Postoperative Issues Flashcards
Initial steps in workup of post-operative fever
- CXR
- Urinalysis
- Urine culture
- Blood culture
5 W’s of Post-Op Fever
- Wind
- Water
- Walking
- Wound
- Wonder drugs
Fever during surgery is almost certainly . . .
. . . drug induced, SPECIFICALLY malignant hyperthermia
Malignant hyperthermia: During surgery. Give high flow O2, dantrolene, cool off. Ppx is FHx screening.
Drugs that cause malignant hyperthermia
- Gas anesthetics except nitrous oxide (basically the fluranes are the most important cause)
- Succinylcholine
- Halothane
- Ether
Fever immediately after surgery
- Likely due to bacteremia from intraoperative infection, especially if you are doing surgery on an inflamed organ or the bowel.
- Diagnose: blood culture
- Treatment: Broad spectrum abx (often vancomycin + pip-tazo)
- Ppx: Maintain sterile field, avoid unncessary interference with bowel
Fever on POD#1
- Most likely to be atelectasis
- Diagnosis: Must rule out pneumonia by CXR
- Treatment: If CXR consistent w/ atelectasis, incentive spirometry and get them walking out of bed.
- Ppx: Have the patient do the above anyway after surgery, as soon as they can.
Fever on POD#2
- Most likely to be pneumonia
- Dx: Fever, cough, consolidation on CXR
- Tx: Broad spectrum abx (vancomycin + pip-tazo)
- Ppx: Incentive spirometry and out of bed
Fever on POD#3
- Most likely to be UTI
- Dx: Urinalysis, urine culture
- Note: If you see WBC casts, likely to be pyelonephritis which they had prior to going to surgery.
- Tx: Abx targeting UTIs
- Ppx: Take Foley out as soon as possible
Fever on POD#5
- Most likely to be DVT / PE
- Less likely, thrombophlebitis
- Often circumference of one leg >2 cm larger than the other
- Dx: Ultrasound of bilateral lower extremities
- Tx: Heparin bridge to warfarin (NOACs and heparin variants also possibilities)
- Ppx: LMWH (hold day of surgery, then resume), OOB
Fever on POD#7
- Most likely to be cellulitis
- Dx: Ultrasound to rule out abscess
- Tx: Abx for cellulitis
- Ppx: Maintain sterile field, keep wound clean post-operatively
Fever on POD#10-14
- Most likely to be an abscess
- Dx: Ultrasound (or CT)
- Tx: Abx, return to OR for incision and drainage
- Ppx: Sterile field, keep would clean post-op
Basically everyone with post-operative chest pain deserves which diagnostic procedures (irrespective of risk factors)
- For MI:
- EKG
- Troponin and CK
- For PE:
- Lower extremity ultrasounds
- Spiral CT
Hurricane mnemonic for post-op fevers
“First, the Wind then the Rain (Water) then you run (Walk) then you trip and fall (Wound), and you Wonder what happened to get the abscess”
Ascending odd #s plus 10 for the abscess:
POD#1 3 5 7 10
Post-surgical altered mental status
- Electrolyte derangements
- Na
- Ca
- If elderly, consider sundowning
- Treat w/ atypical antipsychotics
- Hypoxemia
- PE
- Atelectasis
- ARDS (will be in context of prolonged intubation, complicated surgery, lots of fluids, etc. These patients will need to be intubated and receive high oxygen, PEEP)
-
Delirium tremens
- HTN, tachycardia. Then tremors (~48-72 hr). Then seizures.
- Treat w/ benzodiazepines (diazepam specifically)
Which benzo is best for delirium tremens and why?
Diazepam, because it is readily absorbed, has a long halflife, and self-tapers
General management of inpatient alcohol withdrawal
- Diazepam is first-line (or lorazepam), but phenobarbital is also an excellent choice (probably better, but RCTs don’t exist yet). Can be given together if necessary.
- Always give IV thiamine too, just in case. A lot. Over several days.
- If mild, BAL > 400, no risk factors or prior history, can send home on gabapentin with followup instead of inpatient management.
Postoperative oliguria
- Normal urine output: 0.5 cc/kg/hr
-
Is there an urge to void?
- Yes: Obstructive picture. Do bladder scan or in-and-out cath (not a Foley). Usually due to anesthesia-induced neurogenic bladder, which is self-limited.
-
No: Might be renal failure. Look at urinary output. If there is truly no output, Foley is likely kinked. If there is some output but it is minimal, this is likely true renal disease.
- Give 500 cc fluid bolus challenge. If urine output increases, you are good, give more fluid. If they don’t, there is intrinsic renal disease.
Post-operative abdominal distension
-
Ileus
- Pathology: Functional
- Presentation: POD#1 or 2, no stool or flatus
- Dx: KUB showing dilated large and small bowel
- Tx: Fluids, potassium, OOB
-
Obstruction
- Pathology: Obstructive
- Presentation: POD#5, still no stool or flatus
- Dx: KUB showing either small bowel obstruction (dilation proximal, compression distal), OR large bowel obstruction (normal small bowel, dilation proximal, compression distal).
- Tx: Repeat surgery to destroy adhesions
-
Ogilvie syndrome
- Pathology: Functional
- Presentation: POD#5, still no stool or flatus, elderly patient
- Dx: KUB showing ileus of colon (complete distension of colon, NO distal area is spared)
- Tx: Decompression (rectal tube), stigmine if rectal tube fails. May need colonoscopy to rule out cancer.
