Capnography and integrated pulmonary index in respiratory distress: Impact on clinical practices in pediatric emergency department

Introduction and Objective: Respiratory distress is a significant factor in the admissions to pediatric emergency departments and may progress to respiratory failure and consequent hypoxia without timely intervention. It is one of the primary causes of cardiopulmonary arrest in pediatric populations. This study seeks to assess the efficacy and reliability of capnography and the Integrated Pulmonary Index (IPI) monitoring relative to conventional pulse oximetry in evaluating the respiratory status and clinical presentation in pediatric patients. Materials and Methods: This prospective observational clinical study was conducted from September 1, 2023, to March 31, 2024, involving pediatric patients who were admitted to the Pediatric Emergency Department at Balcalı Hospital, Çukurova University Faculty of Medicine. These patients presented with respiratory distress and were prediagnosed with conditions such as pneumonia, bronchiolitis, croup, and asthma, necessitating close monitoring. Capnography parameters, including ETCO2 and IPI, were measured at baseline and at 1, 2, 3, and 4 hours, as well as prior to either discharge or hospital admission. Recorded data encompassed demographic information, comorbidities, medication usage, symptoms, findings from physical examinations, imaging outcomes, laboratory assessments, vital signs, in-hospital monitoring processes, and clinical outcomes. Results: In the present study, we included 100 pediatric patients with a pre-diagnosis of respiratory diseases. The distribution of final diagnoses among these patients was as follows: 70% pneumonia, 19% bronchiolitis, 7% croup, and 4% asthma. The mean age of the participants was 61.8±56.3 months, with a male predominance of 57%. Clinical parameters, including fever, respiratory rate, respiratory frequency, and heart rate, as well as laboratory values such as pH, PaCO2, ETCO2, and IPI, demonstrated improvement during the follow-up period in comparison to baseline measurements. Upon admission, 26% of the patients exhibited acidosis (pH<7.35), 33% exhibited hypercapnia (pCO2>45 mmHg), and 64% exhibited hypoxemia (pO2<60 mmHg). Our analyses revealed a significant linear correlation between ETCO2 and PaCO2 (p<0.001). Within the groups stratified for assessing the prognostic utility of IPI, it was noted that the elevation in baseline IPI values was more pronounced in patients with a favorable prognosis compared to those with an unfavorable prognosis. Notably, 11 patients in the poor prognosis cohort exhibited IPI-0 values of 7 or below, despite oxygen saturation levels measured by pulse oximetry being 93% or greater. Univariate logistic regression analyses identified baseline oxygen saturation and the pediatric early warning score (PEUS) as significant risk factors for IPI. Additionally, the increase in IPI values was statistically significantly greater in patients who received high-flow nasal cannula oxygen therapy compared to those who did not undergo this treatment (p=0.014). The prognostic capability of IPI was evaluated using ROC curve analysis. An initial IPI value exceeding 6.5 was found to predict a favorable prognosis with an area under the curve (AUC) of 75%, a sensitivity of 55.1%, and a specificity of 91%. This threshold value exhibited statistical significance (p<0.001). Conclusion: This study elucidates the clinical importance of ETCO2 and IPI metrics in pediatric patients experiencing acute respiratory distress. For cases preliminarily diagnosed with pneumonia, bronchiolitis, croup, and asthma, low initial ETCO2 and IPI values were regarded as early indicators of potential deterioration in the clinical condition. These findings imply that these parameters may exhibit greater sensitivity compared to conventional vital signs. The continuous surveillance afforded by capnography presents the capability to swiftly identify alterations in respiratory function. This feature may facilitate early detection and prompt intervention of complications that may emerge during the treatment process. In summary, the comprehensive integration of ETCO2 and IPI in routine clinical practices may prove beneficial in managing pediatric patients with acute respiratory failure. Validation of these findings through larger studies will contribute significantly to the refinement of pediatric emergency medicine and intensive care protocols.