Pharyngeal pressure in preterm infants receiving nasal continuous positive airway pressure

Pharyngeal pressures in 11 preterm infants, receiving binasal Hudson prong continuous positive airway pressure (CPAP) pressurised by bubbling bottles, were measured. The mean (95% confidence interval) pressure drop from the prongs to the pharynx was 3.2 (2.6 to 3.7) cm H(2)O with mouths open and 2.2 (1.6 to 2.8) cm H(2)O with mouths closed. Mouth closure augments CPAP transmission.     

Tracheal colonization in preterm infants supported with nasal continuous positive airway pressure

Background: The aim of this study was to examine endotracheal bacteriological status in premature infants who are supported by nasal continuous positive airway pressure (CPAP) without any history of tracheal intubation. Methods: In this prospective study, we enrolled 60 premature infants with respiratory distress; of these, 30 were supported by CPAP without tracheal intubation, and 30 were intubated and mechanically ventilated. Infants were enrolled at a postnatal age of <24 h. Endotracheal (ET) cultures were taken at 24 h and at the 5th day of life. In the CPAP group, a suction catheter was sterilely inserted into the trachea while directly visualizing the vocal cords using a laryngoscope. Results: ET cultures taken on the 1st day of life showed colonization in 7/30 (23%) in the CPAP group versus 19/30 (63%) in the mechanically ventilated group (P= 0.002). Tracheal cultures on day 5 were positive in 5/30 (17%) and 11/30 (37%), respectively (P= 0.093). Klebsiella ssp. represented the most frequently isolated organism in both groups. A positive tracheal culture at 5 days was associated with a longer duration of respiratory support in the CPAP group (P= 0.05) but not in the ventilation group. Endotracheal culture at 5 days was associated with mortality in the ventilation group (8/11 vs 5/19, P= 0.02), but not in the CPAP group (1/5 vs 2/25, P= 0.45). Early endotracheal cultures did not relate with mortality in either of the groups. Conclusion: The trachea of premature infants supported with CPAP is at risk for bacterial colonization. Predisposing factors, mechanisms and clinical implications of these novel findings need to be studied.     

Long-term outcome of preterm infants treated with nasal continuous positive airway pressure

This study’s aim was to assess neurodevelopmental and growth outcome until the age of 4 years of premature infants placed on early nCPAP, in the setting of the neonatal intensive care unit (NICU) and follow-up program of the Division of Neonatology of the Department of Pediatrics of the University Hospital, Lausanne, Switzerland. All consecutive inborn infants weighing <1500 g or <32 weeks of gestational age admitted to the NICU during two periods of 12 months—7.1996–6.1997 and 7.1998–6.1999—were compared before and after the systematic application of early nCPAP. Of 172 infants admitted to the NICU, 150 (87%) survived. 126 (84%) were tested at 6 months’ corrected age, 121 (81%) at 18 months’ corrected age, and 117 (78%) at the age of 4 years. Detailed perinatal data were collected. Follow-up included neurological examination, developmental testing and measurement of growth parameters. Statistical analyses were performed. Early application of nCPAP and avoidance of mechanical ventilation showed no adverse effects on neurodevelopment and growth. A significantly higher developmental quotient was found in the nCPAP group at 18 months’ corrected age. Several trends were also noted in the nCPAP group with a decrease of intraventricular hemorrhage and in “abnormal neurodevelopment” at 6 months corrected age, a bigger head circumference at all different tested ages and a greater height at 6 and 18 months corrected ages. In conclusion, our study of developmental outcome documents the absence of any harmful effect of early application of nCPAP to treat respiratory failure in very low birthweight infants.     

In vitro comparison of nasal continuous positive airway pressure devices for neonates

OBJECTIVE: To compare the resistance in vitro of different devices used for the delivery of nasal continuous positive airway pressure (NCPAP) in neonates. DESIGN: Flows of 4-8 litres/min were passed through a selection of neonatal NCPAP devices (single prong, Duotube, Argyle prong, Hudson prong, Infant Flow Driver), and the resultant fall in pressure measured using a calibrated pressure transducer. RESULTS: The decrease in pressure (cm H(2)O) for each device (size in parentheses) at a constant flow of 6 litres/min was: Duotube: (2.5), 21; (3.0), 6.2; (3.5), 2.3; single prong: (2.5), 4.4; (3.0), 2.1; (3.5), 1.2; Argyle prong: (XS), 3.6; (S), 1.9; (L), 1.5; Hudson prong: (0), 3.1; (1), 1.8; (2), 0.6; (3), 0.4; (4), 0.3; Infant Flow Driver: (small), 0.3; (medium), -0.3; (large), -0.5. CONCLUSIONS: A large variation in the potential fall in pressure may occur in the clinical setting. Devices with short double prongs had the lowest resistance to flow. These results have implications in the selection of the optimal device/s for clinical application and for future comparisons in randomised trials of NCPAP in neonates.     

气泡式与鼻塞式持续气道正压通气在早产儿呼吸窘迫综合征的疗效比较

目的 比较气泡式持续气道正压通气（BNCPAP）与鼻塞式持续气道正压通气（nCPAP）在早产儿呼吸窘迫综合征（NRDS）呼吸支持中的疗效及安全性。方法 回顾性分析使用过BNCPAP（69例）或nCPAP（61例）呼吸支持的130例早产NRDS患儿的临床资料,比较两组的死亡率、呼吸支持时间、是否使用肺表面活性物质（PS）以及治疗失败、支气管肺发育不良（BPD）、早产儿视网膜病（ROP）的发生情况,和上机后血气分析的pH、氧分压、二氧化碳分压的变化情况,并评价其安全性。结果 BNCPAP、nCPAP两组患儿在性别分布、出生胎龄及体重、1 min及5 min Apgar评分及出生方式、NRDS严重程度等方面的差异无统计学意义（P > 0.05）。BNCPAP组无患儿死亡,nCPAP组有1例死亡,但两组病死率的差异无统计学意义（P > 0.05）。BNCPAP组及nCPAP组无创辅助通气的时长、治疗失败率、BPD和ROP的发生率以及需要使用或需要重复使用PS比例的差异均无统计学意义（P > 0.05）。两组患儿上机后8~12 h的pH值变化及氧合指数变化的差异无统计学意义（P > 0.05）,但BNCPAP组患儿的二氧化碳分压下降较nCPAP组患儿多（P < 0.05）。两组患儿气胸及鼻中隔、鼻黏膜损伤发生率的差异无统计学意义（P > 0.05）。结论 BNCPAP和nCPAP在早产儿NRDS呼吸支持中的疗效和安全性相近。     

Early nasal continuous positive airway pressure and low threshold for intubation in very preterm infants

AIM: To determine if selective intubation, use of early nasal continuous positive airway pressure (NCPAP) at birth with a low threshold for early surfactant treatment, reduces the need for intubation in very preterm infants in the first days after birth. METHODS: Two cohorts of very preterm infants < or = 32 weeks, born at the Leiden University Medical Center in the Netherlands, were compared retrospectively before (1996-1997) and after (2003-2004) introducing selective intubation and use of early NCPAP. A FiO(2)> or = 0.40 was used as criterion for intubation. Primary outcome measure was intubation < 72 h of age. Bronchopulmonary dysplasia (BPD) was a secondary outcome. RESULTS: The rate of intubation in the delivery room (69% vs. 46%, p < 0.001) and within 72 h of age (73% vs. 57%, p < 0.001) was lower following the change in policy. Early NCPAP was, in 2003-2004, increasingly used as primary treatment (10% vs. 33%, p < 0.001) with higher maximum NCPAP levels (4.0 (0.9) vs. 5.8 (1.5), p < 0.001). There was no change in BPD (14.3% vs. 15.2%, p = 0.82). CONCLUSION: Avoiding intubation by using early NCPAP while maintaining a low-threshold for surfactant treatment decreased the need for intubation.     

Influence of three nasal continuous positive airway pressure devices on breathing pattern in preterm infants

The pattern of breathing was studied in 13 premature newborns treated by variable-flow Nasal Continuous Positive Airway Pressure (NCPAP), conventional NCPAP, and nasal cannulae. Compared to constant-flow NCPAP and nasal cannulae, the variable-flow NCPAP increases tidal volume and improves thoraco-abdominal synchrony, suggesting that variable-flow NCPAP provides more effective ventilatory support than conventional NCPAP or nasal cannulae.     

Post-extubation prophylactic nasal continuous positive airway pressure in preterm infants: Systematic review and meta-analysis

