Clinical characteristics of severe meconium aspiration syndrome / 소아과

PURPOSE: This study aims to describe the clinical characteristics of severe meconium aspiration syndrome (MAS) which required mechanical ventilation over 48 h and to delineate the progress of respiratory failure and radiographic findings in severe MAS. METHODS: Twelve infants admitted to the Neonatal Intensive Care Unit (NICU) of the Seoul National University Bundang Hospital diagnosed with severe MAS from January 2004 to July 2007 were analyzed retrospectively. RESULTS: The presence of persistent pulmonary hypertension of the newborn (PPHN) is the only independently significant risk factor for a longer hospital stay and longer duration of mechanical ventilation. Surfactant replacement therapy (SRT) was not randomized but only performed in infants with radiographic findings for respiratory distress syndrome (RDS). In the presence of radiographic findings for RDS, the duration of high-frequency oscillatory ventilation was significantly longer. PPHN developed in 8 infants (75%). The PPHN group had a significantly longer duration of mechanical ventilation. All infants who received SRT showed radiographic improvement within 12 h, but there was no significant change in the severity score during the same period. Infants without the PPHN complications showed significant decrease in the severity score within 12 h after SRT, whereas infants with PPHN complications did not. CONCLUSION: The clinical course of severe MAS differed significantly depending on the development of PPHN. SRT conferred radiographic improvement in infants who showed radiographic findings for RDS, but did not influence the clinical course of MAS significantly.

The outcome of surfactant replacement therapy in above nearterm neonates with severe pulmonary disease / 소아과

PURPOSE: We performed this study to investigate the outcome of surfactant replacement therapy (SRT) in above nearterm neonates who were required mechanical ventilatory care due to meconium aspiration pneumonia (MAP), respiratory distress syndrome (RDS) or other severe pneumonia (PN). METHODS: 48 patients, gestational period 36 weeks, who were admitted in NICU of Dongsan Medical Center, Keimyung University between July 1999 and June 2004 were enrolled. They were divided into three groups, MAP group (15 cases), RDS group (27 cases) and PN group (6 cases). All patients were received SRT and evaluated several clinical data (gestational age, oxygen index, duration of ventilator care) and outcome (complications and mortality rate) between pre-SRT and post-SRT. The mean dose of surfactant (modified bovine surfactant, Newfacten, Yuhan Co., Seoul, Korea) was 120 mg/kg. RESULTS: Among each groups, mean pre-SRT OI was higher in MAP group (213.2) than other groups, mean duration (days) of ventilatory care and oxygen therapy were similar distributions. Compared with pre-SRT values, significant improvements (P<0.05) in mean values for FiO2 and oxygenation index were documented at 12 hours after SRT. Early complications (persistent pulmonary hypertension of newborm, pneumothorax) and survival rate were lower in MAP group. Within RDS group, earlier SRT (given before 12 hours of life) revealed significantly lower early complication rate than later SRT (given after 12 hours of life) (13.3% vs 58.3%, P<0.05) CONCLUSION: Our study suggested that SRT seems to be an effective therapy in above nearterm neonates with severe pulmonary disease, and earlier SRT tends to reduce complications in RDS group than later therapy.

Comparison of Clinical Progress between Single- and Multiple-dose Surfactant Treatment in Neonatal Respiratory Distress Syndrome / 소아과

PURPOSE: In the case of serious respiratory distress syndrome (RDS) or relapse of clinical appearances after single treatment, we obtained more effective results with multiple-dose surfactant replacement therapy. We carried out this investigation for comparing and observing clinical progress between single-dose (group S) and multiple-dose (group M) pulmonary surfactant treatment group of neonatal RDS. METHODS: We investigated 48 neonates who were diagnosed as RDS and treated with pulmonary surfactant (PS) replacement therapy in NICU of Kyunghee University hospital from January 2002 to March 2004, then we compared and verified clinical progress of 32 neonates in group S with that of 16 neonates in group M. RESULTS: There were no significant statistical differences in average birth weights, average gestational periods, initial pH values of birth, whether operation of resuscitation at that time of birth was made or not, whether prenatal steroid prescription for mother, RDS classification standardized by Bomsel, and ventilation index (VI) before instillation of PS of two groups. However, there was significant statistical difference in a/A PO2 (P< 0.05). We could observe changes of VI and a/A PO2 within 72 hours have been continuously improved at group S rather than group M. In spite of relapses, group M changed for the better after second dose. There were also no significant differences between the two groups in duration of ventilator therapy, mortality within 28 days after birth, intraventricular hemorrhage by complication, retinopathy of premature, necrotizing enterocolitis, chronic lung diseases, sepsis, and DIC. CONCLUSION: In these relapse cases, as there were no significant differences in the mortality rate and the occurence of complication between group S and group M, the requirement of multiple-dose PS replacement therapy which brought improvement of prognosis was emphasized.

