Incidence and Associated Factors of Emergence Delirium in Pediatric Patients Undergoing ENT Surgery at Tikur Anbessa Specialized Hospital. A Prospective Cross-sectional Study

Abstract

Background: Pediatric Emergence Delirium (PED) is common after General Anesthesia (GA) in children, characterized by agitation and confusion. Though brief, it can cause injury, distress, and prolonged hospital stays. This study aimed to assess the incidence and associated factors of PED in children undergoing ENT surgery at Tikur Anbessa Specialized Hospital (TASH), Addis Ababa, Ethiopia.

Objectives: To determine the incidence of PED and identify associated risk factors in pediatric patients undergoing ENT surgeries under GA.

Method: A prospective cross-sectional study was conducted from September 2023 to April 2024. A total of 88 children aged 2–12 years undergoing elective ENT surgeries were included. Data were collected using a structured questionnaire. The Pediatric Anesthesia Emergence Delirium (PAED) scale was used to assess PED, with a score ≥12 indicating PED. Binary logistic regression identified predictors of PED.

Results: The incidence of PED was 21.6%. Significant risk factors included toddler and preschooler age (AOR=4.83, p=0.039), preoperative maladaptive behavior (AOR=12.16, p=0.003), lack of premedication (AOR=0.11, p=0.043), and moderate to severe postoperative pain (AOR=11.05, p=0.005).

Recommendations: Premedication should be routinely administered to reduce PED risk. Preoperative maladaptive behaviors need to be addressed, and effective pain management strategies should be implemented. Additionally, caregivers should be educated about PED to enhance their understanding and support during the recovery process.

Pediatric patients aged 2–12 years, classified as ASA I, II, or III who underwent elective ENT surgery under General Anesthesia (GA) during the study period.

Exclusion Criteria:

• Patients who are mechanically ventilated for a prolonged period following surgery.
• Patients transferred to the Intensive Care Unit (ICU) after surgery.
• Patients diagnosed with cognitive developmental delay.

Sampling

Sample size and Sampling techniques: A total of 88 pediatric patients who have undergone elective ENT surgery between the period of September 2023 and April 2024 in TASH were included in the study using the Consecutive sampling technique.

Variables

Independent: Age, Sex, ASA class, Comorbidity/Coexisting disease, Preoperative behavior, Premedication, Type of anesthesia, Anesthesia duration, and Postoperative pain

Dependent: Emergence delirium

Data Collection

After receiving informed oral consent, the data was collected using a standardized questionnaire. The data was gathered starting from the immediate post-extubating period in the OR and then in the PACU by the principal investigator, anesthesiology residents, and anesthetists assigned to the ENT OR table. PAED scale was used to assess for ED and a PAED scale of 12 or more was taken as PED.

Operational definition

• Maladaptive behaviors – behavior that prevents an individual from adjusting well to certain situations. This behavior includes anxiety, withdrawal, agitation, uncooperative behavior, temper tantrums, or aggressions.
• Premedication – administration of medications to patients before induction of general anesthesia for a surgical procedure to reduce their anxiety, induce sedation, or prevent pain.
• Cognitive developmental delay – condition in which children lag in intellectual functioning and whose behavior and communication are significantly below expectations.
• Pediatric emergence delirium – patients with a PAED score of 12 or more were taken as having emergence delirium.
• FLACC pain scale – is a behavioral pain assessment scale scored 0-10 where 0 = relaxed and comfortable, 1-3 = mild discomfort, 4-6 = moderate pain, 7-10 = severe pain or discomfort.

Data Analysis and Procedures

The data collected was reviewed by the main investigator and checked for quality and any missing documents before data input and analyzed manually using SPSS version 26 software. Bivariate logistic regression analysis was carried out to examine the predictors of the outcome variable. Variables with a p-value of < 0.25 on bivariant logistic analysis were taken to multivariable logistic regression analysis and a p-value of less than 0.05 was taken as a statistically significant predictor of postoperative delirium. The Hosmer-Lemeshow goodness of fit test was used to evaluate the appropriateness of the logistic regression model, with p > 0.05. Descriptive statistics was done for all variables and the results are presented in tables, graphs, and pie charts.

