Upper airway obstruction assessment: Peak inspiratory flow and clinical COPD Questionnaire

Background Residual paralysis increases the risk of pulmonary complications but is difficult to detect. To test the hypothesis that accelerometry predicts effects of residual paralysis on pulmonary and upper airway function, the authors related tests of pulmonary and pharyngeal function to accelerometry of adductor pollicis muscle in 12 partially paralyzed volunteers. Methods Rocuronium (0.01 mg/kg + 2-10 microg x kg-1 x min-1) was administered to maintain train-of-four (TOF) ratios (assessed every 15 s) of approximately 0.5 and 0.8 over a period of more than 5 min. The authors evaluated pharyngeal and facial muscle functions during steady state relaxation and performed spirometric measurements every 5 min until recovery. Upper airway obstruction was defined as a mean ratio of expiratory and inspiratory flow at 50% of vital capacity of greater than 1. The TOF ratio associated with "acceptable" pulmonary recovery (forced vital capacity and forced inspiratory volume in 1 s of > or =90% of baseline) was calculated using a linear regression model. Results At peak blockade (TOF ratio 0.5 +/- 0.16), forced inspiratory flow was impaired (53 +/- 19%) to a greater degree than forced expiratory flow (75 +/- 20%) with a mean ratio of expiratory and inspiratory flow at 50% of vital capacity of 1.18 +/- 0.6. Upper airway obstruction, observed in 8 of 12 volunteers, paralleled an impaired ability to swallow reported by 10 of 12 volunteers. In contrast, all volunteers except one could sustain a head lift for more than 5 s. The authors calculated that a mean TOF ratio of 0.56 (95% confidence interval, 0.22-0.71) predicts "acceptable" recovery of forced vital capacity, whereas forced inspiratory volume in 1 s was impaired until a TOF ratio of 0.95 (0.82-1.18) was reached. A 100% recovery of TOF ratio predicts an acceptable recovery of forced vital capacity, forced inspiratory volume in 1 s, and mean ratio of expiratory and inspiratory flow at 50% of vital capacity in 93%, 73%, and 88% of measurements (calculated negative predictive values), respectively. Conclusion Impaired inspiratory flow and upper airway obstruction frequently occur during minimal neuromuscular blockade (TOF ratio 0.8), and extubation may put the patient at risk. Although a TOF ratio of unity predicts a high probability of adequate recovery from neuromuscular blockade, respiratory function can still be impaired.

Download Full-text

Analysis of Inspiratory Flow Shapes in Patients With Partial Upper-Airway Obstruction During Sleep

CHEST Journal ◽

10.1378/chest.119.1.37 ◽

2001 ◽

Vol 119 (1) ◽

pp. 37-44 ◽

Cited By ~ 47

Author(s):

Tero Aittokallio ◽

Tarja Saaresranta ◽

Päivi Polo-Kantola ◽

Olli Nevalainen ◽

Olli Polo

Keyword(s):

Airway Obstruction ◽

Upper Airway ◽

Inspiratory Flow ◽

Upper Airway Obstruction ◽

Partial Upper Airway Obstruction

Download Full-text

Assessment of Changes in Upper Airway Obstruction by Automatic Identification of Inspiratory Flow Limitation During Sleep

IEEE Transactions on Biomedical Engineering ◽

10.1109/tbme.2009.2023079 ◽

2009 ◽

Vol 56 (8) ◽

pp. 2006-2015 ◽

Cited By ~ 10

Author(s):

Christian Morgenstern ◽

Matthias Schwaibold ◽

Winfried J. Randerath ◽

Armin Bolz ◽

Raimon Jane

Keyword(s):

Airway Obstruction ◽

Upper Airway ◽

Inspiratory Flow ◽

Upper Airway Obstruction ◽

Automatic Identification ◽

Flow Limitation

Download Full-text

Inspiratory Flow Volume Loops and the Diagnosis of Upper Airway Obstruction

Clinical Pulmonary Medicine ◽

10.1097/cpm.0b013e3181857e7c ◽

2008 ◽

Vol 15 (5) ◽

pp. 274-282 ◽

Cited By ~ 2

Author(s):

Carl R. Pavel ◽

Michael J. Morris ◽

Karin L. Nicholson ◽

Jackie A. Hayes

Keyword(s):

Airway Obstruction ◽

Upper Airway ◽

Inspiratory Flow ◽

Upper Airway Obstruction ◽

Flow Volume

Download Full-text

Assessment of upper airway obstruction by measuring peak oral and nasal inspiratory flow

