Elsevier

Surgery

Volume 122, Issue 4, October 1997, Pages 737-741
Surgery

Use of the rapid/shallow breathing index as an indicator of patient work of breathing during pressure support ventilation

https://doi.org/10.1016/S0039-6060(97)90081-7Get rights and content

Abstract

Background. Measuring patient work of breathing (WOBpt) has been suggested to provide safe, aggressive weaning from mechanical ventilation. We compared WOBpt and pressure-time-product (PTP) to routine weaning parameters [breath rate (f), tidal volume (VT), frequency/tidal volume ratio (f/VT)] at different levels of pressure support ventilation (PSV).

Methods. Fifteen patients in the surgical intensive care unit requiring prolonged weaning (more than 3 days) were entered in the study. A balloon-tipped esophageal catheter was placed and position confirmed by inspection of pressure and flow waveforms. Each patient was randomly assigned to breathe with 5, 10, 15, and 20 cm H2O of PSV. After 30 minutes, 40 breaths were recorded and analyzed. Measurement of WOBpt, PTP, f, VT and f/VT were made using the Bicore CP-100 monitor. Mean values for each parameter were calculated. PTP and WOBpt were plotted against f/VT to determine correlation coefficient.

Results. PTP, WOBpt, and f/VT decreased in a stepwise fashion as PSV was increased. The f/VT correlated most closely with WOBpt (r = 0.983) and PTP (r = 0.972). Monitoring f alone also correlated with WOBpt (r = 0.894) and PTP (r = 0.881). All patients were weaned from the ventilator (mean duration, 22 ± 5.9 days). Nine patients required tracheostomy before final liberation from the ventilator.

Conclusions. Direct measurement of WOBpt is invasive, expensive, and may be confusing to clinicians. Monitoring f/VT may be useful when changing PSV during weaning.

References (20)

  • KH Lee et al.

    Rapid shallow breathing (frequency-tidal volume ratio) did not predict extubation outcome

    Chest

    (1994)
  • R Peters

    Work of breathing and abnormal mechanics

    Med Clin North Am

    (1974)
  • MJ Banner et al.

    Breathing frequency and pattern are poor predictors of work of breathing in patients receiving pressure support ventilation

    Chest

    (1995)
  • A Esteban et al.

    A comparison of four methods of weaning patients from mechanical ventilation

    N Engl J Med

    (1995)
  • NR MacIntyre

    Weaning from mechanical ventilatory support: volume-assisting intermittent breath versus pressure-assisting every breath

    Respir Care

    (1988)
  • KL Yang et al.

    A prospective study of indexes predicting the outcome of trials of weaning from mechanical ventilation

    N Engl J Med

    (1991)
  • LR Jabour et al.

    Evaluation of a new weaning index based on ventilatory endurance and the efficiency of gas exchange

    Am Rev Respir Dis

    (1991)
  • JF Fiastro et al.

    Comparison of standard weaning parameters and the mechanically ventilated patients

    Chest

    (1988)
  • SA Shikora et al.

    The oxygen cost of breathing may predict weaning from mechanical ventilation better than the respiratory rate to tidal volume ratio

    Arch Surg

    (1994)
  • BP Krieger et al.

    Evaluation of conventional criteria for predicting successful weaning from mechanical ventilatory support in elderly patients

    Crit Care Med

    (1989)
There are more references available in the full text version of this article.

Cited by (25)

  • Diaphragmatic rapid shallow breathing index for predicting weaning outcome from mechanical ventilation: Comparison with traditional rapid shallow breathing index

    2019, Egyptian Journal of Anaesthesia
    Citation Excerpt :

    In contrast to the original study of Yang and Tobin [20] our results showed that weaning failure patients had a lower RSBI at 1 min it was 63.68 ± 10.99 and 66.78 ± 12.3 in group I and II respectively and at 30 min it was 78.94 ± 9.6 in group I and 78.64 ± 14.2 in group II. The predictive value of RSBI was variable in different studies that could be attributed to differences in study populations, ventilator settings, underlying illness, body position, and size of endotracheal tube [21–26]. It was reported that RSBI is not a good predictor for patients whose primary problem was related to poor cough, increased secretions and compromised airway protection [27,28].

  • Serial measurements of f/V<inf>T</inf> can predict extubation failure in patients with f/V<inf>T</inf> ≤ 105?

    2008, Journal of Critical Care
    Citation Excerpt :

    In a recent review of 65 studies of weaning predictors, Meade et al [6] verified that f/VT was the main promising predictor in trials of unassisted breathing, but pooled results for this parameter were still limited (highest likelihood ratio, 2.23). Measurements of f/VT have been shown to be affected by ventilatory support settings and by factors unrelated to respiratory muscle capacity, such as sex, age, ETT size, body position, underlying illness, use of sedatives, anxiety, agitation, and arousal [10,16,20]. Epstein et al [16,18] suggested that f/VT accuracy depends on the underlying illness, and Vallverdú et al [13] found that respiratory failure was a potential cause for misinterpretation.

  • Variations in the measurement of weaning parameters: A survey of respiratory therapists

    2002, Chest
    Citation Excerpt :

    The original report identified a threshold value of 105, obtained with patients breathing through a T-tube.2 Other investigators have examined the ratio with patients receiving partial support (CPAP or PS) or combinations of both modes with different levels of pressure or have followed the ratio over time.21,22,23 They have either reported a decline in its predictive capability or a need to adjust the ratio higher when using added pressure.

View all citing articles on Scopus

Presented at the Fifty-fourth Annual Meeting of the Central Surgical Association, Chicago, Ill., March 7–9, 1997.

View full text