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  • Poster presentation
  • Open Access

High-frequency oscillatory ventilation in acute respiratory distress syndrome in adult patients

  • 1,
  • 1 and
  • 1
Critical Care200610 (Suppl 1) :P21

https://doi.org/10.1186/cc4368

  • Published:

Keywords

  • Pneumothorax
  • Acute Respiratory Distress Syndrome
  • Oxygenation Index
  • Sustained Improvement
  • Acute Respiratory Distress Syndrome Patient

Objective

To evaluate the efficacy of high-frequency oscillatory ventilation (HFOV) in acute respiratory distress syndrome (ARDS) in adult patients.

Setting

A 30-bed medical and surgical ICU of a tertiary care hospital.

Design

A prospective clinical study over a period of 12 months.

Methods

ARDS patients receiving mechanical ventilation as per the ARDSnet protocol and requiring positive end expiratory pressure (PEEP) ≥ 12 cmH2O and FiO2 ≥ 0.7 to maintain oxygen saturation ≥ 88% were considered for HFOV. Initial settings of HFOV were selected based upon the mean airway pressure (MAP), PO2/FiO2 ratio, PCO2 and oxygenation index (OI) (OI = MAP × FiO2 × 100 / PO2). Predetermined protocols for HFOV adjustments and weaning from HFOV were implemented. Continuous hemodynamic, plethysmographic monitoring was performed. Arterial blood gas parameters were documented at 1, 6 and 24 hours after initiation of HFOV.

Results

A total of 18 patients were ventilated with HFOV for 80.82 ± 58.70 hours. Baseline characteristics before initiation of HFOV were: APACHE II score 21.11 ± 4.65, hours of conventional ventilation 61.83 ± 52.77, PEEP of 14.16 ± 3.7 cmH2O, plateau pressure (Pplat) of 29.44 ± 4.93 cm, FiO2 of 0.89 ± 0.11 and average ≥ 3 organs failure. There was an improvement in oxygenation status at 6 and 24 hours. The ratio PO2/FiO2 increased from a baseline of 97.47 ± 27.92 to 181.26 ± 110.37 and 256.41 ± 130.85 at 6 and 24 hours, respectively. The OI reduced from a baseline of 26 ± 10.98 to 23.59 ± 16.98 and 15.95 ± 12.38 at 6 and 24 hours, respectively. Out of 18 patients 13 were 'Responders' – i.e. showed progressive and sustained improvement in oxygenation and were successfully weaned to 'T' piece oxygen (≥ 12 hours without any ventilatory assistance). The remaining five were 'Non Responders' and did not show sustained improvement in oxygenation and died of resistant hypoxia.

Subgroup analysis

The Responder (n = 13) and Non Responder (n = 5) groups were similar in Pre HFOV baseline characteristics such as age, APACHE II score, number of organs failed, Pplat, ratio and OI. The PO2/FiO2 ratios at 6 hours were PO2/FiO2 208.81 ± 110.96 vs 109.61 ± 77.41 (P = 0.04) in Responders and Non Responders, respectively. PO2/FiO2 ratios at 24 hours were 290.78 ± 117.43 vs 167.05 ± 132.58 (P = 0.03) in Responders and Non Responders, respectively. The reduction in OI in the Responder group at 6 and 24 hours was significant as compared with Non Responders: 17.27 ± 8.37 vs 40.01 ± 23.42 at 6 hours (P = 0.003) and 11.17 ± 4.28 vs 28.36 ± 18.16 at 24 hours (P = 0.002). One patient developed pneumothorax and one patient had endotracheal tube displacement while on HFOV.

Conclusion

HFOV is effective in adult patients with severe ARDS failing conventional ventilation. Progressive and sustained improve-ment in the PO2/FiO2 ratio and the reduction in the OI at 6 and 24 hours are strongly associated with successful response to HFOV.

Authors’ Affiliations

(1)
Deenanath Mangeshkar Hospital and Research Centre, Pune, India

Copyright

© Biomed central limited 2001

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