Karen E. A. Burns MD, FRCPC, MSc (Epid) Clinician Scientist, - PowerPoint PPT Presentation

Karen E. A. Burns MD, FRCPC, MSc (Epid) Clinician Scientist, Associate Professor Unity Health Toronto (St. Michael’s Hospital) Li Ka Shing Knowledge Institute Toronto, Canada Karen.Burns@unityhealth.to

DISCLOSURE I have nothing to disclose Within the last 12 months I have not had any type of financial arrangement or affiliation with commercial interests related to the content of this continuing education activity that requires disclosure.

 Approximately 40% of the total time spent on invasive MV is dedicated to weaning [1].  Invasive MV is associated with important complications, including VAP, sinusitis, gastrointestinal bleeding, and muscle weakness.  Strategies to limit the duration of invasive MV and ventilator- related complications have been identified as key research priorities in Critical Care [2]. 1. Esteban A, Chest 1994;106:1188-93. 2. MacIntyre NR, Chest 2001;6 Suppl:375-95.

 Over the past two decades, investigators conducted RCTs to evaluate aspects of weaning that reduce the time patients spend on MV including use of:  Screening protocols  SBT techniques  Strategies to reduce ventilator support for patients who fail an initial SBT

 Early RCTs of protocol-directed screening (largely led by RTs and RNs) were mostly positive ◦ Ely 1996 ◦ Kollef 1997 ◦ Marelich 2000  No benefit - selected populations ◦ Namen 2001 (neurosurgical patients) ◦ Randolph 2002 (pediatric patients)  No benefit - highly structured settings ◦ Krishnan 2004 (Johns Hopkins)

 Blackwood et al, summarized 17 trials (n = 2,434) comparing protocolized (largely led RTs and RNs) vs. non-protocolized weaning in a SR/MA.  Most trials compared ‘once daily’ screening to ‘usual care’.  **Usual care required a physician order to conduct SBTs. Blackwood B, Cochrane D, 2014; Issue 11: CD006904 .

Compared to non-protocol based weaning, protocolized weaning:  26% reduction in total duration of MV [n = 14 trials, 95% CI (13% - 37%), p = 0.0002]  70% reduction in weaning time [n = 8 trials, 95% (CI 27% - 88%), p = 0.009]  11% reduction in ICU stay [n = 9 trials, 95% CI (3% - 19%), p = 0.01

 Only 1 trial (n=385) compared ‘ twice daily screening’ to ‘ usual care’ and found a significantly shorter duration of MV and a trend toward a lower VAP in ‘twice daily screening’.  No trial compared a strategy of ‘more frequent screening’ to ‘ once daily ’ screening. Marelich, CHEST, 2000;118:459-67 .

 A Cochrane review (n=9 trials) compared PS and T-piece weaning strategies in critically ill adults.  Nonsignificant differences between PS and T-piece weaning  weaning success  pneumonia  reintubation  In a subgroup analysis, patients were significantly more likely to pass a PS (vs. a T-piece) SBT [RR 1.09, 95% CI 1.02 to 1.17] in 4 trials (n= 940). Ladiera et al, Cochrane Database 2014 May 27;(5):CD006056.

 Published a SR/MA (n=12 trials, n=2161) compared PS and T- piece weaning in critically ill adults (including tracheostomized patients).  PS vs. T-piece weaning did not influence:  weaning success  reintubation  ICU mortality  A subgroup analysis suggested that PS weaning may be superior to T-piece weaning with regard to weaning success  for simple weaning patients [RR 1.44 (1.12 – 1.86)]  but not for difficult [RR 1.45 (0.73 – 2.88)] or prolonged [RR 0.85 (0.69 – 1.05)] weaning patients. Pelligrini et al, Respir Care. 2016;61(12):1693-1703 .

 Study Design : Randomized or quasi-randomized trials  Patients: Critically ill adults or children  Interventions : Directly comparing 2 or more SBT techniques Excluded trials - evaluated SBTs as part of a weaning strategy  Primary Outcomes: SBT success, extubation success, reintubation Burns KE, Crit Care 2017 Jun 1;21(1):127 .

3,785 unique citations 3,602 citations excluded 183 potentially relevant citations 152 citations excluded 65 crossover studies 31 not randomized 27 weaning studies 13 SBT vs. no SBT 8 physiologic 8 other 31 included trials (n=3,541) *11 (T-piece vs. PS) 9 (T-piece vs. CPAP)

9 trials n=1,901 p=0.96 RR 1.00 [0.89, 1.11] I 2 = 77% Post hoc 8 trials n=1,381 p=0.03 RR 1.06 [1.01,1.12] I 2 = 0%

Quality assessment No of patients Effect No of Quality Risk of Inconsisten Indirectn Imprecisi Pressure Relative Risk tria ials T-piece bias cy ess on Support (95% CI) Difference [n] Operative trials (<24 hours): Low Pre-test Probability 2 no serious 1 not serious 2 173/274 226/274 RR 0.86 115 fewer ÅÅOO tria ials serious serious (63.1%) (82.5%) (0.61 to per 1000 LOW [548] 48] risk of 1.22) (-322, bias + 181) Non-operative trials: Greater than Low Pre-test Probability 7 7 no not serious not not serious 536/680 499/673 RR 1.07 52 more ÅÅÅÅ tria ials serious serious (78.8%) (74.1%) (1.01 to per 1000 HIGH [1353] 353] risk of 1.13) (+7, +96) bias p=0.3

11 trials n=1,904 p=0.007 RR 1.06 [1.02, 1.10] I 2 = 0% Post hoc 10 trials n=1,384 p=0.03 RR 1.06 [1.01, 1.12] I 2 = 0% Burns KE, Crit Care 2017 Jun 1;21(1):127 .

1. PS SBTs may facilitate extubation decision-making. 2. Even if PS SBTs underestimate post-extubation WOB passing an SBT may: -offset clinician reluctance to extubate some patients -result in more timely and successful extubation

Pre-test probability T-piece SBTs may be appropriate in selected patients  Especially for patients that we think have a low likelihood of extubation success (e.g., LV dysfunction, neuromuscular weakness)  When we wish to prioritize a low FP rate for passing an SBT (to avoid the risks associated with extubation failure).  However, when we use T-piece SBTs (vs. PS SBTs) in patients with a high likelihood of extubation success they may induce a higher FN rate.

Setting ting: : 18 ICUs Spain; Inter terven entio tions ns: : 30 min PS 8 cm H 2 O SBT (n=557) vs vs. 2 hr T-piece SBT (n = 578) SBT T succ cces ess s (PS vs. T-piece): iece): 532/575 (92.5%) vs.486/578 (84.1%); p<0.001 Extubation tubation success cess (PS vs. T-piece): iece): 473/575 (82.3%) vs. 428/578 (74.1%); p<0.001 Reintu intubat ation ion rates es: : 11.1% vs. 11.2% Subira et al, JAMA, 2019

Current RCTs include pts < 24 hrs and ‘pts with a high pretest probability of success’ Bedeneau, AJRCCM, 2016; 195:772-83 .

To understand how ICU physicians discontinue MV in practice We conducted a cross-sectional survey of adult ICU physicians practicing in 6 geographic regions:  Canada India  United Kingdom (UK) Europe (excluding the UK)  Australia/New Zealand United States (USA)

In a self-administered, multinational survey, we sought to 1. Characterize magnitude and extent of weaning practice variation  Identify weaning candidates  Conduct SBTs  Use of ventilator modes  Use of written directives to guide aspects of care  Use of NIV in the weaning & peri-extubation period  Personnel involved in weaning 2. Assess for regional differences in weaning practices 3. Identify predictors of practice variation

 We used rigorous survey methodology to design, test, and administer our survey.  We collaborated with regional critical care societies to administer our questionnaire  Canada (CCCS, CCCTG, QICS) Goal: Achieve 200 responses  India (ISICM) from each region  UK (UKICS)  Europe (ESICM) Proportionate sampling  Aus/NZ (ANZICS)  USA (SCCM)  We analyzed 1,144 questionnaires (Canada, 156; India, 136; UK, 219; Europe, 260; Australia/New Zealand, 196; USA, 177).

Across regions, most respondents screened patients once daily to identify SBT candidates (regional range, 70.0% – 95.6%) Less often screened twice daily (range, 12.2% – 33.1%) or more than twice daily (range, 1.6% – 18.2%)

Most respondents used PS alone (range, 31.0% – 71.7%) or PS with SBTs (range, 35.7% – 68.1%) to wean patients. Intensivists infrequently or rarely used other modes (volume-assist control alone, SIMV, pressure-assist control, and PLVG) to wean. When used, these modes were employed in combination with SBTs.

Two modes were predominantly used to conduct SBTs:  PS with PEEP (56.5% – 72.3%)  T-piece (without CPAP; off the ventilator; 8.9% – 59.5%) They infrequently or rarely used  CPAP (without PS; 6.5% – 18.9%)  ATC (2.6% – 21.1%)  T-piece with CPAP = 0 on the ventilator (1.2% – 11.8%)  PS without PEEP (1.6% – 7.7%)

 Use of written guidelines, protocols, or policies varied significantly across regions with most respondents affirming having no directive  Directives for sedation administration were the most commonly used directives across regions (range, 37.5% – 75.4%)  Broader variation in the use of written directives to guide  Conduct of SBTs (range, 10.4% – 73.5%)  Adjustment of ventilator support (range, 15.5% – 55.6%)  Directives to guide delirium management were infrequent (range, 21.8% -37.0%).

Across indications - NIV was most commonly used for patients with COPD Significant variation in the use of NIV for weaning and peri-extubation for patients with COPD, CPE, OSA, and in postoperative patients