Surfactant replacement therapy in neonatal respiratory distress syndrome

We conducted a prospective, randomized, controlled trial comparing the efficacy of two doses of a reconstituted bovine surfactant (Surfactant TA) in premature infants requiring mechanical ventilation shortly after birth for respiratory distress syndrome. Forty-six infants weighing 1000–1499 g were randomized into two groups: a low-dose group (23 infants given a single dose of 60 mg surfactant lipid/kg) and a high-dose group (23 infants given a single dose of 120 mg/kg). The mean (SD) age at which surfactant was given was 5.5 (±1.2) h in the low-dose group and 6.0 (±1.5) h in the high dose group. Both treatments improved oxygenation (increased arterial-alvcolar PO₂ ratio) with decreased mean airway pressure, the high-dose surfactant having a more beneficial effect in prolonging the response. Infants in the high-dose group had significantly less (P<0.05) incidence of both intraventricular haemorrhage and bronchopulmonary dysplasia. This prospective trial documents that a greater benefit can be obtained by increasing the dose of surfactant (120 mg/kg) beyond 60 mg/kg in the treatment of premature infants with severe respiratory distress syndrome (RDS).Abbreviations RDS respiratory distress syndrome - Surfactant TA Surfactant Tokyo-Akita - 5 kDa 5 kilodaltons - ELISA enzyme-linked immunosorbent assay - PDA patent ductus arteriosus - a/APO₂ arterial-alveolar oxygen tension ratio - MAP mean airway pressure - ^99mIc-DTPA 99m technetium diethylenetriamine pentacetate     

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］     

不同正压通气方式联合肺表面活性物质在早产儿呼吸窘迫综合征中的应用

目的比较双水平气道正压通气( BiPAP) 和鼻塞式持续气道正压通气( NCPAP) 联合肺表面活性物质( PS) 在早产儿呼吸窘迫综合征( RDS) 中的应用效果。方法选择本科 2009年2月至 2012年2月收治的 80 例 RDS 早产儿,常规使用 PS 进行替代治疗后,随机分入 BiPAP 通气模式组( BiPAP 组) 和 NCPAP 通气模式组( NCPAP 组) ,每组各 40 例。观察两组工作参数、氧动力学指标、正压通气时间、氧疗时间、治疗成功率及气胸、支气管肺发育不良、早产儿视网膜病等并发症的发生率。结果 ( 1) 两组通气模式工作参数: 吸入氧浓度( FiO2) 、呼气末正压/呼气相正压( PEEP/EPAP) 均随通气时间延长逐渐降低,0 h( 上机时) 差异无统计学意义( P > 0. 05) ,上机后6 h、12 h、24 h、48 h BiPAP 组 FiO2、PEEP/EPAP 均低于 NCPAP 组,差异有统计学意义( P <0. 05 或0. 01) 。( 2) 两组均能保持较好的氧分压( PaO2) 、动脉血氧分压/吸入氧浓度比值( P/F) 、动脉/肺泡氧分压比值( PaO2/ PAO2) ,且均有上升趋势,二氧化碳分压( PaCO2) 呈降低趋势,两组在0 h 时各指标差异均无统计学意义( P >0. 05) ,BiPAP 组上机后 6 h、12 h、24 h、48 h PaO2、P/F、PaO2/ PAO2均明显高于 NCPAP 组( P <0. 05 或 0. 01) ,PaCO2低于 NCPAP 组( P <0. 05) 。( 3) BiPAP 组通气时间、氧疗时间明显短于 NCPAP 组,治疗成功率高于 NCPAP 组( P <0. 05) 。( 4) 两组气胸、支气管肺发育不良、早产儿视网膜病发生率差异无统计学意义( P >0. 05) 。结论 BiPAP 联合 PS 治疗 RDS早产儿的疗效优于 NCPAP,其具有高效、安全等优点,值得推广。     

Continuous Positive Airway Pressure for Spontaneously Breathing Premature Infants with Respiratory Distress Syndrome

Objective

To analyze the outcome of inborn preterm neonates with respiratory-distress-syndrome(RDS), using the approach of administering nasal-continuous-positive-airway-pressure(CPAP) alone and administering surfactant only if they require mechanical ventilation(MV).

