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28 Cards in this Set
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SZ18 ANZCA version [2004-Aug] Q147, [2005-Apr] Q76, [Mar06]Q148 slight difference in options [Apr07]
The physiological change most likely to be associated with infrarenal cross-clamping of the aorta is A. decreased coronary blood flow B. decreased renal blood flow C. increased cardiac output D. increased heart rate E. reduction in myocardial wall motion abnormalities |
ANSWER B
Although it is clear that a suprarenal cross-clamp will decrease renal blood flow up to 80% an infrarenal cross-clamp also causes a decrease in renal cortical blood flow with an associated decrease in GFR. (Yao and Artusio, 6E Ch 11 p 291) |
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SC29 ANZCA Version [Jul06] Q120
A 40-year-old man with Marfan's syndrome has undergone successful thoracoabdominal aortic reconstruction for aortic dissection. He has a CSF (cerebrospinal fluid) drain in situ. 48 hours post-operatively the CSF is noted to be bloodstained and he becomes obtunded. The most appropriate urgent investigation is A. CSF microscopy and culture B. MRI (magnetic resonance imaging) brain C. MRI spine D. non-contrast head CAT scan E. serum electrolytes |
ANSWER D
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SC28 ANZCA Version [Jul06] Q143
A 25-year-old man with Marfan's syndrome is scheduled for aortic arch reconstruction under circulatory arrest. Cooling to 18 degrees is planned. The maximum time for circulatory arrest at this temperature after which the risk of long term neurological injury increases markedly is A. 15 minutes B. 25 minutes C. 35 minutes D. 45 minutes E. 55 minutes |
ANSWER C
From the following reviews CACC 2006;17:109-117 and JTCS 2001;121:425-427 [jm] > 25 minutes associated with temporary neurological dysfunction > 40 minutes associated with increased risk of CVA > 60 minutes associated with increased mortality There is a marked increase in the stroke rate after 40 minutes of circulatory arrest, and a sharp increase in the mortality rate beyond 65 minutes of circulatory arrest. |
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ANZCA version [Apr 07]
A 40y.o. man with Marfan's syndrome is to undergo thoraco-abdominal aortic reconstruction for chronic aortic dissection. An intrathecal catheter is inserted. The purpose of this is to A. allow drainage of CSF B. allow intrathecal admin of metabolic substrates C. allow intrathecal admin of neuroprotective drugs D. cool the spinal cord E. facilitate spinal cord function monitoring |
ANSWER A
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PC49 [Apr07] Q121
The action of which drug is unchanged in a recipient following cardiac transplantation A. Adenosine B. Adrenaline C. Atropine D. Digoxin E. Isoprenaline |
ANSWER E
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MH43 ANZCA version [2002-Mar] Q92, [2003-Apr] Q61, [2003-Aug] Q9, [2005-Apr] Q15, [Jul07]
The thromboelastogram pattern typical of that seen in haemophilia is labelled MCQ_61_apr03_diagram.png A. A B. B C. C D. D E. E |
ANSWER B
Haemophilia -Prolonged R and K -Reduced alpha -MA normal |
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MZ79 [Jul07]
In Marfan’s Syndrome which is NOT related: A. If develop aortic disease most likely to be aortic stenosis B. At risk iliac aneurysm C. development of mitral valve prolapse is more likely than in general population D. Cardiac myopathy due to medial cystic necrosis/atrophy/ degeneration E. Intracranial aneurysm |
ANSWER A
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Black Bank March 2010
116. Asystolic aortic arch repair. The best method for cerebral protection is: A. anterograde perfusion via coronary vessel B. retrograde perfusion via jugular vein C. thiopentone IV D. hypothermia to 20 degrees celcius |
ANSWER D
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SC33 [Mar10] [Aug10]
A 7 kg Infant with tetralogy of Fallot, post Blalock-Taussig shunt. Definitive repair at later date. Paralysed and ventilated. Baseline saturation 85%, now 70%, BEST treatment: A. Increase FiO2 from 50 to 100% B. Esmolol 70 mcg C. Phenylephrine 35 mcg D. Morphine 1 mg E. 1/2 NS with 2.5% dextrose 70 mls |
ANSWER C
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SC31 [Apr07] Q109
