Hypertension Definition: the force exerted by the blood against the walls of the bleed vessels ...
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Transcript of Hypertension Definition: the force exerted by the blood against the walls of the bleed vessels ...
HypertensionHypertension
Definition:Definition: the force exerted by the the force exerted by the blood against the walls of the bleed blood against the walls of the bleed vessels vessels
Adequate to maintain tissue perfusion Adequate to maintain tissue perfusion during activity and restduring activity and rest
Arterial blood pressure: primary Arterial blood pressure: primary function of cardiac output and function of cardiac output and systemic vascular resistancesystemic vascular resistance
HypertensionHypertension
Arterial BP = Cardiac Output (CO) x Arterial BP = Cardiac Output (CO) x Systemic Systemic vascular resistance vascular resistance (SVR)(SVR)
Cardiac OutputCardiac Output = stroke volume x beats per min = stroke volume x beats per min
Systemic vascular resistanceSystemic vascular resistance = force opposing = force opposing the movement of blood within the blood vesselsthe movement of blood within the blood vessels
What is the effect on BP if SVR increased What is the effect on BP if SVR increased and CO remains constant?and CO remains constant?
HypertensionHypertension Mechanisms that Regulate Mechanisms that Regulate
BPBP
Sympathetic Nervous Sympathetic Nervous SystemSystem
Vascular EndotheliumVascular Endothelium
Renal SystemRenal System
Endocrine SystemEndocrine System
HypertensionHypertensionMechanisms that Regulate Mechanisms that Regulate
BPBPSympathetic Nervous System (SNS)Sympathetic Nervous System (SNS) – – norepinephrine released from norepinephrine released from sympathetic nerve endings - to receptors sympathetic nerve endings - to receptors alpha1, alpha2, beta 1 & beta2alpha1, alpha2, beta 1 & beta2
Reacts within secondsReacts within secondsIncreases Heart Rate - chronotropicIncreases Heart Rate - chronotropicIncreased cardiac contractility - Increased cardiac contractility - inotropicinotropic
Produces widespread vasoconstriction Produces widespread vasoconstriction in peripheral arteriolesin peripheral arterioles
Promotes release of renin from the Promotes release of renin from the kidneykidney
HypertensionHypertensionMechanisms that Regulate Mechanisms that Regulate
BPBPSympathetic Nervous System (SNS)Sympathetic Nervous System (SNS)––
Sympathetic Vasomotor Center – located Sympathetic Vasomotor Center – located in the medulla – interacts with many areas in the medulla – interacts with many areas of the brain to maintain BP within normal of the brain to maintain BP within normal range under various conditionsrange under various conditions
Exercise – changes to meet oxygen demandExercise – changes to meet oxygen demandPostural Changes – peripheral vasoconstrictionPostural Changes – peripheral vasoconstriction
HypertensionHypertensionMechanisms that Regulate Mechanisms that Regulate
BPBPSympathetic Nervous Sympathetic Nervous System (SNS)System (SNS) – –
BaroreceptorsBaroreceptors: specialized nerve cells : specialized nerve cells the carotid arteries and the aortic archthe carotid arteries and the aortic arch
Sensitive to BP changes:Sensitive to BP changes:Increase: Inhibits SNSIncrease: Inhibits SNS – peripheral vessel – peripheral vessel
dilation. Decreased heart rate, and dilation. Decreased heart rate, and decreased contractility of the heart + decreased contractility of the heart + increased parasympathetic activity (vagus increased parasympathetic activity (vagus nerve) decreased heart ratenerve) decreased heart rate
Decrease: Activates SNSDecrease: Activates SNS – peripheral – peripheral vessel constriction, increased heart rate, vessel constriction, increased heart rate, and increased contractility of the heartand increased contractility of the heart
