 d (range, 1-627 d). Correlation analysis between the pulmonary valve transvalvular pressure gradient and changes in Z score of tricuspid valves after decompression was performed.ResultsOne patient died of refractory hypoxemia due to circulatory shunt postoperatively and family members gave up treatment. There were 2 (16.67%) patients received postoperative intervention. The pulmonary transvalvular gradient after decompression was 31.95±21.75 mm Hg. Mild pulmonary regurgitation was found in 7 patients, moderate in 2 patients, and massive in 1 patient. The median time of mechanical ventilation was 30.50 h (range, 6.00-270.50 h), and the average duration of ICU stay was 164.06±87.74 h. The average postoperative follow-up time was 354.82±331.37 d. At the last follow-up, the average Z score of tricuspid valves was 1.32±0.71, the median pressure gradient between right ventricle and main pulmonary artery was 41.75 mm Hg (range, 21-146 mm Hg) and the average percutaneous oxygen saturation was 92.78%±3.73%. Two children underwent percutaneous balloon pulmonary valvoplasty at 6 and 10 months after surgery, respectively, with the rate of reintervention-free of 81.8%. There was no significant correlation between pulmonary transvalvular gradients after decompression and changes in Z score of tricuspid valves (r=–0.506, P=0.201).ConclusionFor children with PA/IVS, the simple pursuit of adequate decompression during right ventricular decompression may lead to severe pulmonary dysfunction, increase the risk of ineffective circular shunt, and induce refractory hypoxemia. The staged decompression can ensure the safety and effectiveness for initial surgery and reduce the risk of postoperative death.
Objective To determine risk factors associated with postoperative hypoxemia after surgery for acute aortic dissection. Methods We retrospectively analyzed clinical data of 116 patients with acute aortic dissection who underwent endovascular stent-graft exclusion or open surgery in Qingdao Municipal Hospital from February 2007 to February 2012. All the 116 patients were diagnosed as acute aortic dissection by CT angiography （CTA），including 60 patients with Stanford type A aortic dissection and 56 patients with Stanford type B aortic dissection. According to whether they had postoperative hypoxemia，all the 116 patients with acute aortic dissection were divided into hypoxemia group［arterial partial pressure of oxygen （PaO2） /fraction of inspired oxygen （FiO2） ＜200 mm Hg］：33 patients including 28 males and 5 females with their age of 52.7±11.4 years； and non-hypoxemia group（PaO2/FiO2≥200 mm Hg）：83 patients including 66 males and 17 females with their age of 55.0±13.8 years. Perioperative clinical data were analyzed and compared between the two groups. Multivariate logistic regression was performed to identify risk factors of postoperative hypoxemia after surgery for acute aortic dissection. Results The incidence of postoperative hypoxemia after surgery for acute aortic dissection was 28.4% （33/116）. Perioperative death occurred in 13 patients（11.2%，including 8 patients in the hypoxemia group and 5 patients in the non-hypoxemia group）. Univariate analysis showed that preoperatively the percentages of patients with body mass index（BMI） ＞ 25 kg/m2，smoking history，duration from onset to operation ＜24 h，preoperative PaO2/FiO2≤300 mm Hg，and patients undergoing open surgery in the hypoxemia group were significantly higher than those in the non-hypoxemia group（P＜0.05）. Deep hypothermic circulatory arrest（DHCA） ratio，blood transfusion in 24 hours postoperatively，mechanical ventilation time，length of ICU stay and hospital stay in the hypoxemia group were significantly higher or longer than those in the non-hypoxemia group（P＜0.05）. Logistic multivariate regression identified BMI＞25 kg/m2（RR=98.861，P=0.006），DHCA（RR=22.487，P=0.007），preoperative PaO2/FiO2≤300 mm Hg（RR=9.080，P=0.037） and blood transfusion＞6 U in 24 hours postoperatively（RR=32.813，P=0.003） as independent predictors of postoperative hypoxemia for open-surgery patients，while BMI＞25 kg/m2 （RR=24.984，P=0.036） and preoperative PaO2/FiO2 ratio≤300 mm Hg （RR=21.145，P=0.042） as independent predictors of hypoxemia for endovascular stent-graft exclusion patients. Conclusion Postoperative hypoxemia is a common complication after surgery for acute aortic dissection. Early interventions for obesity and preoperative hypoxemia，and reducing perioperative blood transfusion may decrease the incidence of postoperative hypoxemia after surgery for acute aortic dissection.
To evaluate the development prevention and treatment of pneumonic injury after operation on aged patients with abdominal infection. We analyzed 77 aged patients (＞60 y) admitted from Jan. 1991 to Dec. 1992: 38 cases of which with abdominal infection (infection group), 39 cases without abdominal infection (non-infection group). All patients were given oxygen therapy and continuous SaO2 monitoring. Results: There were 28 patients with hypoxemia (SaO2＜95%) in infection group, with an occurrence rate of 73.7%. In non-infection group (12 patients), the rate of hyoxemia was 30.8%, which has significant difference between two groups (Ｐ＜0.001). All patients with hypoxemia were given oxygen therapy and 31 patients′ SaO2 was elevated. The efficient rate was 77.5%. Other 9 patients developed ARDS, the rate was 2.5% (9/40). In the infection group 8 patients developed ARDS with an occurrence rate of 21.1%. There was one patient with ARDS in the non-infection group, the rate was 2.6%. There was significant difference between two group (Ｐ＜0.05). Conclusions: The results suggest that hypoxemia is liable to occur in aged patients with abdominal infection after operation and these patients were liable to develop ARDS. Oxygen therapy and SaO2 monitoring is the important managements to these patients in prevention of pneumonic injury.
ObjectiveTo explore the reason of failure in noninvasive positive pressure ventilation (NPPV) for treatment of postoperative hypoxemia, in order to better guide use of NPPV after cardiac surgery. MethodsWe retrospectively analyzed the clinical data of 64 patients after heart surgery with undergoing NPPV treatment due to hypoxemia in our hospital between January 2012 and December 2013 year.There were 49 males and 15 females at age of 28 to 87 years. There were 17 patients with NPPV failure. The related factors for failure of NPPV were analyzed. ResultsFactors associated with failure of NPPV included smoking history, preoperative pulmonary function abnormalities, blood transfusion amount > 1 000 ml, simplified acute physiology score Ⅱ(SAPS Ⅱ) before NPPV > 35 points, oxygenation index (PaO2/FiO2) < 100 mm Hg before NPPV, PaO2/FiO2 < 150 mm Hg after NPPV treatment for 1 h, mechanical ventilation time > 72 h at the first time, and pneumonia (P < 0.05). The SAPS Ⅱ > 35 points before NPPV and pneumonia were the independent risk factors for NPPV treatment failure for postoperative hypoxemia. ConclusionPostoperative NPPV for heart disease should be according to the cause of low oxygen and severity. For patients with SAPS less than 35 points before NPPV or patients with pneumonia, NPPV should not be used. In the process of NPPV, if clinical effect is not satisfied, it should be converted to invasive ventilation immediately.