Data Quality Assurance

The data collectors were briefly trained before data collection on pediatric emergence delirium and there was a daily meeting during the data collection to clear up any ambiguity. The data collected from the questionnaire was reviewed by the main investigator and checked for completeness every day.

Ethical Considerations

The study participants and their attendants were informed about the aim of the study before the data collection began and that they were able to withdraw from the study at any point during the research, then oral consent was obtained from each patient’s parents or legal guardians. To ensure confidentiality, no patient identifiers were used in the data collection process. Instead, each participant was assigned a unique code number to maintain anonymity. Ethical clearance and support letter were obtained from Addis Ababa University College of Health Science Department of Anesthesiology, Critical Care and Pain Medicine and submitted to Tikur Anbessa Comprehensive Specialized Hospital Chief Clinical and Academic Director Offices.

Dissemination

Results to be shared with academic institutions, hospitals, and health bureaus, published in journals, and presented at workshops.

Results

Sociodemographic and Preoperative Data

A total of 88 pediatric patients who underwent elective ENT surgery between September 2023 and April 2024 at Tikur Anbessa Specialized Hospital (TASH) were included in the study. Of these, 31 (35.2%) were toddlers and preschoolers, while 57 (64.8%) were school-aged children. The sample included 42 (47.7%) females and 46 (52.3%) males. Regarding coexisting conditions, 59 (67%) had no coexisting diseases, while 29 (33%) had other coexisting medical conditions. In terms of preoperative management, 19 (21.6%) were premedicated with ketamine. Behaviorally, 51 (58%) of the children were calm, while 37 (42%) displayed maladaptive behavior during separation from their parents in the waiting room (Table 1).

Intraoperative Data

During induction in the OR, 29 (33%) were calm, 44 (50%) had maladaptive behavior, and 15 (17%) were previously sedated in the waiting room area. All 88 patients were given inhalational anesthesia as maintenance of anesthesia. 69 (78.4%) of the patients had surgery duration of less than 45 minutes and anesthesia duration of less than 1 hour, compared to 19 (21.6%) patients whose surgery and anesthesia duration was greater than 45 minutes and 1 hour respectively (Table 2).

Postoperative Data

None of the 88 patients who underwent surgery had vital sign derangement in the PACU. 58 (65.9%) had mild or no pain in contrast to the 30 (34.1%) who experienced moderate to severe pain. Out of the 88 patients, 19 (21.6%) had ED (Table 3).

Factors Associated with Pediatric Emergence Delirium Following ENT Surgery

To test the relationship between pediatric emergence delirium and the independent variables, bivariate binary logistic regression analysis was performed on selected independent variables with the dependent variable. Variables having a p-value of < 0.25 were selected and then included in the multivariable logistic regression analysis. These variables were age, sex, the behavior of the patient during parental separation, premedication, anesthesia duration, and post-operative pain scale in the PACU. The odds of developing emergence delirium were 4.8 times higher in toddlers and preschoolers [AOR=4.831 (95% CI: 1.08–21.62)] compared to school-age children. Patients with maladaptive behavior like anxiety, agitation, and restlessness were found to be 12 times more at risk of pediatric emergence delirium [AOR=12.16 (95% CI: 2.278–64.91)] compared to those who were calm during their separation from parents in the waiting room area. Those patients who were premedicated before induction of anesthesia were 89% less likely to develop emergence delirium [AOR=0.11 (95% CI: 0.013–0.928)] than those who did not receive premedication. Patients with moderate to severe pain postoperatively were 11 times more likely to have emergence delirium [AOR=11.05 (95% CI: 2.058–59.34)]

compared to those with mild or no pain in the PACU. (Table 4)

