Definitions of extubation success in very premature infants: a systematic review.
ABSTRACT Studies of extubation in preterm infants often define extubation success as a lack of reintubation within a specified time window. However, the duration of observation that defines extubation success in preterm infants has not been validated. The purpose of this study was to systematically review published definitions of extubation success in very preterm infants and to analyse the effect of the definition of extubation success on the reported rates of reintubation.
Studies including very preterm infants published between 1 January 2002 and 30 June 2012 that reported reintubation as an outcome were reviewed for definitions of extubation success. Stepwise multivariable linear regression was used to explore variables associated with rate of reintubation.
Two independent reviewers performed the search with excellent agreement (κ=0.93). Of the 44 eligible studies, 31 defined a window of observation that ranged from 12 to 168 h (7 days). Extubation and reintubation criteria were highly variable. The mean±SD reintubation rate across all studies was 25±9%. In studies of infants with median birth weight (BW) ≤1000 g, reintubation rates steadily increased as the window of observation increased, without apparent plateau (p = 0.001). This trend was not observed in studies of larger infants (p = 0.85).
Variability in the reported definitions of extubation success makes it difficult to compare extubation strategies across studies. The appropriate window of observation following extubation may depend on the population. In infants with BW ≤1000 g, even a week of observation may fail to identify some who will require reintubation.
- [Show abstract] [Hide abstract]
ABSTRACT: When preterm infants have been given intermittent positive pressure ventilation (IPPV) for respiratory failure, weaning from support and tracheal extubation may be difficult. A significant contributing factor is thought to be the relatively poor respiratory drive and tendency to develop hypercarbia and apnea, particularly in very preterm infants. Methylxanthine treatment started before extubation might stimulate breathing and increase the chances of successful weaning from IPPV. In preterm infants being weaned from IPPV and in whom endotracheal extubation is planned, does treatment with methylxanthine reduce the use of intubation and IPPV, without clinically important side effects? The standard search strategy of the Cochrane Neonatal Review Group was used. This included searches of the Oxford Database of Perinatal Trials, The Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 3 2002), MEDLINE (1966 to October 2002). All published trials utilising random or quasi-random patient allocation, in which treatment with methylxanthines (theophylline or caffeine) was compared with placebo or no treatment to improve the chances of successful extubation of preterm or low birth weight infants, were included. The standard methods of the Cochrane Collaboration and its Neonatal Review Group were used. The second author assessed the quality of trials and extracted data independently. Results are expressed as relative risk (RR) and risk difference (RD) with 95% confidence intervals. Overall analysis of the six published trials shows that methylxanthine treatment results in a reduction in failure of extubation within one week [summary RR 0.47 (0.32, 0.70)]. Overall there is an absolute reduction of 27 % in the incidence of failed extubation [summary RD -.27 (-.39, -.15)]. Thus, overall in these six trials the number needed to treat (NNT) with methylxanthine to prevent one case of failed extubation is 3.7 (2.7, 6.7). There is significant heterogeneity in the RD meta-analysis (p=0.007) related to the large variation in baseline rate in the control groups (range 20 - 100%). One study (Durand 1987) found that treatment was effective in reducing failed extubation in those born at less than 1000 grams and who were less than one week old. In the small prespecified subgroups in this trial, infants of less than 1 kg birth weight and older than one week and those of birth weight 1000-1250 grams who had failed extubation once, no significant benefit was found. Implications for practice. Methylxanthines increase the chances of successful extubation of preterm infants within one week. One trial suggests that this benefit is principally in infants of extremely low birth weight extubated in the first week. There is insufficient information to assess side effects or longer term effects on child development. Implications for research. Further trials are required comparing methylxanthines with placebo for extubation of very preterm infants. There is a need to stratify infants by gestational age (a better indicator of immaturity) rather than birth weight in future studies. Caffeine, with its wider therapeutic margin (Blanchard 1992, Steer 2002) would be the better treatment to evaluate against placebo. Side effects and neuro-developmental status at follow up should be included as outcomes.Cochrane database of systematic reviews (Online) 02/2003; · 5.94 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: Nasal continuous positive airway pressure (NCPAP) is used to support preterm infants recently extubated, those experiencing significant apnoea of prematurity and those with respiratory distress soon after birth as an alternative to intubation