Relative contraindications to mediastinoscopy include A. Cervical spondylosis B. Emphysema C. Mediastinal lymphadenopathy D. Poor left ventricular function E. Superior vena cava syndrome |
ANSWER E
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SC30 [Apr07] [Jul07]
For a patient positioned for left lateral for posterolateral incision for thoracotomy A. right brachial plexus is at risk if shoulder flexed > 90 degrees B. radial nerve is most common injury C. flex the non-dependant leg, and straighten the dependant leg D. place axillary roll under chest to improve surgical exposure E. the neck should be extended to allow access to the airway |
ANSWER A
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SC26 [Mar06] Q147, [Jul06] Q89
A patient is scheduled for coronary artery bypass surgery (CABG) 2 hours after receiving tirofiban (Aggrastat) during coronary angiography and an unsuccessful coronary stenting procedure. The most useful strategy to treat or prevent excessive peri-operative bleeding is A. concentrated factor VIII B. administration of cryoprecipitate C. delaying surgery another 2 hours D. haemofiltration during bypass E. platelet transfusion |
ANSWER C
Tirofiban has a half life of 2 hrs. Wait 3-5 half lives. It is cleared by mainly by renal excretion, some in the faeces. Is removed by dialysis and filtration. Will inhibit new platelets transfused. My plan would be: 1. delay surgery if this is feasible for a total of 4-6hrs based on patient condition 2. consider off pump to minimise platelet effects 3. aprotinin 4. dialyse/filter on pump 5. transfuse platelets afterwards if bleeding clinically or on TEG. The one thing that will consistently benefit the patient is haemofiltration during bypass. |
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SC23 ANZCA version [2004-Aug] Q123
The incidence of major focal neurological deficits after coronary artery bypass grafting (CABG) is A. less than 1% B. 3% C. 6% D. 9% E. over 12% |
ANSWER B
Types and initial incidences of neurological complications after cardiac surgery Fatal brain injury 0.3% Non fatal diffuse encephalopathy Depressed conscious level 3% Behavioural changes 1% Intellectual / cognitive dysfunction 30-79% Seizures Choreoathetosis 0.3% Ophthalmological Visual field defects 25% Reduced visual acuity 4.5% Focal brain injury (Stroke) 2-5% Primitive reflexes 39% Spinal cord injury 0-0.1% Peripheral nerve injury Brachial plexopathy 7% Other peripheral neuropathy 6% |
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SC22 ANZCA version [2003-Aug] Q139, [2005-Apr] Q96, [2005-Sep] Q92
With respect to intra-arterial cannulation and monitoring A. following cardiopulmonary bypass, a cannula in the brachial artery will tend to give a more accurate blood pressure reading than in the radial artery B. radial artery cannulation is not contra-indicated in Raynaud's Disease C. the Allen's test is a reliable predictor of the adequacy of collateral flow D. The axillary artery is not suitable for use in cardiac surgery E. the infective rate of all cannulation sites is approximately 5% |
ANSWER A
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SC22b ANZCA Version [Jul07]
Femoral artery cannulation for arterial pressure monitoring A. is associated with more major complications than radial artery cannulation B. is frequently unreliable in the immediate post-bypass period C. should be performed with an approach from above the inguinal ligament D. should be performed with a large bore cannula to avoid erosion of the vessel wall E. should not be used for over 24 hours because of the risk of infection |
ANSWER A
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SC19 ANZCA version [2001-Apr] Q140, [2001-Aug] Q100
A 60 year old patient presents for elective coronary artery bypass grafts. The cardiac catheter report shows three vessel disease, and an ejection fraction of 30%. A pulmonary artery (PA) catheter inserted preinduction showed a baseline PA pressure of 30/15 mmHg. The patient is anaesthetised and 45 minutes into the procedure the PA pressure has risen to 65/40 mmHg. The ECG is unchanged. This observed change could be due to 1. respiratory acidosis 2. sympathetic stimulation 3. left ventricular ischaemia 4. alveolar hypoxia |
All True
