Study Guide Exam 3 Patho

Secretory Diarrhea

• Increased mucosal secretion of chloride or bicarbonate-rich fluid OR decreased sodium absorption → excessive water loss, large volume diarrhea

• excess fluid/electrolyte secretion into bowel

• diarrhea persists despite fasting (cholera, VIPoma)

Osmotic Diarrhea

• Nonabsorbable solutes in the intestines draw water into intestinal lumen by osmosis→ increased stool weight and volume (large volume diarrhea).

• non-absorbable solute pulls water

• stops when fasting

• Excessive ingestion of Synthetic, nonabsorbable sugars: Sorbitol, mannitol.

• Tube feeding formulas (hyperosmolar), full strength.

• Dumping syndrome after gastric resection draws water into intestinal lumen.

• Malabsorption conditions

Exudative Diarrhea

• Mucosal inflammation → pus/blood in stool

• Inflammatory Bowel Disease

Motility Diarrhea

• Decreased intestinal transit time reduces fluid absorption.

• Causes:

  • Small Intestinal resection (short bowel syndrome).

  • Surgical bypass or fistula between bowel loops.

  • IBS–diarrhea predominant (IBS-D).

  • Diabetic neuropathy (autonomic dysfunction).

  • Hyperthyroidism.

  • Laxative abuse.

• fever, bloody stools, tenesmus

IBD- Ulcerative Colitis

• located only in colon

• continuous pattern

• depth to superficial mucosa

• blood stool common

• complicated by toxic megacolon

• A chronic inflammatory bowel disease that causes inflammation and ulcers in the lining of the colon and rectum. Symptoms include abdominal pain, diarrhea, and rectal bleeding.

IBD- Chron’s disease

• located anywhere from mouth to anus

• skip lesion pattern

• depth to transmural 

• steatorrhea

• complicated by fistulas or strictures

• characterized by inflammation that can affect all layers of the intestinal wall, often leading to complications such as abscesses and strictures. Symptoms may include abdominal pain, diarrhea, and weight loss.

Peptic Ulcer Disease

• Caused by breakdown of mucosal barrier

• Most common causes:

  • H. pylori

  • NSAID use

Pancreatic Insufficiency

• decrease in pancreatic enzymes leads to inability to digest nutrients

• causes fat malabsorption and steatorrhea

Chronic gastritis and Pernicious Anemia

• Loss of parietal cells and atrophy of gastic mucosa causes a decrease in intrinsic factor

• poor vitamin b12 absorption

• characterized by symptoms such as fatigue, weakness, and neurological issues.

Diverticulitis

• obstructed diverticula leads to infection and inflammation

• characterized by LLQ pain and fever

• treated with abx and bowel rest

Hepatic Encephalopathy

• liver failure leads to increaed ammonia levels causing AMS

• treated with lactulose and rifaximin

• a condition where toxins accumulate in the brain due to liver dysfunction, leading to confusion, altered level of consciousness, and in severe cases, coma.

Ascites (Portal Hypertension)

• increased hydrostatic pressure leads to fluid shifts into the peritoneum

• key treatments include spironolactone and paracentesis if severe

Mechanical Causes of Bowel Obstruction

• adhesions (most common)

• hernia

• tumor

• volvulus (twisting)

• intussusception (telescoping bowel)

Clinical Manifestations of SBO

• colicky abdominal pain

• vomiting early

• visible peristalsis

Clinical Manifestations of LBO

• gradual pain

• contipation early

• abdominal distention prominent

Assessment Finding of Bowel Obstruction

·       Absent or high-pitched bowel sounds

·       Abdominal distention

·       No flatus or stool

Treatment of Bowel Obstruction

·       NPO

·       NG tube to decompress

·       IV fluids

·       Surgery if complete obstruction or strangulation

Continuous severe pain + rebound suggests ischemia or perforation → requires immediate surgery.

