13 - Post-op Fever Flashcards
Malignant hyperthermia
A life threatening elevation in body temperature
Malignant hyperthermia etiology
o Inhalation of general anesthetics (Halothane)
o Combination of muscle relaxants (succinylcholine)
Malignant hyperthermia incidence
o 1/12,000 pediatric anesthetics
o 1/40,000 adult anesthetics
Malignant hyperthermia theory
o Sarcoplasmic reticulum contains approx. 3000 times the amount of calcium normally found in the sarcoplasm
o Normal muscle contraction and relaxation involves the release and resequester of Ca++
o In malignant hyperthermia, the resequester of calcium does not occur
Malignant hyperthermia signs and symptoms
o Arrythmias o Masseter muscle spasm o Fever with increased body temp. o Tachypnea and tachycardia o Profuse hyperhidrosis o Metabolic and respiratory acidosis o Hyperkalemia
Malignant hyperthermia labs
o Abnormal ECG
o Elevated CPK
Malignant hyperthermia treatment
o Stop administration of anesthesia o Change tubing (due to residual medication) o Hyperventilate with 100% o2 o Correction of acidosis o Cool the patient (ice baths)
Malignant hyperthermia medication
Dantrolene – don’t need to know doses
o Rapid IV push until symptoms subside, also use post op
Malignant hyperthermia pre-op prophylaxis
o Dantrolene (before, during, after) o Dantrium (pre-op)
Malignant hyperthermia safe drugs
o Propofol, opioids, benzodiazepine, barbiturates, ketamine, local anesthetics, pancuronium/vecuronium, nitrous oxide
Post op temperature
- Normal = 36.5 - 37.4 c (97.7-99.5)
- Abnormal = Body temp >100.4 during post-op period is significant
Intra-op temperature
- Heat pyrexia – the patient is just cold, so the body is trying to warm up
- Malignant hyperthermia
Fever immediately post-op
- Heat pyrexia: occurs during surgery and up to 1 hour post-op
- Caused by trauma of the procedure resulting in inflammation (release of pyrogenic cytokines: IL-6,TNF, Interferon-Ɣ) and ↑ permeability
- Act on the anterior hypothalamus and cause a release of prostaglandins
5 W’s OF POST-OP FEVER***
KNOW THIS ****
Day 1-2 = Wind (atelectasis) Day 2-3 = Water (UTI) Day 3-7 = Wound (infection) Day 5-7 = Walking (DVT) Day >7 = Wonder (drugs)
12-48 hrs post-op
Atelectasis / pneumonia
o Visible collapse on x-ray
Aspiration pneumonia
o Fluid accumulation on x-ray
Spirometry
o Helps to expand the lungs to avoid the complication of pneumonia
o If you don’t have spirometry, tell the patient to cough every hour
2-3 days post-op
- Urinary tract infection *** - This is the “big one” we will see, but starting to get into wound infection time
- Constipation
- Benign post-op fever
- Hematoma (you will see fluctuance under incision site – hematoma or seroma is a risk of infection)
3-7 days post-op
Wound infection
o 5 constitutional signs of infection/inflammation (unless immune-suppressed)
o Look for the wound opening back up when it shouldn’t be
o Can’t always distinguish between infection and just edema from the surgery
5-7 days post-op
- Thrombo phlebitis
- Pulmonary embolism due to DVT
o Risk for DVT - Immobilization, Virchow’s triad = hemostasis, endothelial damage, hypercoagulability
o So much edema is present in limb, weeping of skin, breakdown of skin, blisters - Benign post-op fever
7 days post-op
Drug fever
Anytime fever
- Drug fever
- Catheter fever
- Reaction to blood transfusion
Emergent cause of early post-operative fever
- Necrotizing soft tissue infections/myonecrosis
- Pulmonary embolism
- Alcohol withdrawal
- Adrenal insufficiency
- Malignant hyperthermia
Post-operative edema
- Excessive amounts of fluid in the intercellular spaces (subcutaneous)
- Variable from one patient to another
Two types:
o 1st Type = short duration (15-30min)
- Caused by factors that increase permeability (serotonin, kinins, prostaglandins)
o 2nd Type = long duration (1-2 days)
- From leakage caused by direct injury. (endothelial destruction)
Treatment for post-op edema
- Ice, elevation, ROM exercises, compression therapy, NSAIDs, short acting corticosteroids
Hematoma vs infection – Hematoma
Hematoma
o Collection or extravasation of blood
o May lead to infection, long term swelling, and disability
Management
- Extravasation, aspiration, drains, steroid Infiltration, accelerated degradation. wound re-entry, prophylactic antibiosis