What is dyspnea in the Cardiovascular Intensive Care Unit (CVICU), its signs and symptoms, treatment options, and relevant management tips?

Dyspnea in CVICU: Assessment, Management, and Clinical Tips

Dyspnea in the Cardiovascular Intensive Care Unit (CVICU) is a prevalent and distressing symptom that requires prompt assessment and management to improve patient outcomes, reduce morbidity, and enhance quality of life. 1

Definition and Prevalence

• Dyspnea is the sensation of breathlessness, shortness of breath, or difficulty breathing commonly experienced by critically ill patients in the CVICU 1
• Approximately 40-44% of critically ill patients experience dyspnea, including those receiving mechanical ventilation 2, 1
• Dyspnea is rated as moderate to severe by 64% of patients in cardiac surgery ICUs 1
• It is often associated with anxiety and can summon a primal fear response that can be worse than pain 2

Signs and Symptoms

• Objective signs of respiratory distress include:

  • Increased respiratory rate (>25 breaths/minute) 1
  • Use of accessory muscles of respiration 3
  • Paradoxical breathing patterns 3
  • Nasal flaring 3
  • Decreased oxygen saturation (<90%) 4
  • Tachycardia (>130 beats/min) 1
  • Hypotension (systolic blood pressure <90 mmHg) 1
  • Jugular vein distension (in cases of right ventricular compression) 1

• Subjective symptoms reported by patients:

  • Sensation of "air hunger" or inability to get enough air 1
  • Chest tightness or constriction 3
  • Feeling of suffocation 2
  • Associated anxiety or panic 1

Assessment Tools

• For communicative patients:

  • 0-10 Numeric Rating Scale (NRS) with anchor words at each end is recommended 1
  • Vertical visual analog scale (VAS) may be preferred by some patients 1
  • Condensed Form of the Memorial Symptom Assessment Scale or Edmonton Symptom Assessment Scale for multiple symptom evaluation 1

• For non-communicative patients:

  • Respiratory Distress Observation Scale - the only known behavioral scale for dyspnea assessment 1, 5
  • Observation of physical and behavioral signs of respiratory discomfort 5
  • In non-communicative patients, dyspnea is termed "respiratory-related brain suffering" (RRBS) 6

Treatment Approaches

Non-pharmacological Interventions

• Patient positioning:

  • Upright sitting position to optimize breathing mechanics and reduce work of breathing 4, 3
  • Proper positioning to preserve joint mobility in immobile patients 3

• Airflow management:

  • Directing cool air toward the face with a fan (may provide relief) 1, 4
  • Maintaining cooler room temperatures 4

• Ventilatory support:

  • High-flow nasal cannula oxygen as first-line therapy for mild to moderate respiratory distress 3
  • Non-invasive ventilation (NIV) for appropriate cases, particularly with helmet NIV preferred over face-mask when available 3
  • Mechanical ventilation (invasive or non-invasive) for respiratory failure 1, 3
  • Low tidal volume ventilation (4-6 ml/kg ideal body weight) for invasive ventilation 4, 3

• Other supportive measures:

  • Early mobilization and muscle training to prevent ICU-acquired weakness 3
  • Chest physiotherapy for secretion clearance 3
  • Adequate nutrition to support respiratory muscle function 3

Pharmacological Management

• Opioids:

  • Opioids are the mainstay of pharmacological management of dyspnea that is refractory to disease-modifying treatments 1, 3
  • "Low and slow" intravenous titration of immediate-release opioid, repeated every 15 minutes until relief 1
  • Around-the-clock dosing for continuous dyspnea, with PRN dosing for episodic dyspnea 1

• Benzodiazepines:

  • Not generally effective as primary treatment for dyspnea 1
  • Can be added as adjunctive therapy when dyspnea is associated with anxiety or when opioids alone are insufficient 1, 3
  • Particularly successful as an adjunct to opioids in patients with advanced COPD 1

• Oxygen therapy:

  • Standard therapy for dyspnea in patients with hypoxemia (oxygen saturation <90%) 1
  • Target oxygen saturation of 92-97% or PaO2 70-90 mmHg 3
  • Limited benefit in non-hypoxemic patients unless it provides subjective relief 4

Disease-Specific Management

• Heart failure:

  • Optimize with inotropes and diuretics 1
  • Consider non-invasive ventilation for cardiogenic pulmonary edema 1

• Respiratory failure:

  • Consider high-flow nasal cannula or non-invasive ventilation before proceeding to intubation in appropriate cases 3
  • For severe cases requiring invasive mechanical ventilation, use low tidal volume ventilation and appropriate PEEP 4

• Cardiac tamponade:

  • Rapid transfer to center with capability for ultrasound-guided pericardiocentesis and/or cardiac surgery 1
  • Ultrasound-guided pericardiocentesis may be considered if expertise is available 1

CVICU-Specific Tips

• Implement systematic dyspnea assessment in routine care, similar to pain assessment protocols 6
• For mechanically ventilated patients experiencing dyspnea, adjust ventilator settings as a first-line intervention 6
• Consider tracheostomy timing based on expected duration of ventilation and patient factors 3
• Avoid disconnections of the ventilator circuit to prevent aerosol generation in infectious cases 3
• Do not delay intubation in rapidly deteriorating patients despite non-invasive support 3
• Avoid excessive sedation that may worsen respiratory function and prolong mechanical ventilation 3
• Do not withhold adequate opioid dosing due to concerns about respiratory depression, as benefits for symptom control often outweigh risks 4, 3
• Involve family members in providing comfort measures when appropriate 1
• Consider weaning from mechanical ventilation when PaO2/FiO2 > 200 mmHg and PEEP < 10 cmH2O 3

Common Pitfalls to Avoid

• Failing to assess dyspnea in non-communicative patients 5
• Withholding opioids due to exaggerated fears of respiratory depression 4
• Relying on nebulized opioids, which are no more effective than nebulized placebo 4
• Using oxygen therapy in non-hypoxemic patients without evidence of subjective relief 4
• Delaying intubation in rapidly deteriorating patients despite non-invasive support 3
• Using lemon-glycerin swabs for mouth care (can worsen xerostomia) 1