Weaning From IABPWeaning From IABP

Ri Ri 王昭閎王昭閎

IntraAortic Balloon PumpIntraAortic Balloon Pump

Settings: catheter-mounted, balloon volume 30-50 ml, central lumen, helium, synchronization.Net effect: myocardial oxygen supply/demand ratio with a small increase in systemic perfusion ( 0.≦5L/min)Timing: Pre-,Peri-,Post-op

IABP WaveformsIABP Waveforms

IABP WaveformsIABP Waveforms

Early Inflation Late Inflation

IABP WaveformsIABP Waveforms

Early Deflation Late Deflation

IndicationsIndications

Cardiogenic shockCardiogenic shock Mechanical complication of AMIMechanical complication of AMI In association with CABGIn association with CABG In association with nonsurgical revascularization In association with nonsurgical revascularization Stabilization of cardiac transplant recipient beforStabilization of cardiac transplant recipient befor

e insertion of ventricular assist device e insertion of ventricular assist device Postinfarction angina Postinfarction angina Ventricular arrhythmias related to ischemiaVentricular arrhythmias related to ischemia

ContraindicationsContraindications

Absolute ContraindicationsAbsolute Contraindications Aortic valve insufficiency; Aortic dissectionAortic valve insufficiency; Aortic dissection

Relative ContraindicationsRelative Contraindications Femoral arterial insertion: Abdominal aortic anFemoral arterial insertion: Abdominal aortic an

eurysm; Severe calcific aortoiliac or femoral areurysm; Severe calcific aortoiliac or femoral arterial disease terial disease

Percutaneous insertion: Recent ipsilateral groiPercutaneous insertion: Recent ipsilateral groin incision; Morbid obesityn incision; Morbid obesity

ComplicationsComplications

Complication rate: 5-47%Complication rate: 5-47% Limb ischemia; aortic dissection; aortoiliac Limb ischemia; aortic dissection; aortoiliac

laceration; perforation; deep wound infectilaceration; perforation; deep wound infectionon

Bleeding at insertion site; superficial wounBleeding at insertion site; superficial wound infections; asymptomatic loss of peripherd infections; asymptomatic loss of peripheral pulse; lymphoceleal pulse; lymphocele

Weaning from IABPWeaning from IABP

Continued satisfactory LV performanceContinued satisfactory LV performance Augmentation curve remains < SBPAugmentation curve remains < SBP No further increase in CO at 1:1 assist rate in coNo further increase in CO at 1:1 assist rate in co

mparinson with 1:2 mparinson with 1:2

Weaning from IABPWeaning from IABP

No experimental or clinical studies have No experimental or clinical studies have been done to evaluate the most effective been done to evaluate the most effective weaningweaning

Traditional method: reduce the assist rate Traditional method: reduce the assist rate from 1:1 to 1:2, etc, because all consoles from 1:1 to 1:2, etc, because all consoles are equipped with it.are equipped with it.

The method of weaning is, at best, The method of weaning is, at best, selected arbitrarily.selected arbitrarily.

Weaning from IABPWeaning from IABP

Traditional method:↓Assist rate while maintaining Traditional method:↓Assist rate while maintaining augmentation.augmentation.

New method: ↓Augmentation while rate at 1:1New method: ↓Augmentation while rate at 1:1 Goal: assure satisfactory cardiac performance indGoal: assure satisfactory cardiac performance ind

ependent of balloon pump assist.ependent of balloon pump assist. Weaning is done in a gradual fashion over a preseWeaning is done in a gradual fashion over a prese

t time interval (in two phases) t time interval (in two phases) Criteria for initiation of IABP weaning: a patient muCriteria for initiation of IABP weaning: a patient mu

st be in hemodynamic class I (Shock box)st be in hemodynamic class I (Shock box)

Weaning from IABPWeaning from IABP

Shock BoxShock Box

Left Ventricular Stroke Work Left Ventricular Stroke Work IndexIndex

LVSWI = (SV/BSA)*(MAP-PLVSWI = (SV/BSA)*(MAP-PCWP)*(0.0136) CWP)*(0.0136)

