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 extremities 1– Zero extremities 0

Aldrete score

• Respiration Score

– 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 +/- 20-50mmHg of pre-anest level 1– BP +/- 50mmHg of pre-anesthetic level 0

Aldrete score

• Consciousness Score

– Fully awake 2– Arousable on calling 1– Not responding 0

Aldrete score

• O2 saturation Score

• 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: