Nurs 241 Patho Midterm

Homeostasis

The maintenance of a relatively stable internal environment regardless of external changes

What may develop if homeostasis is not internally maintained?

Disease

Medical interventions may be necessary to achieve homeostasis

• Can be temporary—ex: fluids to correct hypovolemia (This is not DISEASE)

• May need to be continuous—ex: daily medications for blood pressure control—This indicates DISEASE

Example of disease related to homeostasis

Daily med for blood pressure control

State of health

Physical, mental, and social well-being are considered and should be within individuals normal health status

Disease

• Deviation from the normal state of homeostasis

• Process with characteristic set of signs and symptoms

Disease develops when

The state of homeostasis cannot be maintained without an intervention

Concept and Scope of Pathophysiology

• Functional (physiologic) changes in the body as a result from disease

• Uses knowledge of basic anatomy and physiology.

• Includes aspects of pathology, which describes structural changes in body tissues caused by disease.

Interruption of the normal functioning of one organ will

Affect other organ systems as well

Cause and effect relationships are defined by

Signs and symptoms which guide the study of a specific disease

What is pathophysiology?

The study of functional or physiologic changes in the body that result from disease processes

We study pathophysiology to increase understanding of

• Complexity of disease processes

• Diagnosis and treatment

• Possible implications of signs and symptoms or a prognosis

• Comprehension of the potential complications of a disease

• Disease prevention!

Gross level

• Organ or system level

• Pathophysiology

Microscopic level

• Cellular level

• Pathology

Biopsy

Excision of small amounts of living tissue

Idiopathic

Cause of disease is unknown

Iatrogenic

Error/treatment/procedure may cause the disease

Predisposing factors

Age, gender, inherited factors, environment (tendencies that promote the development of disease)

Prophylaxis

Preserve health, prevent spread of disease

Prevention of disease

Vaccinations; Dietary/lifestyle modifications; Prevention of potentially harmful activities

Remission

Period which manifestations subside

Exacerbation

A worsening of severity

Precipitating factor

Condition that triggers an acute episode

Complications

New secondary or additional problems

Subclinical state

Pathologic changes, no obvious manifestations

Latent state

• No symptoms or clinical signs evident

• In infectious diseases: incubation period

Prodromal period

• Early development of the disease

• Signs are nonspecific or absent

Manifestations

• Clinical evidence with signs and symptoms

  • Local: at site of the problem

  • Systemic: general indicators of illness, i.e. fever

Morbidity

Disease rates within a group

Mortality

Relative number of deaths resulting from the disease

Autopsy

Postmortem examination

Epidemiology

• Tracking the pattern or occurrence of disease

• Major data collection centers: WHO and CDC

Incidence

Number of new cases in a given population within a given time period

Prevalence

Number of new, old, or existing cases within a given population and time period

Epidemics

A higher number of expected cases of an infectious disease occur within an area

Pandemic

Involve a higher number of infectious diseases in many regions of the globe

Atrophy

• Decrease in size of cell

  • Decreases tissue mass

Hypertrophy

• Increase size of cells

  • Increases tissue mass

Hyperplasia

• Increase in number of cells

  • Increases tissue mass

Metaplasia

Mature cell type is replaced by a different mature cell type

Dysplasia

Cells vary in size and shape within a tissue

Neoplasia

“New growth” of cells—tumor

LOOK AT PIC FOR TEST

Hormones increasing blood pressure

• Antidiuretic hormone (inc. BP)

• Aldosterone (inc. bld volume, inc. BP)

• Renin-angiotensin-aldosterone (vasoconstriction, inc. BP)

Meds for Hypertension

• Diuretics

• ACE inhibitors

• Beta blockers

• Calcium channel blockers Angiotensin Receptor Blockers Alpha adrenergic blockers

