What is the management plan for desaturation in a ward setting?

Ward Management of Desaturation

For any patient with desaturation in a ward setting, immediately administer high-flow oxygen at 15 L/min via reservoir mask if SpO₂ <85%, or 2-6 L/min via nasal cannulae if SpO₂ 85-93%, while simultaneously performing rapid ABCDE assessment to identify and treat the underlying cause. 1

Immediate Oxygen Delivery Based on Severity

Critical Desaturation (SpO₂ <85%)

• Administer the highest possible inspired oxygen concentration using a reservoir mask at 15 L/min immediately, regardless of COPD status or hypercapnic risk, until the situation stabilizes 1
• This applies to all patients, even those with known risk factors for hypercapnia, as life-threatening hypoxemia takes priority 1

Moderate Desaturation (SpO₂ 85-93%)

• Start oxygen at 2-6 L/min via nasal cannulae or 5-10 L/min via simple face mask 1
• Target SpO₂ 94-98% for most acutely ill patients 2, 1
• For patients with known COPD, morbid obesity, cystic fibrosis, chest wall deformities, neuromuscular disorders, or bronchiectasis, target SpO₂ 88-92% instead 2, 1

Mild Desaturation (SpO₂ >93% but below baseline)

• Initiate supplemental oxygen to maintain target range 2
• Document baseline oxygen requirements and adjust accordingly 2

Rapid Clinical Assessment Algorithm

Verify Equipment Function First

• Check pulse oximetry signal quality, proper probe placement, and adequate waveform that correlates with pulse rate 1
• Verify oxygen delivery system connections, as disconnections cause serious incidents 2
• Ensure adequate oxygen supply is available 2

ABCDE Assessment

• Airway: Assess for patency and obstruction; consider simple airway maneuvers or adjuncts if compromised 3
• Breathing: Record respiratory rate (>30 breaths/min requires increased oxygen flow rates), work of breathing, and auscultate for pneumothorax, pulmonary edema, or bronchospasm 2, 1
• Circulation: Check heart rate, blood pressure, and signs of shock or low cardiac output 3
• Disability: Assess level of consciousness and mental status changes 3
• Exposure: Look for contributing factors like fever, trauma, or signs of pulmonary embolism 1

Life-Threatening Causes Requiring Immediate Intervention

• Tension pneumothorax 1
• Massive pulmonary embolism 1
• Acute pulmonary edema 1
• Complete airway obstruction 3

Oxygen Titration and Monitoring

Adjusting Oxygen Delivery

• If saturation falls below target range, increase oxygen concentration; if saturation rises above target range, decrease oxygen concentration 2
• Record new saturation and delivery system/flow rate on observation chart after 5 minutes of treatment at new oxygen concentration 2
• Each change must be documented by clinician trained to administer oxygen 2

When to Obtain Blood Gases

• Patients at risk of hypercapnic respiratory failure (target 88-92%) require repeat blood gas assessment 30-60 minutes after any increase in oxygen therapy to ensure CO₂ is not rising 2
• For patients with no hypercapnic risk and stable clinical status, pulse oximetry monitoring alone is sufficient 2
• If saturation fails to rise following 5-10 minutes of increased oxygen, or if clinical concern exists, repeat blood gases 2

Continuous Monitoring Requirements

• Pulse oximetry to detect early desaturation 3
• Respiratory rate, heart rate, blood pressure, and mental status 3, 1
• Document oxygen saturation and delivery device on respiratory section of observation chart 2

Special Patient Populations

COPD or Risk of Hypercapnic Respiratory Failure

• Use 24% Venturi mask at 2-3 L/min (or 28% Venturi mask at 4 L/min) with target SpO₂ 88-92% pending blood gas results 2
• Never abruptly discontinue oxygen in these patients, as this causes life-threatening rebound hypoxemia with rapid fall below baseline SpO₂ 1
• If pH and PCO₂ are normal on initial blood gases, may increase target to 94-98% unless history of previous hypercapnic failure requiring NIV 2
• Recheck blood gases at 30-60 minutes even if initial PCO₂ was normal 2

Obese Patients

• Position in head-up position (25-30°) to improve functional residual capacity 3, 4
• These patients are at higher risk for rapid desaturation due to reduced functional residual capacity 3

Cardiac Patients

• Do not routinely administer oxygen if SpO₂ ≥94%, as supplemental oxygen in normoxemic acute coronary syndrome patients increases myocardial injury and infarction size 1
• Only give oxygen if SpO₂ <94%, signs of heart failure, shock, or breathlessness present 1

Escalation of Respiratory Support

When Standard Oxygen Fails

• If patient remains hypoxemic despite high-flow oxygen via reservoir mask, consider non-invasive positive pressure ventilation (NIPPV) with CPAP 5-10 cmH₂O 2, 4
• High-flow nasal oxygen (HFNO) at 30-70 L/min is an alternative, though NIPPV has stronger evidence for preventing critical desaturation 2, 4
• Position patient head-up at 35° to reduce airway swelling and improve oxygenation 3

Preparing for Intubation

• If desaturation persists despite maximal non-invasive support, prepare for definitive airway management 3
• Continue preoxygenation with NIPPV or HFNO until ready to intubate 2, 4
• Have backup airway plan ready, limiting intubation attempts to three 3

Critical Pitfalls to Avoid

Oxygen Management Errors

• Never delay oxygen therapy for seriously ill patients to obtain baseline saturation measurements 2
• Do not reduce oxygen too rapidly in patients with hypercapnic risk; step down gradually to lowest level maintaining target saturation 1
• Increasing oxygen flow rate into a Venturi mask does not increase oxygen concentration delivered; it only compensates for high respiratory rates 2

Monitoring Errors

• Pulse oximetry may be inaccurate below 80% saturation 3
• Supplemental oxygen may mask hypoventilation by delaying onset of hypoxemia 3
• Transient desaturations may occur without consequence, but persistent desaturation requires intervention 3

Clinical Assessment Errors

• Endobronchial intubation causes nearly one-fifth of all desaturations under anesthesia; always verify tube position 5
• Failure to position patient head-up is the most common error in managing hypoxemic patients 4
• Do not assume desaturation is benign; half of cases are due to underlying lung disease, secretions, or obesity requiring specific management 5