Complex effects of high-flow nasal cannula therapy on hemodynamics in the pediatric patient after cardiac surgery

Effects of High-Flow Nasal Cannula on Right Heart Dysfunction in Patients with Acute-on-Chronic Respiratory Failure and Pulmonary Hypertension

High-flow nasal cannula (HFNC) has several benefits in patients affected by different forms of acute respiratory failure, based on its own mechanisms. We postulated that HFNC may have some advantages over conventional oxygen therapy (COT) on the heart function in patients with acute-on-chronic respiratory failure with concomitant pulmonary hypertension (PH). We therefore designed this retrospective observational study to assess if HFNC improves the right and left ventricle functions and morphologies, arterial blood gases (ABGs), and patients' dyspnea, compared to COT. We enrolled 17 hospitalized patients receiving HFNC, matched with 17 patients receiving COT. Echocardiographic evaluation was performed at the time of admission (baseline) and 10 days after (T10). HFNC showed significant improvements in right ventricular morphology and function, and a reduction in sPAP. However, there were no significant changes in the left heart measurements with HFNC application. Conversely, COT did not lead to any modifications in echocardiographic measurements. In both groups, oxygenation significantly improved from baseline to T10 (in the HFNC group, from 155 ± 47 to 204 ± 61 mmHg while in the COT group, from 157 ± 27 to 207 ± 27 mmHg; p < 0.0001 for both comparisons). In conclusion, these data suggest an improvement of oxygenation with both treatments; however, only HFNC was able to improve the right ventricular morphology and function after 10 days from the beginning of treatment in a small cohort of patients with acute-on-chronic respiratory failure with PH.

Application of high-flow nasal cannula in fibreoptic bronchoscopy after congenital heart surgery: a retrospective cohort study

BACKGROUND

The purpose of this study was to compare the effectiveness and safety of high-flow nasal cannula (HFNC) and conventional oxygen therapy (COT) in fibreoptic bronchoscopy (FB) after congenital heart surgery (CHS) in children.

METHODS

We did a retrospective cohort study using patients from the electronic medical record system of Fujian Children's Hospital in China. The study population was children who underwent FB in the cardiac intensive care unit after CHS for 1 year (May 2021-May 2022). Children were classified into HFNC and COT groups according to their oxygen therapy during FB. The primary outcome was oxygenation indices during FB, including pulse oximeter oxygen saturation (SpO2) and transcutaneous oxygen tension (TcPO2) during FB. Secondary outcomes were the number of interruptions during FB and their causes, and complications after FB.

RESULTS

We identified 107 children from the electronic medical record system, and 102 children after CHS were finally included in the study (53 in the HFNC group and 49 in the COT group). During the FB examination, TcPO2 and SpO2 were significantly higher in the HFNC group than in the COT group (TcPO2: 90.3±9.3 vs 80.6±11.1 mm Hg; SpO2: 95.6±2.5 vs 92.1%±2.0%, p<0.001) and the transcutaneous carbon dioxide tension was significantly lower than in the COT group (39.6±3.0 vs 43.5±3.9 mm Hg, p<0.001). During the FB, a total of 20 children in the COT group had 24 interruptions, and 8 children in the HFNC group had 9 interruptions (p=0.001). In terms of postoperative complications, eight cases had complications in the COT group and four complications in the HFNC group (p=0.223).

CONCLUSIONS

Among children undergoing FB after CHS, the application of HFNC was associated with better oxygenation and fewer procedural interruptions compared with COT, without an increased risk of postoperative complications.

Cardiopulmonary outcomes following high flow nasal cannula in pediatric population: A systematic review

BACKGROUND

The high-flow nasal cannula (HFNC) has received much attention in various clinical settings and has been approved recently for application in pediatric care.

OBJECTIVES

To determine whether HFNC use improves cardiopulmonary outcomes in pediatric patients with the cardiac disease more effectively than alternative oxygen therapies.

METHODS

Systematic review was performed using PubMed, Scopus, and Web of Science databases. Randomized controlled trials comparing HFNC with alternative oxygen therapies and observational studies that solely reported on the use of HFNC in the pediatric population were included between 2012 and 2022.

