End-tidal carbon dioxide measurements as a surrogate to arterial carbon dioxide during pediatric laparoscopic surgeries: a prospective observational cohort study

Hala Saad Abdel-Ghaffar; Mohammed Abdel-Moneim Bakr; Mohamed Abdel-Kadr Osman; Sarah George Labib Hanna; Wesam Nashat Ali

doi:10.1016/j.bjane.2021.07.036

End-tidal carbon dioxide measurements as a surrogate to arterial carbon dioxide during pediatric laparoscopic surgeries: a prospective observational cohort study

Braz J Anesthesiol. 2021 Aug 16:S0104-0014(21)00326-2. doi: 10.1016/j.bjane.2021.07.036. Online ahead of print.

Authors

Hala Saad Abdel-Ghaffar¹, Mohammed Abdel-Moneim Bakr², Mohamed Abdel-Kadr Osman³, Sarah George Labib Hanna², Wesam Nashat Ali²

Affiliations

¹ Assiut University, Faculty of Medicine, Anesthesia and Intensive Care Department, Assiut, Egypt. Electronic address: hallasaad@yahoo.com.
² Assiut University, Faculty of Medicine, Anesthesia and Intensive Care Department, Assiut, Egypt.
³ Assiut University, Faculty of Medicine, Pediatric Surgery Department, Assiut, Egypt.

PMID: 34411630
DOI: 10.1016/j.bjane.2021.07.036

Abstract

Background: Maintaining normocapnia during mechanical ventilation in anesthetized children during laparoscopic surgeries is highly recommended. There is a debate regarding the use of capnography (ETCO₂) as a trend monitor for evaluation of arterial carbon dioxide levels (PaCO₂). We analyzed the relationship between ETCO₂ and PaCO₂ with time in elective pediatric laparoscopic surgeries.

Methods: This study was a prospective observational cohort analysis of 116 paired comparisons between PaCO₂ and ETCO₂ computed from 29 children (ASA I, 12-72 months). Arterial blood samples were withdrawn before, at 15 minutes and 30 minutes during pneumoperitoneum and 1 minute after deflation. ETCO₂ value was recorded simultaneously, while arterial blood was withdrawn. PaCO₂-ETCO₂ relationship was evaluated by Pearson's correlation coefficients and Bland Altman Method of agreement.

Results: Out of the 116 comparisons analyzed, a PaCO₂-ETCO₂ difference beyond 0 to ≤ 5 mmHg was recorded in 71 comparisons (61.2%) with negative difference in 34 comparisons (29.3%). A positive significant correlation between PaCO₂ and ETCO₂ was recorded before (r = 0.617, p = 0.000) and at 15 minutes (r = 0.582, p = 0.001), with no significant correlation at 30 minutes (r = 0.142, p = 0.461), either after deflation (r = 0.108, p = 0.577). Bland-Altman plots showed agreement between ETCO₂ and PaCO₂ before inflation with mean PaCO₂-ETCO₂ difference 0.14 ± 5.6 mmHg (limits of 95% agreement -10.84-11.2, simple linear regression testing p-value 0.971), with no agreement at 15 minutes (0.51 ± 7.15, -13.5-14.5, p = 0.000), 30 minutes. (2.62 ± 7.83, -12.73-17.97, p = 0.000), or after deflation (1.81 ± 6.56, -10.93-14.55, p = 0.015).

Conclusion: Usage of capnography as a trend monitor in pediatric laparoscopic surgeries may not be a reliable surrogate for PaCO₂ levels.

Trial registration: Clinical Trials. gov (Identifier: NCT03361657).

Keywords: Anesthesia; Arterial carbon dioxide; Children; End tidal carbon dioxide; Laparoscopy; Mechanical ventilation.

Associated data

ClinicalTrials.gov/NCT03361657