Surgery Pretest Flashcards
Complication of jejunoileal bypass surgery that may cause nephrolithiasis?
Hyperoxaluria
GI conditions that cause hypomagnesemia?
malnourishment, large GI fluid loses (Crohns, UC, diarrhea)
EKG differences between hypocalcemia and hypomagnesemia?
Hypocalcemia: Long QT, T-wave inversion, heart blocks
Hypomagnesemia: Long QT and PR, ST depression, flattening or inversion of P waves, tornado de pointe
Neuromuscular effects of hypomagnesemia?
Resembles hypocalcemia: paresthesias, hyperreflexia, muscle spasm, ultimately tetany.
Antibiotic therapy for elective colon resections: # of doses, route, spectrum, need for additional doses?
: only one dose, less than one hour before surgery
Route: IV and non-absorbable oral (colon only)
Spectrum: Aerobes and anaerobes (again, colon spec)
Additional: Based on drug half-life if case is long and complex. No Abx for more than 24 hours.
In a patient with hx of MI more than 6 months ago, what is the appropriate testing for elective surgical clearance?
Cardio stress test followed by echocardiogram.
Exercise stress test is appropriate if patient is able, otherwise persantine thallium pharmacologic test is done.
Sign of uncompensated metabolic alkalosis?
normal PCO2. Respiratory compensation raises PCO2, and metabolic processes affect HCO3, not PCO2.
Patient with NG tube, hypochloremic, hypokalemic metabolic alkalosis. Tx? Pathophys?
Tx: Normal saline infusion, +/- KCl infusion.
Pathphys: Volume depletion leads to Na and water retention, reducing kidney’s output and ability to excrete HCO3. Volume replenishment reverses this.
Indications for placement of vena cava filter
1 - contraindication to heparin
2 - Failure of anticoagulation therapy (i.e. PE with adequate anticoagulation, etc.)
3 - known, free floating venous clot,
4 - previous history of PE
In other words, try anticoagulation first and place filter later if needed
Effect of transfusion reaction? Sx of intraoperative and postoperative transfusion reaction?
Diffuse loss of clot integrity. Hot compliment mediated hemolysis causes hypotension, activates coagulation and DIC. fever, chills, pain, redness on infused vein, respiratory distress, anxiety, oliguria
Intra: Sudden appearance of diffuse bleeding
Post-op: unexplained fever, apprehension, headache
HIT: Complications, immediate treatment, long term tx?
Complications: venous and/or arterial thromboembolic events.
Immed Tx: DC all heparins, use non-heparin anticoag like lepirudin or agatroban (direct thrombin inhibitors)
Long term tx: transition to warfarin only after plt > 100,000
Stages of SIRS and sepsis and their definitions?
SIRS: T 38+/36- HR 90+ R 20+/PCO2 32- WBC 12+ 4-
Sepsis: SIRS + documented infection
Severe Sepsis: Sepsis + organ dysfunction OR hypo perfusion (lactic acidosis, oliguria, AMS)
Septic shock: Sepsis + organ dysfunction AND hypo perfusion (SBP 90- or 90+ with pressors)
Timing of feeding post intestinal surgery?
Early enteral nutrition is recommended. Stomach is uncoordinated for ~24 hrs after surgery, but small intestine accepts nutrients promptly (less than 24hrs) via nasoduodenal or jejunal catheter.
Def high output fistula?
500+ mL/day
Factors that predispose to fistulae formation or prevent closure?
FRIENDS:
Foreign body, Radiation, Inflammation, Epithelialization of the tract, Neoplasm, Distal obstruction, Steroids
Signs of adrenal insufficiency?
AMS, fever, CV collapse, hypoglycemia, hyperkalemia.
Like sepsis, but with glycemic and K+ changes
Pre-op care for patients with hemophilia A?
A is for Eight! VIII deficiency
Mild hemophilia: DDAVP
Severe hemo: DDAVP and E-aminocaproic acid (anti fibrinolytic)
Replacement fluids for fluid loss in various parts of the GI tract?
Duodenum, jejunum, ileum and bile = Ringer Lactate
Saliva, gastric juice, right colon = High K+, low Na+
Pancreatic secretions = High bicarb
Kayexalate MOA?
Cation exchange resin that exchanges sodium for K+ in the gut.
symptoms of zinc deficiency?
Alopecia, poor wound healing, night blindness or photophobia, anosmia, neuritis, skin rashes. Often develops with diarrhea.
Symptoms of selenium deficiency?
Development of cardiomyopathy
Symptoms of molybdenum deficiency?