Perinatal Factors Influencing Clinical Response to Surfactant Replacement Therapy in Neonates with Respiratory Distress Syndrome

PURPOSE: Surfactant replacement therapy significantly decreases neonatal complications and mortality in neonates with respiratory distress syndrome (RDS), but clinical responses to the treatment is not consistent. An analysis of the perinatal factors influencing the clinical response to the therapy is important for early detection of high risk and prognosis. The purpose of this study is to analyze the clinical responses to the therapy and to assess the perinatal factors influencing the clinical response. METHODS: From April 1992 to Dec. 1995, 80 infants were enrolled in this study. Medical records were reviewed, and the clinical response to the therapy was defined by a change in the ventilatory index (VI). The perinatal factors were compared according to the clinical response. RESULTS: "Good" response was found in 58 infants (72.5%), "poor" in 14 infants (17.5%), and eight infants (10%) had a "relapse". The factor affecting the response to the therapy in the comparison among the three groups was pretreatment VI, reflecting the severity of the underlying disease. In the comparison between the initial response group and initial non-responders, pretreatment FiO2, pretreatment arterial pH, a/APO2, and VI were significantly different. With control of compounding variables, only pretreatment VI was a significant independent risk factor of the "poor" response. CONCLUSION: The clinical response to surfactant replacement therapy is only influenced by the severity of RDS. According to the results, we speculate that the dosage of surfactant in high pretreatment VI is needed to be increased, and further studies are required to determine the adequate dosage of surfactant in high risk infants.

Prognostic Factors for Mortality in Neonates with Respiratory Distress Syndrome After Surfactant Replacement Therapy

PURPOSE: To evaluate the association between neonatal mortality and the initial response to surfactant replacement therapy, and to examine the correlation between the response type and other prognostic factors. METHODS: Sixty-seven neonates with respiratory distress syndrome (RDS) were divided into two groups; group I (n=51) who survived and group II (n=16) who died within the first 28 days of life after one trial of surfactant therapy. We observed the serial changes of several respiratory indices within the first 24 hours following surfactant therapy and performed a multiple linear logistic regression analysis to evaluate significant prognostic factors that reflected neonatal mortality. RESULTS: In group II, fraction of inspired oxygen (FiO2), respiratory rate (RR), peak inspiratory pressure (PIP), and mean airway pressure (MAP) were significantly higher for 24 hours after surfactant therapy (P<0.05). The mean serum pH was significantly lower before and at 30 minutes and 6 hours after surfactant administration (P<0.05), but mean PaCO2 was higher (P<0.05). Ventilation index (VI) and oxygenation index (OI) were higher before and for 1 day after surfactant therapy (P<0.05), but arterial/alveolar oxygen tension ratio (a/APO2) was lower (P<0.05). In multiple linear logistic regression analysis, birthweight, MAP and VI at 6 hours and PIP at 12 hours were significant indicators of neonatal mortality after surfactant replacement therapy (P<0.05). CONCLUSION: The response to surfactant treatment within the first 24 hours may be also a significant prognostic indicator for neonatal mortality as other factors are, such as birthweight.