Methods

All preterm neonates diagnosed as RDS from 01-May-2006 to 10-July-2010 were prospectively enrolled for the study at a referral centre in India. Nasal-CPAP alone was administered to all spontaneously breathing neonates. Surfactant was administered in babies <28 wk gestational age if the baby was intubated for resuscitation at birth. For the remaining babies, surfactant was administered if the baby required ventilation for RDS in first 72 h. The primary outcome assessed was survival to discharge.

Results

Of the 83 babies with RDS, 33(39.76%) neonates needed MV of which one baby was transferred due to non-availability of ventilator. Of the remaining 32 babies administered MV, 31 were administered surfactant. Fifty (61.24%) babies were managed with CPAP alone. Overall, 72/82(87.8%) babies managed at the authors’ center survived the neonatal period, and 71/82(86.8%) babies were discharged to home. Among the neonates who were ventilated, 26/32(81.25%) survived the neonatal period, and 25/32(78.12%) were discharged home. Among the babies receiving CPAP, 46/50 (92%) survived and were discharged to home.

Conclusions

Institution of CPAP alone in all spontaneously breathing preterm babies with RDS and administration of surfactant to only those needing MV reduces the need for intubations and surfactant administration without affecting the outcome adversely. Extreme preterms with RDS, however, may be given surfactant if they happen to be intubated for resuscitation at birth.

     

Comparison of Infasurf (calf lung surfactant extract) to Survanta (Beractant) in the treatment and prevention of respiratory distress syndrome

OBJECTIVE: To compare the relative safety and efficacy of Infasurf (calf lung surfactant extract; ONY, Inc, Amherst, NY, IND #27169) versus Survanta (Beractant, Ross Laboratories, Columbus, OH) in reducing the acute severity of respiratory distress syndrome (RDS) when given at birth and to infants with established RDS. DESIGN: A prospective, randomized, double-blind, multicenter clinical trial. SETTING: Thirteen neonatal intensive care units participated in the treatment arm: seven of these concurrently participated in the prevention arm. PATIENTS: The treatment arm enrolled infants of 相似文献   

新生儿呼吸窘迫综合征应用肺表面活性物质治疗后并发症的对照研究

目的：探讨肺表面活性物质(PS)替代治疗新生儿呼吸窘迫综合征(RDS)的并发症发生情况。方法：采用前瞻性临床对照研究方法,将98例RDS患儿分为PS治疗组和对照组,研究两组机械通气的天数、氧疗时间、住院天数、存活率以及并发呼吸机相关性肺炎、动脉导管未闭、颅内出血、肺出血、肺气漏、支气管肺发育不良(BPD)及呼吸暂停的发生情况。结果：治疗组机械通气的天数、氧疗天数缩短[(9.5±6.2)d vs(7.0±5.4)d,(13.2±8.1)d vs(10.0±6.4)d],存活率由69.2％上升为87.0％,差异均具有显著性(P<0.05)。治疗组合并肺气漏发生率由32.7％下降为15.2％,呼吸机相关性肺炎由44.2％下降为23.9％,差异有显著性意义(P<0.05)。存活者中治疗组较对照组未合并BPD的比例由75.0％上升为92.5％,未合并颅内出血由77.8％上升为95.0％,同时未合并BPD和颅内出血的比例由58.3％上升为80.0％,其差异均有显著性意义(P<0.05)。结论：PS替代治疗RDS可以明显缩短机械通气的天数、氧疗时间及提高存活率,降低气漏及呼吸机相关性肺炎发生率,降怠浪存活者中脑损害和肺损伤的发生率,提高了早产儿的生存质量。 [中国当代儿科杂志,2003,5(1):31-34]     

无创高频与加温湿化高流量鼻导管通气在早产儿呼吸窘迫综合征序贯撤机的临床应用

目的:探讨经鼻无创高频振荡通气(noninvasive high frequency oscillatory ventilation,nHFOV)与加温湿化高流量鼻导管通气(heated humidified high flow nasal cannula,HHHFNC)在极低出生体重早产儿呼吸窘迫综合征(respir...     

