Effect of stepwise reduction in minute ventilation on PaCO2 in ventilated newborns.
Indian Pediatr
;
2004 Aug; 41(8): 779-85
Article
in English
| IMSEAR
| ID: sea-6900
ABSTRACT
OBJECTIVE:
To study the effect of step reduction of expired minute ventilation (MV) on PaCO2 in ventilated newborns and to determine whether MV within a defined range can predict PaCO2.DESIGN:
Prospective descriptive.SETTING:
Referral neonatal unit of a teaching hospital.METHODS:
Forty neonates stable on mechanical ventilation receiving minute ventilation in the range of 150-210 ml/kg/min. were studied. The spectrum of disorders for which the babies were ventilated included apnea of prematurity in 16, pneumonia in 14, meconium aspiration syndrome in 6 and hyaline membrane disease in 4. Median age at study was 6 days and median weight at study was 2.1 kgs. The MV was reduced from 210 to 150 mL/kg/min in three steps and concomitant PaCO2 was measured. Reductions were not done if PaCO2 was more than 50 mmHg. MVs were plotted against PaCO2 and a regression equation to predict PaCO2 from MV was calculated.RESULTS:
A stepwise increase was seen in CO2 with reduction of MV over the range studied. The median MV and median PaCO2 achieved in the three steps were 201 mL/kg/min and 36.7 mm of Hg, 180 mL/kg/min and 41.7 mm of Hg, 160 mL/kg/min, and 44.3 mm of Hg. The regression equation to predict PaCO2 was PaCO2 = 70 - 0.17 x MV in mL/kg/min, r = -0.45, r2 = 0.20, residual variance (s2) = 39.37; gave a predicted PaCO2 within 12.5 mmHg. for a given MV.CONCLUSION:
Reducing minute ventilation led to an increase in the levels of PaCO2. Minute volumes of 160 ml/kg/min correlated with PaCO2 value of 44.3 mm of Hg. MV as low as 160 mL/kg/min are well tolerated by newborns.
Full text:
Available
Index:
IMSEAR (South-East Asia)
Main subject:
Partial Pressure
/
Respiration, Artificial
/
Respiratory Tract Diseases
/
Blood Gas Analysis
/
Humans
/
Infant, Newborn
/
Carbon Dioxide
/
Tidal Volume
Language:
English
Journal:
Indian Pediatr
Year:
2004
Type:
Article
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