PERIOPERATIVE PERIOPERATIVE HYPERTENSIONHYPERTENSION

The Role of The Role of

DA-1 Agonists DA-1 Agonists (Fenoldopam)(Fenoldopam)

R. Sheinbaum M.D.

O. Wenker M.D.

Perioperative HTNPerioperative HTNIncidenceIncidence

DefinitionDefinitionWide range of definitionsWide range of definitions

systolic systolic >110-170>110-170

diastolicdiastolic 95-100-10795-100-107

% change in BP% change in BP

– Leslie JB Acta Anaesthesiol Scand 1993; 37: 5-9

Perioperative HTNPerioperative HTNIncidenceIncidence

Patient FactorsPatient Factors• underlying risk factorsunderlying risk factors• increasing age base of populationincreasing age base of population• higher risk procedureshigher risk procedures

Type of SurgeryType of Surgery• cardiac cardiac 40-60 %40-60 %• non cardiacnon cardiac 5 % 5 %

– Estafanos FG Am Heart J 1973 ; 85 : 732-738

– Viljoen JF J Thorac Cardiovasc Surg 1976 ; 71 : 548

– Leslie JB Acta Anaesthesiol Scand 1993 ; 37 : 5-9

Perioperative HTNPerioperative HTNEtiologyEtiology

Primary HTNPrimary HTN Secondary HTNSecondary HTN Surgically Associated HTNSurgically Associated HTN Anesthesia Related HTNAnesthesia Related HTN OtherOther

Perioperative HTNPerioperative HTNSignificanceSignificance

Organ DamageOrgan Damage• heartheart

• brainbrain

• kidneykidney

Surgical ConsiderationsSurgical Considerations MorbidityMorbidity

HypertensionHypertensionTreatmentTreatment

BP = Q x SVRBP = Q x SVRQ = HR x SV

SV preload, contractility, afterload

SVR viscosity, vessel radius

Blood PressureBlood Pressure

Sympathetic Nervous System Sympathetic Nervous System Regulation of Blood PressureRegulation of Blood Pressure

Adrenergic Adrenergic ToneToneBaroreceptor Baroreceptor

ReflexesReflexes

Volume/Volume/PressurePressure

Renin/AngiotensinRenin/Angiotensin

PreloadPreload

Cardiac OutputCardiac Output

CatecholaminesCatecholamines

Adrenal Adrenal GlandGland

CNSCNS

VeinsVeins ArteriesArteries

CapacitanceCapacitance ResistanceResistance

HeartHeartKidneyKidney

AfterloadAfterload

Anti HTN AgentsAnti HTN AgentsFENOLDOPAMFENOLDOPAM

Ideal CharacteristicsIdeal Characteristics– effectiveeffective– predictable onsetpredictable onset– easily titratableeasily titratable– few side effectsfew side effects– metabolically inertmetabolically inert

Comparison to NitroprussideComparison to Nitroprusside• just as effective in just as effective in reaching target BPreaching target BP

• just as quick in reaching just as quick in reaching target BPtarget BP

• Panacek EA Acad Emerg Med 1995 ; 2 : 959-965

Anti HTN AgentsAnti HTN AgentsFENOLDOPAMFENOLDOPAM

Fenoldopam Fenoldopam versus versus

NitroprussideNitroprusside BenefitsBenefits

• HeartHeart• > EF, CI> EF, CI• < PCWP, PVR< PCWP, PVR• minimal change in HR (dose related)minimal change in HR (dose related)

• RenalRenal• > renal blood flow, Na excretion> renal blood flow, Na excretion• > Cr Cl> Cr Cl

• Elliot WJ Circulation 1990 ; 81 : 970-977• Shusterman NH Am J Med 1993 ; 96 : 161-168• Hill AJ J Cardiothorac Vasc Anesth 1993 ; 7 : 279-284

Comparison of Renal Effects Comparison of Renal Effects in Severe Hypertensionin Severe Hypertension

140

Fenoldopam

Nitroprusside

Cha

nge

from

Bas

elin

e (%

)

0

20

40

60

80

100

120

-10

Urinary Flow Rate Sodium Excretion Creatinine Clearance

Elliott WJ, et al. Circulation 1990;81:970-977

CONTROLCONTROL

CORLOPAMCORLOPAMAdvantagesAdvantages

ControlControl EffectivenessEffectiveness End Organ BenefitsEnd Organ Benefits Unique ActionUnique Action Potential Renal BenefitsPotential Renal Benefits

Perioperative HTNPerioperative HTNSummarySummary

IncidenceIncidence End Organ EffectsEnd Organ Effects Impact on Morbidity/ MortalityImpact on Morbidity/ Mortality Treatment ImpactTreatment Impact Treatment OptionsTreatment Options