STEER Weaning Protocol:Liberating Patients From Mechanical Ventilation

Julie Emerick, RRT

ICU Coordinator

Respiratory Therapy

UCSD Medical Center

Weaning From Mechanical Ventilation

Can account for >40% of time on ventilator1

Clinical judgment often inaccurate in predicting the success of extubation.

Reintubation is associated with increase in mortality and morbidity

1. Esteban Chest 106:1188-93 1994

Purposes of Weaning

Assure medical team that patient can tolerate extubation

Train respiratory muscles

Good News! Simpler Is Better.

Old, Complex Way Daily clinical estimate of

weaning potential Weaning parameters:

VE < 15, TV < 4ml/kg,

f < 38, MIP > 15 Randomly reduce IMV and

PS

New, Simple Way Try nearly everyone daily

f/TV < 105

Intermittent “sprints” based on bedside assessment

STEER Weaning Protocol

Help clinician determine which class patient is in at any given time.

Give clinician more complete information

Continuously update data

STEER

Screen for contraindications

Trial of minimum support breathing

Exercise according to protocol

Evaluate progress

Report information to the clinicians.

Classes of Mechanically Ventilated Patients

Class 1extubationpredicted

f/V t < 100

Class 2Progress

tow ardextubation

Class 3Not Progressing

tow ardextubation

Class 4No sprint

contraindicated

Screen for Contraindications

Assessment Procedure: Step 1

Are sprintscontraindicated

by clin ical info? .

All O thersperform 1 minute sprint

PS = 5, CPAP = PEEP

Class 4No sprint

contraindicated

M echanicallyventilatedpatients

assessed qAM .

Does the patient have…...

Neuromuscular blockers PEEP > 5 FiO2 > 45% or Sa02 < 92% Hemodynamic instability Increased ICP Sedation drip (Propofol, Ativan, Versed, etc.) Unstable angina Temp > 39 Physician has requested patient not to be weaned

Who Is Ready to Wean?

300 ventilated patients were screened daily for four criteria.1 » pO2 / FiO2 > 200

» PEEP < 5» adequate cough» no pressors or sedative drips

Randomized: physician vs protocol weaning

1. Ely NEJM 335(21):1864-9 1996

Trial of Minimum Support Breathing

Who Is Ready to Wean?

Traditional Method Physicians not told

of screening results. Weaning entirely

based on clinical judgment.

Protocol Method “Sprint” (CPAP) for 1

min, if tolerated... Sprint for 2 hours, if

tolerated… “Doctor, your patient is

ready to be extubated.”

Ely NEJM 335(21):1864-9 1996

Outcomes

Wean time(days)

M.V. time(days)

reintubate(percent)

ICU cost(X$10,000)

0

2

4

6

8

Wean time(days)

M.V. time(days)

reintubate(percent)

ICU cost(X$10,000)

Traditional Protocol

“Sprintable” Patient-Days

Protocol25%

Non-Protocol

75%

UCSD Med CTR 10/2000 – 2/2001

“Sprintable” Patient-DaysProtocol

Sprint23%

Protocol No Sprint

1%

Non-protocol

Sprint33%

Non-protocol No

Sprint43%

UCSD Med CTR 10/2000 – 2/2001

Predictors of Successful Extubation

required VE (on ventilator)– VCO2, VO2

– Vd/Vt

A-a gradient Compliance

– Vt/(PIP-PEEP)

Negative inspiratory force– strength

Weaning Predictors: combining concepts

Vital Capacity– strength, compliance

Tidal Volume– strength, compliance

Respiratory Frequency– strength, compliance, ventilatory requirements

Minute Ventilation– strength, compliance, ventilatory requirements

Frequency/Tidal Volume Ratio

strength, compliance, ventilatory requirements high number (>105): rapid, shallow breathing

» capacity to breath >> work of breathing

Multiple “weaning parameters” measured on 100 consecutive ventilated adults

Extubation by clinicians blinded to results

Predictors of Successful Wean

Yang and Tobin. NEJM 324(21):1445-50 1991

Definitions

Sensitivity(good WP and extubated for 24 hrs)

all pts extubated for 24 hrs

Specificity(poor WP and not extubated for 24 hrs)

all not extubated for 24 hrs

Predictors of Extubation for >24h

78%

18%

92%

36%

97%

54%

100%

11%

97%

64%

0

0.2

0.4

0.6

0.8

1

Ve f TV MIP f/TV

Sensitivity Specificity

Yang and Tobin. NEJM 324(21):1445-50 1991

Assessment Procedure: Step 2

W as f/Vt afterone m inute

<= 100?

Class 1extubationexpected

All O thersassess sprintprogress for

previous 48 hrs .