不同维持剂量枸橼酸咖啡因对极早产儿呼吸窘迫综合征撤机影响：前瞻性随机对照研究

目的 分析不同维持剂量枸橼酸咖啡因对胎龄≤32周极早产儿呼吸窘迫综合征（respiratory distress syndrome,RDS）撤机成功率的影响。 方法 前瞻性选取2016年1月至2018年12月该院收治的胎龄≤32周、需有创机械通气的162例RDS早产儿为研究对象,随机分为咖啡因高剂量组和低剂量组,每组81例。两组患儿生后6 h内均给予负荷量咖啡因20 mg/kg治疗,24 h后高、低剂量组分别给予每日10 mg/kg和5 mg/kg的咖啡因维持剂量治疗。比较两组患儿撤机后48 h内的重新插管率、总通气时间、氧疗时间、肠内喂养及体重增长情况、住院期间并发症和不良反应的发生率。 结果 高剂量组撤机后48 h内再插管率低于低剂量组（P<0.05）,两组主要撤机失败原因均为频繁呼吸暂停。高剂量组总机械通气时间及氧疗时间均短于低剂量组（P<0.05）。两组患儿达完全肠内喂养时间、平均每天体重增长量、出院时体重及住院期间并发症（支气管肺发育不良、早产儿视网膜病、坏死性小肠结肠炎、颅内出血）和不良反应（心动过速、高血压、喂养不耐受）发生率比较差异均无统计学意义（P>0.05）。 结论 高维持剂量咖啡因可安全有效降低胎龄≤32周早产儿RDS撤机后呼吸暂停发生率和撤机失败率,值得临床推广应用。 引用格式:     

撤机前加用一剂维持量咖啡因在早产儿呼吸窘迫综合征中的应用价值：前瞻性随机对照试验

目的 探讨≤ 32周呼吸窘迫综合征（RDS）伴有创机械通气的早产儿,在撤机前1 h加用1剂维持量（5 mg/kg）枸橼酸咖啡因注射液对提高撤机成功率的效果。方法 将2017年1月至2019年12月厦门市妇幼保健院新生儿重症监护病房（NICU）收治的338例≤ 32周并给予有创机械通气的RDS早产儿随机分为观察组（n=169）和常规组（n=169）。两组患儿均给予早期咖啡因常规治疗,观察组在撤机前1 h加用1剂维持量咖啡因。比较两组撤机后48 h的再插管率、呼吸暂停的发作次数;撤机后2 h的血气分析及血糖、心率、平均血压的变化,以及住院期间主要并发症的发生率。结果 观察组撤机后48 h内再次插管率较常规组明显降低（P=0.034）,呼吸暂停发作次数（≥ 2次/d）较常规组明显减少（P=0.015）。撤机后2 h,观察组动脉血气分析pH值较常规组升高,PaCO₂较常规组降低（P < 0.05）;两组患儿PaO₂、血糖、心率、平均血压比较,差异均无统计学意义（P > 0.05）。观察组住院期间颅内出血发生率低于常规组（P=0.048）;两组患儿支气管肺发育不良、坏死性小肠结肠炎、脑白质损伤、早产儿视网膜病发生率及病死率比较,差异均无统计学意义（P > 0.05）。结论 撤机前1 h加用1剂维持量的枸橼酸咖啡因能安全有效地提高早产儿RDS的撤机成功率,值得临床推广应用。     

Treatment of severe meconium aspiration syndrome with porcine surfactant: a multicentre, randomized, controlled trial

Aim: A randomized, controlled clinical trial was performed in 19 Chinese neonatal intensive care units to evaluate the safety and efficacy of exogenous surfactant replacement therapy for severe meconium aspiration syndrome (MAS) in term and near‐term neonates. Methods: Sixty‐one term infants with severe MAS were randomly assigned to either a surfactant or a control group within 36 h after birth. The infants in the surfactant group (n=31) received an initial dose of porcine lung‐derived surfactant (Curosurf®) at 200 mg/kg, and repeated doses of 200, 100 and 100 mg/kg were given at 6–12 h intervals to a maximum of four doses if oxygenation index (OI) deteriorated by >2 from baseline. The primary outcomes were a reduction of OI to less than 10 and an increase of the pre‐treatment a/A PO₂ ratio of 100% over baseline 24 h after surfactant treatment. The secondary outcomes were duration of mechanical ventilation, incidence of complications and survival to discharge from hospital. Results: The general demographic characteristics of the study subjects were similar. There was a trend for surfactant‐treated infants to have an improvement in arterial oxygenation compared to the control group. In comparison with the control group at 24 h, the surfactant group had a lower mean OI (8.1 vs 10.9), more infants with a 100% increase of a/A PO₂ (83% vs 48%, p<0.01) over baseline, and a larger area under the curve for PaO₂/FiO₂ over baseline (3762±1877 vs 2715±1644 mmHg^.h, p<0.05). Repeated measures of these parameters were also in favour of the surfactant group during 24 h to 3 and 7 d compared to the baseline (p<0.05). No differences were found in mean duration of mechanical ventilation, incidence of major complications and number of survivors between the two groups. Conclusion: Surfactant replacement therapy improved oxygenation in the study subjects, suggesting that surfactant may have a role in the treatment of severe MAS in term and near‐term infants.     

