Effects of high flow nasal cannula on the coordination between swallowing and breathing in postextubation patients, a randomized crossover study

Abstract

Background Timing of swallows in relation to respiratory phases is associated with aspiration events. Oxygen therapy possibly affects the timing of swallows, which may alter airway protective mechanisms. Objectives To compare the coordination between swallowing and respiration during water infusion in post-extubation patients using high flow nasal oxygen (HFNO) with the coordination in those using low flow nasal oxygen (LFNO). Methods We conducted a randomized controlled crossover study in post-extubation patients. The patients extubated within 48 h were randomly assigned to two groups, namely, HFNO and LFNO. The eligible patients in each group received either HFNO with fraction of inspired oxygen (FiO2) 0.35, flow 50 L per minute (LPM), and temperature 34 °C or LFNO 5 LPM for 5 min. The coordination between swallowing and respiration was observed during continuous infusion of 10-ml water one minute three times. Respiratory phases and swallowing were monitored using electrocardiogram (EKG)-derived respiratory signals and submental electromyography (EMG), respectively. The swallowing frequency and timing of swallows in relation to respiratory phases were recorded. The coordination between swallowing and respiration was classified into 4 patterns, namely I, E, I-E, and E-I swallows. (I; inspiration and E; expiration) Subsequently, after a 5-min washout period, the patients were switched to the other type of oxygen therapy using the same procedure. The Wilcoxon Signed-Rank Test was used for statistical analysis. Results A total of 22 patients with a mean age of 56 years were enrolled in the study. The major indication for invasive mechanical ventilation was pneumonia with a median duration of endotracheal intubation of 2.5 days. The median total swallowing numbers (three minutes) were 18.5 times in the HFNO period and 21 times in the LFNO period (p = NS). The most common swallowing pattern was E-swallow. The patients using HFNO had higher numbers of E-swallow pattern (74.3% in HFNO vs 67.6% in LFNO; p = 0.048) and lower numbers of I-swallow pattern (14.3% in HFNO vs 23.1% in LFNO; p = 0.044). The numbers of other swallowing patterns were not different between the 2 groups. Conclusions Compared with LFNO, HFNO significantly increased the E-swallow and decreased the I-swallow in post-extubation patients. The findings indicated that HFNO might reduce a risk of aspiration during the post-extubation period. Clinical trial No.: Thai clinical trial TCTR20200206004 Registered February 4, 2020. URL: http://www.clinicaltrials.in.th/index.php?tp=regtrials&menu=trialsearch&smenu=fulltext&task=search&task2=view1&id=5740.

Assessment of Swallowing Function in Healthy Adults While Using High‐Flow Nasal Cannula

“…Despite widespread inpatient use, including for respiratory support of critically-ill patients eating by mouth, there are no accepted guidelines for HFNC flow rates that permit safe swallowing, and limited literature exists on this topic. [10][11][12][13][14][15][16] In our study, we assessed swallowing safety in nondysphagic, healthy individuals using FEES, one of the gold standards for oropharyngeal swallowing evaluation, with different textures under varying, randomized flow rates of HFNC (0, 30, 40, 50, and 60 LPM). PAS scores of 1 to 5 were considered safe swallows, and scores of 6 to 8 were considered unsafe swallows.…”

“…HFNC has been shown to alter the timing of swallows in relation to inspiration and expiration in a cohort of 22 postextubation, critically ill patients. 11 Flores et al 12 conclude starting ill patients on HFNC on an oral diet should be considered on a case by case basis after considering multiple patient factors.…”

“…Knowing this, it is reasonable to expect that introducing a new factor, HFNC, into the respiratory‐swallowing dynamic, may impact swallowing efficiency and safety. Although HFNC has been widely adopted for respiratory support, limited literature exists on the effect of HFNC on swallowing function in healthy adults and in ill patients 10‐16 …”

“…Although HFNC has been widely adopted for respiratory support, limited literature exists on the effect of HFNC on swallowing function in healthy adults and in ill patients. [10][11][12][13][14][15][16] To date, 4 prior studies have investigated the effect of HFNC on swallowing physiology and safety in healthy cohorts, as summarized in Table 1. [13][14][15][16] Sanuki et al 13 evaluated laryngeal electromyography after administration of a bolus of water with respiratory inductance plethysmography in 9 healthy adults at 4 flow rates.…”

Biomechanical mechanism of reduced aspiration by the Passy-Muir valve in tracheostomized patients following acquired brain injury: Evidences from subglottic pressure

“…There is a highly stable and coordinated relationship between swallowing and respiration in healthy adults, in which swallowing usually occurs during the expiratory phase and further exhalation occurs after swallowing ( Rattanajiajaroen and Kongpolprom, 2021 ). After tracheostomy, a significant and persistent expiratory airflow leak occurs, which might counteract the protective effect of expiration on the upper airway, resulting in unsafe swallowing, and possible aspiration ( Eibling and Gross, 1996 ).…”