Non invasive monitoring in mechanically ventilated pediatric patients

Two-site regional oxygen saturation and capnography monitoring during resuscitation after cardiac arrest in a swine pediatric ventricular fibrillatory arrest model

To investigate the use of two-site regional oxygen saturations (rSO₂) and end tidal carbon dioxide (EtCO₂) to assess the effectiveness of resuscitation and return of spontaneous circulation (ROSC). Eight mechanically ventilated juvenile swine underwent 28 ventricular fibrillatory arrests with open cardiac massage. Cardiac massage was administered to achieve target pulmonary blood flow (PBF) as a percentage of pre-cardiac arrest baseline. Non-invasive data, including, EtCO₂, cerebral rSO₂ (C-rSO₂) and renal rSO₂ (R-rSO₂) were collected continuously. Our data demonstrate the ability to measure both rSO₂ and EtCO₂ during CPR and after ROSC. During resuscitation EtCO₂ had a strong correlation with goal CO with r = 0.83 (p < 0.001) 95% CI [0.67–0.92]. Both C-rSO₂ and R-rSO₂ had moderate and statistically significant correlation with CO with r = 0.52 (p = 0.003) 95% CI (0.19–0.74) and 0.50 (p = 0.004) 95% CI [0.16–0.73]. The AUCs for sudden increase of EtCO₂, C-rSO₂, and R-rSO₂ at ROSC were 0.86 [95% CI, 0.77–0.94], 0.87 [95% CI, 0.8–0.94], and 0.98 [95% CI, 0.96–1.00] respectively. Measurement of continuous EtCO₂ and rSO₂ may be used during CPR to ensure effective chest compressions. Moreover, both rSO₂ and EtCO₂ may be used to detect ROSC in a swine pediatric ventricular fibrillatory arrest model.

Correlation between Regional Cerebral Saturation and Invasive Cardiac Index Monitoring after Heart Transplantation Surgery

The present study assessed the correlations between cerebral regional saturation detected by near infrared spectroscopy (NIRS) and cardiac index (CI) measured by pulmonary artery catheter. This was a retrospective cohort study conducted in the cardiac intensive care unit in a tertiary care children's hospital. Patients younger than 18 years of age who underwent heart transplantation and had a pulmonary artery catheter on admission to the pediatric cardiac intensive care unit between January, 2010, and August, 2013, were included. There were no interventions. A total of 10 patients were included with median age of 14 years (range, 7-17). Indications for transplantation were dilated cardiomyopathy ( n  = 9) and restrictive cardiomyopathy ( n  = 1). Mixed venous oxygen saturation (SvO 2 ), cerebral regional tissue saturation (rSO 2 ), and CI were recorded hourly for 8 to 92 hours post-transplantation. Spearman's rank correlation coefficient was used to assess correlations between SvO 2 and cerebral rSO 2 and between CI and cerebral rSO 2 . A total of 410 data points were collected. Median, 25th and 75th percentiles of cerebral rSO 2 , CI, and SvO 2 were 65% (54-69), 2.9 L/min/m 2 (2.2-4.0), and 75% (69-79), respectively. The correlation coefficient between cerebral rSO 2 and CI was 0.104 ( p  = 0.034) and that for cerebral rSO 2 and SvO 2 was 0.11 ( p  = 0.029). The correlations between cerebral rSO 2 and CI and between cerebral rSO 2 and SvO 2 were weak. Cerebral rSO 2 as detected by NIRS may not be an accurate indicator of CI in critically ill patients.

Correlation between minute carbon dioxide elimination and pulmonary blood flow in single-ventricle patients after stage 1 palliation and 2-ventricle patients with intracardiac shunts: A pilot study

BACKGROUND

Assessment of pulmonary blood flow and cardiac output is critical in the postoperative management of patients with single-ventricle physiology or 2-ventricle physiology with intracardiac shunting. Currently, such hemodynamic data are only obtainable by invasive procedures, such as cardiac catheterization or the use of a pulmonary artery catheter. Ready availability of such information, especially if attainable noninvasively, could be a valuable addition to postoperative management.

AIMS

The aim of this study was to assess the correlation between volume of CO₂ elimination obtained by volumetric capnography and pulmonary blood flow in pediatric patients with single-ventricle physiology after stage 1 palliation as well as in patients with other cardiac lesions associated with intracardiac shunting.

METHODS

This prospective cohort study included children with congenital or acquired heart disease who underwent cardiac catheterization as part of clinical care. Cardiac output, pulmonary blood flow, and volume of CO₂ elimination were simultaneously collected. Spearman's rank correlation coefficients were used to assess correlation between measurements after controlling for minute ventilation.

RESULTS

Thirty-five patients were enrolled and divided into 3 groups. Group 1 (n = 8) included single-ventricle patients after stage 1 palliation. Group 2 (n = 10) patients had structural heart disease with 2 ventricles and intracardiac shunting. Group 3 (n = 17) had structurally normal hearts. Among Group 1 patients, the correlation coefficients (R² ) between volume of CO₂ elimination and pulmonary blood flow and volume of CO₂ elimination and cardiac output were 0.60 (P = .02) 95% CI [0.01-0.79] and 0.29 (P = .74) 95% CI [-0.91 - 0.86], respectively. In patients with 2 ventricles associated with intracardiac shunts (Group 2), the correlation coefficients between volume of CO₂ elimination and pulmonary blood flow and volume of CO₂ elimination and cardiac output were 0.86 (P = .001) 95% CI [0.53 - 0.97] and 0.73 (P = .001) 95% CI [0.29 - 0.95], respectively. Among Group 3 patients, the correlation coefficient between volume of CO₂ elimination and pulmonary blood flow was 0.66 (P = .038) 95% CI [0.29 - 0.87].

CONCLUSION

Volume of CO₂ elimination may be a surrogate marker of pulmonary blood flow in single-ventricle patients and patients with biventricular physiology with intracardiac shunting. Also, among patients with normal cardiac anatomy, volume of CO₂ elimination may be a marker of cardiac output.

Current Use of Invasive and Noninvasive Monitors in Academic Pediatric Intensive Care Units

To describe the current use of noninvasive monitoring compared with traditional invasive monitoring in Pediatric Critical Care Medicine (PCCM) accredited fellowship programs in the United States. A web-based survey with the primary aim of describing the utilization of noninvasive monitoring compared with invasive monitoring was distributed to PCCM program directors (PDs) at the 64 accredited fellowship training programs. Questions focused on demographics and the utilization of invasive and noninvasive monitoring for specific patient populations and disease states. Forty-two (66%) PDs responded to the survey. Capnography and near-infrared spectroscopy (NIRS) were the most commonly reported noninvasive monitoring technology. Arterial and central venous catheters were widely used. Other invasive monitoring devices were used sparingly. Despite widespread use of both invasive and noninvasive monitoring in academic pediatric critical care units across the United States, there is significant variability in the use of noninvasive monitoring compared with invasive monitoring. Further investigation is needed to define the standard of care for the use of noninvasive monitors as practitioners attempt to optimize care while minimizing risks and complications.

Is there still a role for high-frequency oscillatory ventilation in neonates, children and adults?

Critically ill patients with respiratory pathology often require mechanical ventilation and while low tidal volume ventilation has become the mainstay of treatment, achieving adequate gas exchange may not be attainable with conventional ventilator modalities. In attempt to achieve gas exchange goals and also mitigate lung injury, high frequency ventilation is often implemented which couples low tidal volumes with sustained mean airway pressure. This manuscript presents the physiology of high-frequency oscillatory ventilation, reviews the currently available data on its use and provides strategies and approaches for this mode of ventilation.