Comparison of three treatment regimens of natural surfactant preparations in neonatal respiratory distress syndrome

The aim of the study was to compare the treatment regimen of three natural surfactants of different extraction and formulation (Alveofact [Surfactant A = SA], Poractant [Surfactant B = SB] and Beractant [Surfactant C = SC]) in neonatal respiratory distress syndrome (RDS). Premature infants of /=0.3 were randomly assigned to receive at least two doses of SA, SB or SC (100 mg/kg per dose). Infants who remained dependent on artificial ventilation with a FiO2 >/=0.3 received up to two additional doses. There were no differences among the groups regarding the necessity for more than two doses. The SA and the SB groups spent fewer days on a ventilator (p-value SA/SB 0.7, SA/SC 0.05, SB/SC 0.043) compared with the SC group, needed fewer days of oxygen administration (p-value SA/SB 0.14, SA/SC 0.05, SB/SC 0.04) and spent fewer days in hospital (p-value SA/SB 0.65, SA/SC 0.04, SB/SC 0.027). There were no statistically significant differences in the incidence of mortality, chronic lung disease, air leaks, necrotising enterocolitis, retinopathy of prematurity and intraventricular haemorrhage among the three groups. CONCLUSION: The Alveofact and Poractant groups spent fewer days on the ventilator, needed fewer days of oxygen administration and spent fewer days in hospital compared with the Beractant group but no differences were observed among the three groups with regards to mortality and morbidity.     

经鼻间歇正压通气辅助呼吸治疗早产儿呼吸窘迫综合征

目的 探讨经鼻间歇正压通气(NIPPy)治疗早产儿呼吸窘迫综合征(RDS)的疗效及安全性.方法 将2010年1-12月本院收治的胎龄小于34周RDS早产儿30例设为NIPPV组,并将2009年3月-2010年11月随机抽取的胎龄小于34周RDS早产儿30例作为经鼻持续正压通气(NCPAP)组,2组患儿胎龄、出生体质量比较差异均无统计学意义.诊断RDSⅢ～Ⅳ级,无严重并发症,均接受肺表面活性物质治疗.结果 NIPPV组辅助通气时间较NCPAP组明显缩短(P＜0.05).机械通气率NIPPV组明显低于NCPAP组,且病死率及肺气漏无增加.2h时,2组呼吸机工作参数比较无统计学差异(P＞0.05),12h、24h和36h时比较差异均有统计学意义(Pa＜0.05),12h、24h和36h时吸氧体积分数比较差异均有统计学意义(Pa＜0.05).呼气末正压12h、24h和36h时比较差异均有统计学意义(Pa＜0.05).2组2h时pH比较无统计学差异(P＞0.05),而12h、24h和36h时pH的差异均有统计学意义.12h时动脉血氧分压比较无统计学差异(P＞0.05),而24h和36h均有统计学差异(Pa＜0.05).NIPPV组极低体质量儿及超极低出生体质量儿12例,NCPAP组10例,均未发生支气管肺发育不全.结论 与NCPAP比较,NIPPV治疗RDS有较好疗效,且可减少RDS患儿的气管再插管和机械通气.     

The role of surfactant and non-invasive mechanical ventilation in early management of respiratory distress syndrome in premature infants

Background

Surfactant replacement therapy has been used for few decades for the treatment of respiratory distress syndrome (RDS) and has significantly improved morbidity and mortality in premature infants. Non-invasive respiratory support has recently emerged as a strategy in the early management of RDS. In this review, we discuss the different strategies of early management of RDS.

Data sources

A literature search of PubMed database was conducted to review the subject. The quality of evidence of key clinical studies was graded according to a modified grading system of the international GRADE group.

Results

Continuous positive airway pressure (CPAP) with selective surfactant is a safe alternative to routine intubation, surfactant and mechanical ventilation in preterm infants with spontaneous breathing, and such an approach has been associated with decreased risk of death and bronchopulmonary dysplasia. There is a risk of pneumothorax when using a high pressure of CPAP (≥8 cm of H₂O), a high partial pressure of carbon dioxide (PCO₂ >75 mm of Hg), and a high fraction of inspired oxygen (FiO₂ >0.6) as a threshold for intubation while on CPAP.

