Incidence and Factors Associated With Post- anesthesia Care Unit Complications at St. Paul’s Hospital, Ethiopia. Observational Study


 Background: Postoperative complications are frequent encounters in the patients admitted to post-anesthesia care units (PACU). The main aim of this study was to assess the incidence and associated factors of complications among surgical patients admitted to PACU.Methods: This is an observational study of 396 surgical patients admitted to PACU. This study was conducted from February 1 to March 30, 2021, in Ethiopia. Study participant's demographics, anesthesia, and surgery-related parameters, PACU complications, and length of stay in PACU were documented. Multivariate and bivariate logistic regression analyses, the odds ratio (OR), and 95% confidence interval (CI) were calculated. P-value < 0.05 was considered as statistically significant.Results: The incidence of complications among surgical patients admitted to PACU was 54.8%. Of these, respiratory-related complications and postoperative nausea/vomiting were the most common types of PACU complications. Being a female (AOR=2.928;95%CI:(1.899-4.512)) was significantly associated with an increased risk of developing PACU complications. Duration of anesthesia >4 hours (AOR=5.406; 95% CI (2.418_12.088) revealed an increased risk of association with PACU complications. The occurrences of intraoperative complications (AOR=2.238; 95% CI (0.991_5.056) during surgery were also associated with PACU complications. Patients who develop PACU complications were strongly associated with length of PACU stay for > 4 hours (AOR=2.177; 95% CI (0 .741_ 6.401)).Conclusion: The identified risk factors for complications in surgical patients admitted to PACU are female sex, longer duration of anesthesia, and intraoperative complications occurrences. Patients who developed complications had a long time of stay in PACU.


Introduction
Post-operative complications in patients admitted to post-anesthesia care units (PACU) are frequent encounters and approximately account for 4.25% -37.3%, with severity ranging from trivial to critical The dearth of Interventional studies revealed that the implementation of a checklist decreased the overall medical errors and rate of preventable adverse events in PACU (18)(19)(20). Other study also showed that using the post-anesthetic care tool (PACT) improves early detection of patients at risk of deterioration, handover to surgical ward nurses, and reduces health care expenses (21). Therefore, prevention and management strategies based on implementing standardized handover protocols, proper sta ng of well-trained experts, monitoring devices, and infrastructures to improve the quality of patient care should be a crucial part of safe anesthesia in PACU.
In previously published studies, patient, anesthesia, and surgery-related risk factors have been identi ed for PACU complications. Further explorations into the etiology of these complications should help develop strategies to prevent and manage those critical incidents.
In a four-centered study done in Canada, ASA physical status, length of anesthesia duration, occurrence of intraoperative complications, and use of pure spinal or narcotic techniques have been identi ed as independent single risk factors for PACU complications (10).
On the other hand, the study done in the Philippines revealed that duration of surgery, the occurrence of intraoperative complications, and postoperative complications were identi ed as signi cant predictors for the length of stay at PACU (22).
Despite the magnitude of the problem in daily clinical activity, there has been very little or no research examined the incidence and factors associated with PACU complications in sub-Saharan countries including Ethiopia. The main objective of this study is to evaluate the incidence and factors associated with postoperative complications in PACU. The study was approved by the St. Paul's hospital ethical clearance committee and informed written consent was obtained from each study participant and/or legal guardians of underage study participants. Con dentiality was assured throughout the research.

Inclusion criteria
During the study period, we included all surgical patients who were admitted to PACU for monitoring and stabilization into this study.

Exclusion criteria
Patients transferred directly from the operation theater to an intensive care unit, ward, or outpatient department were excluded.

Postoperative and Post-anesthesia care
On the arrival of patients from OR to the PACU, the responsible nurses applied the standard monitoring.
Nurses are available at all times, and anesthetists/anesthesiologist supervise the overall activities based on patients' conditions.
In the institution, there is a lack of uniform and standardized checklist used for discharging the patients from one department to others; however, each patient admitted to PACU were monitored for a minimum of 1 to 4 hours, and discharged to the respective wards/units.

Sample size and sampling techniques
We calculated the sample size from the primary outcome variable by using single population formula, which is the incidence of PACU complications. Since there is no preliminary data in the study setting P=0.5(prevalence of PACU complications 50%) was taken for the calculation to get the largest sample size, 95% con dence interval, and 5% margin of error gives us 384 study subjects. Since the studied population in a year is less than 10,000, the corrected sample size formula was used, and the nal sample size becomes 396 by adding a 10% attrition rate. A convenient sampling technique was used to select the study participants.

Data collection techniques
We collected our data using pretested questioner by trained 4 PACU nurses and anesthetists data collectors. Demographics and preexisting co-morbidity variables were documented from patient medical chart. The occurrences of complications and length of PACU stay was recorded from bedside observation, monitoring devices, and documentation of attending nurses until discharging patients to the respective department. The principal investigator cross-checked the collected data to ensure accuracy and completeness.

Data analysis
We entered and analyzed data using Statistical Package for Social Sciences (SPSS version 26). We used descriptive statistics to summarize the frequency table, and the standardized residual tests to test the outlier data. Multi-collinearity was checked by VIF, tolerance, and con dence index. All independent variables were analyzed using bivariate analysis, and the variables that had an association at a p-value less than or equal to 0.25 were entered into a multivariable logistic regression model, and P-value < 0.05 was considered to be risk factors for PACU complications during the postoperative period in this study. The results of associated variables were presented as frequency table, crude, and adjusted odds ratio with 95% con dence interval. Hosmer Lemeshow test was used to check the goodness of the model, and the model was the best t with a P-Value of 0.689.