Causes of ACUTE pulmonary hypertension: * Physiological: hypoxic vasoconstriction, hypercarbia and acidosis * Volume related: hypervolaemia, redistribution of blood volume to central blood volume from high sympathetic tone * Left heart dysfunction: LV dysfunction probably the only thing that happens acutely except LA myxoma plopping. * Pulmonary arterial: pulmonary emboli (clot, fat, amniotic fluid), alpha agonist direct pulmonary vasoconstriction (references vary). |
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SC18 ANZCA version [2002-Aug] Q99
Aortic dissection is most commonly seen in association with A. Atherosclerosis B. Blunt chest trauma C. Chronic renal failure D. Marfans syndrome E. Hypertension |
ANSWER E
Risk factors Hypertension Bicuspid aortic valve Co-arctation Pregnancy post-aortotomy Marfans Advanced age Male Trauma |
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SC17 ANZCA version [2001-Aug] Q20, [2002-Mar] Q6
During cardio-pulmonary bypass perfusion for cardiac surgery, total body hypothermia is often utilised. This hypothermia: A. will NOT ensure, on its own, amnesia and analgesia below a core temperature of 30 degrees Celsius B. increases the transfer of oxygen from blood to tissues due to a shift in the oxyhaemoglobin dissociation curve C. induces some degree of red blood cell lysis D. decreases the solubility of oxygen in arterial blood E. results in decreased effectiveness of heparin as an anticoagulant |
ANSWER A
A. TRUE B. FALSE : hypothermia causes a left shift of the HDC C. FALSE : bypass causes cell lysis D. FALSE : temp increases solubility E. FALSE : anticoagulant effects of heparin are increased by hyperthermia and hypothermia |
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SC15b ANZCA version [2002-Aug] Q92
The most significant predictor for inotrope requirement to wean a patient from cardiopulmonary bypass is A. use of warm cardioplegia B. insulin dependent diabetes mellitus C. an elevated creatinine D. cardiomegaly on chest X-ray E. left main coronary artery disease |
ANSWER D
Factors which increase risk of Low CO Syndrome (LCOS) after Bypass -Age >70 -Female gender -weight -LAD disease -triple vessel disease -congestive heart failure -recent myocardial infarction -ejection fractions <20% -renal failure -COPD -preoperative use of diuretics, digitalis and ß-adrenergic blockers, -Redo surgery -duration of surgery -CPB time- aortic cross-clamping time -reperfusion time. No affect -height -BMI -history of hypertension -diabetes mellitus -long-term therapy with ACE inhibitors, calcium-blocking drugs, nitroglycerin and antidysrhythmic drugs |
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SC13 ANZCA version [Jul00] [2003-Apr] Q89, [2003-Aug] Q58, [2005-Sep] Q63
The most appropriate investigation to diagnose Type A aortic dissections in potentially unstable patients is A. angiography B. CAT scan C. magnetic resonance imaging (MRI) D. transoesophageal echocardiography E. transthoracic echocardiography |
ANSWER D
Sensitivity Specificity MRI 95-100 95-100 TTE 35-80 39-96 TEE 98 63-96 Aortography 86-88 75-94 CT 83-94 87-100 |
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SC11b ANZCA version [2001-Aug] Q82
Assuming correct positioning, complications of an intra-aortic balloon pump may include all of the following EXCEPT A. systemic infection B. peripheral vascular ischaemia C. gas embolism D. renal failure E. neurological injury |
ANSWER E
The complications of IABP are: • ischaemia of the leg • dissection of the aorta • thrombus formation and embolisation • renal artery occlusion • splenic mesenteric and spinal cord infarction • internal mammary occlusion • thrombocytopaenia • infection • gas embolisation Aortic plaque sheared of or trashed to kidneys, brain (especially during placement, seldinger technique, wire going up aorta) • inability to place the IABP |
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SC10 [Jul98] (type K)
Which of the following decreases the effectiveness of an intra-aortic balloon pump? 1. Irregular heart beat 2. Vasodilators 3. Aortic regurgitation 4. Adrenaline infusion ?vasoconstrictors |
ANSWER 1, 2, 3
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SC09 [Jul98] (type K)
A patient has increased risk of CVA with aortic valve replacement if: A. Atheroma of ascending aorta B. Elderly patients C. Intra-aortic balloon pump (IABP) use D. Use of CO2 to insufflate ?pericardium E. Atrial fibrillation |
ANSWER ???
Overall incidence of stroke is 4.6% Incidence by surgery -CABG 3.8% -beating-heart CABG 1.9% -aortic valve surgery 4.8% -mitral valve surgery 8.8% -double or triple valve surgery 9.7% -CABG and valve surgery 7.4% Multivariable analysis revealed 10 variables that were independent predictors of stroke: 1. history of cerebrovascular disease 2. peripheral vascular disease, diabetes 3. hypertension 4. previous cardiac surgery 5. preoperative infection 6. urgent operation 7. CPB time more than 2 hours 8. need for intraoperative hemofiltration 9. high transfusion requirement |
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SC07 [Mar94] [Aug94] [Mar95] [Aug95] [Apr96] [Aug96]
Cardioplegia - mechanism of arrest in diastole: A. Hyperpolarisation of membrane by high K+ B. Sodium channel block due to depolarisation caused by high concentration of K+ C. Hypothermia from cold solution D. Reduced calcium entry into the cell due to low calcium in plegia solution E. ? |
ANSWER B
The resulting increase in extracellular potassium concentration reduces the transmembrane potential (less negative inside). The latter progressively interferes with the normal sodium current during depolarization, decreasing the rate of rise, amplitude, and conduction velocity of subsequent action potentials (see Chapter 19). Eventually, the sodium channels are completely inactivated, action potentials are abolished, and the heart is arrested in diastole. |
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SC05 [1988]
Mitral valve replacement. Problems post-bypass: A. Atrial fibrillation B. Atrial flutter C. Complete heart block D. Ventricular tachycardia E. Ventricular fibrillation |
ANSWER ALL
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SC03 ANZCA version [2001-Apr] Q141
Intra-aortic balloon counterpulsation decreases 1. left ventricular work 2. peak arterial pressure 3. myocardial oxygen requirements 4. diastolic pressure-time index |
ANSWER 1 and 3
The IABP remains the first mechanical line of defense for perioperative LV dysfunction. The IABP decreases cardiac work (MVO2) by deflating during systole, thereby reducing afterload, and augmenting coronary perfusion with inflation during diastole. IABP counterpulsation is designed to increase the myocardial oxygen supply during diastole and to decrease myocardial oxygen demand during systole The major effects of IABP are:1. Increased diastolic blood pressure 2. Decreased systolic blood pressure - note, the assisted systolic pressure peak is lower than the unassisted systolic pressure peak 3. Decreased LV systolic work, tension, and myocardial oxygen consumption 4. Decreased afterload - note, the pre-systolic pressure with IABP is LOWER than the unassisted end-diastolic pressure 5. Improved RV function (2° increased myocardial blood flow and unloading of LV pressures) Balloon inflation:The balloon is inflated with helium, to a volume of between 20-40 ml. The newer, smaller diameter sets (8.5, 9.5 Fr) have lower incidence of complications than the older (50 to 80ml) sets. Aim is not to occlude the aorta, just to displace blood during diastole. 85% occlusion is optimal. Gases for inflation:Carbon dioxide: Dense & therefore slow to inflate & deflate balloon - Requires a larger diameter drive line with increased injury to artery, however is rapidly dissolved in blood if accidentally introduced. Helium: Low density [therefore reduced Reynold’s number] & therefore able to rapidly inflate & deflate balloon: Requires only a narrow diameter drive line, however source of emboli if accidentally introduced into blood. Helium in volumes used in the IABP released into the descending aorta is promptly distributed to the cerebral & coronary vessels & is rapidly fatal. Location: The balloon is usually positioned just distal to the left subclavian take-off The device can also be placed in the proximal descending aorta (placed intraoperatively) Timing:Inflation should be synchronous to the dicrotic notch on arterial pressure trace. The most common method of triggering the IAB is from the R wave of the patient’s ECG signal. Mainly