RESULTS

Nine studies with approximately 656 patients were reported in this review. HFNC significantly increased systemic oxygen saturation across all literature investigating this parameter. Other notable outcomes in HFNC patients included normalizing heart rate, partial blood pressure, and PaO₂/FiO₂ ratio. However, some studies reported a complication rate concurrent with traditional oxygen therapies, and a suggested HFNC failure rate of 50% was observed.

CONCLUSIONS

Compared with traditional oxygen therapies, HFNC can reduce anatomical dead space and normalize systemic oxygen saturation, PaO2/FiO2 ratio, heart rate, and partial blood pressure. We advocate using HFNC therapy in children with cardiac diseases as the currently available evidence supports HFNC use over other oxygenation treatments in the pediatric population.

Comparison of High-Flow Nasal Cannula Versus Conventional Oxygen Therapy After Extubation in Children Undergoing Cardiac Surgery: A Meta-analysis

This meta-analysis aims to compare high-flow nasal cannula (HFNC) and conventional oxygen therapy (COT) post-extubation in pediatric cardiac surgical patients. The present meta-analysis was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Two authors independently searched three electronic databases including PubMed, Embase, and the Cochrane Library to identify relevant articles published in English from inception to February 2023. Searching was conducted using keywords and medical subject headings (MeSH), which included "conventional oxygen therapy," "high-flow nasal cannula," "extubation," "pediatrics," and "cardiac surgery." Our primary outcome was extubation failure defined as the need for reintubation within 24 to 72 hours after planned extubation. Secondary outcomes assessed in this meta-analysis included partial pressure of arterial oxygen (PaO2), partial pressure of arterial carbon dioxide (PaCO2), and the ratio of PaO2 and FiO2 (fraction of inspired oxygen). A total of three studies were included in the meta-analysis, with a total of 227 patients.  No significant difference was found between the two groups (the HFNC group and the COT group) in terms of reintubation (RR: 0.88, 95% CI: 0.34, 2.30, p-value: 0.80). Pooled meta-analysis showed that PaO2 was significantly greater in patients receiving HFNC at six hours (MD: 33.73, 95% CI: 18.33, 49.14, p-value<0.001), at 12 hours (MD: 44.90, 95% CI: 28.59, 61.22, p-value<0.001) and at 24 hours (MD: 43.53, 95% CI: 29.16, 57.91, p-value<0.001) of extubation. PaCO2 was significantly lower in patients receiving HFNC at six hours (MD: -5.40, 95% CI: -7.94, -2.85, p-value<0.001) and at 12 hours (MD: -5.93, 95% CI: -9.78, -2.09, p-value<0.001) of extubation. However, no significant difference was reported between the two groups after 24 hours of extubation (MD: -0.84, 95% CI: -9.04, 7.37, p-value: 0.84) and PaO2/FiO2 was significantly greater in patients receiving HFNC at six hours (MD: 64.14, 95% CI: 36.10, 92.17, p-value<0.001), at 12 hours (MD: 70.73, 95% CI: 20.46, 121.01, p-value<0.001) and at 24 hours (MD: 82.18, 95% CI: 50.03, 114.32, p-value<0.001) of intubation. In conclusion, the meta-analysis revealed that compared with COT, HFNC significantly increased PaO2 and the ratio of PaO2 to FiO2, and decreased PaCO2. No significant differences were observed in the rate of reintubation between the two groups. This is the first meta-analysis comparing HFNC and COT in pediatric cardiac surgical patients.