All O thersperform 1 m inute sprint

PS = 5, CPAP = PEEP

Class 4No sprint

contraindicated

Exercise According to Protocol

Sprint Procedure: Class 1 Patients

Two hour CPAP sprint with f/Vt < 100» extubation success highly probable» physician notified, asked re: extubation

Fatigue during 2 hour CPAP» repeat sprint after a 4-6 hour rest

Stop sprint if not tolerated for…..

BP < 90 or > 170 systolic RR > 35 X 5 minutes Change in HR of 20% or > 130 BPM SaO2 < 90/ or within MD specified limits 50% reduction in minute volume Temp > 39 Arrhythmias* (Contact MD/RN. Don’t

repeat sprint until MD approval)

Sprint Procedure: Class 1

Tw o hourCPAP trialtolerated?

yesnotify M .D.

norepeat trial

in afternoon

Class 1extubationpredicted

f/V t < 100

Class 2Sprint

programprogressing

Class 3Sprint

programno progress

Class 4No sprint

contraindicated

Sprint Procedure: Class 2 Patients

Class 1extubationpredictedf/V t < 100

Record Progress

Sprint Protocol

Class 2Sprint

programprogressing

Class 3Sprint

programno progress

Class 4No sprint

contra ind icated .

Training Respiratory Muscles

partially unload muscles so that they may grow stronger with exercise

muscle fatigue (intended goal) muscle exhaustion (setback) clinican becomes coach

Sprint Procedure: Class 2

Work intervals alternating with rest Place patient on CPAP/PS 20 and

decrease PS until RR is in the mid 20’s Sprint BID X 30 min on the same PS Gradually increase respiratory load

» decreasing support until CPAP is tolerated Move to Class 1

Predictors of Extubation for >48 h

88%76%

85%73%

0

0.2

0.4

0.6

0.8

1

30 min sprint (n=270) 120 min (n=256)

Completed sprint Stayed extubated for 48 hours

Esteban et al. AJRCCM 159: 512-518 1999

Classes of Mechanically Ventilated Patients

Class 1extubationpredicted

f/V t < 100

Class 2Progress

tow ardextubation

Class 3Not Progressing

tow ardextubation

Class 4No sprint

contraindicated

Comparison of Four Weaning Methods1

132 vent’d adults who did not tolerate 2 hour sprints were randomized to:» Twice daily reduction in IMV rate» Twice daily reduction in PS level

» Twice daily “sprints” (CPAP 5cm H20)

» Once daily “sprint” (CPAP 5cm H20)

Esteban. NEJM 332(6):345-60 1995

Median Duration of Weaning

54

3 3

0

1

2

3

4

5

Da

ys

IMV PS Sprint X 2 Sprint X 1

Patients Weaned Within 14 Days

69% 62%82%

71%

0%

25%

50%

75%

100%

IMV PS Sprint X 2 Sprint X 1

Evaluate Progress

Documenting Sprint Progress

Evaluate after last sprint of the day

Was best sprint > than best sprint 48 hours ago?

Which sprint trial is hardest?

1) PS = 15, IMV=10, duration=2 hours

2) PS = 10, IMV=15, duration=2 hours

3) PS = 5, IMV=10, duration= 30 min

4) PS = 10, IMV=5, duration=30 min

5) PS = 20, IMV=0, duration=2 hours

6) PS = 10, IMV=0, duration=1 hour

7) PS = 7, IMV=0, duration=30 min

How to Assess Progress

Weaning technique must be simple Technique must not change daily Duration of sprint must be constant

Which sprint trial is hardest?

1) PS = 20, IMV=0, duration=30 min

2) PS = 15, IMV=0, duration=30 min

3) PS = 10, IMV=0, duration=30 min

4) PS = 5, IMV=0, duration=30 min

5) PS = 5, IMV=0, duration=60 min

6) PS = 5, IMV=0, duration=90 min

7) PS = 5, IMV=0, duration=120 min

Sprint: Class 3 Patients

Class 1extubationpredictedf/V t < 100

Class 2Sprint

programprogressing

Record Progress

Sprint Protocol

Notify M .D .about lack

of progress(further w /u?)

Class 3Sprint

programno progress

Class 4No sprint

contra ind icated .

Sprint Procedure: Class 3 Patients

Same sprint routine

Investigate causes of failure to wean

Causes Of Weaning Failure

Gas Exchange Inadequacies General Metabolic Illness Respiratory Pump Failure

Report Information to the Clinicians.

Classes of Mechanically Ventilated Patients

Class 1extubationpredicted

f/V t < 100

Class 2Sprint

programprogressing

Class 3Sprint

programno progress

Class 4No sprint

contraindicated

M echanicallyventilatedpatients

assessed qAM .