balloon inflation is set automatically to start in the middle of the T wave and to deflate prior to the ending QRS complex Indications:Torchiana and colleagues reviewed the Massachusetts General Hospital experience of 4756 IABP patients from 1968 to 1995. In their series the use of an IABP intraoperatively or postoperatively was associated with 35.7% and 35.9% mortality rates, respectively, along with a trend toward increased preoperative use. Ghali and colleagues examined the use of the IABP in 12 Massachusetts hospitals. There was a 13.4% use in CABG cases. Many reports show an increase in IABP placement preoperatively in patients with decreased LV function. This does not include failed PTCA/stenting, postinfarction refractory angina, or cardiogenic shock patients undergoing urgent or emergency placement. Holman and colleagues did not show a survival advantage with preoperative IABP but did show improved convalescence and decreased hospital LOS. The overall use of the IABP has been reviewed by the Benchmark Counterpulsation Outcomes Registry. Between June 1996 and August 2000, 203 hospitals worldwide (90% in the United States) examined 16,909 patient case records. The indications for the IABP use included: support during or after cardiac catheterization (20.6%), cardiogenic shock (18.8%), weaning from CPB (16.1%), preoperative placement in high risk cardiac surgery patients (13.0%), and refractory unstable angina (12.3%). The two major indications for IABP placement are: 1. myocardial ischaemia that is intractable to maximal medical therapy 2. LV dysfunction inadequately managed with inotrope therapy When the traditional common femoral artery percutaneous or open approach is not possible, or the ankle-brachial index (ABI) is less than 0.9 (severe peripheral vascular disease), aortic arch placement of the IABP is considered. This requires reoperation for removal and is associated with a higher incidence of postoperative neurological events. Absolute contraindications for IABP are few: 1. Severe aortic valve disease 2. Aortic dissection 3. Severe peripheral valve disease Complications: Cx related to femoral IABP placement occur in 8% to 25% of patients. Aortic perforation, aortoilial dissection, retroperitoneal hematoma, limb ischemia, local nerve root compression, AV fistulas, pseudoaneurysms, and wound hematomas have all been reported. Female gender, increasing patient age, and peripheral vascular disease (PVD) are independent risk factors for morbidity. |
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SC02
The aortic balloon pump: A. Decreases afterload B. Increases myocardial contractility C. Is more efficient with helium than oxygen D. Patient must be heparinised |
ANSWER A and C
The IABP remains the first mechanical line of defense for perioperative LV dysfunction. The IABP decreases cardiac work (MVO2) by deflating during systole, thereby reducing afterload, and augmenting coronary perfusion with inflation during diastole. IABP counterpulsation is designed to increase the myocardial oxygen supply during diastole and to decrease myocardial oxygen demand during systole The major effects of IABP are:1. Increased diastolic blood pressure 2. Decreased systolic blood pressure - note, the assisted systolic pressure peak is lower than the unassisted systolic pressure peak 3. Decreased LV systolic work, tension, and myocardial oxygen consumption 4. Decreased afterload - note, the pre-systolic pressure with IABP is LOWER than the unassisted end-diastolic pressure 5. Improved RV function (2° increased myocardial blood flow and unloading of LV pressures) Balloon inflation:The balloon is inflated with helium, to a volume of between 20-40 ml. The newer, smaller diameter sets (8.5, 9.5 Fr) have lower incidence of complications than the older (50 to 80ml) sets. Aim is not to occlude the aorta, just to displace blood during diastole. 85% occlusion is optimal. Gases for inflation:Carbon dioxide: Dense & therefore slow to inflate & deflate balloon - Requires a larger diameter drive line with increased injury to artery, however is rapidly dissolved in blood if accidentally introduced. Helium: Low density [therefore reduced Reynold’s number] & therefore able to rapidly inflate & deflate balloon: Requires only a narrow diameter drive line, however source of emboli if accidentally introduced into blood. Helium in volumes used in the IABP released into the descending aorta is promptly distributed to the cerebral & coronary vessels & is rapidly fatal. Location: The balloon is usually positioned just distal to the left subclavian take-off The device can also be placed in the proximal descending aorta (placed intraoperatively) Timing:Inflation should be synchronous to the dicrotic notch on arterial pressure trace. The most common method of triggering the IAB is from the R wave of the patient’s ECG signal. Mainly balloon inflation is set automatically to start in the middle of the T wave and to deflate prior to the ending QRS complex Indications:Torchiana and colleagues reviewed the Massachusetts General Hospital experience of 4756 IABP patients from 1968 to 1995. In their series the use of an IABP intraoperatively or postoperatively was associated with 35.7% and 35.9% mortality rates, respectively, along with a trend toward increased preoperative use. Ghali and colleagues examined the use of the IABP in 12 Massachusetts hospitals. There was a 13.4% use in CABG cases. Many reports show an increase in IABP placement preoperatively in patients with decreased LV function. This does not include failed PTCA/stenting, postinfarction refractory angina, or cardiogenic shock patients undergoing urgent or emergency placement. Holman and colleagues did not show a survival advantage with preoperative IABP but did show improved convalescence and decreased hospital LOS. The overall use of the IABP has been reviewed by the Benchmark Counterpulsation Outcomes Registry. Between June 1996 and August 2000, 203 hospitals worldwide (90% in the United States) examined 16,909 patient case records. The indications for the IABP use included: support during or after cardiac catheterization (20.6%), cardiogenic shock (18.8%), weaning from CPB (16.1%), preoperative placement in high risk cardiac surgery patients (13.0%), and refractory unstable angina (12.3%). The two major indications for IABP placement are: 1. myocardial ischaemia that is intractable to maximal medical therapy 2. LV dysfunction inadequately managed with inotrope therapy When the traditional common femoral artery percutaneous or open approach is not possible, or the ankle-brachial index (ABI) is less than 0.9 (severe peripheral vascular disease), aortic arch placement of the IABP is considered. This requires reoperation for removal and is associated with a higher incidence of postoperative neurological events. Absolute contraindications for IABP are few: 1. Severe aortic valve disease 2. Aortic dissection 3. Severe peripheral valve disease Complications: Cx related to femoral IABP placement occur in 8% to 25% of patients. Aortic perforation, aortoilial dissection, retroperitoneal hematoma, limb ischemia, local nerve root compression, AV fistulas, pseudoaneurysms, and wound hematomas have all been reported. Female gender, increasing patient age, and peripheral vascular disease (PVD) are independent risk factors for morbidity. |
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SC01
Counterpulsation intra-aortic balloon pump: A. Improves coronary blood flow and decreases afterload B. Optimal position just distal to left subclavian artery C. Helium is better than CO2 for inflation D. Must always be heparinised |
ANSWER A B C
