Continuous negative extrathoracic pressure or continuous positive airway pressure for acute hypoxemic respiratory failure in children

Intestinal muscularis propria increases in thickness with corrected gestational age and is focally attenuated in patients with isolated intestinal perforations

PURPOSE

Intestinal perforations are common in premature infants, leading to a diagnostic dilemma between necrotizing enterocolitis and isolated intestinal perforation (IIP). IIP is thought to result from a congenital or acquired absence of the muscularis propria. However, developmental events leading to IIP are not well understood. This study examines the relationship between corrected gestational age (CGA) and intestinal muscle development in controls and patients with IIP.

METHODS

Specimens from stillbirths and infants undergoing intestinal surgery from 8 to 48weeks' CGA were collected from 2005 to 2012. Twelve patients with IIP were identified. Control specimens were collected during 25 fetal autopsies and 39 bowel resections. In each case, three sections of intestine were examined histologically for muscularis mucosa, circular and longitudinal muscle thickness. Comparisons of control and perforated specimens were performed via linear regression and ANOVA.

RESULTS

Controls and adjacent normal segments in IIP showed a linear relationship between thickness of circular and longitudinal muscles with CGA. Circular and longitudinal muscles were thinner in perforated segments than in adjacent normals and CGA-matched controls (p<0.05).

CONCLUSION

Intestinal muscularis propria increases in thickness with CGA. Muscle thickness is focally attenuated in patients with isolated intestinal perforations, while the remaining intestine is normal, suggesting that primary repair is an appropriate treatment.

Continuous negative extrathoracic pressure or continuous positive airway pressure compared to conventional ventilation for acute hypoxaemic respiratory failure in children

BACKGROUND

Acute hypoxaemic respiratory failure (AHRF) is an important cause of mortality and morbidity in children. Positive pressure ventilation is currently the standard care, however, it does have complications. Continuous negative extrathoracic pressure (CNEP) ventilation or continuous positive airway pressure (CPAP) ventilation delivered via non-invasive approaches (Ni-CPAP) have shown certain beneficial effects in animal and uncontrolled human studies.

OBJECTIVES

To assess the effectiveness of CNEP or Ni-CPAP compared to conventional ventilation in children (at least one month old and less than 18 years of age) with AHRF due to non-cardiogenic causes for improving the mortality or morbidity associated with AHRF.

SEARCH METHODS

We searched CENTRAL 2013, Issue 6, MEDLINE (January 1966 to June week 3, 2013), EMBASE (1980 to July 2013) and CINAHL (1982 to July 2013).

SELECTION CRITERIA

Randomised or quasi-randomised clinical trials of CNEP or Ni-CPAP versus standard therapy (including positive pressure ventilation) involving children (from one month old to less than 18 years at time of randomisation) who met the criteria for diagnosis of AHRF with at least one of the outcomes reported.

DATA COLLECTION AND ANALYSIS

We assessed risk of bias of the included studies using allocation concealment, blinding of intervention, completeness of follow-up and blinding of outcome measurements. We abstracted data on relevant outcomes and estimated the effect size by calculating risk ratio (RR) and risk difference (RD) with 95% confidence intervals (CI).

MAIN RESULTS

We identified two eligible studies: one of CPAP and one of CNEP (published as an abstract). Both were unblinded studies with mainly unclear risk of bias due to lack of adequate information to assess this. The CPAP study enrolled 37 children to oxygen mask and CPAP and reported improvement in respiratory rate and oxygen saturation in both arms after 30 minutes of application. The CNEP study was published as an abstract and included 33 infants with bronchiolitis. In the CNEP study there was a reduction in the fraction of inspired oxygen (FiO2) (less than 30% within one hour of initiation of therapy) in four participants in the CNEP group compared to none in the control group (RR 10.7, 95% CI 0.6 to 183.9). One infant required CPAP and mechanical ventilation in the control group while all infants in the CNEP group were managed without intubation (RR for both outcomes 0.40, 95% CI 0.02 to 9.06). None of the trials reported on mortality. No adverse events were reported in ether of the included trials.

AUTHORS' CONCLUSIONS

There is a lack of well-designed, controlled trials of non-invasive modes of respiratory support in children with AHRF. Studies assessing the outcomes mortality, avoidance of intubation and its associated complications, hospital stay and patient comfort are needed.

Use of continuous positive airway pressure during stabilisation and retrieval of infants with suspected bronchiolitis

AIM

Infants with viral bronchiolitis are often hospitalised with a proportion requiring respiratory support. The aim of this review was to examine the use of nasal prong continuous positive airway pressure (CPAP) as a management strategy for infants with a diagnosis of bronchiolitis, who required stabilisation and transport to a tertiary centre.

METHOD

A retrospective audit of infants with bronchiolitis requiring CPAP during transport between January 2003 and June 2007.

RESULTS

Nasal CPAP was initiated in 54 infants with 51 of these (34 ex-preterm, 17 term) subsequently continuing on CPAP during retrieval. Mean CPAP pressure was 7 cmH(2)O. Oxygenation improved between stabilisation and the end of retrieval (P < 0.01). During retrieval, there was no significant increase in transcutaneous CO(2), no infant required endotracheal ventilation and no adverse events were noted. Five infants were intubated within the first 24 h of admission at the receiving hospital.

