Harsharon Chopra, BS1, Josh Malo, MD, John Sakles, MD2, Cameron Hypes, MD, MPH2,3, John W Bloom, MD2, Jarrod Mosier MD2,3

1The University of Arizona College of Medicine, 2Section of Pulmonary, Critical Care, Allergy and Sleep, Department of Medicine, The University of Arizona, 3Department of Emergency Medicine, The University of Arizona

Neuromuscular Blockade Improves First Attempt Success for Intubation in the ICU: A Propensity Adjusted Analysis

BACKGROUND

Tracheal intubation in critically ill patients is a commonly required procedure that is fraught with risk and there is controversy over who should perform intubations in the ICU, what device(s) should be used, and what the optimal method of pharmacologic assistance is.

Neuromuscular blocking agent (NMBA) use has been shown to improve first attempt success and decrease procedurally related complications in the OR and ED, yet remains controversial in the ICU. The goal of this study is to compare first attempt success in patients intubated with the use of a NMBA in the medical ICU with patients intubated without a NMBA. Subgroup analyses were identified a priori, which included comparing first attempt success and intubating conditions achieved with succinylcholine versus rocuronium, and the effect of neuromuscular blockade on the patients intubated with video laryngoscopy.

RESULTS

• 711 patients were intubated. Patients were excluded for flexible fiberoptic intubations (42), nasal intubation (1) and medical-student intubation (4) giving a total of 664 patients

for the study. • 496 (75%) were intubated with NMBA and 168 (25%) were

intubated without NMBA. • Patients without NMBA-use had higher median DACs

(2.4 vs. 1.8 p<0.001) and higher use of ketamine (39.3% vs. 8.9%, p<0.001).

• First attempt success higher in patients using a NMBA (401/496, 81%, 95% CI 77-84%) compared to those intubated without a NMBA (117/168, 70%, 95% CI 62-76%).

• The unadjusted odds ration of first attempt success using a NMBA was 1.84 (95% CI 1.24-2.74, p=0.003). Propensity adjusted multivariate regression controlling for confounds demonstrated an odds ration of 2.17 (95% CCI 1.29-3.66, P<0.01) for FAS when a NMBA was used.

RESULTS (cont.)ROCURONIUM COMPARED TO SUCCINYLCHOLINE

VIDEO LARYNGOSCOPY SUBGROUP

MATERIALS AND METHODS

• Single-center prospective observational analysis of 664 consecutive ICU intubations performed from January 1, 2012 to June 30, 2014 at a major academic referral center with a 20+ bed medical ICU.

• All intubations are performed under supervision by faculty skilled in airway management.

• All patients intubated using direct laryngoscopy (DL) or video laryngoscopy (VL) were included in this study.

• Following each intubation, the operator completed a data collection form, which included information such as patient demographics, operator specialty, indication for intubation, paralytic agent, sedative agent, device(s) used, presence of certain difficult airway characteristics (DACs), pre-oxygenation methods, number of attempts at intubation and the outcome of each attempt, including complications.

• Propensity adjustment was performed for likelihood of NMBA use.

• The primary outcome measured was successful first attempt intubation.

CONCLUSIONS

In this observational study of intubations in the ICU, the use of a neuromuscular blocking agent to facilitate intubation was associated with higher odds of first attempt success after controlling for potential confounding variables. In the video laryngoscopy subgroup, NMBA use was also associated with higher odds of first attempt success and improved laryngoscopic view. These data suggest that a NMBA is an attractive option when faced with intubation in a critically ill ICU patient.

First Attempt Success Rate

MULTIVARIATE REGRESSION MODEL FOR SUCCESS

#729

0.64

0.66

0.68

0.7

0.72

0.74

0.76

0.78

0.8

0.82

RSINon-RSI

DIFFICULT AIRWAY PREDICTOR DEMOGRAPHICS

Characteristic 

Paralytic%, (n=496)

No Paralytic%, (n=168)

p-Value

DAPs      

Total DAPs (median) 1.8 2.4 <0.001

None 21.7% (108) 15.6% (26) 0.10

Cervical immobilization 2.2%(11) 4.2% (7) 0.18

Blood in Airway 14.9% (74) 16.2% (27) 0.71

Vomit in Airway 5.03% (25) 7.2% (12) 0.33

Facial/neck Trauma 0.6% (3) 0.6% (1) 1.00

Obesity 27.8% (138) 33.5% (56) 0.17

Short Neck 22.5% (112) 28.1% (47) 0.14

Large Tongue 12.1% (60) 16.8% (28) 0.15

Airway Edema 7.0% (35) 10.8% (18) 0.14

Small Mandible 13.9% (69) 19.2% (32) 0.11

Hypoxia 26.2% (130) 29.9% (50) 0.37

Hemodynamic Instability 21.3% (106) 28.1% (47) 0.07

Limited Mouth Opening 10.1% (39) 23.9% (32) <.001

Secretions 17.9% (69) 23.9% (32) 0.16

Variable

Adjusted Odds Ratio

(aOR)

 95% CI

 p-Value

Paralytic use 2.16 1.28–3.64 0.004

Total number of DAPs 0.83 0.74-0.94 0.004

Sedative      

None [Reference]    

Etomidate 0.13 0.01-1.45 0.10

Ketamine 0.19 0.04-0.98 0.05

Versed 0.26 0.02-3.41 0.30

Propofol 0.15 0.02-0.99 0.05

Device      

Direct Laryngoscopy [Reference]    

Glidescope Video Laryngoscopy 4.12 1.92-8.78 <0.001

CMAC Video Laryngoscopy 3.03 1.59-5.76 0.001

Other Video Laryngoscopes 2.25 0.23-22.46 0.50

Operator PGY      

1 [Reference]    

2 1.96 0.90-4.27 0.09

3 1.03 0.46-2.28 0.95

4 3.08 1.42-6.66 0.004

5 3.14 1.44-6.84 0.004

6 2.48 1.02-6.02 0.05

Attending 21.22 2.30-196.24 0.007

Propensity Score 2.65 0.23-30.00 0.43

Outcome Succinylcholine Rocuronium p-Value First attempt Success

83% (267/323) 77% (125/162) 0.18

CL I or II 85% (273/323) 78% (127/162) 0.10POGO Score (mean)

71% 73% 0.67

Outcome Paralytic No Paralytic p-Value First attempt Success

85% (334/395) 69% (103/149) <0.001

CL I or II 87% (343/395) 78% (116/149) 0.02POGO Score (mean)

77% 71% 0.05