optimal perioperative fluid management h yang professor & chair department of anesthesia

Optimal Perioperative Fluid Management

H YangProfessor & Chair

Department of Anesthesia

Conflict of Interest

• No payment by industry• No shares in industry

Objectives

• Review fluid management principles over the years & decades

• Understand the variability of fluid shifts• Describe the physiology behind fluid

management• Discuss management principles

THE PENDULUM SWINGS

Perioperative Fluid Management

• Maintenance– 4:2:1 Rule

• Replacement– Previous losses: fasting; NG; pyloric stenosis; bleeding– Previously 1 – 2 L at start of Sx

• On-going Losses– Bleeding– Ascites– 3rd space: 1 – 2 L/hr– Sepsis

Ann Surg 1961;154:803-10

Fluid Restriction

• Lobo – 20 elective colonic resection– Restriction resulted in earlier return of bowel

function• Brainstrup – 141 colorectal surgery

– Restriction reduced incidence of anastomic leakage, pulmonary edema, & wound infection

• Holte & Kehlet – systematic review of 80 clinical trials– Avoid “fluid overload in major surgical procedures”

WE ARE NOT BUILT THE SAME!

Ann Surg 1961;154:803-10

Lindenauer et al. NEJM 2005; 353:349 - 61

Fluid Requirements

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f P

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Elective

Major fluid shift or blood loss

3rd Space: fact or fiction?

• Tissue injury & swelling• Isotope measurements now called into

question due to kinetics of fluid shifts• Difficult to measure• Common sense: just because it is hard to

measure does not mean it doesn’t exist

PHYSIOLOGY

Total Body Water

ICF 40%(28 L)

PV 5%(3.5 L)

ISV 15%(10.5 L)

3rd space loss – 4cc/kg/hr x 4 hr = 280cc/hr x 4= 1120 cc

Maintenance – 120 cc/hr

Total Body Water

ICF 40%(28 L)

PV 5%(3.5 L)

ISF 15%(10.5 L)

Hypervolemia• Increases

leakage into ISF (endothelial glycocalyx)

Why worry about fluid replacement?

• Hemodynamic stability• Tissue perfusion

– Renal (urine output)– Surgical Site (not measureable)

It is dynamic, not static!• PAOP, CVP, & formula for replacement are all

assuming static kinetics• Preop – elective versus non-routine, bowel

prep• Intraop - anesthetic, epidural, phenylephrine

infusions, inotropes, surgical trauma, ascites, cardiac function (ischemia, diastolic dysfunction, systolic heart failure)

MANAGEMENT PRINCIPLES

Complex

TEE – IVC, hepatic vein, RWMA,

Non-RoutineNICOM, fluid challenge

Routine (elective)

Fluid restriction, monitor component losses

diastolic function

Dynamic

• Fluid restriction works for most routine cases• Be alert to the non-routine cases

– Keep track of component losses– Be ready to move up the intervention ladder:

NICOM, TEE, TTE• Be a little behind but not too much• Keep track of the pharmacology (anesthetics,

regional, vasoprressors)

• Take care of the endothelial glycocalyx!