Invasive Mechanical Ventilation, Weaning, and Noninvasive Positive Pressure Ventilation

Invasive Mechanical Ventilation
Darioli R, Perret C. Mechanical controlled hypoventilation in status asthmaticus. Am Rev Respir Dis 1984;129:385-7. Noteworthy for being the first description of permissive hypercapnea and low tidal volumes during mechanical ventilation of asthmatics with high airway pressures. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=6703497

Marini JJ, Pierson DJ, and Hudson LD. Acute lobar atelectasis: a prospective comparison of fiberoptic bronchoscopy and respiratory therapy. Am Rev Resp Dis 1979;119:971-8. This study found FOB, for the sole purpose of atelectesis, followed by RT was no better than RT alone at 24-48 hours. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=453712

Ventilator Weaning
Ely EW, Baker AM, Dunagan DP, et al. Effect on the duration of mechanical ventilation of identifying patients capable of breathing spontaneously. N Engl J Med 1996; 335:1864-9. RCT found protocol of daily weaning parameters followed by trials of spontaneous breathing in appropriate patients and subsequent notification of physicians of successful trials reduced the duration of mechanical ventilation compared to usual care (daily weaning parameters only). http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=8948561

Esteban A, Frutos F, Tobin MJ, et al. A comparison of four methods of weaning patients from mechanical ventilation. N Engl J Med 1995; 332:345-50. Prospective, randomized study found once daily or multiple daily trials of spontaneous breathing (T-piece or CPAP <5 cm) resulted in more rapid successful extubation than gradual weaning of pressure support or IMV. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=7823995

Brochard L, Rauss A, Benito S, et al. Comparison of three methods of gradual withdrawal from ventilatory support during weaning from mechanical ventilation. Am J Respir Crit Care Med 1994; 150:896-903. Prospective, randomized study found weaning with pressure support mode superior to SIMV mode and T-piece trials. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=7921460

Yang KL, Tobin MJ. A prospective study of indexes predicting the outcome of trials of weaning from mechanical ventilation. N Engl J Med 1991; 324:1445-50. Study in a VA population found the rapid shallow breathing index (RSBI = RR/Vtidal) was the single best predictor of weaning success (sensitivity 0.97, specificity 0.64).   http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=2023603

Girard T, Kress J, Fuchs B, et al.  Efficacy and safety of paired sedation and ventilator weaning protocol for mechanically ventilated patients in intensive care (Awake and Breathing Controlled trial): a randomised controlled trial.  Lancet 2008;371:126-34. This RCT found the combination of daily sedation holiday and daily weaning trials resulted in reduced ventilator days and reduced mortality compared to daily weaning trials alone (HR 0.68, p = .01, NNT to save one life 7).  http://www.ncbi.nlm.nih.gov/pubmed/18191684

**See also ARDS, Neurology Critical Care, Noninvasive Ventilatory Support, Sedation and Analgesia

Noninvasive mechanical ventilation
COPD
Brochard L, Mancebo J, Wysocki M, et al. Noninvasive ventilation for acute exacerbations of COPD. N Engl J Med 1995; 333:817-22. Landmark prospective, randomized study found use of NIPPV in selected patients with COPD exacerbations resulted in fewer intubations, complications, days in hospital, and lower in-hospital mortality compared to standard treatment. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=7651472

Nava S, Ambrosino N, Clini E, et al. Non-invasive mechanical ventilation in the weaning of patients with respiratory failure due to chronic obstructive pulmonary disease. Ann Intern Med 1998;128:721-8. Oft-cited RCT included 50 patients intubated for a COPD exacerbation who failed a T-piece trial.  Patients randomized to immediate extubation to NIPPV had decreased duration of mechanical ventilation and improved survival compared to the control group undergoing PS wean with twice daily spontaneous breathing trials. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9556465

Hypoxemic respiratory failure (all types)
Declaux C, L'Her E, Alberti C, et al. Treatment of acute hypoxemic nonhypercapnic respiratory insufficiency with CPAP delivered by facemask. JAMA 2000;284:2352-60. Prospective, randomized, multicenter study compared oxygen to oxygen plus CPAP in this population (123 patients; 17% cardiac etiology, 83% ALI). Study found no difference in the need for intubation, length of hospital stay, or hospital mortality, and the CPAP group had an increased incidence of adverse events. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11066186

Antonelli M, Conti G, Rocco M, et al. A comparison on NIPPV and conventional mechanical ventilation in patients with acute respiratory failure. N Engl J Med 1998; 339:429-35. Randomized study compared NIPPV with immediate intubation and conventional ventilation in 64 patients with acute, non-hypercapnic, hypoxemic respiratory failure (19% cardiogenic and 25% ARDS).  Use of NIPPV resulted in gas exchange and survival comparable to conventional ventilation but was associated with fewer serious complications and shorter ICU stays. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9700176

Ferrer M, Esquinas A, Leon M, et al. Non-invasive ventilation in severe hypoxemic respiratory failure: a randomized clinical trial. Am J Respir Crit Care Med 2003;168:1140-4. Study of 105 non-hypercapnic patients found NIPPV decreased need for intubation and improved 90-day survival compared to oxygen therapy alone.  Unlike some prior studies, subgroup analysis found the 34 patients with pneumonia had the greatest benefit while mask ventilation did not appear to reduce the need for intubation in patients with ARDS and cardiogenic edema. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=14500259

Cardiogenic hypoxemic respiratory failure
Bersten AD, Holt AW, Vedig AE, et al. Treatment of severe cardiogenic pulmonary edema with CPAP delivered by facemask. N Engl J Med 1991;325:1825-30. Randomized study of 39 patients with hypercapnic cardiogenic respiratory failure found use of CPAP plus oxygen resulted in better gas exchange in the first 24 hours and less need for intubation than use of oxygen alone. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=1961221

Masip J, Betbese AJ, Paez J, et al. Non-invasive pressure support ventilation versus conventional oxygen therapy in acute cardiogenic pulmonary edema: a randomized trial.  Lancet 2000; 356:2126-32. Study of 37 patients (of whom 43% had hypercapnia) found pressure support by mask reduced the need for intubation (5% vs. 33%).  There was no difference in duration of hospital stay or mortality. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11191538

Nava S, Carbone G, DiBattista, N, et al. Non-invasive ventilation in cardiogenic pulmonary edema: a multicenter randomized trial.  Am J Respir Crit Care Med 2003; 168:1432-7.  This larger study (130 patients) found non-invasive pressure support did not improve outcomes compared to conventional therapy.  Mask ventilation reduced intubations in the 64 patients with PaCO2 > 45 mmHg (6% vs. 29%), but this difference was not significant after regression analysis. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12958051

Following extubation
Ferrer M, Valencia M, Nicolas JM, et al.  Early noninvasive ventilation averts extubation failure in patients at risk: a randomized trial.  Am J Respir Crit Care Med. 2006; 173:164-70. This RCT enrolled 162 mechanically ventilated patients who tolerated a spontaneous breathing trial after recovery from the acute episode but had increased risk for respiratory failure after extubation. Early use of noninvasive ventilation averted respiratory failure after extubation and decreased intensive care unit mortality among patients at increased risk. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=16224108&query_hl=12&itool=pubmed_DocSum