Effect of nasal continuous positive airway pressure and Bi-phase positive airway pressure on oxygen exchange indexes in newborns with mild to moderate neonatal respiratory distress syndrome / 中华实用儿科临床杂志

Objective To observe the effect of nasal continuous positive airway pressure (nCPAP) and Biphase positive airway pressure (BIPAP) on the oxygen exchange indexes in newborns with mild to moderate neonatal respiratory distress syndrome (NRDS).Methods After infusion of pulmonary suffactant into lung bilaterally,116 cases with mild to moderate NRDS were treated with nCPAP(nCPAP group,n =75) and BIPAP(BIPAP group,n =41) respectively.Oxygen exchange indexes including arterial partial pressure of oxygen [pa (O2)],modified oxygenation index (P/F),alveolar-arterial oxygen tension difference (A-aDO2),respiratory index (RI),artery/alveolar oxygen partial pressure ratio[pa (O2)/pA (O2)] and pulmonary shunt fraction (Qs/Qt) were measured or calculated at 0 (before treatment),2,8 and 24 h after being treated with nCPAP or BIPAP.Results Six different oxygen exchange indexes of Pa (O2),P/F,A-aDO2,RI,pa (O2)/pA(O2) and Qs/Qt in both groups didn't show statistical significance at 0 hour:pa(O2) (kPa) (6.1 ±0.6 vs 6.1 ±0.6,t =0.11,P ＞0.05),P/F(kPa) (15.59 ± 1.45 vs 15.71 ± 1.45,t =1.59,P ＞ 0.05),A-aDO2(kPa)(6.04 ±0.64 vs 6.24 ±0.69,t =1.59,P ＞0.05),RI(6.0 ± 1.0 vs 6.2 ± 1.1,t =1.35,P ＞ 0.05),p,(O2)/pA(O2) (0.24 ±0.02 vs 0.25 ±0.03,t =1.63,P ＞0.05)and Qs/Qt(％)(11.9±1.6 vs 11.6 ± 1.6,t =1.10,P ＞ 0.05).A-aDO2,RI,pa (O2)/pA (O2) and Qs/Qt of BIPAP group had more improvement than those of nCPAP at 2 and 24 h,and oxygen exchange indexes at 2 h of BIPAP group and those of nCPAP group were:A-aDO2 (kPa) (3.83 ±0.49 vs 4.24 ± 0.67,t =18.26,P ＜ 0.05),RI(2.7 ± 0.5 vs 3.3 ±0.7,t =20.59,P ＜ 0.05),p,(O2)/pA(O2) (0.35 ±0.03 vs 0.32 ±0.04,t =15.35,P ＜0.05) and Qs/Qt(％) (8.8 ± 1.6 vs 9.8 ±2.0,t =7.68,P ＜ 0.05) ; 24 h indexes in BIPAP group and the indexes of nCPAP group were:A-aDO2 (kPa) (2.29 ± 1.19 vs 3.07 ± 1.67,t=18.43,P ＜0.05),RI(1.4 ±1.4 vs 2.3 ± 1.6,t=25.02,P ＜0.05),pa(O2)/pA(O2) (0.49 ±0.10 vs 0.42 ±0.11,t =14.96,P ＜0.05) and Qs/Qt(％) (6.5 ±3.0 vs 8.5 ±4.4,t =9.59,P ＜0.05).pa(O2) and P/F of both groups didn't show statistical difference significantly [Pa (O2)(kPa) (12.6 ± 1.0 vs 12.7 ± 1.0,t =3.76,P ＞ 0.05),P/F(28.49 ± 3.17 vs 31.85 ± 2.85,t =3.76.P ＞ 0.05)].Nineteen cases in nCPAP group needed invasive mechanical ventilation,and only 3 cases in BIPAP group underwent the procedure;there was a significant difference (x2 =4.01,P ＜ 0.05).Oxygen exchange indexes in both groups were gradually improved from 2 h,8 h to 24 h,but 22 deteriorated cases showed no improvement,who underwent invasive ventilation.Positive end-expiratory pressure (PEEP) positive airway pressure (EPAP) was (0.42 ± 0.19) kPa in BIPAP group,and (0.56 ± 0.23) kPa in nCPAP group (t =3.45,P ＜ 0.01).Conclusions 1.BIPAP and nCPAP can improve the ability of oxygen exchange in newborns with mild to moderate NRDS,but BIPAP is more effective than nCPAP,which can shorten the possibility of invasive ventilation and reduce the PEEP level.2.p,(O2),P/F,pa (O2)/pA (O2) and RI may be more suitable for evaluating oxygen exchange for neonatal NRDS.

