PMCCPMCCPMCC

Search tips
Search criteria 

Advanced

 
Logo of archdischfnArchives of Disease in Childhood - Fetal & NeonatalVisit this articleSubmit a manuscriptReceive email alertsContact usBMJ
 
Arch Dis Child Fetal Neonatal Ed. 2007 November; 92(6): F444–F448.
Published online 2007 April 25. doi:  10.1136/adc.2006.103929
PMCID: PMC2675387

Cardiorespiratory effects of changes in end expiratory pressure in ventilated newborns

Abstract

Background

Positive pressure ventilation in premature infants can improve oxygenation but may diminish cerebral blood flow and cardiac output. Low superior vena cava (SVC) flow increases risk of intraventricular haemorrhage, and higher mean airway pressure is associated with low SVC flow. Whether this is a direct effect of positive pressure ventilation or a reflection of severity of lung disease is not known. This study aimed to determine if positive end expiratory pressure (PEEP) in ventilated newborns could be increased without clinically relevant cardiorespiratory changes.

Method

Ventilated newborns were studied before and 10 min after increasing PEEP (5 cm H2O to 8 cmH2O) and again when PEEP returned to baseline. Echocardiographic and respiratory function measurements were collected during the intervention.

Results

In 50 infants, increased PEEP was associated with a non‐significant difference in mean SVC flow of −5 ml/kg/min (95% CI −12 to 3 ml/kg/min) but a significant reduction in right ventricular output of 17 ml/kg/min (95% CI 5 to 28 ml/kg/min). The increase in lung compliance was non‐significant (median difference 0.02 ml/cmH2O/kg) and the decrease in lung resistance (18 cmH2O/l/s; 95% CI 10 to 26 cm H2O/l/s) was significant. Changes (%) in lung compliance and SVC flow, when corrected for Paco2, were positively associated (regression coefficient 0.4%; 95% CI 0.2% to 0.6%).

Conclusion

A short‐term increase in PEEP does not lead to significant changes in systemic blood flow, although 36% of infants in the present study had clinically important changes in flow (±25%). The intervention can improve dynamic lung function, especially airway resistance. Improvements in compliance tend to be associated with improvements in blood flow.


Articles from Archives of Disease in Childhood. Fetal and Neonatal Edition are provided here courtesy of BMJ Group