The clinical application and significance of TcpCO2 after weaning of machanical ventilation in very or extreme low birth weight infants

Objective To analysis the transcutaneous carbon dioxide pressure(TcpCO2)in very low birth weight infant (VLBW) and extremely low birth weight infant (ELBW) after the time of tube drawing, and further guidance the management of premature ventilator breathing. Methods Premature infants with gestational age less than 32 weeks, birth weight below 1 500 g, hospitalized from March 2016 to December 2018 in our hospital, who needed early mechanical ventilation due to respiratory distress within 24 hours after birth and intended to be withdrawn were enrolled.Fifty-five infants in the observation group were monitored by TcpCO2 and blood gas was collected at 1 h, 6 h, 12 h, 24 h, 48 h, and 72 h after weaning; 55 infants in the control group were collected arterial blood gas only.When TcpCO2 monitoring and PaCO2 indicated hypercapnia, clinical intervention was actively given.The value of blood gas PaCO2 in the two groups and the TcpCO2 value of the observation group were recorded at different time points (1 h, 6 h, 12 h, 24 h, 48 h, 72 h) after weaning, and the failure of weaning was recorded in both group. Results There was no significant difference in the general information (gender, gestational age, birth weight, and whether prenatal maternal glucocorticoids) between the two groups (P>0.05). There were no significant differences in mechanical ventilation time, noninvasive ventilation mode and time between the two groups(P>0.05). The failure rate of withdrawal within 24 h and 72 h was lower in the observation group than the control group[3.6% (2/55) vs.14.0% (8/55), 7.3% (4/55) vs. 21.0% (12/55)], the difference was statistically significant (P 0.05). The values of TcpCO2 and PaCO2 had no significant difference in the observation group at the same time point (P>0.05), and there was a correlation between them(r=0.761, P<0.05). Conclusion VLBW and ELBW undergoing mechanical ventilation are given continuous TcpCO2 monitorings after weaning, which not only has the characteristics of continuous and non-invasive monitoring, but also help to identify hypercapnia early and give symptomatic treatment, and reduce the incidence of weaning failure.And it proves a good correlation between TcpCO2 and PaCO2. Key words: Transcutaneous carbon dioxide pressure; Partial pressure of carbon dioxide; Extubation withdrawal; Very low birth weight infant; Extremely low birth weight infant