Pulmonary Issues in Critical Care

STUDENT LEARNING OUTCOMES

  • Describe causes and types of acute lung injury.

  • Differentiate acute lung injury, acute respiratory failure, and ARDS.

  • Manage ARDS.

  • Identify types of pulmonary embolism.

  • Manage pulmonary embolism.

ACUTE RESPIRATORY FAILURE

  • Defined by failure of ventilation and failure of oxygenation.

EARLY RECOGNITION

  • Clinical signs to watch:

    • Tachypnea

    • Tachycardia

    • Accessory muscle use

    • Nasal flaring

    • Abnormal chest wall movements

    • Labored breathing

  • Late signs include:

    • Falling SpO2

    • Diaphoresis

    • Mental status changes

    • Anxiety

    • Air hunger

    • Bradypnea

ACUTE RESPIRATORY DISTRESS SYNDROME (ARDS)

  • ARDS is a syndrome, not a disease.

  • Pathogenesis involves:

    • Inflammatory event

    • Neutrophil adherence and migration

    • Activation of inflammatory response

    • Injury to alveolar-capillary membrane.

ARDS CHARACTERISTICS

  • A: Atelectasis

  • R: Refractory hypoxemia

  • D: Decreased lung compliance

  • S: Decrease in surfactant

COLLABORATIVE MANAGEMENT OF ARDS

  • Focus on promoting oxygenation:

    • Use mechanical ventilation and supportive settings.

    • Patient positioning (proning).

  • Maintain hemodynamics:

    • Use ECMO and drug therapies (antibiotics).

  • Supportive care is primary; no single therapy has proven effective.

PEEP IN ARDS

  • PEEP increases in low PaO2 situations to lower FIO2.

  • Recruits alveoli for better gas exchange.

  • May raise intra-thoracic pressure and decrease preload, leading to edema.

ARDS PROGNOSIS

  • Mortality rate: 30% to 40%.

  • Highest mortality: sepsis; lowest: trauma.

PULMONARY EMBOLISM

  • Leading cause of preventable in-hospital death.

COMMON SIGNS/SYMPTOMS OF PE

  • Tachypnea, dyspnea, pleuritic pain, apprehension, cough, crackles, tachycardia, acute distress, hemoptysis, shock/cardiac arrest.

DIAGNOSIS AND MANAGEMENT OF PE

  • Use: D-dimer, CT Angiogram (CTA), V/Q scan, ultrasound for DVT, chest X-ray, echocardiogram, ECG, ABG.

EMERGENCY MANAGEMENT OF PE

  • Maintain ABCs: Airway, Breathing, Circulation.

  • Initiate anticoagulation and consider fibrinolytics.

VENTILATOR ISSUES

  • Machine-based checks: kinks, tube placement, pilot balloon.

  • Patient-based checks: biting on tube, need for suctioning, lung auscultation.

  • Consider increasing sedation or neuromuscular blockade if needed (e.g., Cisatracurium, vecuronium).