Pulse oximetry for perioperative monitoring

 

Abstract

Background

Pulse oximetry is extensively used in the perioperative period and might improve patient outcomes by enabling an early diagnosis and, consequently, correction of perioperative events that might cause postoperative complications or even death. Only a few randomized clinical trials of pulse oximetry during anaesthesia and in the recovery room have been performed that describe perioperative hypoxaemic events, postoperative cardiopulmonary complications, and cognitive dysfunction.

Objectives

The objective of this review was to assess the effects of perioperative monitoring with pulse oximetry and to clearly identify the adverse outcomes that might be prevented or improved by the use of pulse oximetry.

Search methods

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2009, Issue 2), MEDLINE (1966 to May 2009), EMBASE (1980 to May 2009), CINAHL (1982 to May 2009), ISI Web of Science (1956 to May 2009), LILACS (1982 to May 2009), and databases of ongoing trials; and checked the reference lists of trials and review articles.

Selection criteria

We included all controlled trials that randomized patients to either pulse oximetry or no pulse oximetry during the perioperative period.

Data collection and analysis

Two authors independently assessed data in relation to events detectable by pulse oximetry, any serious complications that occurred during anaesthesia or in the postoperative period, and intra- or postoperative mortality.

Main results

Searching identified five reports. We considered the studies with data from a total of 22,992 patients that were eligible for analysis. Results indicated that hypoxaemia was reduced in the pulse oximetry group, both in the operating theatre and in the recovery room. During observation in the recovery room, the incidence of hypoxaemia in the pulse oximetry group was 1.5 to three times less. Postoperative cognitive function was independent of perioperative monitoring with pulse oximetry. The one study in general surgery showed that postoperative complications occurred in 10% of the patients in the oximetry group and in 9.4% in the control group. No statistically significant differences were detected in cardiovascular, respiratory, neurologic, or infectious complications in the two groups. The duration of hospital stay was a median of five days in both groups, and an equal number of in-hospital deaths was registered in the two groups. Continuous pulse oximetry has the potential to increase vigilance and decrease pulmonary complications after cardiothoracic surgery, however routine continuous monitoring did not reduce transfer to an intensive care unit (ICU) or overall mortality.

Authors' conclusions

The studies confirmed that pulse oximetry can detect hypoxaemia and related events. However, we have found no evidence that pulse oximetry affects the outcome of anaesthesia for patients. The conflicting subjective and objective results of the studies, despite an intense methodical collection of data from a relatively large general surgery population, indicate that the value of perioperative monitoring with pulse oximetry is questionable in relation to improved reliable outcomes, effectiveness, and efficiency. Routine continuous pulse oximetry monitoring did not reduce either transfer to ICU or mortality, and it is unclear if there is any real benefit from the application of this technology in patients who are recovering from cardiothoracic surgery in a general care area.

 

Plain language summary

Perioperative monitoring with pulse oximetry does not appear to affect the outcomes of anaesthesia

The pulse oximeter is a non-invasive clinical monitor that measures the oxygen saturation of blood. The greatest value of pulse oximetry is its ability to provide an early warning of low oxygen levels (hypoxaemia). Although pulse oximetry can detect a deficiency of oxygen in the blood, its use does not appear to influence a person's cognitive function, length of hospital stay, or incidence of complications after anaesthesia. The conflicting subjective and objective results of the studies, despite an intense methodical collection of data from a relatively large population, indicate that perioperative monitoring with pulse oximetry can reduce pulmonary events. In general however, monitoring does not lead to improvements in patient outcomes, or in the effectiveness and efficiency of care. The results of perioperative pulse oximetry studies indicate that pulse oximetry was not a breakthrough which could reduce the number of postoperative complications. The question does remain whether pulse oximetry improves outcomes in other situations. Future work in this area would benefit from greater attention to methods of randomization as we found only a few appropriately randomized studies.

