Carbon dioxide monitoring in children-A narrative review of physiology, value, and pitfalls in clinical practice

Accuracy and Interpretation of Transcutaneous Carbon Dioxide Monitoring in Critically Ill Children

OBJECTIVES

Transcutaneous carbon dioxide (Tc co2 ) monitoring can noninvasively assess ventilation by estimating carbon dioxide ( CO2 ) levels in the blood. We aimed to evaluate the accuracy of Tc co2 monitoring in critically ill children by comparing it to the partial pressure of arterial carbon dioxide (Pa co2 ). In addition, we sought to determine the variation between Tc co2 and Pa co2 acceptable to clinicians to modify patient care and to determine which patient-level factors may affect the accuracy of Tc co2 measurements.

DESIGN

Retrospective observational cohort study.

SETTING

Single, quaternary care PICU from July 1, 2012, to August 1, 2020.

PATIENTS

Included participants were admitted to the PICU and received noninvasive ventilation support (i.e., continuous or bilevel positive airway pressure), conventional mechanical ventilation, or high-frequency oscillatory or percussive ventilation with Tc co2 measurements obtained within 15 minutes of Pa co2 measurement.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Three thousand four hundred seven paired arterial blood gas and Tc co2 measurements were obtained from 264 patients. Bland-Altman analysis revealed a bias of -4.4 mm Hg (95% CI, -27 to 18.3 mm Hg) for Tc co2 levels against Pa co2 levels on the first measurement pair for each patient, which fell within the acceptable range of ±5 mm Hg stated by surveyed clinicians, albeit with wide limits of agreement. The sensitivity and specificity of Tc co2 to diagnose hypercarbia were 93% and 71%, respectively. Vasoactive-Infusion Score (VIS), age, and self-identified Black/African American race confounded the relationship between Tc co2 with Pa co2 but percent fluid overload, weight-for-age, probe location, and severity of illness were not significantly associated with Tc co2 accuracy.

CONCLUSIONS

Tc co2 monitoring may be a useful adjunct to monitor ventilation in children with respiratory failure, but providers must be aware of the limitations to its accuracy.

Procedural sedation and analgesia in pediatric diagnostic and interventional radiology: An expert DELPHI consensus document developed by the ITALIAN scientific society of anesthesia, analgesia, resuscitation and intensive care (SIAARTI)

BACKGROUND

Children undergoing diagnostic and interventional radiology procedures often require sedation to achieve immobility and analgesia if the procedure is painful. In the past decades, leading scientific organizations have developed evidence-based guidelines for procedural sedation and analgesia in children outside of the operating room. Their recommendations are being applied to procedural sedation in radiology. However, some questions remain open regarding specific aspects contextualized to the radiology setting, such as elective prone sedation, the urgency of the procedure, when venous access or airway protection is required, and others.

AIMS

To address the unresolved issues of procedural sedation and analgesia in pediatric diagnostic and interventional radiology.

METHODS

An expert panel of pediatricians, pediatric anesthesiologists, intensivists, and neuroradiologists selected topics representative of current controversies and formulated research questions. Statements were developed by reviewing the literature for new evidence, comparing expertise and experience, and expressing opinions. Panelists' agreement with the statements was collected anonymously using the DELPHI method.

RESULTS

Twelve evidence-based or expert opinion incorporate are presented, considering risks, benefits, and applicability.

CONCLUSIONS

This consensus document, developed by a multidisciplinary panel of experts involved in the field, provides statements to improve the quality of decision-making practice in procedural sedation and analgesia in pediatric radiology.

Highly sensitive and selective colorimetric sensing of CO2 for biomedical applications

The concentration of carbon dioxide (CO2) in unhealthy people differs greatly from healthy people. High-precision CO2 detection with a quick response time is essential for many biomedical applications. A major focus of this research is on the detection of CO2, one of the most important health biomarkers. We investigated a low-cost, flexible, and reliable strategy by using dyes for colorimetric CO2 sensing in this study. The impacts of temperature, pH, reaction time, reusability, concentration, and dye selectivity were studied thoroughly. This study described real-time CO2 analysis. Using this multi-dye method, we got an average detection limit of 1.98 ppm for CO2, in the range of 50-120 ppm. A portable colorimetric instrument with a smartphone-assisted unit was constructed to determine the relative red/green/blue values for real-time and practical applications within 15 s of interaction and the readings are very similar to those of an optical fiber probe. Environmental and biological chemistry applications are likely to benefit greatly from this unique approach.

Review of pediatric hypercarbia and intraoperative management

PURPOSE OF REVIEW

Hypercarbia in pediatric patients is an important component of intraoperative management. Despite marked advances in medicine and technology, it is uncertain what the physiological CO2 range in neonates, infants and small children. This data is extrapolated from the adult population. We are going to review advantages and disadvantages of CO2 measurement techniques, causes and systemic effects of hypercarbia. We are going to discuss how to approach management of intraoperative hypercarbia.

RECENT FINDINGS

Although physiological range in this patient population may not be fully understood, it is known that any rapid change from a child's baseline increases risks of complications. Any derangements in CO2 are further compromised by hypoxia, hypotension, hypothermia, anemia, all of which may occur in a dynamic operating room environment.

SUMMARY

Pediatric anesthesiologists and their teams must remain vigilant and anticipate these developments. Care must be taken to avoid any rapid changes in these vulnerable patients to minimize risks of adverse outcomes.

Understanding pediatric ventilation in the operative setting. Part II: Setting perioperative ventilation

Approaches toward lung-protective ventilation have increasingly been investigated in recent years. Despite evidence being found in adults undergoing surgery, data in younger children are still scarce and controversial. From a physiological perspective, however, the continuously changing characteristics of the respiratory system from birth through adolescence require an approach based on the analysis of each individual patient. The modern anesthesia workstation provides such information, with the technical strengths and weaknesses being discussed in a review preceding the present work (see Part I). The present summary aims to provide ideas on how to translate the information displayed on the anesthesia workstation to patient-oriented clinical ventilation settings.

Understanding pediatric ventilation in the operative setting. Part I: Physical principles of monitoring in the modern anesthesia workstation

The modern anesthesia workstation provides a wealth of information some of which is of particular interest when it comes to optimizing ventilation settings. This knowledge gains even more importance in the therapy of pediatric patients. In the absence of evidence-based recommendations on optimal ventilation settings in pediatric patients, the evaluation of individual factors becomes crucial and challenging at the same time. Even when equipped with the latest sensor technology, the user will always have to be in charge of interpreting the provided monitoring variables. The purpose of this review is to outline the clinical impact, technological background, and reliability of the most relevant information measured and calculated by a modern anesthesia workstation. It aims at translating the technical knowledge into a more competent and vigilant application in the clinical setting.