Gas Exchange/Acid-Base Balance

Gas Exchange Risk Factors

Older age; air pollution and allergies; tobacco use; neurologic, cognitive, and mobility conditions; COPD; asthma.

Causes of Impaired Gas Exchange

Decreased surfactant production; atelectasis; obesity/musculoskeletal disorders affecting chest-wall compliance; air, blood, or excess fluid in pleural space; airway narrowing from secretions or bronchospasm; obstructive disorders including sleep apnea, emphysema, bronchitis, and foreign body.

Surfactant

Surfactant keeps the alveoli open; decreased surfactant production can contribute to impaired gas exchange.

Early Respiratory Deterioration

Dyspnea; tachypnea; cough; restlessness; chest auscultation may initially be normal or reveal fine scattered crackles.

Late Respiratory Deterioration

Increased fluid accumulation and decreased lung compliance; obvious discomfort; increased work of breathing; suprasternal retractions; tachycardia; diaphoresis; decreased mentation/changes in sensorium; cyanosis; pallor.

Systemic Findings of Impaired Gas Exchange

CNS: decreased LOC, restlessness, drowsiness, agitation, confusion. Cardiovascular: decreased cardiac output, weak/bounding pulse, hypotension, dysrhythmias, palpitations, chest pain, JVD. Pulmonary: rapid shallow breathing, dyspnea, cyanosis, retractions, tripod position, accessory muscles, nasal flaring. Renal: decreased urine output. GI: ascites, constipation, decreased bowel sounds, nausea/vomiting, distention, anorexia. Skin: cool, clammy, pale, cyanotic.

Symptoms and Severity of Acute Lung Failure

The severity of symptoms does NOT necessarily predict the degree of hypoxemia or hypercapnia.

Pharyngeal vs Endotracheal Tube

Pharyngeal tube = shorter and extends to the oropharynx. Endotracheal tube = longer and extends from the mouth into the trachea.

Bronchoscopy Diagnostic Uses

Can evaluate smoke inhalation, pulmonary injury after chest trauma, and acute upper-airway obstruction.

Bronchoscopy Therapeutic Uses

Can assist with difficult intubation or remove an obstruction/foreign body.

Post-Bronchoscopy Nursing Interventions

Maintain airway; observe sputum for bleeding; keep patient NPO until gag reflex returns after sedation wears off; notes specify approximately 2 hours.

Bronchoscopy Complications

Fever; vomiting; anaphylactic reaction; infection; hypotension; respiratory failure; dysrhythmias; pneumothorax; hemorrhage; hypoxemia; cardiac arrest.

Thoracentesis

Removal of fluid from the pleural space for diagnostic or therapeutic purposes; fluid may be sent to the laboratory to evaluate pleural effusion or other conditions such as cancer.

Thoracentesis Complications

Pain; pneumothorax from lung puncture; re-expansion pulmonary edema.

Pulmonary Function Tests

PFTs detect abnormalities in lung function, can identify restrictive disorders or lung cancer, and help determine why a patient is having difficulty breathing.

V/Q Scan

Used mainly for pulmonary embolism; can identify pulmonary edema, airway obstruction, and problems with pulmonary-artery blood flow/occlusion. Perfusion = injected dye. Ventilation = inhaled radioactive gas.

V/Q Scan Complications

Infection or bleeding at IV site; rare medication allergy or anaphylactic reaction.

Tension Pneumothorax

QUICK and potentially FATAL. Rising pleural pressure collapses the lung, shifts the trachea OPPOSITE the collapsed lung, impairs venous return, compresses the heart, and decreases cardiac output/perfusion.

Tension Pneumothorax Causes

Barotrauma from PEEP; invasive procedures; blunt-force trauma.

Tension Pneumothorax Assessment

Distended neck veins; HYPOTENSION; absent breath sounds on one side; respiratory distress; sudden chest pain; cyanosis; dyspnea; hemodynamic instability.

Tension Pneumothorax Priority Nursing Action

Recognize the patient as an emergency; prepare for/assist with immediate needle decompression; then prepare for tube thoracostomy/chest tube; monitor respiratory and hemodynamic status.

Tension Pneumothorax Needle Decompression

Needle decompression is performed at the 2nd intercostal space at the midclavicular line, followed by tube thoracostomy/chest tube.

