Respiratory and Renal Pathophysiology

Topics in Human Pathophysiology Fall 2011Gilead Drug Safety and Public Health

Outline

Respiratory Disorders Respiratory Interface Lung function Respiratory Disorders

Kidneys and Renal Function Overview of system Nephrons Disorders of Urinary System

Figure 10.8

Figure 10.7

Viral and bacterial infections

fungal infections (Pulmonary aspergillosis)

Cystic fibrosis (and accompanying infections)

Pneumonia

Asthma

Selected Respiratory Disorders

• Cause– Influenza virus

• Symptoms– Fever– Sore throat– Cough– Body aches– Headache– Chills– Fatigue– Vomiting and diarrhea

Flu

Susceptible populations

Antivirals for influenza – Tamiflu (oseltamivir), Relenza (zanamivir), peramivir

Complications Pneumonia and respiratory failure Bronchitis Ear infections Sinus infections

Flu

Inherited disorder causing a defect in a cell membrane Cl- channel

Causes thick sticky mucus buildup in airways and ducts of pancreas, etc.

Shortens lifespan because of pneumonia, malnutrition, etc.

Cystic fibrosis

Fungal lung infection - Pulmonary aspergillosis

Common with AIDs patients and cystic fibrosis patients

Treated with Ambisome (amphoterocin B), one of several antifungals, alters fungal cell permeability

Fungal Lung Infections

Pulmonary Aspergillosisfrom an AIDS patient during autopsy

http://www.ispub.com/ostia/index.php?xmlFilePath=journals/ijid/vol6n1/aspergillosis.xml

Fluid buildup in lung alveoli

Thickens respiratory interface, interrupting diffusion of gases

Caused by a wide variety of microorganisms including bacteria, aspergillus and pneumocystis fungi, influenza virus (Tamiflu), cytomegalovirus

Pneumonia

Pneumonia

Asthma

Gilead treatments for lung infections

• Cayston® (aztreonam) for Pseudomonas aeruginosa

• Tamiflu for influenza viruses• Ambisome for aspergillus fungus• Vistide for cytomegalovirus

Chest X-ray

Pulmonary function tests

Sputum cultures

Pulse oximetry

Arterial Blood Gases (ABGs)

Tests for Lung Function

Pneumonia X-ray

http://www.med-ed.virginia.edu/courses/rad/cxr/pathology3chest.html

Spirometry

Sputum Culture

• Patient donates a sputum sample

• It is cultured with various media to determine causative agent of lung infection

Pulse Oximetry

• Measures arterial hemoglobin oxygen saturation

• Normal is > 95%• Indicator of effectiveness

of respiratory interface and gas diffusion

pH

PCO2

PO2

O2 Saturation

HCO3-

Arterial Blood Gases

Renal Pathophysiology

Kidneys maintain homeostasis

Excrete nitrogenous wastes

Maintain water balance

Regulate salt balance

Maintain acid-base balance and blood pH

Control production of red blood cells

Activate an inactive form of vitamin D

Figure 15.2

Normal Kidney Anatomy

The nephron is the functional unit of the kidney

Figure 15.6

Overview of Nephron Actions

Figure 15.4

Glomerular Apparatus

The glomerular capillaries filter the blood.Glomerular filtration rate is an indicator of kidney health.

Figure 25.16

Tubules reabsorb nonwastes, and secrete wastes, allow urine to be concentrated, control electrolyte balance.

Kidney DisordersAcute Renal Failure

Causes: Decreased blood flow to kidneys Large kidney stones Infections Burns Severe injuries Toxic drugs and or chemicals (antivirals,

especially anti-HIV drugs) Tubule damage is typical and signs include

problems with reabsorption and secretion and thus changes in serum electrolytes

Can be reversed by eliminating the cause

32

From: radiology.rsna.org/ content/242/1/175/F5.expansion

Signs & symptoms Oliguria or anuria Swelling / edema Mental status changes

Tests Urinalysis Serum creatinine blood urea nitrogen

(BUN) serum potassium Kidney ultrasound or X-

ray to rule out obstructions to urine

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Acute Renal Failure

Generally caused by long term damage to nephrons reducing GFR and urine output

Risks include hypertension, diabetes mellitus, untreated acute renal failure

Increased leakage through glomerulus leads to Proteinuria- proteins in urine Hematuria – blood in urine Azotemia – excess nitrogen containing compounds in

blood Edema Hypertension

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Kidney DisordersChronic Renal Failure - End Stage Renal Disease (ESRD

Kidneys maintain homeostasis

Excrete nitrogenous wastes

Maintain water balance

Regulate salt balance

Maintain acid-base balance and blood pH

Control production of red blood cells

Activate an inactive form of vitamin D

37Stage 1

Stage 2

Stage 3 Stage 4

Stage 5

Increased GFR90mL/min or above

Normal orGFR 60-90 mL/min

GFR 30-59 mL/min

GFR 15-29 mL/min

GFR <15 mL/min

Some evidence of kidney damage (microalbuminuria/proteinuria, hematuria, or histologic changes) Asymptomatic

Kidney damage with mild decrease in GFRAsymptomatic

Kidney damage with moderate decrease in GFRAsymptomatic, may have anemia

Kidney damage with severe decrease in GFRHyperkalemiaAnemia

Kidney failure; renal replacement therapy needed to sustain lifeUremia, platelet dysfunction, encephalopathy, peripheral neuropathy, anorexia, nausea and vomiting, pericarditis, pruritus, lethargy and increased somnolence)Metabolic acidosis, Protein catabolismRenal bone diseaseSodium & water retentionedema, pulmonary hypertension, systolic hypertension

Treatment for Renal Failure

Control the underlying cause, i.e. diabetes, HTN, drug therapy

Controlled fluid intake

Diet

rhEPO

Kidney Transplant

Dialysis

Dialysis Treatment

Complete medical and medication history

Complete physical examination

Microscopic exam---clues in the urine sediment (eg. hematuria)

Urinalysis---any protein, WBCs, blood?

BUN and creatinine, electrolytes, GFR, quantitative protein, urine and serum potassium

Renal ultrasound

Renal biopsy

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Clinical Tests for Renal Function

Topics in Human Pathophysiology Fall 2011Gilead Drug Safety and Public Health

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