and ventilation. This review focuses exclusively on identifying the most effective pressure source and interface for NCPAP delivery in preterm infants. To determine which technique of pressure generation and which type of nasal interface for NCPAP delivery most effectively reduces the need for additional respiratory support in preterm infants extubated to NCPAP following intermittent positive pressure ventilation (IPPV) for respiratory distress syndrome (RDS) or in those treated with NCPAP soon after birth. The strategy included searches of MEDLINE (1966 - 2006), the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 4, 2006) CINAHL, abstracts from conference proceedings, cross-referencing of previous reviews and the use of expert informants. Randomised or quasi-randomised trials comparing different techniques of NCPAP pressure generation and/or nasal interfaces in preterm infants extubated to NCPAP following IPPV for RDS or treated with NCPAP soon after birth. Data was extracted and analysed by the first three authors. Dichotomous results were analysed using the relative risk (RR), risk difference (RD) and number needed to treat (NNT). 1. Preterm infants being extubated to NCPAP following a period of IPPV for RDS:Meta-analysis of the results from Davis 2001 and Roukema 1999a demonstrated that short binasal prongs are more effective at preventing re-intubation than single nasal or nasopharyngeal prongs [typical RR 0.59 (CI: 0.41, 0.85), typical RD -0.21 (CI: -0.35, -0.07), NNT 5 (CI: 3, 14)]. In one study comparing short binasal prong devices (Sun 1999), the re-intubation rate was significantly lower with the Infant Flow Driver than with the Medicorp prong [RR 0.33 (CI: 0.17, 0.67), RD -0.32 (CI: -0.49, -0.15), NNT 3 (CI: 2, 7)]. The other study comparing short binasal prong devices (Infant Flow Driver versus INCA prongs, Stefanescu 2003) demonstrated no significant difference in the re-intubation rate but did show a significant reduction in the total days in hospital in the Infant Flow Driver group [MD -12.60 (95% CI: -22.81, -2.39) days].2. Preterm infants primarily treated with NCPAP soon after birth:In the one trial identified, Mazzella 2001 found a significantly lower oxygen requirement and respiratory rate in those randomised to short binasal prongs when compared with CPAP delivered via nasopharyngeal prong. The requirement for intubation beyond 48 hours from randomisation was not assessed.3. Studies randomising preterm infants to different NCPAP systems using broad inclusion criteriaThe studies of Rego 2002 and Buettiker 2004 did not examine the primary outcomes of this review. Of the secondary outcomes, Rego 2002 demonstrated a significantly higher incidence of nasal hyperaemia with the use of the Argyle prong compared with Hudson prongs [RR 2.39 (95% CI: 1.27, 4.50), RD 0.28 (95% CI: 0.10, 0.46)]. One study comparing different techniques of pressure generation is awaiting further assessment as it is currently available in abstract form only. Short binasal prong devices are more effective than single prongs in reducing the rate of re-intubation. Although the Infant Flow Driver appears more effective than Medicorp prongs the most effective short binasal prong device remains to be determined. The improvement in respiratory parameters with short binasal prongs suggests they are more effective than nasopharyngeal CPAP in the treatment of early RDS. Further studies incorporating longer-term outcomes are required. Studies are also needed to determine the optimal pressure source for the delivery of NCPAP.Cochrane database of systematic reviews (Online) 02/2008; · 5.94 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: Despite more than 2 decades of outcomes research after very preterm birth, clinicians remain uncertain about the extent to which neonatal morbidities predict poor long-term outcomes of extremely low-birth-weight (ELBW) infants. To determine the individual and combined prognostic effects of bronchopulmonary dysplasia (BPD), ultrasonographic signs of brain injury, and severe retinopathy of prematurity (ROP) on 18-month outcomes of ELBW infants. Inception cohort assembled for the Trial of Indomethacin Prophylaxis in Preterms (TIPP). A total of 910 infants with birth weights of 500 to 999 g who were admitted to 1 of 32 neonatal intensive care units in Canada, the United States, Australia, New Zealand, and Hong Kong between 1996 and 1998 and who survived to a postmenstrual age of 36 weeks. Combined end point of death or survival to 18 months with 1 or more of cerebral palsy, cognitive delay, severe hearing loss, and bilateral blindness. Each of the neonatal morbidities was similarly and independently correlated with a poor 18-month outcome. Odds ratios were 2.4 (95% confidence interval [CI], 1.8-3.2) for BPD, 3.7 (95% CI, 2.6-5.3) for brain injury, and 3.1 (95% CI, 1.9-5.0) for severe ROP. In children who were free of BPD, brain injury, and severe ROP the rate of poor long-term outcomes was 18% (95% CI, 14%-22%). Corresponding rates with any 1, any 2, and all 3 neonatal morbidities were 42% (95% CI, 37%-47%), 62% (95% CI, 53%-70%), and 88% (64%-99%), respectively. In ELBW infants who survive to a postmenstrual age of 36 weeks, a simple count of 3 common neonatal morbidities strongly predicts the risk of later death or neurosensory impairment.JAMA The Journal of the American Medical Association 04/2003; 289(9):1124-9. · 30.39 Impact Factor