Gas Exchange, Pneumonia, & COPD

gas exchange

process by which oxygen is transported to the cells and carbon dioxide is transported from the cells

ischemia

insufficient blood to tissues that may result in hypoxemia and subsequent cell injury or death

hypoxemia

reduced oxygenation of arterial blood

hypoxia

insufficient oxygen reaching cells

anoxia

total lack of oxygen in body tissues

ventilation

lungs inhale oxygen and exhale carbon dioxide

transport

ability of hemoglobin to carry oxygen from lungs to cells and carbon dioxide from cells to lungs

pathology of inadequate ventilation

oxygen unavailable in environment (ex. high altitude)

narrowed airways (ex. COPD, asthma)

anatomical problem (ex. rib fracture, spinal cord injury)

poor gas diffusion in lung alveoli (ex. pneumonia)

pathology of inadequate transport

low RBCV or Hgb levels (anemia, blood loss, sickle cell crisis)

pathology of inadequate perfusion

decreased cardiac output

blockages (thrombus, vasoconstriction)

blood loss

mild pathology consequences

fatigue

increased HR

increased RR

moderate pathology consequence

decreased metabolism

acid build up

respiratory or metabolic acidosis

severe pathology consequence

cell ischemia

cell necrosis

death

risk factors

very young

very old

tobacco use

chronic diseases (COPD, asthma)

immunosuppression

altered LoC

respiratory vital signs

SpO2: 95-100%

HR: 60-100 bpm

RR: 14-20/min

respiratory physical exam

work of breathing (accessory muscle use, pursed-lip breathing)

skin and nails (cyanosis, clubbing)

chest wall diameter

trachea position

tactile fremitus

respiratory auscultation

lung sounds (crackles, wheezing, stridor, rhonchi, rubbing)

egophony (e to a)

respiratory testing

pH

PaCO2

HCO3

PaO2

SaO2

CBC (Hgb, Hct, RBC)

ABG normal range

pH: 7.35 - 7.45

PaCO2: 35-45 mm Hg

HCO3: 22-26 mEq/L

PaO2: 80-100 mm Hg

SaO2: > 95%

CBC normal ranges

Hgb: 12-18 g/dL

Hct: 37-52%

total RBC: 4.2-6.1 x (10^12)/L

respiratory imaging

chest xray

CT

V/Q scan

PET

other respiratory tests

sputum culture

skin tests

pulmonary function tests (PFTs) - spirometry

bronchoscopy

pneumonia

infection of functional tissues of the lungs (parenchyma)

pneumonia etiology

aspiration

inhalation

hematogenous spread (from elsewhere in body)

pneumonia classifications

community acquired (CAP)

hospital acquired (HAP)

ventilator associated (VAP)

pneumonia causitive agent

virus

bacteria

fungus (opportunistic)

pneumonia pathophysiology

inflammation

airway edema

fluid in alveoli

hypoxia

atelectasis

consolidation

pneumonia signs and symptoms

cough

fever/chills

dyspnea

tachypnea

decreased SpO2

pleuritic chest pain

discolored sputum

fine or coarse crackles (!!)

egophony (e to a)

increased fremitus (vibration of chest wall)

elderly: confusion, dehydration, maybe no fever

pneumonia diagnostic testing

history

physical assessment: lung auscultation, VS

chest xray

bronchoscopy

ABGs

CBC

sputum culture

pneumonia prevention

pneumococcal vaccine

infection control

deep breathing after surgery

pneumonia treatment

antibiotics (if bacterial)

oxygen - keep at/above 95% on room air

deep breathing and ambulation

supportive care (fever, pain control, position changes)

hydration and nutrition

monitor labs, VS, lung sounds

pneumonia risk factors

> 65 y/o

immobility

chronic diseases

immunocompromised

smoking

intubation

contact w/ high population numbers (colleges, food kitchens, long term care facilities)

COPD

progressive and persistent airflow limitation; chronic inflammation of airways

COPD causes

smoking

inhalation of noxious particles or gas

genetics

COPD pathophysiology

airflow limitation not fully reversible during forced exhalation

loss of elastic alveoli

airflow obstruction (increased mucus, edema, bronchospasm)

air trapping (!!)

decreased gas exchange

COPD signs and symptoms

develop slowly

chronic cough

chronic sputum production

dyspnea

wheezing/decreased lung sounds

chest tightness

fatigue

weight loss

anorexia

tripod position

pursed lips

barrel chest

hypoxemia

hypercapnia

ruddy skin

cyanosis

COPD complications

pulmonary hypertension

cor pulmonale (R sided heart failure)

acute exacerbations

acute respiratory failure

COPD diagnostic tests

spirometry

chest xray

pulse-ox

ABGs

validated questionnaires

COPD classification

GOLD (1 - 4, mild to severe)

based on FEV1 (forced expiratory volume over 1 second)

COPD management

smoking cessation

vaccination

assessment (lung sounds)

oxygenation (88-92% at rest)

drug therapy (stepwise treatment)

surgery

respiratory care

nutrition

ambulation

preventing secondary complications

psychosocial

COPD risk factors

smoking

infection

asthma

pollution

occupation

age

genetics

alpha-1 antitrypsin deficiency