Conclusion

Not all preterm infants need surfactant treatment, and non-invasive respiratory support is a safe and effective approach.     

早期应用牛肺泡表面活性物质对晚期早产儿及足月儿呼吸窘迫综合征治疗的随机对照研究

目的 观察牛肺泡表面活性物质（PS）治疗晚期早产儿及足月儿呼吸窘迫综合征（RDS）的有效性。方法 采用随机对照研究观察按照不同时间和不同剂量气管内应用PS 对胎龄≥ 35 周及氧合指数（OI）在10~20的RDS 患儿的有效性。治疗1 组（n=58）入院6 h 内应用PS 50 mg/kg,治疗2 组（n=58）在入院6 h 内应用PS70 mg/kg,对照组（n=59）在入院6 h 内不给予PS,入院6 h 后若单纯应用机械通气等综合治疗后病情无缓解应用PS 50 mg/kg,各组用药后观察12 h 无缓解可以给予第二剂PS 50 mg/kg。结果 3 组病死率差异无统计学意义;治疗2 组住院费用及机械通气时间低于治疗1 组和对照组,且治疗1 组低于对照组;治疗2 组住院时间和呼吸机相关肺炎比率低于治疗1 组和对照组;治疗1 组和治疗2 组的PS 2 次及以上应用率、最高OI 值、CPAP 应用时间及气漏综合征、肺动脉高压发生率均低于对照组。结论 早期足量应用PS 可减少晚期早产儿及足月儿PS 2 次应用、住院费用及RDS 并发症的发生,缩短机械通气及住院时间。     

肺表面活性剂(珂立苏)治疗新生儿呼吸窘迫综合征多中心临床试验

目的 评价肺表面活性剂(珂立苏)治疗新生儿呼吸窘迫综合征(RDS)的效果和安全性.方法 在全国七大城市儿童医院进行随机的、有对照的、多中心临床试验.研究对象主要入选标准:临床诊断新生儿RDS,出生体质量＜2 500 g,a/APO2＜0.22.入选合格病例107例,其中给药组57例,对照组50例.北京双鹤药业生产的珂立苏以混悬液形式从气管插管滴入,剂量70 mg/kg;对照组以同样方法注入空气.结果 给药后3 d内RDS患儿氧合及通气功能(PaO2、a/APO2、FiO2、PaCO2)明显改善,a/APO2在给药2、8及24 h明显高于对照组,差异有非常显著性(P＜0.01).呼吸机重要参数(PIP)、MAP、PEEP)给药后2 d内在各时间点均显著低于对照组(P＜0.05).根据首剂给药后a/APO2的改变判断疗效,有良好反应者占84.2%.X线胸片改变提示,给药后8 h和24 h,肺含气情况有显著改善.除1/3病例在给药时有短暂气道阻塞表现外,无其他不良反应.给药组与对照组并发症发生率差异无显著性(P＞0.05).结论 珂立苏治疗RDS有效、安全.     

不同时间给予肺表面活性物质治疗对呼吸窘迫综合征早产儿的影响

目的探讨早期或晚期给予肺表面活性物质(PS)治疗对呼吸窘迫综合征(RDS)早产儿的影响。方法本院新生儿科2009—2010年收治的RDS早产儿,按照PS的给予时间分为早期组(出生2 h内给药)和晚期组(出生2～12 h给药),比较两组机械通气时间、氧疗时间、病死率以及并发症发生率方面的差异。结果早期组48例,晚期组51例,早期给予PS能显著减少机械通气时间和氧疗时间[机械通气时间:(4.1±1.9)天比(5.4±2.2)天,氧疗时间:(5.8±3.4)天比(8.1±5.5)天,P<0.05]。但未影响气漏、肺出血、动脉导管未闭、坏死性小肠结肠炎、严重脑室内出血和支气管肺发育不良的发生率以及RDS早产儿的病死率。结论早期给予PS治疗能显著减少RDS早产儿的机械通气时间和氧疗时间。     