Discussion

Emergence Delirium (ED) is a common occurrence in pediatric patients in the post-anesthesia care unit (PACU), with an overall incidence ranging between 10% and 80% across various procedures. In this study, the prevalence of ED was 21.6%, aligning closely with previous findings from Michigan, USA (18%), Iran (17.9%), Germany (23%), and South Asia (22.4%). However, studies focusing on pediatric patients undergoing ENT surgeries have reported a broader range of incidences, from as low as 1.3% at the University of Texas to as high as 56% in Turkey. These variations may be attributed to differences in patient demographics, preoperative anxiety levels, anesthetic management, and study methodologies. Age emerged as a significant risk factor for ED in this study, with toddlers and preschool-aged children displaying a higher likelihood of experiencing delirium upon emergence from anesthesia (p=0.039). This finding aligns with a retrospective study from the University of Texas Southwestern Medical Center, which reported that toddlers had a higher prevalence of ED than preschoolers (p=0.04), middle-aged children (p<0.001), and teenagers (p=0.01). Similarly, a prospective observational study in Addis Ababa found that children aged 2–6 years were twice as likely to develop ED compared to those aged 7–12 years (p=0.042). The increased susceptibility in younger children may be due to their limited ability to comprehend and communicate their emotions, heightened separation anxiety, and immature cognitive development, all of which contribute to elevated stress levels. Contrary to a retrospective study from the University of Texas Southwestern Medical Center and a prospective observational study in India, both of which reported a higher prevalence of ED in boys (p=0.03 and p=0.04, respectively), our study found no significant association between male gender and ED (p=0.071). This discrepancy may be due to differences in anesthesia duration between genders in previous studies, whereas in our study, both sexes had comparable anesthesia times. Additionally, the Indian study had a male-dominated sample (82.4% boys vs. 17.6% girls), whereas our study had a more balanced gender distribution (52.3% boys vs. 47.7% girls). Supporting our findings, an observational study conducted in South Asia also did not establish a significant correlation between gender and ED. Preoperative anxiety and maladaptive behaviors during parental separation in the waiting area significantly influenced the incidence of ED (p=0.003). Children exhibiting agitation, anxiety, restlessness, uncooperativeness, and exaggerated displays of anger were more likely to develop ED. Similar findings were reported in studies conducted in South Asia (p=0.0005), Iran (p<0.005), Amhara (p=0.02), and India (p=0.01). The underlying mechanism may be related to the increased stress levels and emotional dysregulation in children with maladaptive behaviors, which could heighten their susceptibility to delirium during the recovery phase. The use of premedication significantly reduced the likelihood of ED in our study (p=0.043). Similar results were reported in a study from Turkey, where children who received oral ketamine premedication had an 18% incidence of ED compared to 56% in those who did not receive premedication (p=0.001). A study in the Amhara region also found that sedative premedication reduced the risk of ED by 58% (p=0.007). The anxiolytic and sedative effects of premedication may help stabilize the emotional state of pediatric patients before surgery, thereby reducing stress and the subsequent risk of delirium. Postoperative pain was strongly associated with the occurrence of ED in our study (p=0.005). Patients experiencing moderate to severe pain in the PACU were 11 times more likely to develop ED. These findings are consistent with studies conducted in Iran (p<0.0005), Amhara (p<0.001), and India (p=0.002), all of which identified pain as a significant risk factor for ED. One possible explanation is that pain disrupts normal brain function, increasing susceptibility to neurocognitive disturbances such as delirium. Some studies have reported a correlation between shorter anesthesia durations and increased ED incidence. However, our study did not find a significant association (p=0.943). Differences in anesthetic agents and techniques may account for these discrepancies. While some studies suggest that rapid emergence from anesthesia predisposes patients to delirium, variations in study methodologies and anesthetic protocols may explain the conflicting findings.

References