CONCLUSION

This review demonstrated that use of nasal prong CPAP to transport infants with bronchiolitis was a safe management strategy in those with moderate to severe disease severity.

The number of failing organs predicts non-invasive ventilation failure in children with ALI/ARDS

PURPOSE

Non-invasive positive pressure ventilation (NIV) is being increasingly used in paediatric critical care, although its use in acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) is still debated. No definite data are available for the prediction of NIV outcome in such selected populations. We aimed to identify which factors might affect NIV failure in paediatric ALI/ARDS patients.

METHODS

A retrospective cohort study using comprehensive predictivity analysis was performed. All children admitted to our paediatric intensive care unit over a 4-year period for ALI/ARDS were reviewed. Basic, clinical, physiological parameters and their change after 1 h of NIV were considered and subjected to univariate analysis. Candidate prognostic variables were then subjected to multicollinearity scrutiny and logistic regression. Finally, variables significant in the logistic regression were subjected to predictivity analysis.

RESULTS

The number of organ failures at admission (NOF) is a strong predictor of NIV failure (odds ratio 5.26; p = 0.004). Having only one organ failure provides a probability of NIV success of 85.7% (sensitivity 87%; specificity 49%). One NIV failure will be predicted and avoided for every four cases in which the presence of other organ failures is incorporated into the clinical decision.

CONCLUSIONS

NOF significantly predicts the NIV failure. Children with no organ failures other than ALI/ARDS may safely be treated with NIV.

Management of acute lung injury/ARDS

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are disorders of pulmonary inflammation characterized by hypoxemia and respiratory failure. Children have varying incidence of ALI/ARDS from 2.2 to 16 per 100,000 pediatric population associated with high morbidity, mortality, and financial burden. The diagnostic criteria include: acute onset, severe arterial hypoxemia resistant to oxygen therapy alone (PaO₂/FIO₂ ratio ≤ 200 for ARDS and ≤ 300 for ALI), diffuse pulmonary inflammation (bilateral infiltrates on chest radiograph) and No evidence of left atrial hypertension. Management includes ventilatory therapy including lower tidal volume, relatively high PEEP and supportive care. Guidelines for diagnosis, ventilator management, rescue therapies and supportive care are being discussed in the protocol.

Continuous negative extrathoracic pressure or continuous positive airway pressure for acute hypoxemic respiratory failure in children

BACKGROUND

Acute hypoxemic respiratory failure (AHRF) is an important cause of mortality and morbidity in children. Positive pressure ventilation is currently the standard care, however, it does have complications. Continuous negative extrathoracic pressure ventilation (CNEP) or continuous positive airway pressure (CPAP) ventilation delivered via non-invasive approaches (Ni-CPAP) have shown certain beneficial effects in animal and uncontrolled human studies.

OBJECTIVES

The primary objective was to assess the effectiveness of CNEP or Ni-CPAP in pediatric patients with AHRF from non-cardiogenic causes.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library 2007, Issue 3); MEDLINE (January 1966 to July 2007); EMBASE (1980 to July 2007); CINAHL (1982 to July 2007); and published abstracts from the meetings of the American Thoracic Society and Pediatric Critical Care Meetings (1992 to 2007).

SELECTION CRITERIA

Randomized or quasi-randomized clinical trials of either CNEP or Ni-CPAP versus standard therapy (including positive pressure ventilation) involving children (at least 1 month old and less than 18 years of age at the time of randomization) who met the criteria for diagnosis of AHRF with at least one of the outcomes reported were included.

DATA COLLECTION AND ANALYSIS

Risks of bias of the included study was assessed using: concealment of allocation, blinding of intervention, completeness of follow up and blinding of outcome measurements. Data on relevant outcomes were abstracted and the effect size was estimated by calculating relative risk (RR) with 95% confidence intervals (CI) and risk difference (RD).

MAIN RESULTS

One eligible study published in an abstract format was identified. It studied 33 infants (18 controls, 15 receiving CNEP) with a clinical diagnosis of bronchiolitis and fraction of inspired oxygen (FiO(2)) > 40% were studied. This allowed a reduction in the FiO(2) (< 30% within one hour of initiation of therapy) in four patients in the CNEP group compared to none in the control group (RR 10.7, 95% CI 0.6 to 183.9). One infant required CPAP and one infant required nasal CPAP in the control group while all infants in the CNEP group were managed without intubation (RR for both outcomes 0.40, 95% CI 0.02 to 9.06).

AUTHORS' CONCLUSIONS

There is a lack of well designed, controlled experiments of non-invasive modes of respiratory support in children with AHRF. Reduction of in-hospital mortality is an important outcome and even a small reduction would be beneficial. Studies assessing other outcomes such as avoidance of intubation and its associated complications, reduction in hospital stay and improvement in patient comfort are also valuable in gauging the overall impact of these strategies.