HypertensionHypertension Mechanisms that Regulate Mechanisms that Regulate
BPBPVascular EndotheliumVascular Endothelium
Single cell layer that lines the blood vesselsSingle cell layer that lines the blood vesselsProduce vasoactive substancesProduce vasoactive substances::
EDRF Endothelium-derive relaxing factorEDRF Endothelium-derive relaxing factor – – Helps maintain low arterial tone at restHelps maintain low arterial tone at rest Inhibits growth of the smooth muscle layerInhibits growth of the smooth muscle layer Inhibits platelet aggregationInhibits platelet aggregation
Vasodilation – prostacyclinVasodilation – prostacyclinEndothelin (ET) potent vasoconstrictor Endothelin (ET) potent vasoconstrictor
Endothelial dysfunction may contribute Endothelial dysfunction may contribute to atherosclerosis & primary to atherosclerosis & primary
hypertensionhypertension
HypertensionHypertensionMechanisms that Regulate Mechanisms that Regulate
BPBPRenal System Renal System Control Na+ excretion & extracellular Control Na+ excretion & extracellular
fluid volumefluid volumeRenal - Renin-angiotensin-aldosteroneRenal - Renin-angiotensin-aldosterone
Renin converts angiotensinogen to Renin converts angiotensinogen to angiotensin Iangiotensin I
Angiotensin-converting enzyme (ACE) Angiotensin-converting enzyme (ACE) converts I into angiotsensin II converts I into angiotsensin II Immediate: Vasoconstrictor – increased Immediate: Vasoconstrictor – increased
systemic vascular resistancesystemic vascular resistanceProlonged: Stimulates the adrenal cortex Prolonged: Stimulates the adrenal cortex
to secret Aldosterone – Na+ and Water to secret Aldosterone – Na+ and Water retentionretention
Renal MedullaRenal Medulla - Prostaglandins - - Prostaglandins - vasodilator effectvasodilator effect
HypertensionHypertensionMechanisms that Regulate Mechanisms that Regulate
BPBPEndocrine System Endocrine System
Stimulates the SNS with Stimulates the SNS with Epinephrine – increases HR and contractilityEpinephrine – increases HR and contractilityActivates B2-adrenergic receptors in peripheral Activates B2-adrenergic receptors in peripheral
arterioles of skeletal muscle = vasodilation arterioles of skeletal muscle = vasodilation Activates A1-adrenergic receptors in peripheral Activates A1-adrenergic receptors in peripheral
arterioles of skin and kidneys = arterioles of skin and kidneys = vasoconstictionvasoconstiction
Adrenal Cortex – Aldosterone – stimulates Adrenal Cortex – Aldosterone – stimulates kidneys to retain Na+kidneys to retain Na+
Increased Na+ stimulates posterior Increased Na+ stimulates posterior pituitary – ADH – reabsorbs ECF/waterpituitary – ADH – reabsorbs ECF/water
HypertensionHypertensionAldosterone MechanismAldosterone Mechanism
• Increased Aldosterone =Increased Aldosterone =• Increases sodium Increases sodium
reabsorption =reabsorption =• Increases water Increases water
reabsorption =reabsorption =• Increases blood volume = Increases blood volume = • Increases cardiac output Increases cardiac output
HypertensionHypertensionMechanisms that Regulate Mechanisms that Regulate
BPBP Regulatory mechanisms in the health person Regulatory mechanisms in the health person
function in response to the demands on the bodyfunction in response to the demands on the body
When Hypertension develops, one or more of When Hypertension develops, one or more of these mechanisms are defectivethese mechanisms are defective
Sympathetic Nervous SystemSympathetic Nervous System
Vascular EndotheliumVascular Endothelium
Renal SystemRenal System
Endocrine SystemEndocrine System
Secondary HypertensionSecondary HypertensionPathophysiologyPathophysiology
Specific cause of hypertension can be Specific cause of hypertension can be identifiedidentified
5+% of adult hypertension5+% of adult hypertension Causes:Causes:
