What are the monitoring requirements for a patient with pre-existing medical conditions such as hypertension, diabetes, or cardiovascular disease in the Post-Anesthesia Care Unit (PACU) during phase 1 and 2 recovery after surgery and anesthesia?

PACU Monitoring Requirements During Phase 1 & 2 Recovery

All patients in the PACU must have continuous ECG, pulse oximetry (SpO₂), non-invasive blood pressure (NIBP), and capnography (if an artificial airway remains in place) from admission through discharge, with one-to-one nursing observation until airway control, respiratory stability, cardiovascular stability, and ability to communicate are regained. 1

Phase 1 Recovery: Immediate Post-Anesthesia Period

Mandatory Continuous Monitoring

• ECG monitoring must be continuous to detect cardiac arrhythmias and ischemia 1
• Pulse oximetry (SpO₂) must be continuous to assess oxygenation 1
• Non-invasive blood pressure (NIBP) should be measured at minimum every 5 minutes, as hypotension occurring between intervals is associated with adverse outcomes 1
• Capnography must continue until any artificial airway device is removed AND the patient responds to verbal contact 1
• Core temperature must be measured on admission and monitored continuously, as hypothermia <35°C is a reportable adverse event 1

Clinical Observation Requirements

• One-to-one observation by a registered PACU practitioner or trained staff member is mandatory until the patient regains airway control, respiratory and cardiovascular stability, and can communicate 1, 2
• An anaesthetist must be immediately available (supernumerary to operating theatre requirements) for all PACU patients 1, 2
• At minimum, two staff members (at least one registered practitioner) must be present when any patient in PACU does not meet discharge criteria 1

Additional Monitoring for Specific Situations

• Quantitative neuromuscular monitoring must continue if neuromuscular blocking drugs were used, until train-of-four ratio >0.9 is confirmed 1
• Blood glucose monitoring should be performed at least hourly in patients with treated diabetes 1
• Processed EEG monitoring should continue if total intravenous anesthesia (TIVA) was used with neuromuscular blocking drugs, at least until full recovery from neuromuscular blockade 1

Critical Parameters to Document

The Association of Anaesthetists mandates recording: 1

• Level of consciousness and airway patency
• Respiratory rate and adequacy of ventilation
• Oxygen saturation continuously
• Blood pressure and heart rate/rhythm
• Core temperature on admission
• Pain severity using standardized scales
• Incidence and severity of nausea/vomiting
• All drugs administered and IV infusions
• Surgical drainage volume

Phase 2 Recovery: Step-Down Period

Continued Monitoring Requirements

• ECG, SpO₂, and NIBP monitoring must continue throughout Phase 2 until discharge criteria are met 1
• Monitoring frequency may be reduced but must not cease until the patient is fully recovered from anesthesia 1
• Clinical observation continues but may transition from one-to-one to less intensive ratios once airway control, respiratory stability, and cardiovascular stability are established 1

Discharge Criteria Assessment

No patient should be discharged until ALL of the following are met: 2

• Fully conscious and able to maintain clear airway with protective reflexes intact
• Breathing and oxygenation satisfactory
• Cardiovascular system stable with pulse and blood pressure approximate to normal preoperative values or within acceptable parameters
• Peripheral perfusion adequate
• Pain and postoperative nausea/vomiting adequately controlled
• Core temperature acceptable (not <35°C)

Special Considerations for High-Risk Patients

Patients with Cardiovascular Disease

• Additional cardiovascular monitoring should be considered based on comorbidity, frailty, or emergency nature of surgery 3
• Cardiac output monitoring may be used to titrate vasoactive infusions and optimize stroke volume 3
• Non-invasive blood pressure should be measured more frequently than every 5 minutes if hemodynamic instability is present 1

Patients with Diabetes

• Blood glucose must be measured at least hourly in all patients with treated diabetes 1
• Patients with diabetic autonomic neuropathy require enhanced hemodynamic monitoring due to increased risk of perioperative instability 3
• Vasopressor requirements correlate with degree of dysautonomia and should be anticipated 3

Patients with Hypertension

• Tight blood pressure control is essential as intra-operative hypotension is associated with adverse outcomes related to both severity and duration 1
• Particular care should be taken that NIBP monitors do not continue to display readings for >5 minutes to reduce risk of displaying outdated values 1

Critical Pitfalls to Avoid

Premature Discharge

• Never discharge patients until cardiovascular system is stable with no unexplained cardiac irregularity and temperature is within acceptable limits 4
• Do not attribute all tachycardia to fever alone, as this relationship deviates from expected norms during pharmacological antipyresis 4

Inadequate Airway Management

• Do not normalize heart rate in compensatory tachycardia where cardiac output depends on rapid rate (e.g., hypovolemia, pain, hypoxia) 4
• If laryngeal mask airway or supraglottic device is present, PACU nurse must be specifically trained in its management and removal 2
• Tracheal tube removal is the anaesthetist's responsibility but may be delegated only to appropriately trained PACU staff who accept this responsibility 2

Monitoring Gaps

• Capnography must not be discontinued until the artificial airway is removed AND response to verbal contact is re-established 1
• Alarm limits must be set to patient-specific values before use, and audible alarms must be enabled 1
• Do not assume autonomic function is preserved in patients with metabolic syndrome or diabetes 3

Equipment and Facility Requirements

Minimum Equipment at Each Bed Space

Every PACU bed must have: 1

• 12 electrical socket outlets (six each side of bed)
• One oxygen pipeline outlet
• One medical air outlet
• Two vacuum outlets
• Adjustable examination light
• Push-button emergency call system
• Physiological monitors with display screen and recording system

Immediately Available Equipment

• Difficult airway equipment 1
• Nerve stimulator for assessing neuromuscular blockade 1
• Thermometer and patient warming devices 1
• All drugs, equipment, fluids and algorithms for resuscitation 1
• Blood gas analysis and hemoglobin measurement capability 1