Tension Pneumothorax Chest Tube Nursing Care

Assist with chest-tube placement and monitor drainage.

Hemothorax

Blood collects in the pleural space, usually after blunt or penetrating trauma. The mediastinum shifts in the SAME direction as the collapsed lung, impairing venous return.

Hemothorax Types

Simple = blood loss

Hemothorax Assessment

Hypovolemia; possible shock; decreased breath sounds; dyspnea; severe anxiety; tachypnea; tachycardia.

Hemothorax Nursing Interventions

Prepare/manage chest tube; administer blood and IV fluids as prescribed to correct hypovolemia; monitor respiratory and hemodynamic status.

Flail Chest

Paradoxical chest movement caused by fractured ribs. Inspiration: intact chest expands while injured segment moves inward. Expiration: intact chest moves inward while injured segment moves outward.

Flail Chest Findings

Anxiety; dyspnea; pain; increased breathing effort; cyanosis; tachycardia; hypotension; paradoxical chest movement; possible hypovolemic shock.

Flail Chest Nursing Interventions

Provide oxygen; monitor ABGs and fluids/electrolytes; provide vigilant respiratory care; control pain; prepare for mechanical ventilation if respiratory failure or shock develops; surgery may be required.

Flail Chest SATA Findings

Select findings associated with flail chest: paradoxical chest movement; dyspnea; pain; increased work of breathing; cyanosis; tachycardia; hypotension; anxiety.

Pulmonary Embolism Pathophysiology

PE creates a ventilation-perfusion problem: ventilation continues while perfusion decreases, causing V/Q mismatch and hypoxemia.

Pulmonary Embolism Findings

Hypoxemia; tachycardia; tachypnea; chest pain; cough; crackles; hemodynamic instability.

Pulmonary Embolism ABGs

Low PaO2; low PaCO2 due to tachypnea; high pH.

Pulmonary Embolism Diagnostics

V/Q scan; D-dimer; ABGs; Doppler ultrasound.

Pulmonary Embolism Risk Factors

Surgery; immobility; atrial fibrillation; hypercoagulability; obesity; recent trauma; burns; pregnancy; postpartum state; oral contraceptives; central venous/arterial catheter; previous PE.

Pulmonary Embolism Anticoagulation

Heparin IV drip is used to slow/prevent further emboli; warfarin is used for long-term control; assess PT/INR.

Greenfield Filter Indications

May be used if anticoagulants are contraindicated, PE continues despite anticoagulants, or the patient previously survived a massive PE.

Pulmonary Embolism Nursing Interventions

Provide oxygenation or ventilator support; monitor for bleeding with thrombolytic/anticoagulant therapy; administer prescribed therapies such as anticoagulants, thrombolytics, sedatives, analgesics, or bronchodilators.

Pulmonary Embolism Patient Education

Teach DVT/PE prevention and precipitating risks such as prolonged flights; report bruising or blood in urine/stool; use a soft toothbrush; use caution when shaving.

Pulmonary Embolism SATA

Select appropriate interventions/findings: oxygenation support; monitor for bleeding; DVT prevention; assess for hypoxemia/tachycardia/tachypnea; administer anticoagulation as prescribed; teach bleeding precautions.

Acute Lung Failure Definition

Most common organ failure in the ICU according to the notes; inadequate exchange of O2 and CO2 so the body cannot meet oxygen needs at rest.

Acute Lung Failure Risk Factors

Older age; air pollution/allergies; tobacco use; neurologic, cognitive, and mobility conditions; COPD; asthma.

Acute Lung Failure Assessment

CNS: decreased LOC, restlessness, drowsiness, agitation, confusion. CV: decreased cardiac output, weak/bounding pulse, hypotension, dysrhythmias, palpitations, chest pain, JVD. Pulmonary: rapid shallow breathing, cyanosis, dyspnea, retractions, tripod position, accessory muscles, nasal flaring. Renal: UOP <30 mL/hr or <400 mL/day. GI: ascites, constipation, decreased bowel sounds, N/V, distention, anorexia. Skin: cool, clammy, pale, cyanotic.

Type I Respiratory Failure

Normocapnic/hypoxemic respiratory failure: LOW PaO2 with NORMAL PaCO2. Causes in notes: asthma, COPD, pneumonia, PE.

