| 摘要: | 研究目的：
術後肺泡塌陷為術後常見的合併症，其可能會導致肺內分流的產生，進而衍生頑固性低血氧及呼吸窘迫等問題。肺泡擴張術似乎可以改善接受心肺手術病人的術後肺泡塌陷。因此我們針對相關的隨機對照研究採用統合分析之方法，探究肺泡擴張術對於心肺手術患者降低術後肺泡塌陷之有效性及安全性。
研究方法：
我們搜尋了Pubmed、Embase、Cochrane library及ClinicalTrials.gov等資料庫，最後搜尋時間為2020年3月。每篇的效果量皆予以標準化，並以隨機效果模式計算合併效應之大小。主要測量指標為術後肺泡塌陷，次要指標則依序為低血氧事件、肺內分流、靜態肺部順應性、氧合指數、肺炎、心臟指數、平均動脈壓及氣胸。
研究結果：
我們回顧了24篇隨機對照試驗，包含2110位病人。結果顯示在接受胸腔手術的受試者中，肺泡擴張術能減少低血氧事件 (相對風險，0.49；95% 信賴區間，0.26–0.93)、肺內分流 (加權平均差，0.03；95% 信賴區間，-0.04–-0.01) 並改善靜態肺部順應性 (加權平均差，2.16；95% 信賴區間，1.14–3.18) 及氧合指數 (加權平均差，44.58；95% 信賴區間，26.16–63.00)，對於平均動脈壓 (加權平均差，0.94；95% 信賴區間，-2.54至4.42) 則沒有顯著的影響。術後肺泡塌陷的風險在介入組較低，但是未達統計上的顯著差異 (相對風險，0.53；95% 信賴區間，0.26–1.08)。在接受心臟手術的受試者中，肺泡擴張術能降低術後肺泡塌陷 (就整體而言：相對風險，0.33；95%信賴區間，0.18–0.61；在使用擴張壓力大於40 cmH2O的組別：相對風險，0.20；95% 信賴區間，0.07–0.57；在使用擴張壓力小於40 cmH2O的組別：相對風險，0.54；95% 信賴區間，0.33–0.89)、低血氧事件 (相對風險，0.23；95% 信賴區間，0.14–0.37)、肺內分流 (加權平均差，-0.07；95% 信賴區間，-0.09–-0.05)、肺炎 (相對風險，0.42；95% 信賴區間，0.18–0.95) 並改善靜態肺部順應性 (加權平均差，12.64；95% 信賴區間，8.74–16.53) 及氧合指數 (加權平均差，58.87；95% 信賴區間，31.24–86.50)，對於心臟指數 (加權平均差，0.22；95% 信賴區間，-0.18至0.61) 及平均動脈壓 (加權平均差，-0.30；95% 信賴區間，-3.19至2.59) 則沒有顯著的惡化。肺泡擴張術對於氣胸的影響在兩組間並沒有達到統計上的顯著差異 (相對風險，1.26；95% 信賴區間，0.57–2.79)。
結論：
肺泡擴張術是可行而且有效的治療方法。肺泡擴張術不僅可以減少術後肺泡塌陷、低血氧事件及肺炎的事件，並能舒緩肺內分流，改善靜態肺部順應性，進而提升氧合指數。肺泡擴張術對於呼吸器引起的壓力性損傷及血液動力學則沒有顯著的影響。因此對於接受心肺手術的患者而言，肺泡擴張術對於術後肺部塌陷的治療效果優於傳統的機械通氣模式。
Purpose:
Pulmonary atelectasis is a common postoperative complication that may lead to intrapulmonary shunt, refractory hypoxemia, and respiratory distress. According to previous studies, recruitment maneuver may relieve pulmonary atelectasis in patients undergoing cardiothoracic surgery. Hence, we conducted a meta-analysis of randomized controlled trials to evaluate the effectiveness and safety of recruitment maneuver in these patients.
Methods:
We conducted a search of PubMed, Embase, Cochrane Library, and the ClinicalTrials.gov registry for trials published before March 2020. Individual effect sizes were standardized, and a meta-analysis was performed to calculate the pooled effect size with the use of random-effects models. The incidence of pulmonary atelectasis was postoperatively assessed. Secondary outcomes included incidence of hypoxic events, intrapulmonary shunt, static lung compliance, partial pressure of oxygen (PaO2)/fraction of inspired oxygen (FiO2) ratio, incidence of pneumonia, cardiac index, mean arterial pressure and incidence of pneumothorax.
Results:
We reviewed 24 trials involving 2,110 patients. Those who received recruitment maneuver with thoracic surgery had a reduced incidence of hypoxic events (risk ratio [RR], 0.49; 95% confidence interval [CI], 0.26–0.93), reduced intra-pulmonary shunt (weighted mean difference [WMD], -0.03; 95% CI, -0.04–-0.01), improved static lung compliance (WMD, 2.16; 95% CI, 1.14–3.18), and an improved PaO2/FiO2 ratio (WMD, 44.58; 95% CI, 26.16–63.00) without disturbing the mean arterial pressure (WMD, 0.94; 95% CI, -2.54 to 4.42). The incidence pulmonary atelectasis favored recruitment maneuver group, but was not statistically significant (RR, 0.53; 95% CI, 0.26–1.08). Patients who received recruitment maneuver with cardiac surgery had a reduced incidence of pulmonary atelectasis (overall: RR, 0.33; 95% CI 0.18–0.61; group with recruited pressure > 40 cmH2O: RR, 0.20; 95% CI, 0.07–0.57; group with recruited pressure < 40 cmH2O: RR, 0.54; 95% CI, 0.33–0.89), reduced incidence of hypoxic events (RR, 0.23; 95% CI, 0.14–0.37), reduced intra-pulmonary shunt (WMD, -0.07; 95% CI, -0.09–-0.05), reduced incidence of pneumonia (RR, 0.42; 95% CI, 0.18–0.95), improved static lung compliance (WMD, 12.64; 95% CI, 8.74–16.53), and an improved PaO2/FiO2 ratio (WMD, 58.87; 95% CI, 31.24–86.50) without disturbing the cardiac index (WMD, 0.22; 95% CI, -0.18 to 0.61) or mean arterial pressure (WMD, -0.30; 95% CI, -3.19 to 2.59) when compared to those who received conventional mechanical ventilation. The incidence of pneumothorax did not differ significantly between the groups (RR, 1.26; 95% CI, 0.57–2.79).
Conclusion:
Recruitment maneuver may reduce postoperative pulmonary atelectasis, hypoxic events, intra-pulmonary shunt, and pneumonia, and improve static lung compliance and PaO2/FiO2 ratios without disturbing the ventilator-induced barotrauma and hemodynamics in patients undergoing cardiothoracic surgery. |
