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lung protective ventilation; low tidal volume ventilation; permissive hypercapnia

The practice of allowing pCO2 to increase (hypercapnia) in order to maintain acceptably low airway pressures. - this diminishes barotrauma from airway pressures necessary to maintain normal or lower pCO2. - in general, permissive hypercapnia leads to improved outcomes. Indications: - Acute Respiratory Distress Syndrome (ARDS) - may be of benefit during general anesthesia for surgery [2] Benefit/risk: - number needed to treat (NNT) for ARDS - 10 for 1 life save at 28 days of hospitalization - 12 for 1 life saved at hospital discharge [1] Procedure: - mechanical ventilation providing a tidal volume of <= 6 ml/kg with plateau pressure of <= 30 cm H2O - peak inspiratory pressure < 30-35 mm Hg - provision of adequate PEEP (5-8 cm H2O) to prevent collapse of unstable alveoli during expiration [3] * contrast with convention mechanical ventilation defined as providing a tidal volume of 10-15 ml/kg range with a plateau pressure of > 30 cm H2O Management: - adjust fraction of inspired oxygen (fiO2) & positive end-expiratory pressure (PEEP) to meet the following goals: - partial pressure of oxygen (PaO2) = 55-80 mm Hg - arterial pH = 7.30-7.45 - plateau pressure <= 30 cm H2O

General

mechanical ventilation (assisted ventilation)

References

  1. The NNT: Lung protective Ventilation Strategy for Intubated Patients with ARDS (Acute Respiratory Distress Syndrome). http://www.thennt.com/nnt/lung-protective-ventilation-for-ards/ - Petrucci N, Iacovelli W. Lung protective ventilation strategy for the acute respiratory distress syndrome. Cochrane Database Syst Rev. 2007 Jul 18;(3):CD003844. PMID: 17636739
  2. Ladha K et al. Intraoperative protective mechanical ventilation and risk of postoperative respiratory complications: Hospital based registry study. BMJ 2015; 351:h3646 PMID: 26174419
  3. Medical Knowledge Self Assessment Program (MKSAP) 17, American College of Physicians, Philadelphia 2015
  4. Laffey JG, O'Croinin D, McLoughlin P, Kavanagh BP. Permissive hypercapnia--role in protective lung ventilatory strategies. Intensive Care Med. 2004 Mar;30(3):347-56. Review. PMID: 14722644