Causes of Pancreatitis

·       Alcohol use

·       Gallstones (most common cause of acute)

Pathophysiology of Pancreatitis

Pancreatic enzymes become prematurely activated, leading to auto-digestion of pancreas

• inflammation

• possible necrosis

• systemic inflammation (leading to systemic inflammatory response syndrome (SIRS)

Clinical Manifestations of Acute Pancreatitis

• severe epigastric pain radiating to back

• pain worsens when lying down, improves leaning forward

• nausea/vomiting

• cullen sign (periumbilical bruising)

• grey-turner sign (flank bruising)

Clinical Manifestations of Chronic Pancreatitis

• recurrent epigastric pain

• steatorrhea (fatty stools)

• weight loss/ malabsorption

• can progress to diabetes

• chronic inflammation/ fibrosis

Diagnostic Critrea of Pancreatitis

• increased lipase (most specific)

• increased amylase

• CT to confirm necrosis or complications

Management of Pancreatitis

• NPO (rest the pancreas)

• IV fluids

• pain control (opioids)

• no alcohol

• treat cause (remove gallstones, stop alcohol)

Hepatitis A

• Transmission: fecal-oral (food/water)

• acute only, self-limiting

• prevention: vaccination available

Hepatitis B

• Transmission: Blood, sexual contact, maternal-fetal

• can become chronic (immune-mediated damage)

• prevention: vaccination available

Hepatitis C

• Transmission: Blood, primarily through sharing needles or unprotected sex

• almost always become chronic and lead to liver cirrhosis or cancer

• no vaccine available, but treatments exist

Clinical Manifestations of Hepatitis

• Fatigue

•  Nausea

• RUQ pain

• Jaundice

• Dark urine / clay-colored stools

• ElevatedAST/ALT

Treatment of Hepatitis A

supportive care and management of symptoms. In some cases, antiviral medications may be used.

Treatment of Hepatitis B

antivirals if chronic, supportive care, and monitoring for complications.

Treatment of Hepatitis C

direct-acting antivirals to cure the infection and supportive care.

Hepatitis D

• bloodborne transmission

• requires hepatitis B

• chronic infection possible

• prevented with Hep B vaccine

• High risk groups: IV drug users, HBV positive patients

• severeand rapid disease progression.

Hepatitis E

• fecal-oral transmission

• does not require Hep B

• no chronic infection

• no vaccine in US

• High risk group: pregnant women- high mortality

• mild except in pregnancy

Causes of Cirrhosis

• chronic alcohol use

• hepatits B or C

• nonalcoholic fatty liver disease

Pathophysiology of Cirrhosis

• Chronic inflammation leads to fibrosis and nodule formation

• liver unable to filter blood, leading to portal hypertension.

Clinical Manifestations of Cirrhosis

• ascites

• esophageal varicies

• jaundice

• hepatic encephalopathy (increased ammonia causes confusion/flapping tremor)

• spider angiomas

Diagnostic Criteria of Cirrhosis

• increased AST and ALT (early)

• decreased albumin

• increased PT/INR

• US or CT

Management of Cirrhosis

• no alcohol

• sodium restriction

• lactulose (decreases ammonia and treats encephalopathy)

• diuretics for ascites

• monitor for bleeding varicies (can cause sudden death)

Hepatorenal Syndrome

Renal failure occurring in advanced cirrhosis due to severe portal hypertension

• renal vasoconstriction

• decreased kidney perfusion

Key features of hepatorenal syndrome

• Low GFR

• Low urine sodium

• normal kidney structure (kidneys are not damaged, just hypo perfused)

Clinical Signs of Hepatorenal Syndrome

• oliguria (low urine output)

• progressive renal failure in cirrhosis patients

Management of Hepatorenal Syndrome

• treat cirrhosis

• albumin infusion

• vasopressors (midodrine, octreotide)

• liver transplant is definitive treatment

Pneumonia

is an infection that inflames the air sacs in one or both lungs, which may fill with fluid or pus. Symptoms often include cough, fever, chills, and difficulty breathing.

