ABSTRACT
Objective To reduce the incidence of the hypocapnia,the cutoff value of the end-tidal carbon dioxide partial pressure[Pet(CO2)] for predicting the hypocapnia so as to understand the suitable adjustment target and target range of the Pet(CO2) in preterm infants under mechanical ventilation.Methods From Jan.2012 to Oct.2013,96 cases of the preterm infants with respiratory distress syndrome(RDS) who needed mechanical support were selected from the Huaian Maternity and Child Health Care Hospital.Pet(CO2) value of each time point(1 h,24 h,48 h and 72 h after mechanical ventilation) were recorded,while radial artery blood was collected for blood gas analysis.The level of pa (CO2) ＜ 35 mmHg(1 mmHg =0.133 kPa) diagnosed hypocapnia;while the level of Pa (CO2) ＞ 60 mmHg was for diagnosing hypercapnia.The diagnostic cutoff and the suitable adjustment target and adjustment target range of the Pet(CO2) were confirmed by receiver operating characteristic (ROC) curve.Results The data from 381 arterial blood gas analysis results were gained,of which 151 times belonged to hypocapnia,and the rate was 39.6％,the other 230 cases were normal,and no case was of hypercapnia.The area under the ROC curve was 0.895,and the area of the standard error was 0.016.There was a statistical significance in Pet(CO2) value for the diagnosis of hypocapnia(P =0.000).The lower the value of Pet (CO2),the greater the likelihood of hypocapnia,and 95 ％ confidence interval area was 0.864-0.926.The Pet (CO2) optimal diagnostic cutoff value determined in accordance with Youden index was 30.5 mmHg.When Pet (CO2) among 41.5 mmHg,sensitivity was 100％.Conclusions Diagnostic cutoff value for forecasting hypocapnia is 30.5 mmHg.The suitable adjustment target of mechanical ventilation parameter adjustment is 41.5 mmHg for the Pet(CO2).The target range of mechanical ventilation parameter adjustment is 30.6-41.5 mmHg for the Pet(CO2).
ABSTRACT
Objective To explore the clinical significance of Downes score in predicting respiratory failure (RF) in term neonates.Methods From June 1, 2011 to December 31, 2013, 243 hospitalized term neonates with dyspnea, who were born at 37 to 42 gestational age and admitted to the hospital within 24 h after birth, were selected from Neonatal Medical Center of Huai'an Maternity and Child Healthcare.Downes scores were evaluated based on five indicators including respiratory rate, skin color, three depressions sign, moaning and lung breath sounds at the time of admission.RF was diagnosed based on clinical menifestations and radial arterial blood gas analysis.Receiver operating characteristic (ROC) curve analysis was performed to evaluate the predictive value of Downes score on RF.Results The average Downes score of the 243 cases was 6.57±0.86 and the RF rate was 69.6％ (169/243).The RF rate was 93.4％ (169/181) when Downes score ≥ 4.5, with the sensitivity, specificity, misdiagnostic rate and missed diagnositic rate of 100.0％, 83.8％, 16.2％ and 0.0％, respectively.While, the RF rate was 80.7％ (130/161) when Downes score ≥ 5.5, with the sensitivity, specificity, misdiagnostic rate and missed diagnositic rate of 76.9％, 58.1％, 41.9％ and 23.1％, respectively.When Downes score ≥ 6.5, the incidence of RF was 97.6％ (123/126), with the sensitivity, specificity, misdiagnositic rate and missed diagnositic rate of 72.8％, 95.9％, 4.1％ and 27.2％, respectively.The cutoff value was 6.5 according to the Youden Index, which with lower rate of misdiagnosis and missed diagnosis.When Downes score ≥ 7.5, the incidence of RF was 100.0％(22/22), with the sensitivity, specificity, misdiagnositic rate and missed diagnosis rate of 13.1％, 100.0％, 0.0％ and 87.0％, respectively.The area under the ROC curve was 0.906 (95％CI: 0.866-0.955).The higher the Downes score, the greater the possibility of RF (P=0.000).Conclusions Dynamic Downes scores in term neonates with dyspnea could predict the risk of RF.The higher the Downes score, the greater the possibility of RF.