Background Within a central operating room area, after general anesthesia (GA) patients are at risk of hypoxemia during transport to the postanesthesia care unit (PACU); however, specific risk factors have not been conclusively clarified and uniform recommendations for monitoring vital signs during transport within a central operating room area complex do not exist. The purpose of this retrospective database analysis was to identify risk factors for hypoxemia during this transport and to determine whether the use of transport monitoring (TM) affects the initial value of peripheral venous oxygen saturation (SpO2) in the PACU.
Material and methods This analysis was performed on a retrospectively extracted dataset of procedures in GA within a central operating room area of a tertiary care hospital from 2015 to 2020. The emergence from GA was conducted in the operating room with subsequent transport to the PACU. The transport distance was between 31 and 72 m. Risk factors for initial hypoxemia in the PACU, defined as peripheral oxygen saturation (SpO2) below 90%, were determined using multivariate analysis. After splitting the dataset into patients without TM (group OM) and with TM (group MM) and propensity score matching, the influence of TM on initial SpO2 and the Aldrete score after arrival in the PACU were examined.
Results and discussion From a total of 22,638 complete datasets included in the analysis, 8 risk factors for initial hypoxemia in PACU were identified: age > 65 years, body mass index (BMI) > 30 kg/m2, chronic obstructive pulmonary disease (COPD), intraoperative airway driving pressure (∆p) > 15 mbar and positive endexpiratory pressure (PEEP) > 5 mbar, intraoperative administration of a long-acting opioids, first preoperative SpO2 < 97%, and last SpO2 < 97% measured after emergence from anesthesia before transport. At least 1 risk factor for postoperative hypoxemia was present in 90% of all patients. After propensity score matching, 3362 datasets per group remained for analysis of the influence of TM. Patients transported with TM revealed a higher SpO2 at PACU arrival (MM 97% [94; 99%], OM 96% [94; 99%], p < 0.001). In a subgroup analysis, this difference between groups remained in the presence of one or more risk factors (MM 97% [94; 99%], OM 96% [94; 98%], p < 0.001, n = 6044) but was not detectable in the absence of risk factors for hypoxemia (MM 97% [97; 100%], OM 99% [97; 100%], p < 0.393, n = 680). Furthermore, the goal of an Aldrete score > 8 at PACU arrival was achieved significantly more often in monitored patients (MM 2830 [83%], OM: 2665 [81%], p = 0.004). Critical hypoxemia (SpO2 < 90%) at PACU arrival had an overall low occurrence within propensity matched datasets and showed no difference between groups (MM: 161 [5%], OM 150 [5%], p = 0.755). According to these results, consistent use of TM leads to a higher SpO2 and Aldrete score at PACU arrival, even after a short transport distance within an operating room area. Consequently, it appears to be reasonable to avoid unmonitored transport after general anesthesia, even for short distances.
Hintergrund Auf Transportwegen innerhalb eines Zentral-OP nach der Narkoseausleitung in den Aufwachraum (AWR) sind Patienten hypoxämiegefährdet. Spezifische Risikofaktoren sind jedoch nicht abschließend geklärt, und einheitliche Empfehlungen zur Überwachung der Vitalparameter bei Transporten innerhalb eines OP-Komplexes existieren nicht. Ziel dieser retrospektiven Datenbankanalyse war es, Risikofaktoren für eine Hypoxämie auf diesen Transporten zu identifizieren und zu prüfen, ob die Verwendung eines Transport-Monitorings (TM) den initialen Wert der peripher-venösen Sauerstoffsättigung (SpO2) im AWR beeinflusst.
Material und Methoden An einem retrospektiv extrahierten Datensatz von Eingriffen in Allgemeinanästhesie innerhalb eines Zentral-OP einer Universitätsklinik von 2015 bis 2020 wurden Risikofaktoren für eine initiale Hypoxämie im AWR (SpO2 < 90 %) mittels multivariater Analyse ermittelt. Nach Aufteilung des Datensatzes in Patienten ohne TM (Gruppe OM) und mit TM (Gruppe MM) und Propensity Score Matching wurde der Einfluss des TM untersucht.
Ergebnisse und Diskussion Acht Risikofaktoren für eine initiale Hypoxämie im AWR konnten identifiziert werden: Alter > 65 Jahre, body mass index (BMI) > 30 kg/m2, chronisch obstruktive Lungenerkrankung (COPD), intraoperativer Beatmungsdruck-Hub (∆p) > 15 mbar und positiver endexpiratorischer Druck (PEEP) > 5 mbar, intraoperative Gabe eines lang wirksamen Opioids, erste präoperative SpO2 < 97 % sowie nach Anästhesieausleitung letzte im OP gemessene SpO2 < 97 %. Bei 90 % aller Patienten lag mindestens ein Risikofaktor für eine postoperative Hypoxämie vor. Bei Vorliegen von Risikofaktoren geht die Verwendung eines TM mit einer geringeren initialen Desaturierung (MM: 97 [94; 99] %, OM: 96 [94; 98] %, p < 0,001) im AWR einher. Demnach erscheint eine konsequente Nutzung von TM auch auf kurzen Transporten innerhalb eines zusammenhängenden OP-Komplexes sinnvoll.