• alveoli fill with fluid

• results in shunting and hypoxemia

Pulmonary Embolism

is a blockage in one of the pulmonary arteries in the lungs, usually caused by blood clots that travel to the lungs from the legs or other parts of the body (deep vein thrombosis). Symptoms can include shortness of breath, chest pain, and coughing up blood.

• ventilated but not perfused

• increased V/Q mismatch

COPD and Emphysema

are chronic lung diseases that obstruct airflow and make it difficult to breathe. COPD encompasses chronic bronchitis and emphysema, with symptoms including chronic cough, sputum production, and dyspnea.

• air trapping leads to decreased surface area

• results in CO2 retention (hypercapnia)

ARDS

• Alveolar-capillary damage leads to protein-rich pulmonary edema

• Result: Severe hypoxemia unresponsive to oxygen

Causes of Pulmonary Edema

• fluid accumulation in alveoli leads to impaired gas exchange

• most common causes:

  • left-sided heart failure (cariogenic)

  • ARDS

  • sepsis

  • kidney failure (non-cardiogenic)

Symptoms of Pulmonary Edema

• Severe dyspnea

• Crackles on auscultation

• Pink, frothy sputum

• Anxiety, hypoxia

Diagnostic Criteria of Pulmonary Edema

• CXR: Bat-wing / diffuse infiltrates 

• may have elevated BNP levels

Management of Pulmonary Edema

• High-flow oxygen

• Diuretics (Furosemide) reduce overload

• Nitrates (decrease preload)

• Treat underlying cardiac cause

Asthma

• Mast cell cause histamine release → bronchoconstriction

• Chronic inflammation causes airway remodeling

• Findings: Wheezing, cough, chest tightness, prolonged expiration

Pathophysiology of Asthma

• Chronic airway inflammation

• hyperresponsiveness

• reversible obstruction

Key triggers of Asthma

• Allergen

• sexercise

• infection

• smoke

Treatment of Asthma

• SABA (Albuterol) → acute relief

• ICS (Fluticasone) = first-line controller

• Severe exacerbation → IV steroids + O2 + nebulized SABA

Causes of Pulmonary Embolism

DVT → travels to pulmonary artery

Risk Factors of PE

• recent surgery

• immobilization

• pregnancy

• cancer

Symptoms of PE

• Sudden dyspnea

• Pleuritic chest pain

• Tachycardia

• Possible hemoptysis

Diagnosis of PE

• CT pulmonary angiography = gold standard

• D-dimer for rule out in LOW-risk patients

Treatment of PE

• Anticoagulation (Heparin → DOAC/Warfarin)

• Massive → thrombolytics

Causes of Pneumothorax

Air in pleural space causing lung collapse

Spontaneous Pneumothorax

• bleb rupture

• tall, thin, young men most at risk

Tension Pneumothorax

• tracheal deviation, hypotension

• trauma patients and mechanical ventillation most at risk

• occurs when air enters the pleural space and cannot escape, leading to increased pressure. This condition can cause severe respiratory distress and cardiovascular compromise.

Symptoms of Pneumothorax

• Sudden unilateral pleuritic pain

• Absent breath sounds on affected side

Treatment of Pneumothorax

• Stable: High-flow O2

• Severe/tension: Needle decompression → chest tube

Pleural Effusion

fluid accumulation in pleural space

Transudative Pleural Effusion

• caused by heart failure, cirrhosis, nephrosis

• low protein in fluid

Exudative Pleural Effusion

• caused by infection, malignancy, or inflammation

• high protein in fluid

Symptoms of Pleural Effusion

• Dullness to percussion

• Decreased breath sounds

• Shortness of breath

• Chest pain

• Coughing

Diagnosis of Pleural Effusion

• CXR → blunted costophrenic angles

• Thoracentesis → determines type

Treatment of Pleural Effusion

• treat underlying cause

• large or symptomatic may require drainagesuch as thoracentesis or chest tube placement.