OBJECTIVES: To determine whether management with nasal continuous positive airway pressure (NCPAP) in preterm infants having their endotracheal tube removed following a period of intermittent positive pressure ventilation (IPPV), leads to an increased proportion remaining free of additional ventilatory support, compared to extubation directly to headbox oxygen. METHODOLOGY: Search Strategy - Searches were made of the Oxford Database of Perinatal Trials, Medline, abstracts of conferences and symposia proceedings, expert informants, journal hand searching mainly in the English language and expert informant searches in the Japanese language. Selection criteria - All trials utilising random or quasi-random patient allocation, in which NCPAP (delivered by any method) was compared with headbox oxygen for postextubation care were included. Methodological quality was assessed independently by the two authors. Data collection and analysis - Data were extracted independently by the two authors. Meta-analysis using event rate ratios (ERRs) and event rate differences (ERDs) was performed using Revman 3.0 statistical software. Prespecified subgroup analysis to determine the impact of different levels of NCPAP and use of aminophylline were also performed using the same package. Similar analysis to investigate the effect of postnatal age on outcomes of interest was also undertaken. RESULTS: Nasal CPAP, when applied to preterm infants being extubated following IPPV, reduces the incidence of adverse clinical events (apnoea, respiratory acidosis and increased oxygen requirements) indicating the need for additional ventilatory support. This result is both statistically significant and clinically important; ERR, 0.62 (0.49, 0.79) and ERD, - 0.175 (- 0.256, - 0.095). A trend towards reduction in the incidence of oxygen dependency at 28 days of age is also seen in the group extubated to NCPAP; ERR, 0.86 (0.67, 1.10) and ERD, - 0.069 (- 0.177, 0.039). CONCLUSION: Nasal CPAP is effective in preventing failure of extubation in preterm infants following a period of endotracheal intubation and IPPV. Further definition of the patient gestational age and weight groups to whom these results apply is required. Optimal levels of NCPAP as well as methods of administration remain to be determined.     

Early prediction of nasal continuous positive airway pressure failure in preterm infants less than 30 weeks gestation

Aim: To predict early nasal continuous positive airway pressure failure within the first 2 h after birth in preterm infants. Methods: Patient and respiratory support variables significantly associated with continuous positive airway pressure failure in the first 72 h after birth were identified in a cohort of preterm infants <30 weeks gestation. Using multivariable logistic regression analysis, risk estimates for early nasal continuous positive airway pressure failure were calculated. Results: From 182 infants included, 62(34%) failed early nasal continuous positive airway pressure. Birth weight ≤800 g, male gender and a fraction of inspired oxygen >0.25 at 1 and 2 h of age were significantly associated with early nasal continuous positive airway pressure failure. Combining these variables in a logistic regression model provided a minimal risk estimate for failure of 0.04[0.01–0.23] (female >800 g, FiO₂ ≤ 0.25 at 1, and 2 h) and maximal estimate of 0.92[0.44–0.99] (male ≤800 g, FiO₂ > 0.25 at 1 and 2 h). Conclusion: Combining gender, birth weight and the fraction of inspired oxygen at 1 and 2 h of age allows for a better and more individualized prediction of early nasal continuous positive airway pressure failure in preterm infants less than 30 weeks gestation.     

A randomised control study comparing the Infant Flow Driver with nasal continuous positive airway pressure in preterm infants

OBJECTIVE: To compare the effectiveness of the Infant Flow Driver (IFD) with single prong nasal continuous positive airway pressure (nCPAP) in preterm neonates affected by respiratory distress syndrome. DESIGN: Randomised controlled study. PATIENTS: Between September 1997 and March 1999, 36 preterm infants who were eligible for CPAP treatment were randomly selected for either nCPAP or IFD and studied prospectively for changes in oxygen requirement and/or respiratory rate. The requirement for mechanical ventilation, complications of treatment, and effects on mid-term outcome were also evaluated. RESULTS: Use of the IFD had a significantly beneficial effect on both oxygen requirement and respiratory rate (p < 0.0001) when compared with nCPAP. Moreover, O(2) requirement and respiratory rate were significantly decreased by four hours (p < 0.001 and p < 0.03 respectively). The probability of remaining supplementary oxygen free over the first 48 hours of treatment was significantly higher in patients treated with the IFD than with nCPAP (p < 0.02). IFD treated patients had a higher success (weaning) rate (94% v 72 %) and shorter duration of treatment (49.3 (31) v 56 (29.7) hours respectively; mean (SD)), although the difference was not significant. CONCLUSIONS: IFD appears to be a feasible device for managing respiratory distress syndrome in preterm infants, and benefits may be had with regard to oxygen requirement and respiratory rate when compared with nCPAP. The trend towards reduced requirement for mechanical ventilation, shorter clinical recovery time, and shorter duration of treatment requires further evaluation in a multicentre randomised clinical trial.     