Dehiscence
Failure of the fascia.
Wound is not open, but underneath the fascial planes are not closed well. Will result in a hernia when the wound heals.
Presents w/ salmon colored serosanguinous drainage. May be able to feel loss of integrity of abdominal wall on exam.
Dx: Clinical
Tx: No straining, use abdominal binder to prevent evisceration. Elective reoperation to close the hernia.
Evisceration
Failure of fascia AND skin.
Loops of bowel popping out of skin. Surgical emergency.
Dx: Clinical
Tx: Apply warm saline dressings immediately, then emergent surgery. NEVER attempt to reduce. This will result in bacterial peritonitis.
Ppx: Don’t strain, don’t get OOB too early
FETID (Fistula mnemonic)
- Foreign body
- Epithelialization
- Tumor
- Irradiation/Inflamed/Inflammatory bowel (Crohn’s)
- Distal obstruction
Fistulas
Dx: Clinical
Tx: Resect fistula. But, may need to divert fistula into otomy, fix ulderlying cause, then reconnect.
While malignant hyperthermia is the #1 concern for intraoperative fever, a broader differential includes. . .
- Febrile nonhemolytic transfusion reaction
- Thyrotoxic crisis
- Anticholinergic syndrome
- Neuroleptic malignant syndrome
- An infection acquired prior to surgery (unlikely, but does happen sometimes)
Fever >1 month after operation
- Surgical site infection by indolent organisms (coagulase negative staphylococci: Staph epidermidis, Staph hominis)
- Delayed cellulitis
- Viral infections acquired from perioperative blood product transfusion (hepatitis viridae, CMV, HIV)
- Infective endocarditis
Most surgical site infections occuring within 1 week of surgery are due to one of these two organisms:
- Streptococcus pyogenes
- Clostridium perfringens
Quick ddx for apparent nosocomial pneumonia
- True nosocomial pneumonia
- Atelectasis
- Aspiration pneumonia
- Ventilator-associated pneumonia
Most common etiologies of aspiration pneumonia, features, and treatment
- Basically caused by mixed anaerobes:
- Klebsiella
- Fusobacteria
- Peptostreptococcus
- Bacteroides
- Risk factors for aspiration present
- Halitosis/foul smelling sputum
- Always consider aspiration pneumonitis (chemical irritation) as component or as ddx
- Tx: If secondary to extubation, re-intubate. Abx not routinely recommended unless abscess is present. If treatment is indicated, use metronidazole + amoxicillin and consider aspiration.
Ventilator-associated pneumonia
- Often caused by P. aeruginosa, sometimes MRSA
- Tx: Vancomycin OR Linezolid plus one beta lactam that covers pseudomonas and pneumococci plus another non-beta lactam antipseudomonal agent, duration 7 days. Also give fluids, mucolytics, antitussives, antipyretics.
- Empiric therapy for ventilator-associated tracheobronchitis is not routinely recommended
- Tx: Vancomycin OR Linezolid plus one beta lactam that covers pseudomonas and pneumococci plus another non-beta lactam antipseudomonal agent, duration 7 days. Also give fluids, mucolytics, antitussives, antipyretics.
Pneumonia patients with structural lung disease or who otherwise have high risk for mortality should receive. . .
. . . double antipseudomonal coverage
Lung abscess
- Risk factors: Preexisting pneumonia (esp. aspiration), altered level of consciousness, immunocompromise, bronchial obstruction
- Pathology: Often polymicrobial oral and gastric anaerobes (Peptosreptococcus, Prevotella, Bacteroides, Fusobacterium). Less commonly monomicrobial S. aureus, K. pneumoniae, GAS, S. anginosus.
- Features: PNA features, indolent progression, hemoptysis, foul-smelling sputum, B symptoms
- Dx: CXR or CT showing irregular cavity w/ air fluid level that is dependent (changes with different body pos)
- Tx: Attempt Abx first w/ anerobe coverage (clindamycin, amp-sulbactam, carbapenems). If this fails, percutaneous drainage or surgical excision (segmentectomy, lobectomy)
Advantages of enteral over parenteral feeding
- Prevents mucosal atrophy by stimulating gut motility
- Lower risk of bloodstream infection
- Less frequent metabolic complications
Basic rule of thumb for nutrition
Oral before enteral
Enteral before parenteral
Metabolic complications of enteral and parenteral feeding
- Refeeding syndrome
- Hyperglycemia
- Hyperlipidemia
- Acalculous cholecystitis
- Gallstone disease
- NAFLD
- Renal damage
- Bone demineralization
Refeeding syndrome
Condition caused by rapid reinitiation of normal nutrition in a chronically malnourished patient (e.g., patients with anorexia nervosa). Caused by a sudden shift from a catabolic to an anabolic state and massive release of insulin, which causes severe electrolyte imbalances (e.g., hypophosphatemia, hypokalemia, hypomagnesemia) and fluid retention.
Clinical features include edema, cardiac arrhythmias, seizures, and ataxia. Management involves close monitoring of electrolyte levels with repletion and slow reintroduction of normal nutrition.
In someone with normal coagulation labs and platelets, __ is the most common cause of post-surgical wound site bleeding within 24 hours.
In someone with normal coagulation labs and platelets, insufficient mechanical hemostasis is the most common cause of post-surgical wound site bleeding within 24 hours.