Normal = 45-75Normal = 45-75 Class I: Minimal failure groupClass I: Minimal failure group Class II: Hypovolemic groupClass II: Hypovolemic group Class III: Hypervolemic-HypeClass III: Hypervolemic-Hype

rdynamic grouprdynamic group Class IV: Classic cardiogenic Class IV: Classic cardiogenic

shock (Hypervolemic-Hypodyshock (Hypervolemic-Hypodynamic group)namic group)

ProtocolsProtocols

Initial set of hemodynamic dataInitial set of hemodynamic data Phase I: 1:2 + 100% V.S. 75% + 1:1Phase I: 1:2 + 100% V.S. 75% + 1:1 Appropriate therapeutic measureAppropriate therapeutic measure Parameters:↓LVSWI or↑PWP > 20%Parameters:↓LVSWI or↑PWP > 20% If not class I, 1:1 + 100% for more 12-24 hr If not class I, 1:1 + 100% for more 12-24 hr Phase II: 1:3 + 100% V.S. 50% + 1:1Phase II: 1:3 + 100% V.S. 50% + 1:1 Flutter mode (<25%) for 10-15 min; Prevent clot Flutter mode (<25%) for 10-15 min; Prevent clot Augmentation(%) adjustment by pressure; variaAugmentation(%) adjustment by pressure; varia

ble balloon volume changesble balloon volume changes

ResultsResults

75% + 1:1 similar to 1:2 + 100%75% + 1:1 similar to 1:2 + 100% Class I p’t in Phase II: min. change between phasesClass I p’t in Phase II: min. change between phases

Phase II as balloon “off” or “flutter”Phase II as balloon “off” or “flutter”

Combined methods is safe and reliable Combined methods is safe and reliable IABP < 3-4 hrs, weaning may be shortened to 1-2 hrsIABP < 3-4 hrs, weaning may be shortened to 1-2 hrs Average time from class IV to I: 48 hrsAverage time from class IV to I: 48 hrs

One Patient’s DataOne Patient’s Data

Criteria for Variant ConditionCriteria for Variant Condition

Preoperatively or acute ventricular dysfunctionPreoperatively or acute ventricular dysfunction ~1 hr devided into two 30-minute phases ~1 hr devided into two 30-minute phases

Criteria for Variant ConditionCriteria for Variant Condition

Emergency basis (at the completion of a cardiac Emergency basis (at the completion of a cardiac operation), operation),

IABP should not be DC early after satisfactory responseIABP should not be DC early after satisfactory response Maybe 12-18 hours later in ICU Maybe 12-18 hours later in ICU

Criteria for Variant ConditionCriteria for Variant Condition

Weaning in Special Situations Weaning in Special Situations

Prolonged Respiratory SupportProlonged Respiratory Support Never weaning simultaneouslyNever weaning simultaneously DC respiratory support first, if possibleDC respiratory support first, if possible 12-24 hr later, weaning may be attempted12-24 hr later, weaning may be attempted COPD or ARDS, IABP may be weaned firstCOPD or ARDS, IABP may be weaned first

Pressor TherapyPressor Therapy Vasopressor to the lowest level before weaningVasopressor to the lowest level before weaning Exception: Leg ischemia. Early removal or change siteException: Leg ischemia. Early removal or change site Change all the pressor drugs to dopamine or dobutamine Change all the pressor drugs to dopamine or dobutamine Decrease to <5mcg/kg/min, then weaning Decrease to <5mcg/kg/min, then weaning Within 12-24 hr after DC IABP, decrease in conc. and DC Within 12-24 hr after DC IABP, decrease in conc. and DC DC pressor but keep IABP as bridge to trans.DC pressor but keep IABP as bridge to trans.

Thanks for Your AttentionThanks for Your Attention

ReferencesReferences

Clinical Application of Intra-Aortic Clinical Application of Intra-Aortic Balloon Pump, Third Edition. HooBalloon Pump, Third Edition. Hooshang Bolooki.shang Bolooki.

Counterpulsation: historical backgCounterpulsation: historical background, technical improvements, hround, technical improvements, hemodynamic and metabolic effectemodynamic and metabolic effects," which appears in Volume 84 s," which appears in Volume 84 (1994) of the journal Cardiology (1994) of the journal Cardiology (pp. 156-167).(pp. 156-167).

Braunwald: Heart Disease: A TextBraunwald: Heart Disease: A Textbook of Cardiovascular Medicine, book of Cardiovascular Medicine, 6th ed. 6th ed.