Recovery from Anesthesia Dr. H Schutte Dept. of Anesthesiology June 2013

Phases of recovery Early recovery –Patient emerges from Anesthesia Intermediate recovery –Patient achieves criteria for discharge Late recovery –Return to pre-operative physiological state

Early Recovery (Phase 1) Commences on discontinuation of anesthetic agent Patient awakens Recovers protective reflexes Resumes motor activity In theatre or PACU (recovery room)

Criteria to leave the operating room Patent airway Adequate ventilation and oxygenation Stable hemodynamics Criteria to leave the operating room

Monitoring during early recovery Pulse oximetry ECG Blood pressure Trained nurse or Anesthesiologist present all the time

Criteria for discharge from PACU Aldrete scoring system –Activity –Respiration –Circulation –Consciousness –O2 Saturation

Aldrete score Activity: Able to move voluntary or on command Score –Four extremities 2 –Two extremities1 –Zero extremities0

Aldrete score RespirationScore –Able to breath and cough freely 2 –Dyspnea, shallow or limited breathing 1 –Apneic 0

Aldrete score Circulation Score –BP +/- 20mmHg of pre-anesthetic level 2 –BP +/ mmHg of pre-anest level 1 –BP +/- 50mmHg of pre-anesthetic level 0

Aldrete score ConsciousnessScore –Fully awake 2 –Arousable on calling 1 –Not responding 0

Aldrete score O2 saturationScore Maintain SO2 > 92% on room air 2 Needs O2 to maintain SO2 > 90% 1 SO2 < 90% even with O2 suppl 0

Aldrete score A score of 9 indicates that a patient is fit to be discharged from the PACU

Intermediate recovery (Phase 2) Usually in the general ward 2 additional criteria applicable –Pain –Nausea and vomiting

Post-anesthesia discharge PADSS scoring system based on 5 criteria –Vital signs –Activity level –Nausea and vomiting –Pain –Surgical bleeding

Vital signs Vital signs must be stable and consistent with age and pre-op baseline Score BP and pulse within 20% of pre-op 2 BP and pulse 20-40% of pre-op 1 BP and pulse > 40% of pre-op 0

Activity level Patient must be able to ambulate at pre-op level. Score Steady gait, no dizziness (Pre-op) 2 Requires assistance 1 Unable to ambulate 0

Nausea and vomiting Patient should have minimal nausea and vomiting before discharge Score Minimal: successfully treated with oral medication 2 Moderate: successfully treated with intramuscular injection 1 Severe: continues after repeated treatment 0

Pain Patient should have minimal or no pain before discharge. Level of pain should be acceptable to the patient Pain should be controllable by oral analgesics Location, type and intensity of pain should be consistent with anticipated post-op discomfort Score Pain acceptable 2 Pain unacceptable 1

Surgical bleeding Post-op bleeding should be consistent with expected blood loss for the procedure Score Minimal: does not require dressing change 2 Moderate: up to two dressing changes required 1 Severe: More than three dressing changes required 0

PADSS score Again a minimum score of 9 is required for discharge from hospital

Complications during recovery Cardiovascular Respiratory complications Hypothermia Restlessness and agitation Nausea and vomiting Pain

Cardiovascular complications Hypotension –Hypovolemia –Neuraxial blocks –Tension pneumothorax –Cardiogenic/Septic shock –Myocardial Ischemia/Arhythmias Hypertension –Pain –Full bladder –Chronic hypertension

Cardiovascular complications Arrythmias –Tachycardia –Bradycardia –Atrial fibrillation/ SVT Myocardial dysfunction –Ischaemia –LV failure

Respiratory complications Airway obstruction –Tongue falling back –Laryngospasm –Glottic edema –Blood, secretions, vomitus, throat packs in airway Hypoventilation –Common, usually mild –Residual effects of anesthetic agents (opioids, muscle relaxants) –Splinting of diaphragm, tight dressings

Respiratory complications Hypoxemia –Hypoventilation –Increased O2 consumption (fever, shivering) –Atelectasis, lung collapse –Pulmonary edema –Aspiration –Pneumothorax –etc

Shivering and hypothermia Intra-operative hypothermia Volatile anesthetic agents Increases O2 consumption Treatment: –Forced air warming blankets –O2 –Pethidien 10-50mg IVI

Nausea and vomiting Prevention better than cure Treatment: –Metoclopramide, –Serotonin antagonists Ondansetron, Granisetron –Dexametazone –(Droperidol)

Restlessness/Agitation A restless patient is hypoxic until proven otherwise Other causes: –Pain –Full bladder –Drugs –Psychiatric conditions

Recovery position

Factors determining speed of recovery Duration of Anesthesia Anesthetic agents used Age Renal or hepatic disease Pre-operative medications (incl Alcohol)

Delayed recovery Failure to regain consciousness 30-60min after general anesthesia Most commonly residual effect of anesthetic, sedative or analgesic drugs. Inadequate reversal of muscle relaxants –Scoline apnea –Phase 2 block –Overdose of muscle relaxants –Abnormal liver/kidney function Hypothermia

Delayed recovery Metabolic disturbances –Hypoxemia/hypercarbia –Hypercalcemia –Hypermagnesemia –Hyponatremia –Hyperglycemia/hypoglycemia Peri-operative stroke

Take home message Hypoxia is by far the most common and dangerous post-operative complication Pay special attention to your patient during recovery so that you don’t spoil a perfect take-off and a safe flight with a landing like this: