anesthesia for vascular surgery

Anesthesia for Vascular Surgery

Neal BadnerAssociate Professor

Department of Anesthesiology & Perioperative Medicine

Seminar Outline

• Preop issues1. Beta-blockers2. Coronary stents

• Intraop management1. Crossclamp pathophysiology2. Renal Protection3. Spinal Cord Protection 4. Endovascular Approach

• Postop1. Pain Management

Beta-blockers ACC/AHA Update

Fleisher LA et al, JACC 2006;47:2343-55 & Anesth Analg 2007;104:15-26.

-blocker study summary

Pts Author Outcome Details

Low risk POBBLELindenauer

Noneharm

927 pts, random663,635 data base

Intermediate risk

ManganoYang

DIPOM

POISE

? BenefitNonenone

dec MI, inc mort

200 no early496, blinded

921 diabetic pts

8,351 pts

High risk Poldermans

Lindenauer

Lower mortality

Lower mortality

112 pts, D-TTE

Seminar Outline




And then there was CARP

Variable Number (%)

Screened 5859

Angiogram 1230

Included 510

2 or more RCRI factors 250 (49)

Nuclear stress imaging 316 (62)

Moderate to large ischemia 226 (44)

Left main disease [excluded] [54]

Triple vessel disease 170 (33)

McFalls EO. NEJM 2004;351:2795-804

CARP – body count

Events re: vascular surgery Revascularize

(n= 258)

Proceed

(n=252)

Revascularized preop 240 (93%) 9 (4%)

CABG : PCI 99 : 141 N/A

Delay before surgery (days) 54 (28-80) 18 (7-42)

Preoperative mortality 10 (4) 1 (0)

Underwent vascular surgery 225 (87%) 237 (94%)

30 day mortality 7 (3%) 8 (3%)

30 day myocardial infarction 26 (12%) 34 (14%)

McFalls EO. NEJM 2004;351:2795-804

CARP – long term survival

McFalls EO. NEJM 2004;351:2795-804

More specifically, stents and vascular surg

Retrospective, database - Godet G. Anesthesiology 2005;102:739-46

Stents clot, so approach to PCI

Balloon angioplasty

Bare-metal stent

Drug-eluting stent

DelayWith ASA

14 days 30-45 days 365 days

Fleisher LA et al, Circulation 2007;116:1971-96

Can’t delay – bridging therapy:(a) ASA & clopidrogel periop(b) ASA & short-acting GIIb/IIIa(c) ASA & clopidrogel postop

Newsome et al, A & A 2008;107:570-90

Seminar Outline




Vascular Anesthesia Goals

• Stable hemodynamics & preserve myocardial function

• Maintain O2 carrying capacity ie. Vol & Hct

• Protect renal function

• Maintain body temp

• Correct biochemical abnormalities that develop i.e., lytes, ph

Intraoperative Myocardial Ischemia

ECG Ischemia Detection

100

96

94

90

82

80

75

61

33

Sensitivity

II, V2 - V5

II, V4 & V5

V3, V4 & V5

V4 & V5

II & V4

II & V5

V5

V4

II

Lead

Effect of X-Clamp

Variable Supraceliac Suprarenal Infrarenal

MAP 54 5 2

PCWP 38 10 0

EF -38 -10 -3

% pts wall motion abN 92 33 0

% MI 8 0 0

% change in variable. From Roizen et al Vascular Sx 1994

Therapeutic Options

• Afterload reduction

1. Volatile - easy, fast

2. SNP - difficult (foil, pump), overshoot

• Preload reduction

1. GTN - myocardial benefit

2. Shunts and/or partial bypass

Seminar Outline




Renal Protection

• Fluids• Mannitol• Dopamine• N-acetyl Cysteine (NACC)

Tang YI & Murray PT. Best Practices & Research Clin Anesth 2004;18:91-111.

Renal Protection (Fluids)

• Etiology of ARF 1. pre-renal azotemia2. ATN 20 (i) ischemia & (ii) nephrotoxins

• Kidneys receive 20 – 25% CO• Autoreg RBF & GFR @ MAP 85 – 180

MAP 60 –70 is on steep desc part curve Htn right shifts curve Lost in ATN

• no studies of extra fluid vs normal vasc• Supranormal CVT - dec C/O (ARF)

Shoemaker Chest 1988:94:1176-86.