Sequential Changes of Chest Radiographic Finding after Exogenous Surfactant Replacement Therapy in Neonates with RDS

PURPOSE: The chest radiograph is useful and reliable in assessing the severity and progression of neonatal respiratory distress syndrome. To evaluate the effect of exogenous surfactant r eplacement therapy, we performed sequential observation of chest radiogratphic findings in neonates with respiratory distress syndrome. METHODS: Two groups of infant with RDS in mechanical ventilation therapy were studied. Surfactant(S-Tx) group(n=36) was treated with Surfactant-TA and control group(n=19) was without use of surfactant. Observation of gestational age, birth weight, clinical severity by ventilatory index, sequential change of radiographic findings and radiological complications in RDS patients were performed. RESULTS: In RDS patients, there was correlation in the radiologic grading and clinical severity. In surfactant treated infants, change of chest radiographic finding was significantly improved than control group. Incidence of pneumothorax and or pulmonary interstial emphysema in S-Tx group was less than that of control group. CONCLUSIONS: Exogenous pulmonary surfactant replacement therapy may contribute the improvement of the clinical and radiological severity and reduction of the incidence of clinical complications. We suggest that surfactant replacement therapy is effective and important useful therapeutic method in neonates with respiratory distress syndrome.

Exogenous surfactant replacement therapy of hyaline membrane disease in premature infants

We conducted a clinical trial to assess whether surfactant-TA given within the first six hours of life could improve oxygenation and reduce the ventilatory support in premature infants with hyaline membrane disease (HMD) during the first 24 hours of life. Eight premature infants with severe HMD requiring ventilation were treated, at a mean age of 2.72 hours, with a single intratracheal instillation of surfactant-TA (120 mg/kg). Arterial oxygenation improved dramatically as reflected by the increase of the a/A PO2 ratio and PaO2 to about 2 times the pretreatment values within 3 hours after surfactant treatment. And thus, oxygen concentrations (FiO2) could be reduced and remained significantly lower than pretreatment values during the first 24 hours after treatment. Infants given surfactant-TA required lower mean airway pressure (MAP) and had a significantly decreased ventilatory index (VI) during the first 24 hours after treatment, which reflect the decreased requirement for ventilatory support. Chest radiograph scores significantly improved within 24 hours after treatment compared with pretreatment scores. In this trial, we found that a single intratracheal dose of surfactant-TA given to infants with HMD resulted in improved respiratory status and radiographic findings during the first 24 hours after treatment.

Exogenous surfactant replacement therapy of hyaline membrane disease in premature infants

We conducted a clinical trial to assess whether surfactant-TA given within the first six hours of life could improve oxygenation and reduce the ventilatory support in premature infants with hyaline membrane disease (HMD) during the first 24 hours of life. Eight premature infants with severe HMD requiring ventilation were treated, at a mean age of 2.72 hours, with a single intratracheal instillation of surfactant-TA (120 mg/kg). Arterial oxygenation improved dramatically as reflected by the increase of the a/A PO2 ratio and PaO2 to about 2 times the pretreatment values within 3 hours after surfactant treatment. And thus, oxygen concentrations (FiO2) could be reduced and remained significantly lower than pretreatment values during the first 24 hours after treatment. Infants given surfactant-TA required lower mean airway pressure (MAP) and had a significantly decreased ventilatory index (VI) during the first 24 hours after treatment, which reflect the decreased requirement for ventilatory support. Chest radiograph scores significantly improved within 24 hours after treatment compared with pretreatment scores. In this trial, we found that a single intratracheal dose of surfactant-TA given to infants with HMD resulted in improved respiratory status and radiographic findings during the first 24 hours after treatment.

ISOLATION OF BOVINE PULMONARY SURFACTANT AND ANALYSIS OF ITS CHEMICAL COMPOSITION AND PHYSICOCHEMICAL PROPERTIES / 第二军医大学学报

Bovine pulmonary surfactant was obtained by endotracheal lavage of lungs from newly slaughtered calves followed by differential centrifugation.Lipid extracts of bovine surfactant contained 86.1?2.1% "of phospholipids (X?SD) , 1.8?1.1%of protein and smaller amounts of cholesterol, fatty acids, glycerides and carbohydrate. Phosphatidylcholine(83.4?5.6%)accounted for most of the phospholipids, of which disaturated phosphatidylcholine was 76.0? 4.7% .The physicochemical properties of bovine surfactant were measured with a modified Wilhelmy film balance made by the authors.The minimum surface tension was 2.4?1.5mN/m, stability index was 1.78?0.15, surface compresibility at 10mN/m was 0.022?0.004 m/mN, and surface concentration of phospholipids at 10mN/m was 1.112?0.283 nmol/cm2. The surfactant spread rapidly and could be quickly absorbed to the surface of the water.The results show that the bovine pulmonary surfactant we isolated is able to meet the criteria for investigations of surfactant replacement therapy.