Predictors of failure of nasal continuous positive airway pressure in treatment of preterm infants with respiratory distress syndrome

A case-control study was carried out on 97 consecutive preterm (< 37 weeks) infants to determine predictors associated with failure of nasal continuous positive airway pressure (CPAP) in the treatment of respiratory distress syndrome (RDS). Logistic regression analysis showed that only three risk factors were significantly associated with failed CPAP. These were: moderate or severe RDS (odds ratio: 5.9; 95 per cent confidence interval (CI): 2.2-16.0); septicemia during CPAP therapy (OR: 8.8; 95 per cent: CI 1.5-50.7); and pneumothorax during CPAP therapy (odds ratio: 6.9; 95 per cent: CI 1.1-41.7).     

Early rescue administration of surfactant and nasal continuous positive airway pressure in preterm infants <32 weeks gestation

Objective  

This study reports our institutional experience on the outcome after prophylactic and early rescue endotracheal instillation of surfactant within 20 minutes of birth, followed by extubation and nasal continuous positive airway pressure (NCPAP) in preterm infants <32 weeks gestational age.     

鼻塞式同步间歇指令通气和持续气道正压通气在早产儿呼吸窘迫综合征中的应用比较

目的：比较鼻塞式同步间歇指令通气(nSIMV)和鼻塞式持续气道正压通气（nCPAP）在早产儿呼吸窘迫综合征（RDS）中的临床应用效果。方法：50例RDS早产儿,常规使用肺表面活性物质进行替代治疗后,随机分入nSIMV组或nCPAP组,观察治疗后临床症状和血气指标的变化。结果：nSIMV组需气管插管行呼吸机通气比率明显低于nCPAP组（24% vs 60%, P<0.05）;nSIMV组CO2潴留和低氧血症的比率分别为12%和24%,明显低于nCPAP组的40%和36%（P<0.05）。结论：nSIMV能更有效地对RDS早产儿进行呼吸支持治疗。［中国当代儿科杂志,2010,12（7）：524-526］     

Sustainable use of continuous positive airway pressure in extremely preterm infants during the first week after delivery

BACKGROUND: Early use of nasal continuous positive airway pressure (nCPAP) may reduce lung damage, but it is not clear how many extremely preterm infants can be cared for without mechanical ventilation on the first days after delivery. OBJECTIVES: To describe our experience of nCPAP in infants born at <27 weeks' gestation and to determine the chance of reintubation of this group of extremely preterm infants. METHODS: A retrospective, observational study examined the period from November 2002 to October 2003, when efforts were made to extubate infants to nCPAP at the earliest opportunity. Data were collected on all infants born at <27 weeks' and gestation admitted to The Neonatal Intensive Care Unit, Queen Charlotte's and Chelsea Hospital, London, UK. The chance of an individual infant requiring reintubation within 48 h of delivery was estimated, calculating the predictive probability using a Bayesian approach, and oxygen requirements at 36 weeks' postmenstrual age were examined. RESULTS: 60 infants, 34 inborn and 26 ex utero transfers, were admitted; 7 infants admitted 24 h after birth were excluded and 5 died within 48 h. The mean birth weight was 788 g and the gestational age was 25.3 weeks. Extubation was attempted on day 1 in 21 of 52 infants on ventilators and was successful in 14; and on day 2 in 14 of 35 and successful in 10 of infants extubated within 48 h of delivery survived to discharge. 5 of 23 infants on mechanical ventilation at 48 h of age were on air at 36 weeks postmenstrual age, and 12 of 26 of those were on nCPAP at 48 h of age. The probability of an individual baby remaining on nCPAP was 66% (95% CI 46% to 86%) on day 1 and 80% (95% CI 60% to 99%) on day 2. The smallest infant to be successfully extubated was 660 g and the youngest gestational age was 23.8 weeks. CONCLUSIONS: Extremely preterm infants can be extubated to nCPAP soon after delivery, with a reasonable probability of not requiring immediate reintubation.     

双管鼻塞式CPAP在早产儿肺透明膜病和新生儿呼吸衰竭中应用

目的探讨双管鼻塞式CPAP对早产儿肺透明膜病(HMD)和新生儿呼吸衰竭的治疗价值。方法对NICU住院的11例HMD和19例不同原因引起的的新生儿呼吸衰竭患儿使用双管鼻塞式CPAP进行治疗,观察治疗前后临床症状、血气指标和胸片改善情况。结果30例患儿除2例治疗无效改用气管插管机械通气外,余28例治疗前后临床症状和血气指标均有明显改善。11例HMD患儿经CPAP治疗后,除1例27周超早产儿无改善外,余10例治疗前后胸片透亮度有明显增加,治疗前后血气指标PaCO2改善较快。结论带空氧混合器和湿化的双管鼻塞式小儿CPAP系列持续正压通气系统对HMD和新生儿呼吸衰竭具有明显的治疗效果,在用氧安全和减少CO2潴留方面具优越性。