The Journal of Laryngology & Otology ◽

10.1017/s0022215115000523 ◽

2015 ◽

Vol 129 (5) ◽

pp. 473-477 ◽

Cited By ~ 4

Author(s):

S Bathala ◽

R Eccles

Keyword(s):

Airway Obstruction ◽

Phase Ii ◽

Flow Rate ◽

Upper Airway ◽

Inspiratory Flow ◽

Upper Airway Obstruction ◽

University Hospital ◽

Inspiratory Flow Rate ◽

Efficacy Measures ◽

Study Participants

AbstractObjective:We wanted to access upper airway obstruction in patients undergoing tonsillectomy by measuring peak oral and nasal inspiratory airflow.Methods:We recruited study participants from a cohort of patients on the waiting list for tonsillectomy, with or without adenoidectomy, at University Hospital of Wales, Cardiff, UK. Fifty patients enrolled on phase I of the study and underwent pre-operative measurement of the rate of peak oral and nasal inspiratory flow; 25 of these patients returned after one month for phase II of the study and underwent post-operative measurement of the rate of both peak oral and nasal inspiratory flow.Results:Of the 25 participants who completed phase II of the study, 17 (68 per cent) showed an increase in post-operative peak oral inspiratory flow rate by an average of 45 per cent, while 18 (72 per cent) showed an increase in post-operative peak nasal inspiratory flow rate by an average of 22 per cent.Conclusion:Both peak oral and nasal inspiratory flow rate measurements may be useful measures of oral and nasal obstruction. Further larger studies are needed to develop these measurements as screening and efficacy measures for adenotonsillectomy to relieve upper airway obstruction.

Download Full-text

The effect of leptin replacement on sleep-disordered breathing in the leptin-deficient ob/ob mouse

Journal of Applied Physiology ◽

10.1152/japplphysiol.00494.2015 ◽

2016 ◽

Vol 120 (1) ◽

pp. 78-86 ◽

Cited By ~ 23

Author(s):

H. Pho ◽

A. B. Hernandez ◽

R. S. Arias ◽

E. B. Leitner ◽

S. Van Kooten ◽

...

Keyword(s):

Airway Obstruction ◽

Duty Cycle ◽

Rem Sleep ◽

Minute Ventilation ◽

Upper Airway ◽

Neuromuscular Control ◽

Inspiratory Flow ◽

Upper Airway Obstruction ◽

Airflow Limitation ◽

Breathing Patterns

Obese leptin-deficient ( ob/ob) mice demonstrate defects in upper airway structural and neuromuscular control. We hypothesized that these defects predispose to upper airway obstruction during sleep, and improve with leptin administration. High-fidelity polysomnographic recordings were conducted to characterize sleep and breathing patterns in conscious, unrestrained ob/ob mice (23 wk, 67.2 ± 4.1 g, n = 13). In a parallel-arm crossover study, we compared responses to subcutaneous leptin (1 μg/h) vs. vehicle on respiratory parameters during NREM and REM sleep. Upper airway obstruction was defined by the presence of inspiratory airflow limitation (IFL), as characterized by an early inspiratory plateau in airflow at a maximum level (V̇imax) with increasing effort. The severity of upper airway obstruction (V̇imax) was assessed along with minute ventilation (V̇e), tidal volume (VT), respiratory rate (RR), inspiratory duty cycle, and mean inspiratory flow at each time point. IFL occurred more frequently in REM sleep (37.6 ± 0.2% vs. 1.1 ± 0.0% in NREM sleep, P < 0.001), and leptin did not alter its frequency. V̇imax (3.7 ± 1.1 vs. 2.7 ± 0.8 ml/s, P < 0.001) and V̇e increased (55.4 ± 22.0 vs. 39.8 ± 16.4 ml/min, P < 0.001) with leptin vs. vehicle administration. The increase in V̇e was due to a significant increase in VT (0.20 ± 0.06 vs. 0.16 ± 0.05 ml, P < 0.01) rather than RR. Increases in V̇e were attributable to increases in mean inspiratory flow (2.5 ± 0.8 vs. 1.8 ± 0.6 ml/s, P < 0.001) rather than inspiratory duty cycle. Similar increases in V̇e and its components were observed in non-flow-limited breaths during NREM and REM sleep. These responses suggest that leptin stabilized pharyngeal patency and increased drive to both the upper airway and diaphragm during sleep.

Download Full-text