Renal Protection (Mannitol)

• Conceptually inc tubular flow & “wash out” debris

• Na-K-Cl pump medullary O2 req• Free radical scavenger• Human studies

• No U/O @ 24 hrs• No CrCl @ 24 hrs

Zacharias et al, The Cochrane Library Issue 1, 2006

• Morbidity: high dose may cause ARF

Renal Protection (Dopamine)

• Low dose stim DA-1 & DA-2 rec • renal a. vasodilation RBF• Na reabsorp natriuesis

• Periop Studies• U/O @ 24 hrs by 0.33 ml/min

(95% CI 0.05 – 0.60)• No CrCl @ 24 hrs• No free H20 clearance

Zacharias et al, The Cochrane Library Issue 1, 2006

• Morbidity: tachyarrhythmias, ischemia, etc

Renal Protection (Fenoldopam)

• Pure DA-1 agonist not available in Can• In animals preserves RBF during

hypotension under GA• No effect contrast nephropathy with CRI

Stone et al JAMA 2003:290:2284-91.

• Maintained CrCl vs dec in control in infrarenal aortic Sx pts (n = 28) Halpenny et al EJA 2002;19:32-39.

Renal Protection (NACC)

• Antioxidant useful in acetaminophen toxicity

• Initial role in prevention of contrast nephropathy (not reproduced) Tepel M et al, NEJM 2000;343:180-4.

• No benefit in preventing ARF in infrarenal aortic Sx in pts with normal renal fx Hynninen MS et al, A &A 2006:102:1638-45.

Seminar Outline




Spinal Cord Blood Supply

Longitudinal view – ant spinal a. NOT continuous

Spinal Cord Blood Supply (2)

3D Cross-sectional – location of feeder

Spinal Cord Blood Flow

Surgical exposure – feeder vessel

Spinal Cord Summary

• Low thoracic levels dependant on variable blood supply

• Anterior fibres more at risk than posterior

• May be source of significant back bleeding when aorta opened

Spinal Cord Protection

• Decrease X-clamp time

• Partial bypass

• Decrease spinal cord perfusion pressure (SCPP = MAP - SCP) using drain

X-Clamp & Outcome in TAA

Time (min) Pts % Paraplegia % ARF

0 - 15 8 0* 0

16 - 30 142 3.5* 4.2

31 - 45 90 10.0 7.8

46 - 60 16 12.5 6.3

> 60 4 25 0

Livesay et al, Ann Thorac Surg 1985;39:37-46. * p < 0.025 vs others

Neurologic Complications

Linear regression curves from Townsend: Sabiston Textbook of Surgery, 17th ed. 2004, Saunders

Partial Bypass

Vascular Anesthesia in Anesthesia ed Miller 6th edition 2005

Need: heparinization & CVT surgeon

CSF Drainage

Need: 1. drainage bag 2. pressure monitor

From animal studies

CSF Drainage - Background

Regression from Coselli et al. J Vasc Surg 2002;35;631-9

CSF Drainage & Paraplegia

CS Cina et al. J Vasc Surg 2004;40:36-44.

CSF Drainage

Indications:1. involvement T9-T12 (artery of Adamkiewicz)

2. Involvement of arch vessels (origin ant. spinal a.)

3. Previous TAA if AAA repair or vice versa

4. Symptomatic spinal ischemia

CSF Drainage

Complications:

n= 1486

Subdural hematoma = 2 with paraplegia

Meningitis (fatal) = 1

Cina CS et al. J Vasc Surg 2004;40:36-44

Seminar Outline




Stent Procedures

Can also use tube grafts & fem-fem crossover

Endovascular Surgery

U.S. vascular procedures

Anderson et al. J Vasc Surg 2004;39:1200-8.

Endovascular Stents

Anatomic prerequisites:1. Aneurysm morphology

2. Distal access artery caliber

3. Proximal & distal landing zones – need 2 cm without major vessel

Submarine analogy

Unlike most procedures you will know of surgical C/O 1st

Surgical Complications

• Conversion to open 1 – 3%

• Endoleak 2 – 10 %

• Migration 1 – 5%

• Thrombosis 1 – 5%

• Rupture < 1 % at 5 yr

Stent Survival

Makaroun MS et al, J Vasc Surg 2005;41:1-9

Endovascular Surgery

Prospective, randomized though unblinded studyDavies MJ et al. Anaesth Intens Care 2002;30:66-70

OAR

N=50

EAR

N=50

General anesthesia 6 3

Combined general and epidural anesthesia 44 0

Combined spinal and epidural anesthesia 0 21

Epidural anesthesia 0 24

Spinal anesthesia 0 2

Pulmonary artery catheter 36 0

Central venous catheter 14 44

TABLE 2 – Anesthesia and Monitoring

Endovascular Surgery (2)

Davies MJ et al. Anaesth Intens Care 2002;30:66-70.

Endovascular Surgery (3)

Davies MJ et al. Anaesth Intens Care 2002;30:66-70.

Endovascular LHSC (1)

OAR EAR Significance O.R time (min.) 249 46 214 44 < 0.0001 General Anesthesia 99 85 (96) C.S.E. 0 4 (4)

0.0033

Epidural 89 1 (1) < 0.0001 Ephedrine (mg) 2.9 6.5 5.4 9.0 0.0253 Phenylephrine use (mcg) 125 271 110 200 ns Blood loss (ml) 1020 588 295 282 < 0.0001 pRBC transfused 29 3 (3) <0.0001 PAC Used 64 26 (29) <0.0001 CVP Used 99 88 (99) ns Crystalloid (ml) 3494 1308 2369 743 < 0.0001 Colloid (ml) 463 396 125 242 <0.0001 Values are mean SD or n (%) Nonrandomized, retrospective

Teague et al, CSA 2006;53:26210


OAR EAR Significance Extubated post-op 89 84 (98) ns PACU hypotension 16 3 (3) 0.0037 PACU hypoxia 49 46 (52) ns Supp. O2 on D/C PACU 91 86 (97) ns ACS or MI 8 4 (4) ns CHF 24 0 <0.0001 Angina 6 8 (9) ns Dysrhythmia 8 3 (3) ns Hypotension 25 4 (4) <0.0001 Neurologic 8 6 (7) ns GI 11 1 (1) 0.0052 Pneumonia 10 2 (2) 0.0278 Values are mean ± SD or n (%) Values are mean SD or n (%) Teague et al, CSA 2006;53:26210


OAR EAR Significance PACU duration (min) 210.9 ± 81.9 196.7 ± 69.7 ns Length of Hospital Stay (days) 12.9 38.3 5.7 4.8 ns Readmission within 30 days 4 4 (4) ns Death before discharge 5 1 (1) ns Death within 30 days 3 0 ns Values are mean SD or n (%) Values are mean SD or n (%) Teague et al, CSA 2006;53:26210

Seminar Outline




Postop Epidural & Outcome

Study Comparison Result Weakness

Yeager ‘87 TEA vs prn Dec mortality (0 vs 4) & costs (50%)

Unblinded, mixed pts, high dose narc GA

Tuman ‘91 TEA vs prn Dec CVT C/O, vasc occlusion

Unblinded, ? Postop pain

Christopherson ‘93 TEA vs PCA Dec vasc occlusion Unblinded

Bois ’97 TEA vs PCA NS Unblinded

Norris ’01 GA ± TEA/PCA

RA ± TEA/PCA

NS underpowered

Park VA ’01 Epi vs PCA

(large)

Subgroup aortic Sx dec CV morbidity

Unblinded & uncontrolled

MASTER ’02

subgoup ’03

Epi vs PCA

(large)

NS

Aortic Sx dec resp C/O

Unblinded & uncontrolled

Postop Epidurals (2)

Beattie, Badner & Choi. A & A 93:853-8, 2001, Nishimori et al. The Cochrane Library Issue 3, 2006


Beattie, Badner & Choi. A & A 93:853-8, 2001,


• Cochrane Library – Aortic Surgery

• Randomized, controlled

• 13 studies, 1224 pts; 597 epi vs 627 sys

• Dec VAS pain scores

• Dec t IPPV (20%), CV C/Os, MI, GI C/Os, renal insuff

• No diff mortality

Nishimori M, Low JHS, Ballantyne JC The Cochrane Library, Issue 3, 2006

Seminar Outline




anesthesia for vascular surgery

Documents

taalivesay et

cristone et

halpenny et

hrszacharias et

roizen et

pcifleisher la et

normal renal fxhynninen

rec renal