 

摘要

背景

脈動式氧合測量器之泛手術期監測

脈動式氧合測量器的監測可以經由早期診斷改善病患預後，並且矯正可能造成術後併發症甚至死亡的泛手術期事件。關於脈動式氧合測量器在麻醉中與恢復室的使用，提到泛手術期低血氧事件、術後心肺併發症以及認知功能障礙的隨機臨床試驗目前並不多。

目標

此回顧的目標是評估泛手術期以脈動式氧合測量器監測的效用，並確切指出脈動式氧合測量器可以預防或改善的不良後果。

搜尋策略

我們搜尋了the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2009年, Issue 2)、MEDLINE (1966 to May 2009)、 EMBASE (1980年 −2009年5月)、 CINAHL (1982年 −2009年5月)、 ISI Web of Science (1956年 −2009年5月)、LILACS (1982年 −2009年5月)、以及進行中試驗的資料庫；並且檢查了試驗以及回顧文章的參考資料清單。

選擇標準

我們收集了所有將病人隨機分配在泛手術期使用或不使用脈動式氧合測量器的對照試驗。

資料收集與分析

兩位作者獨立評估： 1. 由脈動式氧合測量器測得事件 2. 麻醉中或手術後發生的所有嚴重併發症 3 手術中或是手術後死亡率

主要結論

搜尋找出了5篇報告。我們認為其中研究，總共來自22,992位病人的資料符合我們分析的需求。 結果顯示脈動式氧合測量器組在手術室與恢復室較少發生低血氧。在恢復室中，脈動式氧合測量器組的低血氧發生率少了1.5至3倍。術後認知功能與泛手術期使用脈動式氧合測量器監測與否無關。另一項研究顯示，術後併發症的比率在脈動式氧合測量器組為10%而在控制組為9.4%。兩組中的心血管、呼吸、神經、感染併發症的比率並無顯著差異。 兩組的平均住院天數皆為五天，住院其間死亡率也相等，同時兩組登錄的住院死亡數相同。 心臟外科手術後持續的使用脈動式氧合測量器可能可以增加警覺性，同時也可以減少肺部併發症，不過常規持續的監測並無法大幅的減少需要送加護病房或是減少總死亡率的可能。

作者結論

這項研究確認脈動式氧合測量器可以測得低血氧及相關事件。然而我們找不到脈動式氧合測量器影響麻醉後果的證據。研究的主、客觀結果衝突(除了一個針對一般外科手術族群，樣本數相對較大，並且採用較佳的研究方法搜集資料的研究除外)，顯示在泛手術期以脈動式氧合測量器監測，對於改善可靠的結果、效益以及功效的價值讓人質疑。 常規使用脈動式氧合測量器並沒有減少轉送加護病房或是減少死亡率。對於正在從心臟外科手術復原的一般病房病人，運用此一技術的實際效益仍不清楚。

翻譯人

本摘要由臺灣大學附設醫院鄭孝良翻譯。

此翻譯計畫由臺灣國家衛生研究院(National Health Research Institutes, Taiwan)統籌。

總結

泛手術期以脈動式氧合測量器監測不能明顯改善麻醉的成果。脈動式氧合測量器是非侵襲性，用以測量血中氧氣飽和度的臨床監視器。脈動式氧合測量器最大的價值在於可以對於低含氧(低氧血)早期發出警訊。雖然脈動式氧合測量器可以測得血氧不足，它的使用並不影響病人的認知功能、住院時間或麻醉後併發症比率。研究的主、客觀結果衝突(除了一個針對一般外科手術族群，樣本數相對較大，並且採用較佳的研究方法搜集資料的研究除外)，顯示在泛手術期以脈動式氧合測量器監測有助於減少肺部事件。不過一般而言，監測並不能改善病人結果、或是照護的效益或功效。泛手術期之脈動式氧合測量器研究顯示，脈動式氧合測量器並無法減少泛手術期併發症數量。而脈動式氧合測量器是否能改善其他狀況病人的結果仍有疑問。 我們只發現少許較為合適的隨機研究，未來，本領域的研究將因較為注重隨機分配的方法而受惠。