PACU

Question 1

What are the guidelines for safe discharge after ambulatory surgery?

Answer 1

Respiration

• Able to take deep breath and cough =2
• dyspnea/ shallow breathing = 1
• apnea = 0

O2 saturation

• able to maintain O2 saturation >92% on room air = 2
• Needs O2 to maintain O2 saturation > 90%=1
• O2 saturation <90% with O2 supplement = 0

Blood pressure

• 20% of baseline =2
• 20-50% of baseline= 1
• 50% of baseline = 0

Consciousness

• Fully awake =2
• arousable by calling = 1
• non responsive = 0

Activity
- able to move 4 extremities = 2
- able to move 2 extremities = 1
able to move 0 extremities = 0

Pain

• pain free = 2
• mild pain handled by oral medication = 1
• severe pain requiring parenteral medication = 0

Ambulation

• Able to stand and walk straight = 2
• vertigo when erect = 1
• dizziness when supine = 0

fast feeding

• able to drink fluids = 2
• nauseated =1
• nauseated and vomiting =0

urine output

• has voided =2
• unable to void but comfortable = 1
• unable to void and uncomfortable =0

Question 2

What are the causes of unexplained coma post surgery?

Answer 2

• Respiratory: Hypoxaemia, hypercarbia
• Cardiovascular: Hypotension, hypertension
• Electrolyte imbalances: HypoNa, hyperNa, TURP syndrome (absorption of irrigation fluid via prostatic venous plexus during bladder irrigation)
• Metabolic: Hypoglycaemia, hyperglycaemia, hypothyroidism
• CNS: New stroke, drugs (atropine)
• Pain, full bladder

Question 3

What are the causes of hypoventilation, desaturation post surgery?

Answer 3

Airway causes

• Airway obstruction: Pharyngeal obstruction by tongue, airway oedema (e.g. ENT surgeries), foreign body (e.g. throat pack left in situ), neck haematoma (e.g. s/p total thyroidectomy), airway secretions, atelectasis
• Laryngospasm, bronchospasm

Central causes (respiratory depression)

• Drugs: Morphine, volatile anaesthetics (inhaled anaesthetics)
• CNS pathology
• Hypothermia

Peripheral causes

• Muscle weakness (inadequate reversal of NMB)
• Pain, abdominal distension
• Obesity, tight dressings
• Pneumothorax

Question 4

What are the causes of hypotension post surgery?

Answer 4

Shock

• Hypovolaemic shock (intra-op blood loss + inadequate replacement)
• Cardiogenic shock (IHD, CHF, arrhythmia)
• Distributive shock (sepsis, anaphylaxis)
• Obstructive shock (pneumothorax, pericardial effusion, pulmonary embolism)

Residual effects of anaesthetic agents

• Vasodilation (reduced total peripheral resistance)
• Myocardial depression
• Depression of intrinsic baroreceptor reflexes that maintain BP

Question 5

What are the causes of acute hypertension post surgery?

Answer 5

• Pain, anxiety, full bladder
• Hypothermia
• Pre-existing HTN
• Hypoxaemia, hypercarbia
• Vasopressor drugs
• CNS pathology, e.g. activation of Cushing reflex (in response to cerebral oedema/haemorrhage)

Question 6

What group of patients have increased risk of post op nausea and vomiting (PONV)

Answer 6

Increased risk if:
- Female
- History of PONV or motion sickness
N- on-smoker
- Use of opioids/N2O/volatile anaesthetics
- Younger patients
- Type of surgery (abdominal, laparoscopic, strabismus, middle ear)
- Long duration of surgery
- Hypotension from spinal anaesthesia