Effects of nasal high flow on nocturnal hypercapnia, sleep, and sympathovagal balance in patients with neuromuscular disorders

The Role of High Flow Nasal Therapy in Chronic Respiratory Failure

High-flow nasal therapy (HFNT) has an increasing role in the management of acute hypoxic respiratory failure. Due to its tolerable interface and ease of use, its role in chronic hypercapnic respiratory failure (CHRF) is emerging. This article examines the literature to date surrounding the short and long-term mechanisms of HFNT in sleep and wakefulness of CHRF patients. It is likely HFNT will have an increasing role in those patients intolerant of non-invasive ventilation.

Perioperative Management in Neuromuscular Diseases: A Narrative Review

Patients with neuromuscular diseases are particularly vulnerable in the perioperative period to the development of pulmonary and cardiac complications, or medication side effects. These risks could include hypoventilation, aspiration pneumonia, exacerbation of underlying cardiomyopathy, arrhythmias, adrenal insufficiency, prolonged neuromuscular blockade, issues related to thermoregulation, rhabdomyolysis, malignant hyperthermia, or prolonged mechanical ventilation. Interventions at each of the perioperative stages can be implemented to mitigate these risks. A careful pre-operative evaluation may help identify risk factors so that appropriate interventions are initiated, including cardiology consultation, pulmonary function tests, initiation of noninvasive ventilation, or implementation of preventive measures. Important intraoperative issues include positioning, airway and anesthetic management, and adequate ventilation. The postoperative period may require correction of electrolyte abnormalities, control of secretions with medications, manual or mechanical cough assistance, avoiding the risk of reintubation, judicious pain control, and appropriate medication management. The aim of this review is to increase awareness of the particular surgical challenges in this vulnerable population, and guide the clinician on the various evaluations and interventions that may result in a favorable surgical outcome.

The Safety of a High-Flow Nasal Cannula in Neuromuscular Disease Patients with Acute Respiratory Failure: A Retrospective Case-Series Study

(1) Background: Although Non-Invasive Ventilation (NIV) is effective in preventing mortality and endotracheal intubation in patients with Acute Respiratory Failure (ARF) linked to a neuromuscular disorder, its efficacy can be affected by patient intolerance. A High-Flow Nasal Cannula (HFNC) appears to have a significant advantage over NIV as far as patient tolerance is concerned. The aim of the study was to investigate HFNC's safety profile in a group of consecutive Neuromuscular Disease (NMD) patients intolerant to NIV who were admitted to an Intermediate Respiratory Care Unit (IRCU) for ARF. (2) Methods: The clinical course of nine NMD patients intolerant to NIV and switched to HFNC was reported. HFNC was provided during daytime hours and NIV during the night-time to the NIV-intolerant patients. HFNC was utilized 24 h a day in those patients who were intolerant of even nocturnal NIV. (3) Results: HFNC was simple to use and it was well tolerated by all of the patients. Three out of nine patients experienced treatment failure, consisting of the need for ETI and/or death during their IRCU stay. The remaining 6 had a favorable outcome. Treatment failure was linked to the utilization of HFNC 24 h a day. (4) Conclusion: HFNC during the daytime hours, together with nocturnal NIV, seems to be a safe therapeutic approach for NMD patients with ARF. A round-the-clock use of HFNC tends to be linked to a high likelihood of failure.

Effects of nasal high flow on sympathovagal balance, sleep, and sleep-related breathing in patients with precapillary pulmonary hypertension

BACKGROUND

In precapillary pulmonary hypertension (PH), nasal high flow therapy (NHF) may favorably alter sympathovagal balance (SVB) and sleep-related breathing through washout of anatomical dead space and alleviation of obstructive sleep apnea (OSA) due to generation of positive airway pressure.

OBJECTIVES

To investigate the effects of NHF on SVB, sleep, and OSA in patients with PH, and compare them with those of positive airway pressure therapy (PAP).

METHODS

Twelve patients with PH (Nice class I or IV) and confirmed OSA underwent full polysomnography, and noninvasive monitoring of SVB parameters (spectral analysis of heart rate, diastolic blood pressure variability). Study nights were randomly split into four 2-h segments with no treatment, PAP, NHF 20 L/min, or NHF 50 L/min. In-depth SVB analysis was conducted on 10-min epochs during daytime and stable N2 sleep at nighttime.

RESULTS

At daytime and compared with no treatment, NHF20 and NHF50 were associated with a flow-dependent increase in peripheral oxygen saturation but a shift in SVB towards increased sympathetic drive. At nighttime, NHF20 was associated with increased parasympathetic drive and improvements in sleep efficiency, but did not alter OSA severity. NHF50 was poorly tolerated. PAP therapy improved OSA but had heterogenous effects on SVB and neutral effects on sleep outcomes. Hemodynamic effects were neutral for all interventions.

CONCLUSIONS

In sleeping PH patients with OSA NHF20 but not NHF50 leads to decreased sympathetic drive likely due to washout of anatomical dead space. NHF was not effective in lowering the apnea-hypopnoea index and NHF50 was poorly tolerated.