Type II Respiratory Failure

Hypercapnic respiratory failure: LOW PaO2 with HIGH PaCO2. Causes in notes: asthma, COPD, drug overdose, flail chest/chest-wall injury.

Hallmark of Acute Lung Failure

HYPOXEMIA.

Alveolar Hypoventilation

Inadequate oxygen enters the alveoli to meet body needs; hypercapnia occurs and is usually associated with extrapulmonary disorders.

Ventilation-Perfusion Mismatch

Ventilation and blood flow are mismatched; blood passes through under-ventilated alveoli and leaves with lower-than-normal oxygen. It is the MOST COMMON cause of hypoxemia.

Intrapulmonary Shunting

Extreme V/Q mismatch in which unoxygenated/shunted blood mixes with oxygenated blood. Can occur with atelectasis or alveoli filled with pus, blood, or fluid.

ALF Diagnostics

ABGs; chest x-ray; V/Q scan; EKG; cardiac output/index; pulmonary-artery catheter; sputum cultures.

ALF Prevention

Smoking cessation; infection control; prevention of postoperative pulmonary complications; immunizations.

ALF Oxygen Goal

Maintain arterial hemoglobin oxygen saturation >90% using the LOWEST oxygen concentration possible; notes state approximately 92% may be adequate.

Oxygen Therapy in ALF

Supplemental oxygen is effective for hypoxemia caused by alveolar hypoventilation and V/Q mismatch. Intrapulmonary shunting requires positive-pressure ventilation.

Noninvasive Ventilation Before Intubation

When tolerated, try noninvasive mask support first to avoid intubation.

ALF Nursing Interventions

Provide oxygen; chest physiotherapy/postural drainage; airway management; repositioning; incentive spirometry; suctioning as needed; adequate hydration; humidification; limit activity; control anxiety; control fever.

ALF Positioning

Place the healthy/least affected lung in the DEPENDENT position—good lung down; elevate HOB 30-45°; reposition every 2 hours.

ALF Desaturation Prevention

Hyperoxygenate before suctioning; perform procedures only when necessary; allow adequate rest between procedures; limit physical activity; control anxiety with sedation when prescribed; control fever.

ALF Secretion Clearance

Provide hydration; humidify oxygen; encourage coughing when secretions are present; suction as needed; use chest physiotherapy.

ALF Pharmacologic Management

Bronchodilators relieve bronchospasm; steroids decrease airway inflammation; sedation decreases work of breathing; neuromuscular paralysis can decrease oxygen consumption when sedation is insufficient; analgesics treat pain; diuretics reduce pulmonary congestion; antibiotics treat infection.

ALF Severe Metabolic Acidosis

Sodium bicarbonate may be used when metabolic acidosis is severe and pH is <7.2; notes state acidosis usually corrects itself.

ALF Nutrition

Enteral nutrition is preferred; early enteral feeds can prevent stress ulcers. Begin before day 3 in well-nourished patients and within 24 hours in malnourished patients; parenteral nutrition is a last resort.

ALF Complications

Ischemic-anoxic encephalopathy; cardiac dysrhythmias; venous thromboembolism.

ALF SATA Nursing Interventions

Select appropriate actions: maintain oxygenation; position good lung down; elevate HOB; reposition q2h; hyperoxygenate before suctioning; provide hydration/humidification; suction PRN; limit unnecessary procedures/activity; control fever/anxiety; provide prescribed respiratory support.

ARDS Definition

Acute Respiratory Distress Syndrome; clinical pulmonary manifestation of MODS and sudden progressive acute respiratory failure.

ARDS Pathophysiology

Non-cardiac pulmonary edema caused by alveolar-capillary membrane damage; alveoli fill with fluid and collapse; lung compliance decreases.

ARDS Classic Findings

Bilateral pulmonary infiltrates/“white-out lungs” and PF ratio <200.

ARDS Causes

Sepsis; aspiration of GI contents; pneumonia; trauma; oxygen toxicity; shock; DIC.

ARDS Assessment

Dyspnea; fatigue; somnolence/difficulty arousing; confusion; delirium; tachycardia that may progress to bradycardia; abnormal breath sounds; initially hypertension followed by hypotension; abdominal distention; late cyanosis and suprasternal retractions.

ARDS Phases

Exudative = hypovolemia and increased work of breathing. Fibroproliferative = alveoli enlarge and lungs become fibrotic. Resolution = recovery with structural and vascular remodeling.