Clinical review of high-flow nasal oxygen therapy in human and veterinary patients

Oxygen therapy is the first-line treatment for hypoxemic acute respiratory failure. In veterinary medicine this has traditionally been provided via mask, low-flow nasal oxygen cannulas, oxygen cages and invasive positive pressure ventilation. Traditional non-invasive modalities are limited by the maximum flow rate and fraction of inspired oxygen (FiO₂) that can be delivered, variability in oxygen delivery and patient compliance. The invasive techniques are able to provide higher FiO₂ in a more predictable manner but are limited by sedation/anesthesia requirements, potential complications and cost. High-flow nasal oxygen therapy (HFNOT) represents an alternative to conventional oxygen therapy. This modality delivers heated and humidified medical gas at adjustable flow rates, up to 60 L/min, and FiO₂, up to 100%, via nasal cannulas. It has been proposed that HFNOT improves pulmonary mechanics and reduces respiratory fatigue via reduction of anatomical dead space, provision of low-level positive end-expiratory pressure (PEEP), provision of constant FiO₂ at rates corresponding to patient requirements and through improved patient tolerance. Investigations into the use of HFNOT in veterinary patients have increased in frequency since its clinical use was first reported in dogs with acute respiratory failure in 2016. Current indications in dogs include acute respiratory failure associated with pulmonary parenchymal disease, upper airway obstruction and carbon monoxide intoxication. The use of HFNOT has also been advocated in certain conditions in cats and foals. HFNOT is also being used with increasing frequency in the treatment of a widening range of conditions in humans. Although there remains conflict regarding its use and efficacy in some patient groups, overall these reports indicate that HFNOT decreases breathing frequency and work of breathing and reduces the need for escalation of respiratory support. In addition, they provide insight into potential future veterinary applications. Complications of HFNOT have been rarely reported in humans and animals. These are usually self-limiting and typically result in lower morbidity and mortality than those associated with invasive ventilation techniques.

Anesthetic management using high-flow nasal cannula therapy during cardiac catheter examination of a neonate with hypoplastic left heart syndrome

Background

Sedation during cardiac catheter examination in neonates with complex congenital heart disease is challenging, as even the slightest change in the circulatory or respiratory status can lead to hemodynamic collapse. Here, we report a case wherein we achieved adequate sedation with a high-flow nasal cannula (HFNC) for catheter examination in a neonate with a congenital cardiac anomaly.

Case presentation

An 11-day-old boy with hypoplastic left heart syndrome was scheduled for a cardiac catheter examination prior to the Norwood procedure. He underwent bilateral pulmonary artery banding (PAB) on day 1 and was receiving dobutamine, milrinone, alprostadil, and dexmedetomidine in addition to air and nitrogen insufflation via HFNC, which was applied following extubation on day 3 and nitrogen therapy on day 6 owing to persistent pulmonary overcirculation symptoms (tachypnea and low arterial blood pressure) despite bilateral PAB. A catheter examination was performed on day 11 with careful monitoring of expired carbon dioxide and observation of chest wall motion. Adequate sedation was provided with supplemental midazolam and fentanyl along with HFNC without tracheal intubation.

Conclusions

The findings from this case suggest that HFNC is a safe and effective tool for oxygenation during cardiac catheter examination under sedation in neonates.

Home High-Flow Nasal Cannula Therapy in Children with Congenital Heart Disease

High-flow nasal cannula (HFNC) therapy has been applied in the perioperative respiratory care for children with congenital heart disease and respiratory problems. However, the information about the feasibility of home HFNC therapy remains lacking among them. We retrospectively reviewed 5 children with congenital heart disease and respiratory problems who underwent home HFNC therapy, and evaluated their feasibility and safety. Age and weight at the introduction of home HFNC therapy were 19 (2-119) months and 5.3 (3.1-11.4) kg, respectively. All subjects had chromosomal anomaly including trisomy 18 in 3 and trisomy 21 in 2 subjects. Cardiac diagnoses included ventricular septal defect in 3, tetralogy of Fallot with complete atrioventricular septal defect in one, and pulmonary atresia with ventricular septal defect in another subject. Other comorbidities involved pulmonary hypertension in 4, micrognathia in 4, West syndrome in one, and bronchial asthma in one subject. Respiratory manifestations involved cyanosis due to upper airway obstruction in 2 and central hypopnea in 2, and recurrent pneumonia in one subject. After home HFNC therapy, systemic oxygen saturation significantly increased from 60 (40-78)% to 83 (83-96)% (P = 0.04), while heart rate and blood partial pressure of carbon dioxide were significantly decreased. There was no adverse event relevant to home HFNC during the follow-up period of 12 (5-49) months. Among them, one patient subsequently underwent tracheotomy at 11 years of age, and two patients weaned to conventional home oxygen therapy at 7 and 23 months of age. Home HFNC is safe and feasible in children with congenital heart disease and respiratory problems.