The IABP remains the first mechanical line of defense for perioperative LV dysfunction. The IABP decreases cardiac work (MVO2) by deflating during systole, thereby reducing afterload, and augmenting coronary perfusion with inflation during diastole. IABP counterpulsation is designed to increase the myocardial oxygen supply during diastole and to decrease myocardial oxygen demand during systole The major effects of IABP are:1. Increased diastolic blood pressure 2. Decreased systolic blood pressure - note, the assisted systolic pressure peak is lower than the unassisted systolic pressure peak 3. Decreased LV systolic work, tension, and myocardial oxygen consumption 4. Decreased afterload - note, the pre-systolic pressure with IABP is LOWER than the unassisted end-diastolic pressure 5. Improved RV function (2° increased myocardial blood flow and unloading of LV pressures) Balloon inflation:The balloon is inflated with helium, to a volume of between 20-40 ml. The newer, smaller diameter sets (8.5, 9.5 Fr) have lower incidence of complications than the older (50 to 80ml) sets. Aim is not to occlude the aorta, just to displace blood during diastole. 85% occlusion is optimal. Gases for inflation:Carbon dioxide: Dense & therefore slow to inflate & deflate balloon - Requires a larger diameter drive line with increased injury to artery, however is rapidly dissolved in blood if accidentally introduced. Helium: Low density [therefore reduced Reynold’s number] & therefore able to rapidly inflate & deflate balloon: Requires only a narrow diameter drive line, however source of emboli if accidentally introduced into blood. Helium in volumes used in the IABP released into the descending aorta is promptly distributed to the cerebral & coronary vessels & is rapidly fatal. Location: The balloon is usually positioned just distal to the left subclavian take-off The device can also be placed in the proximal descending aorta (placed intraoperatively) Timing:Inflation should be synchronous to the dicrotic notch on arterial pressure trace. The most common method of triggering the IAB is from the R wave of the patient’s ECG signal. Mainly balloon inflation is set automatically to start in the middle of the T wave and to deflate prior to the ending QRS complex Indications:Torchiana and colleagues reviewed the Massachusetts General Hospital experience of 4756 IABP patients from 1968 to 1995. In their series the use of an IABP intraoperatively or postoperatively was associated with 35.7% and 35.9% mortality rates, respectively, along with a trend toward increased preoperative use. Ghali and colleagues examined the use of the IABP in 12 Massachusetts hospitals. There was a 13.4% use in CABG cases. Many reports show an increase in IABP placement preoperatively in patients with decreased LV function. This does not include failed PTCA/stenting, postinfarction refractory angina, or cardiogenic shock patients undergoing urgent or emergency placement. Holman and colleagues did not show a survival advantage with preoperative IABP but did show improved convalescence and decreased hospital LOS. The overall use of the IABP has been reviewed by the Benchmark Counterpulsation Outcomes Registry. Between June 1996 and August 2000, 203 hospitals worldwide (90% in the United States) examined 16,909 patient case records. The indications for the IABP use included: support during or after cardiac catheterization (20.6%), cardiogenic shock (18.8%), weaning from CPB (16.1%), preoperative placement in high risk cardiac surgery patients (13.0%), and refractory unstable angina (12.3%). The two major indications for IABP placement are: 1. myocardial ischaemia that is intractable to maximal medical therapy 2. LV dysfunction inadequately managed with inotrope therapy When the traditional common femoral artery percutaneous or open approach is not possible, or the ankle-brachial index (ABI) is less than 0.9 (severe peripheral vascular disease), aortic arch placement of the IABP is considered. This requires reoperation for removal and is associated with a higher incidence of postoperative neurological events. Absolute contraindications for IABP are few: 1. Severe aortic valve disease 2. Aortic dissection 3. Severe peripheral valve disease Complications: Cx related to femoral IABP placement occur in 8% to 25% of patients. Aortic perforation, aortoilial dissection, retroperitoneal hematoma, limb ischemia, local nerve root compression, AV fistulas, pseudoaneurysms, and wound hematomas have all been reported. Female gender, increasing patient age, and peripheral vascular disease (PVD) are independent risk factors for morbidity. |