ARDS Management

Early positive-pressure ventilation; treat underlying infection or trauma; promote gas exchange; support body systems; maximize cardiac output/perfusion; provide oxygenation and ventilation.

ARDS Positioning

Place the least damaged/healthiest lung in the DEPENDENT position—good lung down.

Prone Position Benefits

Improves oxygenation; improves perfusion to less-damaged lung areas; improves ventilation-perfusion matching.

Prone Position Contraindications

Recent abdominal surgery; increased intracranial pressure; hemodynamic instability; inability to tolerate the position.

Prone Position Nursing Care

Lubricate eyes; tape eyes shut; safely secure and position tubes and lines; keep equipment out of the way.

Rotation Therapy

Improves V/Q matching and oxygenation and helps prevent pulmonary complications from ventilation/bed rest. Complications include tube dislodgement and pressure ulcers; use padding.

Rotation Therapy Contraindication

Do not use in hemodynamically unstable patients; rotation therapy does NOT replace manual turning.

ARDS SATA

Select appropriate findings/interventions: bilateral infiltrates; PF ratio <200; early positive-pressure ventilation; prone positioning when appropriate; good-lung-down positioning; treatment of underlying cause; monitoring for hypotension and oxygenation problems.

Barotrauma

Alveolar rupture/overdistention caused by excessive PEEP.

Volutrauma

Lung injury caused by excessive tidal volume.

Stress Ulcer Prophylaxis

Pantoprazole, famotidine, omeprazole; early enteral feeding can help prevent stress ulcers.

Renal Failure During ARDS

May result from inadequate kidney oxygenation/AKI, hypovolemia, hypotension, hypercapnia, or nephrotoxic antibiotics.

Artificial Airway Purpose

Maintain airway patency and support oxygenation and ventilation.

Pharyngeal Airway

The shorter tube extends to the oropharynx and keeps the tongue out of the way. Incorrect tube length can cause complete airway obstruction.

Oropharyngeal Airway

Patient must be UNCONSCIOUS with an ABSENT or DIMINISHED gag reflex.

Endotracheal Tube

Used for short-term airway management, usually 7-10 or 12-14 days according to the notes. Daily chest x-ray confirms placement; auscultate breath sounds.

ETT Complications

Wrong placement during intubation; aspiration; oral/nasal trauma; cardiac arrest; pressure ulcer.

ETT Nursing Interventions

Have suctioning equipment ready before placement because of aspiration risk; auscultate breath sounds; confirm placement by chest x-ray; rotate tube left to right to reduce pressure injury; provide oral/skin care; keep airway secure.

Tracheostomy

Used for long-term airway management.

Tracheostomy Insertion Complications

Hemorrhage; tube displacement; laryngeal nerve injury; pneumothorax; cardiac arrest.

Tracheostomy Post-Placement Complications

Stoma infection; hemorrhage; tube obstruction; tube displacement; pressure ulcer.

Artificial Airway Nursing Management

Maintain oral airway and cuff pressure; provide proper skin and mouth care; ensure airway is stable and secure; prevent aspiration; provide humidification when oxygen is used.

Suctioning Indications

Coughing with visible secretions; rhonchi; decreased O2 saturation; tachycardia; bradycardia.

Suctioning Nursing Interventions

Suction ONLY PRN after assessing need; HYPEROXYGENATE before suctioning; limit each suction pass; suction pressure <150 mmHg.

Suctioning SATA

Select appropriate actions: assess need before suctioning; hyperoxygenate first; suction when indicated; limit suction-pass time; use pressure <150 mmHg; monitor oxygen saturation and heart rate.

Alternative Communication for Artificial Airways

Establish communication using hand signals, picture boards, or another alternative method.

Extubation vs Decannulation

Extubation = removal of the endotracheal tube. Decannulation = removal of the tracheostomy tube.

Mechanical Ventilation Purpose

Protect airway; improve gas exchange; decrease work/breathing effort; increase lung volume; assist lung function.

Mechanical Ventilation Indications: VOPS

Ventilation; Oxygenation; airway/lung Protection; Secretions.

Positive vs Negative Pressure Ventilation

Positive pressure = internal through an endotracheal tube or tracheostomy. Negative pressure = external with a mask connected to the ventilator.