Hypotension and Hypertension

Types of hypovolemic shock

Inflammation - mediators, dilation, and increased permeability

Trauma - rupture and third spaces sequestration

Hemorrhagic loses - lower intravascular volume

Non-hemorrhagic loses - lower intravascular volume

Integration and pathophysiology of hypotension

Hypovolemic shock:

precipitous fall in cardiac output due to decreased blood volume due to hemorrhage, fluid loss, or fluid sequestration

Physical examination (PE) findings during shock states

Circulatory collapse due to venous pooling of blood and peripheral vasodilatation:

Neurogenic: trauma CNS.

Anaphylactic: systemic allergic response.

Anesthetic: overdose of general anesthetics

Stage I: compensated: Hypotension is presented

Neurohumoral responses maintain adequate tissue perfusion to vital organs to avoid hypoxia.

Mechanisms included baroreceptors, renin/angiotensin/aldosterone, and antidiuretic hormone

Bodies response to Stage I

increased sympathetic activity(tachycardia, peripheral vasoconstriction, increased ventricular contractility), oliguria, and renal retention of salt and water.

Stage II: progressive

Compensatory mechanisms now fail to maintain the arterial blood pressure, hypotension is

sustained, and tissue perfusion falls

Cellular hypoxia and organ dysfunction will predominate

Appropriate treatment(intravenous fluid and transfusion therapy) will restore cardiovascular functions

Stage III: irreversible

Cellular injury due to hypoxia damages the vascular smooth muscle, endothelial cells, and the ventricular myocardium.

This leads to loss of vascular tone, extravasation of fluid to the intestinal lumen, and blood stasis in vascular beds.

Blood stasis activates the clotting system, and disseminated intravascular coagulation develops, Ultimately superimposing different forms of shock at the same time.

When systolic blood pressure is below what number you are cooked?

50 mmHg, a compensatory response is unable to restore the blood pressure

Systemic Hypertension: dogs and cats

Persistently elevated systemic arterial blood pressure

Idiopathic hypertension

the cause is not recognized (human beings)

Secondary hypertension:

known cause (dogs and cats)

Systemic hypertension

Associated with complications, such as:

Progressive renal disease.

Retinal and choroidal injury.

Heart failure.

Hypertensive encephalopathy.

Clinical signs of systemic hypertension

initially asymptomatic.

Unrecognized for months until lesions are almost irreversible

Systemic Hypertension: dogs and cat Causes

Chronic kidney disease: kidney and hypertension, Hyperthyroidism, Hyperaldosteronism, Diabetes mellitus.

Hyperadrenocorticism, or Cushing's syndrome.

Pheochromocytoma (adrenal gland tumor).

Xenobiotics.

Salt consumption: dogs and cats are less sensitive than humans.

Systemic Hypertension: dogs and cats Consequences

Ocular clinical signs: retinal detachment.

Cardiovascular: heart

Left ventricular hypertrophy, Increase afterload, Pulmonary congestion

Ventricular stiffness and reduced diastolic filling (reduce ventricular COMPLIANCE).

Rise in ventricular diastolic pressure.

HYPERTENSION IN CATS:

the therapeutic goal is to keep the systolic blood pressure below 160 mmHg