Following cardiac surgery, infants often remain endotracheally intubated upon arrival to the cardiac ICU. High-flow nasal cannula and non-invasive positive pressure ventilation are used to support patients following extubation. There are limited data on the superiority of either mode to prevent extubation failure.

We conducted a single-centre retrospective study for infants (<1 year) and/or <10 kg who underwent cardiac surgery between 3/2019–3/2020. Data included patient and clinical characteristics and operative variables. The study aimed to compare high-flow nasal cannula versus non-invasive positive pressure ventilation following extubation and their association with extubation failure. Secondarily, we examined risk factors associated with extubation failure.

There were 424 patients who met inclusion criteria, 320 (75%) were extubated to high-flow nasal cannula, 104 (25%) to non-invasive positive pressure ventilation, and 64 patients (15%) failed extubation. The high-flow nasal cannula group had lower rates of extubation failure (11%, versus 29%, p = 0.001). Infants failing extubation were younger and had higher STAT score (p < 0.05). Compared to high-flow nasal cannula, non-invasive positive pressure ventilation patients were at 3.30 times higher odds of failing extubation after adjusting for patient factors (p < 0.0001).

Extubation failure after cardiac surgery occurs in smaller, younger infants, and those with higher risk surgical procedures. Patients extubated to non-invasive positive pressure ventilation had 3.30 higher odds to fail extubation than patients extubated to high-flow nasal cannula. The optimal mode of respiratory support in this patient population is unknown.

Duchenne muscular dystrophy is associated with progressive cardiorespiratory failure, including left ventricular dysfunction.

Males with probable or definite diagnosis of Duchenne muscular dystrophy, diagnosed between 1 January, 1982 and 31 December, 2011, were identified from the Muscular Dystrophy Surveillance Tracking and Research Network database. Two non-mutually exclusive groups were created: patients with ≥2 echocardiograms and non-invasive positive pressure ventilation-compliant patients with ≥1 recorded ejection fraction. Quantitative left ventricular dysfunction was defined as an ejection fraction <55%. Qualitative dysfunction was defined as mild, moderate, or severe. Progression of quantitative left ventricular dysfunction was modelled as a continuous time-varying outcome. Change in qualitative left ventricle function was assessed by the percentage of patients within each category at each age. Forty-one percent (n = 403) had ≥2 ejection fractions containing 998 qualitative assessments with a mean age at first echo of 10.8 ± 4.6 years, with an average first ejection fraction of 63.1 ± 12.6%. Mean age at first echo with an ejection fraction <55 was 15.2 ± 3.9 years. Thirty-five percent (140/403) were non-invasive positive pressure ventilation-compliant and had ejection fraction information. The estimated rate of decline in ejection fraction from first ejection fraction was 1.6% per year and initiation of non-invasive positive pressure ventilation did not change this rate.

In our cohort, we observed that left ventricle function in patients with Duchenne muscular dystrophy declined over time, independent of non-invasive positive pressure ventilation use. Future studies are needed to examine the impact of respiratory support on cardiac function.

Continuous positive airway pressure (CPAP) improves outcomes in patients with respiratory distress. Additional benefits are seen with CPAP application in the prehospital setting. Theoretical safety concerns regarding Basic Life Support (BLS) providers using CPAP exist. In Delaware’s (USA) two-tiered Emergency Medical Service (EMS) system, BLS often arrives before Advanced Life Support (ALS).

This study fills a gap in literature by evaluating the safety of CPAP applied by BLS prior to ALS arrival.

This was a retrospective, observational study using Quality Assurance (QA) data collected from October 2009 through December 2012 throughout a state BLS CPAP pilot program; CPAP training was provided to BLS providers prior to participation. Collected data include pulse-oximetry (spO2), respiratory rate (RR), heart rate (HR), skin color, and Glasgow Coma Score (GCS) before and after CPAP application. Pre-CPAP and post-CPAP values were compared using McNemar’s and t-tests. Advanced practitioners evaluated whether CPAP was correctly applied and monitored and whether the patient condition was “improved,” “unchanged,” or “worsened.”

Seventy-four patients received CPAP by BLS; CPAP was correctly indicated and applied for all 74 patients. Respiratory status and CPAP were appropriately monitored and documented in the majority of cases (98.6%). A total of 89.2% of patients improved and 4.1% worsened; CPAP significantly reduced the proportion of patients with SpO2<92%, RR>24, and cyanosis (P<.01). The GCS improved from mean (standard deviation [SD]) 13.9 (SD=1.9) to 14.1 (SD=1.9) after CPAP (mean difference [MD]=0.17; 95% CI, -0.49 to 0.83; P=.59). The HR decreased from 115.7 (SD=53) to 105.1 (SD=37) after CPAP (MD=-10.9; 95% CI, -3.2 to -18.6; P<.01). The SpO2 increased from 80.8% (SD=11.4) to 96.9% (SD=4.2) after CPAP (MD=17.8; 95% CI, 14.2-21.5; P<.01).

The BLS providers were able to determine patients for whom CPAP was indicated, to apply it correctly, and to appropriately monitor the status of these patients. The majority of patients who received CPAP by BLS providers had improvement in their clinical status and vital signs. The findings suggest that CPAP can be safely used by BLS providers with appropriate training.

SahuN, MatthewsP, GronerK, PapasMA, MegargelR. Observational Study on Safety of Prehospital BLS CPAP in Dyspnea. Prehosp Disaster Med. 2017;32(6):610–614.

Non-invasive positive pressure ventilation (NIPPV) is used to treat severe acute respiratory distress. Prehospital NIPPV has been associated with a reduction in both in-hospital mortality and the need for invasive ventilation.

The authors of this study examined factors associated with NIPPV failure and evaluated the impact of NIPPV on scene times in a critical care helicopter Emergency Medical Service (HEMS). Non-invasive positive pressure ventilation failure was defined as the need for airway intervention or alternative means of ventilatory support.

A retrospective chart review of consecutive patients where NIPPV was completed in a critical care HEMS was conducted. Factors associated with NIPPV failure in univariate analyses and from published literature were included in a multivariable, logistic regression model.

From a total of 44 patients, NIPPV failed in 14 (32%); a Glasgow Coma Scale (GCS) <15 at HEMS arrival was associated independently with NIPPV failure (adjusted odds ratio 13.9; 95% CI, 2.4-80.3; P=.003). Mean scene times were significantly longer in patients who failed NIPPV when compared with patients in whom NIPPV was successful (95 minutes vs 51 minutes; 39.4 minutes longer; 95% CI, 16.2-62.5; P=.001).

Patients with a decreased level of consciousness were more likely to fail NIPPV. Furthermore, patients who failed NIPPV had significantly longer scene times. The benefits of NIPPV should be balanced against risks of long scene times by HEMS providers. Knowing risk factors of NIPPV failure could assist HEMS providers to make the safest decision for patients on whether to initiate NIPPV or proceed directly to endotracheal intubation prior to transport.

LeeJS , O’DochartaighD , MacKenzieM , HudsonD , CouperthwaiteS , Villa-RoelC , RoweBH . Factors Associated with Failure of Non-invasive Positive Pressure Ventilation in a Critical Care Helicopter Emergency Medical Service. Prehosp Disaster Med2015; 30(2): 1–5