RESUMO
RATIONALE: Although continuous positive airway pressure is used extensively in neonatal intensive care units, and despite the belief that positioning is considered vital to the maintenance of good lung ventilation, no data exist on regional ventilation distribution in infants on continuous positive airway pressure ventilatory support. OBJECTIVES: To investigate the effect of body position on regional ventilation in preterm infants on continuous positive airway pressure ventilatory support using electrical impedance tomography. DESIGN: Randomized crossover study design. SETTING: Neonatal intensive care unit. PATIENTS: Twenty-four preterm infants on continuous positive airway pressure were compared to six spontaneously breathing preterm infants. INTERVENTIONS: Random assignment of the order of the positions supine, prone, and quarter prone. MEASUREMENTS AND RESULTS: Changes in global and regional lung volume were measured with electrical impedance tomography. Although there were no differences between positions, regional tidal volume was increased in the posterior compared with the anterior lung (p < .01) and in the right compared with the left lung (p < .03) in both the spontaneously breathing infants and in the infants on continuous positive airway pressure. The posterior lung filled earlier than the anterior lung in the spontaneously breathing infants (p < .02), whereas in the infants on continuous positive airway pressure the right lung filled before the left lung (p < .01). There was more ventilation inhomogeneity in the infants on continuous positive airway pressure than in the healthy infants (p < .01). CONCLUSIONS: This study presents the first results on regional ventilation distribution in preterm infants on continuous positive airway pressure using electrical impedance tomography. Gravity had little impact on regional ventilation distribution in preterm infants on continuous positive airway pressure or in spontaneously breathing infants in the supine or prone position, indicating that ventilation distribution in preterm infants is not gravity-dependent but follows an anatomical pattern. AUSTRALIA NEW ZEALAND CLINICAL TRIALS REGISTRY:: ACTRN12606000210572.
Assuntos
Pressão Positiva Contínua nas Vias Aéreas , Recém-Nascido Prematuro , Postura/fisiologia , Respiração Artificial , Estudos Cross-Over , Impedância Elétrica , Feminino , Humanos , Recém-Nascido , Unidades de Terapia Intensiva Neonatal , Pulmão/fisiologia , Masculino , Decúbito Ventral/fisiologia , Mecânica Respiratória , Decúbito Dorsal/fisiologia , Tomografia/métodosRESUMO
BACKGROUND: Assisted mechanical ventilation is a necessity in the neonatal population for a variety of respiratory and surgical conditions. However, there are a number of potential hazards associated with this life saving intervention. New suctioning techniques have been introduced into clinical practice which aim to prevent or reduce these untoward effects. OBJECTIVES: To assess the effects of endotracheal suctioning without disconnection in intubated ventilated neonates. SEARCH METHODS: The review has drawn on the search strategy for the Cochrane Neonatal Review Group. A comprehensive search of Cochrane databases, MEDLINE and CINAHL, and the Society for Pediatric Research abstracts was undertaken by the review authors (July 2011). SELECTION CRITERIA: All trials that utilised random or quasi-random patient allocation and in which suctioning with or without disconnection from the ventilator was compared. DATA COLLECTION AND ANALYSIS: Standard methods of the Cochrane Neonatal Group were used. Each review author separately reviewed trials for eligibility and quality and extracted data; they then compared and resolved differences. Analysis was performed using the fixed-effect model and outcomes were reported using relative risk (RR) for categorical data and mean difference (MD) for outcomes measured on a continuous scale. MAIN RESULTS: Four trials (252 infants) were included in this review. The trials employed a cross-over design in which suctioning with or without disconnection was compared. Suctioning without disconnection resulted in a reduction in episodes of hypoxia (typical RR 0.48, CI 95% 0.31 to 0.74; 3 studies; 241 participants). There were also fewer infants who experienced episodes where the transcutaneous partial pressure of oxygen (TcPO(2)) decreased by > 10% (typical RR 0.39, 95% CI 0.19 to 0.82; 1 study; 11 participants). Suctioning without disconnection resulted in a smaller percentage change in heart rate (weighted mean difference (WMD) 6.77, 95% CI 4.01 to 9.52; 4 studies; 239 participants) and a reduction in the number of infants experiencing a decrease in heart rate by > 10% (typical RR 0.61, CI 0.40 to 0.93; 3 studies; 52 participants).The number of infants having bradycardic episodes was also reduced during closed suctioning (typical RR 0.38, CI 95% 0.15 to 0.92; 3 studies; 241 participants). AUTHORS' CONCLUSIONS: There is some evidence to suggest suctioning without disconnection from the ventilator improves the short term outcomes; however the evidence is not strong enough to recommend this practice as the only method of endotracheal suctioning. Future research utilising larger trials needs to address the implications of the different techniques on ventilator associated pneumonia, pulmonary morbidities and neurodevelopment. Infants less than 28 weeks also need to be included in the trials.
Assuntos
Intubação Intratraqueal , Respiração Artificial/efeitos adversos , Sucção/métodos , Estudos Cross-Over , Frequência Cardíaca , Humanos , Recém-Nascido , Ensaios Clínicos Controlados Aleatórios como Assunto , Respiração , Desmame do RespiradorRESUMO
BACKGROUND: Chest physiotherapy (CPT) has been used in many neonatal nurseries around the world to improve airway clearance and treat lung collapse; however, the evidence to support its use has been conflicting. Despite the large number of studies there is very little evidence of sufficiently good quality on which to base current practice. OBJECTIVES: To assess the effects of active CPT techniques, such as percussion and vibration followed by suction compared with suction alone, on the respiratory system in infants receiving mechanical ventilation. Additionally, differences between types of active CPT techniques were assessed. SEARCH STRATEGY: Our search included The Cochrane Library (Issue 2, 2007), MEDLINE (1966 to 2007), EMBASE (1988 to 2007), CINAHL, Science Citation Index, previous reviews including cross-references, abstracts, conference proceedings and grey literature. SELECTION CRITERIA: Trials in which ventilated newborn infants up to four weeks of age were randomly or quasi-randomly assigned to receive active CPT or suction alone. Infants receiving CPT for the extubation period were excluded. DATA COLLECTION AND ANALYSIS: Two review authors independently conducted quality assessments and data extraction for included trials. We analysed data for individual trial results using relative risk (RR) and mean difference (MD). Results are presented with 95% confidence intervals (CI). Due to insufficient data, we could not undertake meta-analysis. MAIN RESULTS: Three trials involving 106 infants were included in this review. In one trial (n = 20) CPT was no better than standard care in clearing secretions. No increase in the risk of intraventricular haemorrhage was noted. Two trials compared different types of active CPT. One trial (n = 56) showed that non-resolved atelectasis was reduced in more neonates receiving the lung squeezing technique (LST) when compared to postural drainage, percussion and vibration (PDPV) (RR 0.25; 95% CI 0.11 to 0.57). No difference in secretion clearance or in the rate of intraventricular haemorrhage or periventricular leucomalacia was demonstrated. The other trial (n = 30) showed that the use of percussion or 'cupping' resulted in an increased incidence of hypoxaemia (RR 0.53; 95% CI 0.28 to 0.99) and increased oxygen requirements (MD -9.68; 95% CI -14.16 to -5.20) when compared with contact heel percussion. There was insufficient information to adequately assess important short and longer-term outcomes, including adverse effects. AUTHORS' CONCLUSIONS: The results of this review do not provide sufficient evidence on which to base clinical practice. There is a need for larger randomised controlled trials to address these issues.