What are reasons for post-op fever?

• Wind (12-24 h)

• • Atelectasis (from muscle relaxers)
  • Post-op hyperthermia
  • Treatment
    • Encourage incentive spirometer
    • Chest x-ray

• Water (~24 h)
  • UTI
  • Treatment
    • Straight catheter
    • Urine analysis (UA) with Gram stain, culture and sensitivity
    • Treat with antibiotics if necessary
• Walk (~48 h)
  • DVT
  • PE
  • Treatment
    •  Heparin or Lovenox protocol
    • Use SCDs, TEDs, or get patient out of bed
• Wound (~72 h)
  • Post-op infection
  • Treatment
    • X-ray, Gram stain, culture and sensitivity, blood culture
    • Begin antibiotic
• Wonder drug (anytime)
  • Drug fever
  • Treatment
    • D/C drug
    • Give reversal drug if necessary

 

When do fever peaks occur?

Between 4-8 pm

 

What part of the brain regulates the body's temperature?

Hypothalamus

 

What is malignant hyperthermia?

A side effect of general anesthesia – tachycardia, hypertension, acid-base and electrolyte abnormalities, muscle rigidity, hyperthermia

 

What is the treatment for malignant hyperthermia?

• Dantrolene (for muscle relaxation)
  • 2.5mg/kg IV x l, then 1 mg/kg IV rapid push q6h until symptoms subside or until max dose of l0 mg/kg

 

If a risk of malignant hyperthermia is suspected, what pre-operative test may be performed?

CPK – elevated in 79% of patients with malignant hyperthermia

 

Anesthetics

What is the mechanism of action for local anesthetics?

Block Na+ channels and conduction of action potentials along sensory nerves

 

What is the toxic dose of lidocaine (Xylocaine)?

300 mg plain (4.5 mg/kg)

500 mg with epi (7.0 mg/kg)

 

What is the toxic dose of bupivacaine (Marcaine)?

175 mg plain (2.5 mg/kg)

225 mg with epi (3.2 mg/kg)

 

How to convert percentage of solution to mg/mL?

Move decimal point of percentage one place to right

(e.g. 1% solution has 10 mg/mL)

 

What are the side effects of lidocaine and bupivacaine associated with systemic exposure?

CNS effects – initial excitation (dizziness, blurred vision, tremor, seizures) followed by depression (respiratory depression, loss of consciousness)

Cardiovascular effects – hypotension, bradycardia, arrhythmias, cardiac arrest

 

What can be given to help reverse local anesthetic-induced cardiovascular collapse?

Intravenous fat emulsion (Intralipid)

 

Is there a risk with intra-articular injections of bupivacaine?

Studies have shown chondrocyte death following prolonged exposure to bupivacaine

 

In what age group should bupivicaine be avoided?

Children <12 year of age

 

How are amides (lidocaine and bupivacaine) metabolized?

Liver

 

How are esters (Novocain) metabolized?

Plasma pseudocholinesterase

 

What is the only local anesthetic with vasoconstriction?

Cocaine

 

How is cocaine metabolized?

Plasma pseudocholinesterase (just like other esters)

 

Can local anesthetics cross the placental barrier?

Yes

 

What does MAC (as in MAC with local) stand for?

Monitored anesthesia care

 

For anesthesia, what cannot be given to a patient with an egg shell allergy?

propofol (Diprivan)