Operational de nitions
Respiratory-related complications: Patients who develop Desaturation, Stridor, and wheezing.
Hypotension: A decrease of the systolic BP by 20% from baseline Hypertension: An increase in systolic BP by 20% from baseline Shock: Hypotension with signs of poor peripheral perfusion Tachycardia: Heart rate >100 for adults, different in different pediatric age groups Bradycardia: Heart rate < 60 for adults and less than 80 for children Central nervous system complications: Patients who experience deep sedation, seizure, and confusion.
Other complications: patients who experience pain, hypothermia, bleeding from the incision site, and unplanned ICU admission.
PACU complications: occurrence of one or more of the above in the PACU.

Results
Demographics and preexisting co-morbidity characteristics of the study participants.
A total of 396 patients admitted to PACU during the study period were enrolled for nal analysis. Of these, 204(51.51%) were males and females accounted for 192 (48.49%). The mean (SD) of the study participants was 38.99(19.47) with a range of 4 months -96 years. Regarding the ASA physical status, the majority 305(77.02%) of patients were ASA class I followed by ASA class II 69 (17.42%) and ≥ASA class III 22 (5.56%). Assessment of preoperative co-morbidity revealed that only 94(23.74%) of patients had preexisting co-morbidity as shown in (Table 1).  Surgery-related characteristics of study participants.
From the total study participants admitted to PACU, the incidence of PACU complications was 217 (54.8%) Figure 1.

Discussion
Our study has study revealed that the overall incidence of postoperative complications in PACU among patients undergoing surgery is 54.6%. Previous studies have been investigated the incidence of complications in PACU in different countries reported that only (4.25% -37.3%) of surgical patients develop PACU complications (1-4).
The low ratio of a trained nurse on PACU compared to work overload intensity (2), and the unstructured and inconsistent handover protocol (16) in the clinical setup could explain the increased rate of complications. In addition, number of sample sizes, operational de nitions, and study design differences might also contribute to the incidence rate.
Of all PACU complications, the majority (17.7%) were respiratory and airway related, which is consistent with previous studies. (5-7). The possible explanation related to respiratory complications is due to hypoventilation caused by hypo-active emergence and residual effects of muscle relaxant agents, as most of the participants had undergone surgery with general anesthesia. (4,23) In contradiction to our nding, other studies (8, 9) reported that the majority of PACU complications were cardiovascular-related. In another study, PONV (10.,23), central nervous system (2,11), and pain (12,13) were reported as the most common PACU complications.
Our study found that female sex, duration of anesthesia, presence of intraoperative complications, and duration of stay in PACU were factors associated with PACU complications.
Female patients were more at risk of developing complications than male counterparts (AOR=2.570;95%CI:(1.621 -4.075)). Similarly, other studies (12,(25)(26)(27)) also found being a female is a risk factor to develop PACU complications. The reason might be (22.12%) incidence of PONV occurred in our study is higher in females, which contributes to the rate of PACU complications. In addition, gynecological procedures are a risk factor to develop PONV, which is con ned in female patients.
Another factor associated with PACU complications in the present study was the duration of anesthesia.
Duration of anesthesia > 4 hours (AOR=5.406; 95% CI (2.418_12.088) and 2 -3 hours (AOR=3.050 (1.690 -5.505) had ve-and three-folds risk for developing PACU complications compared to the duration of anesthesia less than or equal to 2 hours respectively. This result is consistent with other studies (6,10, 25,28) that reported the risk of developing PACU complications is higher in patients with prolonged duration of anesthesia.
Inconsistent with our ndings, other studies revealed that types of anesthesia, the urgency of surgery, ASA class, preexisting disease, and other factors are associated with PACU complications. The standard of clinical setup, types of surgery performed, level of expertise, available medications, sustainable training, and attention given to the health sector might contribute to the dissimilarity of the ndings.
The length of stay in PACU greater than 4 hours (AOR=4.538;95% CI (2.089 -9.857) were strongly correlated with the incidence of PACU complication, our study also observed that patients who encountered PACU complications signi cantly required a prolonged duration of stay than initially planned compared to patients without complications (9,22).

The limitation of the study
This study was conducted in a single-center hospital which is di cult to conclude the overall features in the country. Secondly, this study identi ed complications that exclusively occurred in PACU and failed to detect any types of complications experienced by patients after discharged from PACU.

Strength of the study
This study is a prospective and observational study used a primary source of data.

Conclusion
The incidence of PACU complications is 54.6% in the present study which is higher than prior studies done in different countries. Female sex, intraoperative complications occurrence, and duration of anesthesia are found to be independent risk factors for developing PACU complications.
Based on the ndings of the present study, we recommend the PACU team need to develop risk predicting tools to improve the quality of care and patient outcomes. Our thanks also go to data collectors and study participants who were involved during the data collection period.
Authors' contributions BA design the methodology and coded data. DZ performed data analysis and draft the manuscript. All authors read and approved the nal manuscript.

Funding
This study did not receive funding.

Availability of data and materials
The dataset during and/or analyzed during the current study available from the corresponding author on reasonable request.
Ethics approval and consent to participate Incidence of PACU complications.