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Inspiratory pressures with CO2 stimulation and weaning from mechanical ventilation in children
D Gozal1, D Shoseyov, T G Keens
1Division of Neonatology and Pediatric Pulmonology, Childrens Hospital Los Angeles, CA 90027.
Insights
Breathing 5% carbon dioxide (CO2) significantly improved maximal respiratory pressures in infants and children, aiding in successful mechanical ventilation weaning. This method offers a reliable approach to establish weaning criteria for young patients unable to cooperate.
Area of Science:
- Pediatric critical care medicine
- Respiratory physiology
- Mechanical ventilation
Background:
- Assessing readiness for mechanical ventilation weaning in infants and children is challenging due to their inability to cooperate.
- Current weaning criteria rely on trial and error, lacking objective measures for this population.
- Maximal transdiaphragmatic (Pdimax) and airway occlusion pressures (PaOmax) are used in adults but are difficult to obtain reliably in non-cooperative children.
Purpose of the Study:
- To investigate if breathing carbon dioxide (CO2) can enhance respiratory drive and yield maximal respiratory pressure values in infants and children.
- To determine if CO2-stimulated pressures can aid in establishing reliable weaning criteria for prolonged mechanical ventilation in pediatric patients.
- To evaluate the efficacy of CO2 inhalation in improving Pdimax and PaOmax measurements for weaning assessment.
Main Methods:
- Measurements of tidal breathing and occluded Pdi and PaOmax were performed in 27 pediatric patients requiring prolonged assisted mechanical ventilation.
- Patients breathed spontaneously on 100% oxygen (O2), 5% CO2 in O2, and 7% CO2 in O2.
- Comparison of Pdimax and PaOmax values obtained under different gas mixtures to assess the effect of CO2.
Main Results:
- Patients achieved significantly higher Pdimax and PaOmax when breathing 5% CO2 compared to 100% O2 or 7% CO2.
- Breathing 5% CO2 resulted in higher Pdimax (73.2 cm H2O) and PaOmax (81.7 cm H2O) than other conditions.
- Seventy percent (19 out of 27) of patients were successfully weaned from mechanical ventilation within 3.2 weeks, with specific Pdimax criteria met in the 5% CO2 condition.
Conclusions:
- Inhaling 5% CO2 effectively maximizes respiratory drive and improves Pdimax and PaOmax measurements in infants and children.
- CO2-stimulated respiratory pressures provide objective and reliable data for establishing weaning criteria in pediatric patients.
- This method demonstrates high sensitivity and specificity for predicting successful weaning from mechanical ventilation in this challenging population.
Abstract:
Maximal transdiaphragmatic (Pdimax) and airway occlusion pressures (PaOmax) have been used to predict weaning from mechanical assisted ventilation in adults, but criteria for weaning are still based on trial and error in infants and young children. Because infants and young children cannot cooperate, crying Pdi and PaOmax against an occlusion have been used, but these may not yield maximal values. We hypothesized that breathing CO2 would achieve better Pdimax and PaOmax values by maximizing respiratory drive and help in establishing weaning criteria. To test this, we measured tidal breathing and occluded Pdi and PaOmax in 27 patients (mean age, 15.0 +/- 31.5 SD months) who required prolonged assisted mechanical ventilation and had failed previous weaning attempts. Measurements were performed while patients were breathing spontaneously 100% O2 and 5% and 7% CO2 in O2. The patients achieved higher Pdimax breathing 5% CO2 (73.2 +/- 24.4 cm H2O) than in O2 (61.6 +/- 24.4 cm H2O; p < 0.0001) or in 7% CO2 (69.1 +/- 23.4 cm H2O; p < 0.0001). They also achieved higher PaOmax in 5% CO2 (81.7 +/- 23.5 cm H2O) than with the other gases (69.9 +/- 25.5 in O2, and 77.5 +/- 24.1 in 7% CO2; p < 0.001); 19 patients (70%) were weaned from assisted ventilation within 3.2 +/- 1.9 wk. In 5% CO2, all patients who were weaned achieved Pdimax > 60 cm H2O and could sustain > 60% Pdimax for more than five successive occluded breaths (100% sensitivity; 100% specificity; p < 0.0005).(ABSTRACT TRUNCATED AT 250 WORDS)