两种无创呼吸支持治疗极低出生体重儿呼吸窘迫综合征疗效分析

目的 探讨早期应用经鼻间歇正压通气（NIPPV）与加温湿化经鼻导管高流量通气（HHHFNC）治疗极低出生体重呼吸窘迫综合征（RDS）早产儿的临床疗效。方法 89例极低出生体重RDS早产儿依据初始呼吸支持治疗方式随机分为NIPPV组（46例）和HHHFNC组（43例）。分析两组患儿初始治疗失败率、肺表面活性物质（PS）使用率、呼吸支持治疗相关数据及各种并发症的发生率。结果 NIPPV组治疗72 h内气管插管率、PS使用率、有创辅助通气时间、无创辅助通气时间及总用氧时间、严重呼吸暂停发生率、肺炎发生率与HHHFNC组的差异无统计学意义（P > 0.05）;NIPPV组支气管肺发育不良、颅内出血、早产儿视网膜病、坏死性小肠结肠炎、动脉导管未闭、气漏的发生率与HHHFNC组的差异均无统计学意义（P > 0.05）;NIPPV组鼻损伤的发生率高于HHHFNC组（P < 0.05）。结论 对于极低出生体重RDS早产儿的初始呼吸支持治疗,HHHFNC与NIPPV疗效相当,是可供临床选择的另一种安全和有效的无创辅助通气治疗方式。     

两种辅助通气方式治疗极低出生体重儿呼吸窘迫综合征临床疗效分析

目的 比较加温湿化经鼻导管高流量通气(HHHFNC)和鼻塞式持续气道正压通气(NCPAP)应用于极低出生体重儿呼吸窘迫综合征的临床疗效。方法 选择呼吸窘迫综合征(RDS)的极低出生体重患儿66例,接受猪肺表面活性物质及相关常规治疗后随机分为HHHFNC组和NCPAP组,观察两组患儿临床症状改善情况及其各种并发症的发生率。结果 与NCPAP组相比,HHHFN组患儿开奶时间及达到全肠道喂养时间明显提前,氧暴露时间和有创通气时间降低,7 d内重新插管、鼻部损伤、气漏、腹胀的发生率降低。结论 与NCPAP组相比,HHHFNC有相关损伤更小、耐受性更好的特点,是可以首选的一种治疗极低出生体重儿RDS的无创通气模式。     

Indomethacin Pharmacodynamics Are Altered by Surfactant: A Possible Challenge to Current Indomethacin Dosing Guidelines Created Before Surfactant Availability

The effect of surfactant administration for respiratory distress syndrome (RDS) on indomethacin (INDO) pharmacodynamics and dosing requirements for patent ductus arteriosus (PDA) closure and renal toxicity was evaluated. A 22-year prospective cohort study including 442 INDO-treated patients given 466 INDO treatment courses. The database included demographic information, medical problems, and medications. Neonates with a PDA confirmed by echocardiography were treated with INDO, 0.25–0.3 mg/kg. Subsequent INDO dosing was based on a combined pharmacokinetic/pharmacodynamic (PK/PD) approach. Data were fit to an Emax model and ANOVA was used to compare mean closure levels between groups. PDA closure was successful in 405 of 442 patients (91.6%) and in 434 of 466 treatment courses (93.1%) using an individualized PK/PD dosing approach. Renal toxicity was documented in 56 of 442 patients (12.7%) or 56 of 466 treatment courses (12.0%). Patients not treated with synthetic surfactant trended toward lower mean INDO concentrations at PDA closure compared to patients treated with synthetic surfactant (1.65 vs. 2.01 mg/l; P > 0.05) and significantly lower mean INDO concentrations at PDA closure compared to patients treated with natural surfactant (1.65 vs. 2.15 mg/l; P < 0.002). This requires an increased total dose of ~0.3 mg/kg or an individual dose increase of 0.1 mg/kg. Administration of natural or synthetic surfactant for RDS may increase the INDO concentrations and doses needed for PDA closure in premature infants.     

The pathophysiology of respiratory distress syndrome in neonates

Respiratory distress syndrome (RDS) occurs predominantly in premature infants and is a direct consequence of surfactant deficiency. The incidence of RDS is inversely related to gestational age and the weight of the newborn. There are a multitude of risk factors for RDS which increase the incidence of the condition. The use of antenatal corticosteroids and early surfactant use along with more gentle modes of ventilation have all contributed to a dramatic improvement in the mortality and morbidity associated with RDS. Over the years our understanding of the pathophysiology of RDS has greatly increased and this has aided the advances in treatment of this condition. This article covers the most up to date and relevant information surrounding the pathophysiology of RDS.