Coarctation or congenital narrowing of the aortaCoarctation or congenital narrowing of the aorta Renal disease – renal artery disease / Renal disease – renal artery disease /
parenchymal parenchymal Endocrine disorders: Pheochromocytoma, Endocrine disorders: Pheochromocytoma,
Cushing Syndrome, HyperaldosteronismCushing Syndrome, Hyperaldosteronism Neurology disorders – brain tumors / head injuryNeurology disorders – brain tumors / head injury Sleep apneaSleep apnea Medications – sympathetic stimulantsMedications – sympathetic stimulants Pregnancy-induced hypertensionPregnancy-induced hypertension
HypertensionHypertensionPathophysiologyPathophysiology
Primary (Essential) Hypertension: Primary (Essential) Hypertension:
Elevated BP without an identified causeElevated BP without an identified causeAccounts for 95% of all cases of Accounts for 95% of all cases of
hypertensionhypertensionCause – unknown Cause – unknown
Contributing Factors: Contributing Factors: Increased SNS Increased SNS activity, overproduction of Na+ retaining activity, overproduction of Na+ retaining hormones & vasoconstrictors, increased Na+ hormones & vasoconstrictors, increased Na+ intake intake
Risk Factors: Risk Factors: Modifiable Modifiable
Primary HypertensionPrimary HypertensionPathophysiologyPathophysiology
Heredity Heredity – interaction of genetic, – interaction of genetic, environmental, and demographic environmental, and demographic factorsfactors
Water & Sodium RetentionWater & Sodium Retention – 20% of – 20% of pts with high Na+ diet develop HTNpts with high Na+ diet develop HTN
Altered Renin-Angiotensin Altered Renin-Angiotensin MechanismMechanism – found in 20% of patients – found in 20% of patients
Stress & Increased SNS ActivityStress & Increased SNS Activity Insulin Resistance & Insulin Resistance &
HyperinsulinemiaHyperinsulinemia Endothelial Cell DysfunctionEndothelial Cell Dysfunction
HypertensionHypertensionClinical ManifestationClinical Manifestation
Dx is made after multiple readings over Dx is made after multiple readings over several weeksseveral weeks
NIH/Joint Committee Definition:NIH/Joint Committee Definition:
CategoryCategory SystolicSystolic Diastolic DiastolicOptimalOptimal <110<110 andand < 80 < 80NormalNormal <120<120 andand <85 <85High NormalHigh Normal 130-139130-139 or or 85-89 85-89
Stage 1 140-159 140-159 or or 90-99 90-99Stage 2Stage 2 160-179160-179 oror 100-109 100-109Stage 3Stage 3 =>180=>180 oror => 110 => 110
Primary HypertensionPrimary HypertensionRisk FactorsRisk Factors
AgeAge AlcoholAlcohol Cigarette SmokingCigarette Smoking Diabetes MellitusDiabetes Mellitus Elevated serum lipidsElevated serum lipids Excess Na+ in dietExcess Na+ in diet GenderGender Family HistoryFamily History ObesityObesity EthnicityEthnicity Sedentary LifestyleSedentary Lifestyle Socioeconomic Socioeconomic StressStress
Primary HypertensionPrimary HypertensionClinical ManifestationsClinical Manifestations
Target Organ ComplicationsTarget Organ Complications::
MyocardiumMyocardium – angina / left ventricular hypertrophy – angina / left ventricular hypertrophy
BrainBrain – TIA / CVA – TIA / CVA
Peripheral vascularPeripheral vascular – Peripheral pulse change – Peripheral pulse change
KidneyKidney – renal failure Creatinine / Proteinuria – renal failure Creatinine / Proteinuria
EyesEyes – Hemorrhages with or without papilledema – Hemorrhages with or without papilledema
Primary HypertensionPrimary HypertensionClinical ManifestationsClinical Manifestations
““Silent Killer”Silent Killer” – asymptomatic and – asymptomatic and insidiousinsidious
Severe HTNSevere HTN – fatigue, reduced – fatigue, reduced activity tolerance, dyspnea, activity tolerance, dyspnea, dizziness, palpitations, angina dizziness, palpitations, angina
HypertensionHypertensionMedical DiagnosisMedical Diagnosis
History and Physical History and Physical ExaminationExamination