Encephalopathy due to accumulation of sulfur containing amino acids
Symptoms of chromium deficiency?
Difficult to control hyperglycemia, peripheral neuropathy, encephalopathy
Thiamine deficiency?
Beri-beri - encephalopathy and peripheral neuropathy. Cardiac symptoms and heart failure may occur as well.
Uses of LR vs NS vs 1/2NS vs Colloids for acute volume resuscitation in trauma?
LR: Isotonic fluid used in 3:1 ratio for replacing blood loss, OK to use high volumes if needed
NS: Isotonic fluid used 3:1 ratio for replacing blood loss, but large volumes may cause non-anion gap acidosis due to inc [Cl-]
1/2NS: Hypotonic fluid should not be used in acute resuscitation, but good for maintenance fluids
Colloids: Controversial in acute fluid resuscitation, but OK to administer in a 1:1 ratio
Definitive treatment for hypovolemic shock?
Volume replenishment i.e. fluid resuscitation
Vasopressors are not definitive treatment
Treatment for rhabdomyolysis?
Urine alkalinization
Loop diuretics
Manitol
Appropriate fluids for pt with NG tube?
Regular maintenance fluids - D5 1/2NS (4mL, 2mL, 1mL/hr)
+/- potassium chloride (dep on renal function)
+ LR or NS equivalent to NG output to replace GI losses
What is the definitive treatment for hyperkalemia?
Removal of K+ ions for the body. Kayexalate accomplishes this, but slowly. A patient may also receive dialysis if it is urgent, esp in the setting of renal failure.
The following are all temporary measures:
Calcium gluconate rapidly resolves cardiac complications. Na-bicarb alkalinizes the blood (think H+/K+ “pumps”). Glucose + insulin also shift K+ into cells.
Dx and Tx of hemolytic transfusion reaction?
Dx: Oliguria + hemoglobinuria: Increased hemoglobin in plasma is cleared by kidneys, causing hemoglobinuria, measured in urine (oliguria also occurs 2/2 hypotension).
Tx: Fluids and mannitol: Aggressive fluid resuscitation and osmotic diuresis.
Treatment of pseudomembranous colitis: first line, second line, indications for surgery?
1st: oral metronidazole
2nd: oral vancomycin
Surgical indications: intractable disease, failure of medical therapy, toxic megacolon, colonic perforation.
Dx: Toxin A or B in stool or characteristic appearance on endoscopy
How are daily caloric requirements affected in starvation? Routine surgery? Burns over 50% of body? Multiple organ failure?
BMR requirements are affected by different physiologic states, reflected in the “stress factor”. Caloric needs are determined by the patients BMR x stress factor.
Starvation: 0.9 or 90% of normal BMR/calories
Routine surgery: 1.1
Burns over 50%: 2.0 (twice the normal daily calorie req’d)
MOF: 1.5
What is the mechanism by which PEEP increases oxygenation?
PEEP increases functional residual capacity by keeping the alveoli open at the end of expiration
Consequences of cardiac tamponade: Pulsus paradoxes, Echocardiogram, swan-ganz reading?
Pulsus: Decrease of more than 10mmHg at end of inspiratory phase
Echo: pericardial fluid and right atrial collapse
Swan-Ganz: equalization of pressures across four chambers
Right atrial and CVP are increased, CO is decreased
Major predictors of cardiac events during surgery?
Unstable angina, recent myocardial infarction, decompensated congestive heart failure, significant arrhythmias, severe valvular disease
Where should epinephrine-containing lidocaine solutions not be used?
In tissues supplied by end arteries, such as fingers, toes, ears, nose, or penis.
Treatment of malignant hyperthermia? Tx for urine? Agents to avoid? Tx for future surgery?
Immediate cessation of anesthetics
Hyperventilation with 100% O2 (MH increases O2 demand and CO2 production)
Administration of dantrolene sodium
Urine: alkalization to prevent myoglobin precipitation
Avoid: succinylcholine
Future: pretreat with dantrolene for 24 hours
Treatment for known aspiration?
Bronchoscopy
Diagnosis for ventilator associated pneumonia?
Bronchoalveolar lavage: Greater than or equal to 10,000 colony-forming units/mL of a single organism is diagnostic
Preferred vasopressors for septic shock?
Norepinephrine and dopamine
Epinephrine only vasoconstricts peripherally, and also increases cardiac contractility, not first line in septic shock
Side effect of succinylcholine? Morphine?
Succ: Increased serum potassium
Morphine: Hypotension