The Effect of Positioning with Mechanically Ventilatory Acute Respitatory Failure Patients on Arterial Oxygen Partial Pressure and Alveolar-arterial Oxygen tension / 성인간호학회지

It is widely recognized that manipulation of body position takes advantage of the influences of gravity for improving oxygenation. The study aims to determine the effects of positioning(supine, prone, right lateral decubitus and left lateral decubitus positions) applied to the mechanically ventilatory acute respiratory failure patients on arterial oxygen partial pressure(PaO2), alveolar arterial oxygen tension difference(AaDO2), mean aterial pressure, peak inspiratory pressure and plateau pressure. Thirty two acute respiratory failure patients admitted to the medical intensive care unit at Kangnam St. Mary's Hospital, The Catholic University of Korea from March 1997 to January 1998, were divided into three groups by radiographic evidence of unilateral or bilateral lung disease. In group 1 with dominant right lung disease were twelve subjects, group 2 with dominant left lung disease had eight subjects and group 3 had twelve subjects with bilateral lung disease. The variables were measured in 30 minutes after each position of supine, prone, good lung down lateral decubitus and sick lung down lateral decubitus position. The position order was done at random by Latin squre design. The results are as follows; 1) With group 1 patients, the PaO2 in the left lateral decubitus and prone position were 126.8+/-30.8 mmHg and 106.7+/-36.8 mmHg, respectively(p=0.0001). 2) With group 2 patients, the PaO2 in the prone and the right lateral decubitus position were 121.7+/-44.7 mmHg and 118.5+/-31.7 mmHg, respectively (p=0.0018). 3) With group 3 patients, the PaO2 was 143.6+/-36.6 mmHg in the prone position (p=0.0001). 4) With group 1 patients, the AaDO2 in the left lateral decubitus and the right lateral decubitus position were 178.1+/-29.7 mmHg and 233.1+/-24.4 mmHg, respectively(p=0.0001). 5) With group 2 patients, the AaDO2 in the prone and the left lateral decubitus postion were 184.0+/-39.5 mmHg and 231.0+/-23.9 mmHg, respectively(p=0.0019). 6) With group 3 patients, the AaDO2 in the prone and the supine postion were 377.1+/-35.6 mmHg and 435.7+/-13.1 mmHg, respectively (p=0.0001). 7) There were no differences among the mean arterial pressure, peak inspiratory pressure and plateau pressure for each of the supine, prone, left lateral decubitus and right lateral decubitus position. The results suggest that oxygenation may improve in mechanically ventilatory patients with unilateral lung disease when the position is good lung dependent and prone, and patients with bilateral lung disease when the position is prone without any effects on the mean arterial pressure and airway pressure. It is suggested that body positions improve ventilation/perfusion matching and oxygenation need to be specified in patient care plans.

Effect of Changes in Fraction of Inspired Oxygen(F1O2) on Pulmonary Shunt Ratio in Respiratory Intensive Care / 대한마취과학회지

For the purpose of recommending appropriate fraction of inspired oxygen(F1O2) for long term mechanical ventilation support by evaluating the effect of changes in F1O2 on pulmonary shunt ratio in respiratory intensive care, the effects of various F1O2 on pulmonary shunt ratio were investigated and analysed with 20 pediatric intensive care patients who had received open heart surgeries for their congenital heart diseases in the department of Pediatrics, Seoul National University Hospital. The results were as follows ; 1. Through the whole process of control of mechanical ventilation the arterial CO2 tension(PaCO2) showed hyperventilation with the average of 31-34mmHg and pH showed pure respiratory alkalosis with the average of 7.45-7.51. As the fraction of inspired oxygen decreased, the arterial oxygen tension decreased. 2. Inspite of the change of F1O2, analysis of central venous blood gas showed no significant change. 3. The alveolar-arterial oxygen tension difference(AaDO2) was positively related to F1O2. 4. The pulmonary shunt ratio(Q's/Q'T) showed no significant difference in the F1O2 range of 0.6 to 1.0. But the Q's/Q'T in the F1O2 range of 0.3 to 0.4 decreased significantly comparing to that of 0.6 to 1.0 F1O2 range. Linear regression analysis of Q's/Q'T showed that the Q's/Q'T was positively related to F1O2 and AaDO2, respectively.