Utility of High Flow Nasal Cannula during Pulmonary Rehabilitation in COVID-19 Patients in Acute Respiratory Failure

High-flow nasal cannula (HFNC) has often been used in the treatment of acute respiratory failure during pulmonary rehabilitation setting. The aim of this retrospective study was to investigate the utility of HCFN during the early rehabilitation in COVID-19 pneumonia. Twenty-two patients (10 males and 12 females, mean age 64.5 ± 5.9 years) with COVID-19 pneumonia were considered. Medical data and rehabilitative scales were used to evaluate acute hypoxemic respiratory failure (PaO2/FiO2 < 300), treated with HFNC three times during evaluation. Overall clinical outcomes from the evaluation of the synergy between HFNC strategy and rehabilitation were evaluated. A statistically significant improvement was observed at T2 (and of treatment) in 1 minute sit to stand test (1STST) (4 ± 3 vs. 17 ± 5, p < 0.05), short physical performance battery (SPPB) (4.3 ± 2.81 vs. 9.15 ± 2.39, p < 0.05), SpO2% post effort (93 ± 1.26 vs. 98 ± 1.01, p < 0.05), respiratory rate post effort (RR) (24 ± 3.91 vs. 20 ± 3.13, p < 0.05), heart rate (HR) (97 ± 11.9 vs. 87 ± 9.17, p < 0.05), P/F rate (235 ± 7.35 vs. 331 ± 10.91, p < 0.05), SpO2 (86 ± 4.54 vs. 97 ± 1.01 p < 0.05), RR (20 ± 4 vs. 12 ± 1.39, p < 0.05). Then, treated HFNC patients showed a good improvement in physical performance at T2 and a good compliance with treatments proved to be extremely useful in the control and reduction of dyspnea and fatigue symptoms.

Nasal High-Frequency Oscillatory Ventilation vs. Nasal Continuous Positive Airway Pressure as Therapy for Postextubation Respiratory Failure in Infants After Congenital Heart Surgery

Objective: This study aimed to evaluate the effects of nasal high-frequency oscillatory ventilation (NHFOV) vs. nasal continuous positive airway pressure (NCPAP) on postextubation respiratory failure (PRF) in infants after congenital heart surgery (CHS). Method: Eighty infants underwent postoperative invasive mechanical ventilation for more than 12 h and planned extubation. The infants were randomized to undergo either NHFOV or NCPAP after extubation. Primary outcomes were the incidence of PRF and reintubation, the average PaCO₂ level, the average oxygenation index (OI), and pulmonary recruitment in the early extubation phase. Secondary outcomes included the NCPAP/NHFOV time, length of hospital stay, treatment intolerance, signs of discomfort, pneumothorax, adverse hemodynamic effects, nasal trauma, and mortality. Results: Except for PaCO₂ within 12 after extubation (39.3 ± 5.8 vs. 43.6 ± 7.3 mmHg, p = 0.05), there was no statistically significant difference for any of the primary outcome measure (PRF, reintubation within 12 h after extubation, oxygenation index within 12 h after extubation, or lung volumes on X-ray after extubation) or secondary outcome measures (duration of non-invasive ventilation, duration of hospital stay, ventilation intolerance, signs of discomfort, pneumothorax, nasal trauma, adverse hemodynamic effects, or death prior to discharge), p > 0.1 for each comparison. Conclusion: NHFOV therapy after extubation in infants after CHS was more efficient in improving CO₂ cleaning than NCPAP therapy, but there was no difference in other outcomes (PRF, reintubation, oxygenation index, and pulmonary recruitment).