Renal FunctionRenal FunctionSerum Creatinine & Urine Serum Creatinine & Urine
Creatinine ClearanceCreatinine ClearanceElectrolytes – especially K+Electrolytes – especially K+Blood Glucose Blood Glucose Serum Lipids/EKGSerum Lipids/EKGAmbulatory BP MonitoringAmbulatory BP Monitoring
Primary HypertensionPrimary HypertensionMedical ManagementMedical Management
Risk StratificationRisk Stratification
Level of BPLevel of BP
Presence of Target Organ Presence of Target Organ DiseaseDisease
Other Risk FactorsOther Risk Factors
Primary HypertensionPrimary HypertensionMedical ManagementMedical Management
Lifestyle modificationLifestyle modification
Nutritional therapyNutritional therapy Alcohol consumptionAlcohol consumption Physical activityPhysical activity Tobacco avoidanceTobacco avoidance Stress managementStress management
Drug TherapyDrug Therapy
Primary HypertensionPrimary HypertensionMedical ManagementMedical ManagementStepped ApproachStepped Approach
Lifestyle modificationLifestyle modificationNot at Goal BPNot at Goal BP
Drug TherapyDrug TherapyNot at Goal BPNot at Goal BP
Substitute med / add a 2nd med/ Substitute med / add a 2nd med/ increase doseincrease dose
Not at Goal BPNot at Goal BP
Continue adding / changing meds until Continue adding / changing meds until controlcontrol
Primary HypertensionPrimary HypertensionMedical Management – Drug Medical Management – Drug
TherapyTherapy DiureticsDiuretics
ThiazideThiazide LoopLoop K+ SparingK+ Sparing
Adrenergic Blockers/ InhibitorsAdrenergic Blockers/ Inhibitors B-Adrenergic BlockersB-Adrenergic Blockers Central Acting Adrenergic AntagonistsCentral Acting Adrenergic Antagonists Peripheral Acting Adrenergic Peripheral Acting Adrenergic
AntagonistsAntagonists A-Adrenergic BlockersA-Adrenergic Blockers
VasodilatorsVasodilators Angiotensin InhibitorsAngiotensin Inhibitors Calcium Channel BlockersCalcium Channel Blockers
Hypertension Hypertension MedicationMedication
Alpha Agonists & Alpha Agonists & VasodilatorsVasodilators
Primary HypertensionPrimary HypertensionLack of Responsiveness to Lack of Responsiveness to
TherapyTherapy Nonadherence to TherapyNonadherence to Therapy
Drug-Related CausesDrug-Related Causes
Associated conditionsAssociated conditions
Secondary HypertensionSecondary Hypertension
Volume overloadVolume overload
Primary HypertensionPrimary HypertensionHypertensive CrisisHypertensive Crisis
DefinitionDefinition: Severe & abrupt elevation : Severe & abrupt elevation of BP with diastolic > 120-130mm Hg.of BP with diastolic > 120-130mm Hg.
CausesCauses::Nonadherence, renovascular changes, Nonadherence, renovascular changes,
pre- eclampsia, eclampsia, pre- eclampsia, eclampsia, Pheochromocytoma, Rebound from Pheochromocytoma, Rebound from abruptly stopping beta blockers, head abruptly stopping beta blockers, head injury, necrotizing vasculitis, acute injury, necrotizing vasculitis, acute aortic dissectionaortic dissection
Hypertensive Encephalopathy:Hypertensive Encephalopathy:headache, N/V, confusion, obtunded, headache, N/V, confusion, obtunded,
stuporous, seizures, blurred vision, stuporous, seizures, blurred vision, transient blindness transient blindness
Primary HypertensionPrimary HypertensionNursing DiagnosesNursing Diagnoses
Assess:Assess: Cardiovascular status; adherence to Cardiovascular status; adherence to therapy; family interaction; risk factor therapy; family interaction; risk factor modification?modification?
Nsg Action: Nsg Action: Supportive & reality-based; Supportive & reality-based; Administer meds; referrals; diagnostic Administer meds; referrals; diagnostic preps; preps; ask questions;ask questions;
supportive care during hospitalization for supportive care during hospitalization for acute crisisacute crisis
Pt/Family Education: Pt/Family Education: Medications; risk factor Medications; risk factor modification; Community supportmodification; Community support