Cardiac Output (CO) =

HR x SV

Angina Pectoris

• Occurs when there is a deficit of oxygen to meet myocardial needs

  • Dec. bld flow/ O2 supply to hrt

  • Heart works harder

  • Comb. of both

• Chest pain may occur in diff. patterns

  • Classic or exertional

  • Variant

Variant Angina

Vasospasm occurs at rest

Unstable angina

Prolonged pain at rest, may precede to MI

Assessments seen in angina

Pallor, Diaphoresis (excessive sweating), Nausea, Chest pain or tightness in the chest, can radiate to neck or arm

Meds to give for angina

• Coronary vasodilators

  • Nitroglycerin

Lab/Diagnostics for angina

12 lead EKG

Interventions for angina

• Rest

• Determine predisposing factors to attacks and minimize frequency

Emergency treatment for angina

• Rest

• Patient seated in upright position

• Check pulse & respirations

• Administer O2 if necessary

• If patient has no history of angina give emergency aid after 2 min of pain

• If pt. known to have angina give 2nd dose of NTG

Myocardial Infarction (MI)

• Occurs when coronary artery is totally obstructed

• Atherosclerosis most common cause

• Thrombus from atheroma may obstruct artery

• Vasospasm is caused in a small percentage

• Size and location of the infarct determine severity of damage

(MI) If collateral circulation can develop before infarction

Size of the infarct can be reduced

(MI) Because lack of blood flow decreases contractility and conduction quickly; If blood flow is restored in 20-30 min

Irreversible damage can be prevented

Assessments for MI

Chest pain, pallor, diaphoresis, dizziness, dyspnea, marked anxiety and fear, hypotension, low-grade fever

Meds for MI pneumonic (M.O.N.O.B.A.S.H.)

•Morphine for pain relief

•Oxygen

•Nitrates --nitroglycerin

•Aspirin chew one and swallow one; use non-enteric coated

•Beta Blockers

•Ace Inhibitors

•Statin drugs

•Heparin

•Thrombolytic therapy

Labs/Diagnostics for MI

• Serum Enzymes Troponin

• Leukocytosis, elevated CRP and ESR

• EKG

Congestive Heart Failure (CHF)

• Heart is unable to pump out sufficient blood to meet metabolic demands of the body

• Usually a complication of another cardiopulmonary condition

• Can be the result of an infarction or valve defect

• One side usually fails 1st depending on cause

  • Left-sided HF

  • Right-sided HF

  • Can progress to BOTH sides

• Various compensation mechanisms maintain CO

  • Some aggravate condition

In congestive heart failure cardiac output or stroke volume decreases causing

• Less blood reaches the various organs

• Decreased cell function

• Fatigue & lethargy

• Mild acidosis develops

(CHF) Backup and congestion develop as coronary demands for oxygen and glucose are not met causing

• Output from vent. is less than the inflow of bld

• Congestion in venous circulation draining into the affected side

  • Left-sided CHF → Pulmonary congestion

  • Right-sided CHF → Systemic congestion, hepatomegaly, JVD, edema of legs and abdomen (ascites)

Nephrons

• Functional units of the kidneys

• Each kidney has over 1 million

Renal corpuscles

• Glomerulus

• Bowman capsule

Renal tubules

• Proximal convoluted tubules

• Loop of Henle

• Distal convoluted tubules

• Collecting duct

Filtration

• In renal corpuscles

• Large volume of fluid passes from glomerular capillaries into the tubule

  • Wastes, nutrients, electrolytes, other dissolved substances

  • Cells and protein remain in the blood

Reabsorption

• Reabsorption of essential nutrients, water, and electrolytes into the peritubular capillaries

• Control of pH and electrolytes

Proximal convoluted tubules

• Most of water reabsorption

• Glucose reabsorption

• Nutrients and electrolytes to maintain homeostasis

Antidiuretic hormone (ADH)

• Secreted by posterior pituitary

• Reabsorption of water in distal convoluted tubules and collecting ducts

Aldosterone

• Secreted by adrenal cortex

• Sodium reabsorption in exchange for potassium or hydrogen

Dilation of AFFERENT arteriole

Increased pressure in glomerulus -increased filtrate

Vasoconstriction of AFFERENT arteriole

Decreased glomerular pressure -decreased filtrate

Vasoconstriction of EFFERENT arteriole

Increased glomerular pressure -increased filtrate

3 factors controlling arteriolar constriction

• Autoregulation

• Sympathetic Nervous System

• Renin (R.A.A.S)

Autoregulation

• Local adjustment in diameter of arterioles

• Made in response to changes in blood flow in kidneys

Sympathetic nervous system

Increases vasoconstriction in both arterioles

Renin (R.A.A.S.)