Effect of postextubation high-flow nasal cannula therapy on lung recruitment and overdistension in high-risk patient

Background

Postextubation high-flow nasal cannula (HFNC) is used as a support therapy in high-risk patients in ICU. This study aimed to determine the effects of HFNC therapy on lung recruitment and overdistension assessed by electrical impedance tomography (EIT).

Methods

Twenty-four patients who received HFNC within 24 h after extubation were prospectively enrolled in this study. EIT was used to monitor regional lung ventilation distributions at baseline (conventional oxygen therapy) and three flow rate levels of HFNC therapy (20, 40, and 60 L/min). Change of end-expiratory lung impedance (ΔEELI), regional recruitment (recruited-pixels) and overdistension (overdistended-pixels), and lung strain change were determined by EIT. EIT images were equally divided into four ventral-to-dorsal horizontal regions of interest (ROIs 1, 2, 3, and 4). “Overdistension-_{by HFNC}” due to HFNC is defined as an increase of overdistened-pixels > 10 than baseline. Patients were divided into two groups: (1) high potential of recruitment (HPR), recruited-pixels > 10 pixels at 60 L/min than baseline, and (2) low potential of recruitment (LPR), recruited-pixels < 10 pixels at 60 L/min than baseline.

Results

When the flow rate gradually increased from baseline to 60 L/min, a significant and consistent increasing trend of global ΔEELI (%) (p < 0.0001), recruited-pixels (p < 0.001), and overdistended-pixels (p = 0.101) was observed. Moreover, the increase of ΔEELI was mainly distributed in ROI2 (p = 0.001) and ROI3 (p < 0.0001). The HPR group (13/24 patients) had significantly higher recruited-pixels than the LPR group (11/24 patients) at 20, 40, and 60 L/min. There were no significant differences in PaO₂/FiO₂, ΔEELI (%), and overdistention pixels between the two groups. The HPR group had 13 patients in which no one had “overdistension-_{by HFNC}”, and the LPR group had 11 patients in which 4 patients had “overdistension-_{by HFNC}” (0/13 vs. 4/11, p = 0.017).

Conclusions

Using EIT could identify diverse effects of HFNC on lung regional ventilation in postextubation situations. Further study is required to validate using “HFNC effect” based on lung recruitment and overdistension by EIT in clinical practice.

Trial registration

The study was retrospectively registered at www.clinicaltrials.gov (no. NCT04245241).

Positive Airway Pressure Versus High-Flow Nasal Cannula for Prevention of Extubation Failure in Infants After Congenital Heart Surgery

OBJECTIVES

Compare the impact of initial extubation to positive airway pressure versus high-flow nasal cannula on postoperative outcomes in neonates and infants after congenital heart surgery.

DESIGN

Retrospective cohort study with propensity-matched analysis.

SETTING

Cardiac ICU within a tertiary care children's hospital.

PATIENTS

Patients less than 6 months old initially extubated to either high-flow nasal cannula or positive airway pressure after cardiac surgery with cardiopulmonary bypass were included (July 2012 to December 2015).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of 258 encounters, propensity matching identified 49 pairings of patients extubated to high-flow nasal cannula versus positive airway pressure. Extubation failure was 12% for all screened encounters. After matching, there was no difference in extubation failure rate between groups (positive airway pressure 16% vs high-flow nasal cannula 10%; p = 0.549). However, compared with high-flow nasal cannula, patients initially extubated to positive airway pressure experienced greater resource utilization: longer time to low-flow nasal cannula (83 vs 28 hr; p = 0.006); longer time to room air (159 vs 110 hr; p = 0.013); and longer postsurgical hospital length of stay (22 vs 14 d; p = 0.015).

CONCLUSIONS

In this pediatric cohort, primary extubation to positive airway pressure was not superior to high-flow nasal cannula with respect to prevention of extubation failure after congenital heart surgery. Compared with high-flow nasal cannula, use of positive airway pressure was associated with increased hospital resource utilization. Prospective initiatives aimed at establishing best clinical practice for postoperative noninvasive respiratory support are needed.