2.1 Study area
The study was conducted at HUCSH, which is situated 273 kilometers away from Addis Ababa in Hawassa City, Sidama Regional State. HUCSH is a teaching hospital and offers a variety of services, including pediatrics. With 400 beds in total, it receives about 5,000 outpatient and emergency visits every month. Both inpatient and outpatient services are offered by the pediatrics department (20).
The study also took place at TASH, which is a teaching center and where 370,000–400,000 patients visit per year, while the precise number is unknown (21).Awide range of specialties provide services for patients, including pediatrics. Patients who are referred by other hospitals can receive care from the pediatrics department (22).TASH has 800 beds and provides services for the most critical patients. Around 13,300 presentations per year are seen at pediatric emergency departments (23).
Emperor Haile Selassie established Saint Peter Specialized Hospital in 1953. It is the first tuberculosis referral hospital in the country. Saint Peter Specialized Hospital has been the sole hospital in the country treating tuberculosis for more than 40 years. It has recently changed to become a multi-service specialty hospital with more than 14 different specialties and an excellence center, including services for pediatrics (24).
2.2 Study design and period
A single-arm prospective multi-center cohort study was conducted, and data collection was carried out from May 1, 2023, to July 30, 2023, at selected hospitals.
2.3 Population
2.3.1 Source of population
Pediatric patients undergoing surgery with GA.
2.3.2 Study population
Pediatric patients (≤ 16 years) undergoing surgery with GA (both elective and emergency) were transferred to the PACU.
2.4 Eligibility criteria
2.4.1 Inclusion criteria
Pediatric patients (≤ 16 years) undergoing surgery (both elective and emergency) with the Endo-Tracheal Tube (ETT) or Laryngeal Mask Airway (LMA) were transferred to the PACU from May 1, 2023, to July 30, 2023.
2.4.2 Exclusion criteria
Preoperative peripheral oxygen saturation (< 95%)
Patients entering the operation room with oxygen therapy
Intra-operative use of methylene blue
Problems with reading SPO2
Patients remained intubated and transferred to the ICU
2.5 Study variables
2.5.1 Independent variables
Pediatric age
Co-existing diseases
Anesthesia type
Surgery type
Anesthesia drugs (opioids and muscle relaxants)
Duration of anesthesia
Duration of surgery
2.5.2 Dependent variable
Incidence of POH
2.6 Operational definition
Postoperative hypoxemia: peripheral oxygen saturation < 95% in the blood for at least a minute exists after extubation.
Pediatrics: patients with an age of ≤ 16 years (25).
GA: pediatrics undergoing surgery either with GA + ETT or GA + LMA.
Prolonged anesthesia time: anesthesia that lasts > 1 hour (26).
Prolonged surgery time: surgery that lasts > 1 hour (26).
2.7 Sample size and sampling technique
2.7.1 Sample size
The sample size was determined by using the incidence of hypoxemia (P = 22.2%), which is taken from a prospective multicenter cohort study done in Nigeria due to the fact that there is no such multicenter cohort study done in Ethiopia. The study included 23,926 pediatric patients, was studied within 2 years, was conducted in 12 study areas, and had similar study participants to our study area (HUCSH, TASH, and St. Peter Specialized Hospital) (27).
4.7.2 Sampling technique
A systematic random sampling technique was applied.
These three hospitals were selected randomly. Situational analysis was done, and information was taken from a recorded logbook. 189, 201, and 209 pediatric cases were done at HUCSH, Saint Peter Specialized Hospital, and TASH in two months (February 1–March 30).
The patient sampling interval was conducted by: k = N/n; (N = 209, n = 292); and k = 209/292 = 1. The first patient was selected randomly.
2.8 Data collection procedure
Data was gathered at three selected hospitals (HUCSH, TASH, and Saint Peter Specialized Hospital) using a structured questionnaire from May 1, 2023, to July 30, 2023. Study participants and parents of study participants (forest parents) were informed about the collection of data, including objectives, benefits, harms, and other issues of the study, in Amharic and other local languages, with translation provided. Data collection was commenced with pediatric patients (≤ 16 years) who had undergone GA and satisfied the inclusion criteria; after the procedure was completed and the patient was extubated, these pediatric patients were followed throughout their stay in the PACU, and pediatric patients with peripheral oxygen saturation < 95% for at least a minute were considered hypoxemic pediatric patients. A questionnaire was developed from patient, anesthesia, and surgery-related information. The data was collected with three nurses assigned to PACU in each selected hospital.
2.9 Data processing and analysis
The statistical software SPSS version 25.00 was used to enter the data. Variables with a p > 0.05 were deemed fit for logistic regression, according to the Hosmer-Lemeshow goodness of fit test. Following binary logistic regression analyses, multivariable analysis was carried out once variables that match the final model were included using a p-value < 0.25. Independent variables were examined for multicollinearity, and those exhibiting a variance inflation factor (VIF) greater than 10 were removed.
Additionally, the association between variables was determined with Pearson chi-square. A p-value of less than 0.05 indicated that a variable was statistically significant. Frequency tables, pie charts, and graphs were used to summarize and illustrate the data that had been gathered. Finally, using the data, the results were compared and discussed, and then a conclusion were forwarded.
2.10 Data quality assurance
Two weeks before data collection started in the selected study area, two days of training on the objectives, data procedure, benefits, harms, relevance of the study, and brief explanations of the data collection tool (questionnaire) of the study were provided to assure the quality of the data. A pre-test data collection tool (a questionnaire) was performed on 5% of patients who satisfied the inclusion criteria but were not included in the study during data collection at selected hospitals. The investigator verified the completeness, accuracy, consistency, and clarity of the gathered data by cross-referencing them with the questionnaire. If there were any questions or misunderstandings among participants, they were reported.