Pulmonary Hypertension

pulmonary artery pressure > 25 mmHg

Causes of Pulmonary Hypertension

• left heart disease

• chronic lung disease (COPD)

• idiopathic

Symptoms of Pulmonary Hypertension

• progressive dyspnea

• loud P2 heart sound

• possible syncope

Treatment of Pulmonary Hypertension

• O2 therapy

• pulmonary vasodilators (sildenafil)

• treat cause (HF, COPD, etc)

Cause of Tuberculosis (TB)

mycobacterium tuberculosis

TB transmission

airborn droplets

Highest Risk of TB

immunosuppressed, crowded living conditions

Symptoms of TB

• chronic cough

• night sweats

• weight loss

• hemoptysis

Diagnosis of TB

• CXR with cavitary lesions in upper lobes

• sputum acid-fast stain/culture

Treatment of TB 

RIPE

• rifampin: orange secretions

• isoniazid: neuropathy (give B6)

• pyrazinamide

• ethambutol: optic neuritis

COPD

chronic, irreversible airflow limitation

Chronic Bronchitis

• COPD subtype

• mucus and cilia dysfunction

• decreased V/Q

• blue bloater (cyanosis)

• hypoxia drives breathing

Emphysema

• COPD subtype

• alveolar destruction

• normal/ increased V/Q early in disease

• pink puffer (pursed breathing)

• air trapping leads to barrel chest

Treatment of COPD

• Smoking cessation (most effective intervention)

• Bronchodilators: SABA/SAMA → LABA/LAMA

• ICS if frequent exacerbations

• O2 therapy if PaO₂ < 55 or SpO₂ < 88%

Delirium

• acute onset

• fluctuating course

• reversible

• key mechanism is altered metabolism

• cognitive disturbance due to medical condition or substance effects.

Dementia

• chronic onset

• progressive course

• not reversible

• key mechanism is neuronal degeneration

• cognitive impairment affecting memory, thinking, and social abilities.

Simple Partial Seizure

• intact consciousness

• localized symptoms

• originate from a specific area of the brain, causing motor, sensory, or autonomic disturbances.

Complex Partial Seizure

• impaired awareness

• key feature is automatisms

• originates from a specific area of the brain, resulting in alteration of consciousness and various symptoms.

Generalized Seizure

• lost consciousness

• key feature is that it affects both hemispheres

• includes types such as tonic-clonic and absence, characterized by widespread electrical discharges in the brain.

Status Epilepticus

a prolonged seizure or series of seizures lasting more than 5 minutes, requiring immediate medical intervention to prevent brain damage or death.

immediate priority is airway and oxygen

Parkinson Disease

• loss of dopamine-producing neurons in substantia nigra

• classic triad: resting tremor, rigidity, bradykinesia

• causes autonomic dysfunction

Autonomic Dysfunction

• othostatic hypotension

• urinary retention

• constipation

• erectile dysfunction

• resulting from impaired autonomic regulation of bodily functions.

Treatment goals of Parkinsons Disease

• increased dopamine activity (levodopa)

• reduce acetylcholine (anticholinergics)

Myasthenia Gravis

• autoantibodies block ACh receptors at neuromuscular junction

• hallmark: muscle weakness worsening with activity

• treated with pyridostigmine and immunosuppression

Schizophrenia

• enlarged ventricles, progressive brain atrophy

• positive symptoms: hallucinations and delusions, r/t increased dopamine

• negative symptoms: flat affect, decreased motivation, depression s/s

Major Depression Neurochemistry

decreased serotonin and norepinephrine 

Symptoms of Major Depression

SIGECAPS

• sleep changes

• interest loss

• guilt

• energy low

• concentration decreases 

• apetite changes

• psychomotor changes

• suicidality

Treatment of Major Depression

• SSRIs (first line), SNRIs, CBT

• monitor for suicidality, esp early in treatment

Bipolar Disorder

characterized by mania- elevated mood, decreased need for sleep, impulsivity

depressive episodes that can last for weeks or months, affecting daily functioning.

Treatment of Bipolar Disorder

• lithium (monitor levels- risk of hyponatremia toxicity)

• valproate, atypical antypsychotics for acute mania

Neurochemistry of Anxiety Disorders

decreased GABA and serotonin