• Secreted by juxtaglomerular cells when blood flow to afferent arteriole is reduced

• Renin-angiotensin mechanism

Pyelonephritis

• Infection spreads from ureters to the kidney involving the renal pelvis and medullary tissue; one or both kidneys can be involved

• Purulent exudate fills pelvis and calyces

• Recurrent or chronic infection can lead to scar tissue formation.

  • Loss of tubule function

  • Obstruction and collection of filtrate → hydronephrosis

  • Eventual chronic renal failure if untreated

Assessment for pyelonephritis

Dysuria, dull aching pain in the lower back or flank area, fever, chills, N/V, malaise

Medications for pyelonephritis

Antibacterial drugs

• Trimethoprim-sulfamethoxazole (Bactrim, Septra, Cotrim)

• Cephalosporins (Keflex)

• Amoxicillin

Labs/Diagnostics test for pyelonephritis

Urinalysis

• May show pyuria, bacteriuria, hematuria, and WBC’s

• Urinary casts are present

Urinary casts

Indicate inflammation of renal tubules

Interventions for pyelonephritis

• Increase water intake

• Cranberry juice**tannin content appears to reduce the ability of E.Coli to adhere to mucosa

Urinary tract infections (UTIs)

Urine is an excellent growth medium; organisms grow in urine and can ascend to the urinary tract

Lower UTI causes

• Cystitis

• Urethritis

Upper UTI causes

Pyelonephritis- can occur from a blood stream infection

Common organism that causes a UTI

Escherichia coli

Who is at higher risk for a UTI?

Women, older adults, and children

Why are UTIs more common in women?

• Shortness of urethra

• Proximity to anus

Why are UTIs common in older men?

• Prostatic hypertrophy

• Urine retention

Why are UTIs common in children?

Congenital abnormalities

Common predisposing factors causing UTIs

• Incontinence

• Retention of urine

• Decreased host resistance

• Direct contamination with fecal material

Urolithiasis (Calculi)

Calculi (stones) can develop anywhere in urinary tract and lead to a decrease in flow of urine

• Stones may be small or very large

Calculi tend to form with

• Excessive amounts of solutes in filtrate

• Insufficient fluid intake—major factor for calculi formation

• Urinary tract infection-struvite stones

Calculi are composed of

• Calcium salts

  • High urine calcium levels due to hypercalcemia

  • Form readily with highly alkaline urine

• Uric acid

  • Hyperuricemia

    • Gout, high-purine diets, cancer chemotherapy

  • Especially with acidic urine

Assessment for urolithiasis

Manifestations only occur with obstruction of urine flow.

• May lead to infection

• Hydronephrosis with dilation of calyces

• If located in kidney or ureter and atrophy of renal tissue

Stones in kidney or bladder often asymptomatic

• Frequent infections may lead to investigation.

• Flank pain possible caused by distention of renal capsule

Renal colic

• Intense spasms of pain in flank area-distention of renal capsule

  • Radiating into groin area

  • Lasts until stone passes or is removed

• Possible nausea and vomiting, cool moist skin, rapid pulse

Renal colic is caused by

obstruction of the ureter

Labs/Diagnostic tests for urolithiasis

• CT Scan or ultrasound

• Urinalysis-hematuria, crystalluria, urine pH, serum Ca+, uric acid, BUN, creat; 24 hour urine.

Treatment for urolithiasis

• Strain urine to pass stones

• Extracorporeal shock wave lithotripsy (ESWL)

• Laser lithotripsy

• Drugs

• Surgery

• Increase fluid intake and changes to diet to adjust the urine pH

• Treat underlying cause