Pre and Postoperative Care Flashcards
One oliguria occurs post operatively how can you differentiate between low output caused by the physiological response to intravascular hypovolemia and that caused by acute tubular necrosis?
Fractional excretion of sodium
A FENa less than 1% supports prerenal – Indicates aggressive sodium reclamation in the tubules.
Urine sodium would be below 20 mEq per liter
Urine osmolality would be over 500 mOsm per kilogram
What is the definitive management of hyponatremia?
Free – water restriction
Infusion of hypertonic saline may be required with symptomatic hyponatremia – Sodium levels less than or equal to 120 mEq per liter, can result in headache, seizures, coma, and signs of increased intracranial pressure
What electrolyte abnormalities could cause the following symptoms: paresthesia, hyperreflexia, muscle spasm, tetany. How would you differentiate the two?
Hypocalcemia and hypomagnesemia
Electrocardiogram
What would an electrocardiogram show with low calcium levels?
Prolonged QT interval, T-wave inversion, heart blocks
What would an electrocardiogram show with low magnesium levels?
Prolonged QT and PR intervals, ST segment depression, flattening or inversion of P waves, torsade
When should antibiotics be given in order to reduce the risk of postoperative infectious complications?
A single preoperative parental dose of antibiotic effective against aerobes and anaerobes to prevent surgical site infections, No greater than one hour prior to the incision.
A patient with a history of myocardial infarction two years ago, peripheral vascular disease should undergo which test for his preoperative workup?
Persantine thallium stress test and echocardiography to assess for his need for coronary angiogram with possible need for angioplasty, stenting, or surgical revascularization prior to surgery.
What are the manifestations of heparin induced thrombocytopenia?
Complications are related to venous and or arterial thromboembolic phenomena. Typically manifests after five days as a decrease in platelet counts by 50% of the highest proceeding value or to a level less than 100,000 per cubic millimeters
What is the management for heparin-induced thrombocytopenia?
Cessation of heparin including low molecular weight heparin’s, institution of a non-heparin anticoagulant such as a direct thrombin inhibitor –lepirudin, argatroban and conversion to warfarin when platelet count is about 100,000/mm3
When do most perioperative infarcts occur?
When the third – space fluids return to the circulation, increasing the preload and thus myocardial oxygen consumption. Generally occurs around the third postoperative day
Severe sepsis
Sepsis + organ dysfunction or hypoperfusion (lactic acidosis, oliguria or altered mental status)
Septic shock
Sepsis + organ dysfunction + hypotension – (systolic blood pressure less than 90 mmHg or on vasopressors)
Treatment for class IV hemorrhagic shock?
Infusion of packed red blood cells and early administration of fresh frozen plasma and platelets prior to return of laboratory values
1:1 ratio ofPRBC:FFP should be initiated upon recognition of the need for massive transfusion.
Define massive blood transfusion
A single transfusion greater than 10 units of packed red blood cells transfused over a period of 24 hours
What is the best method for delivering post operative nutrition?
Enteral feeding within 24 hours postoperatively – The small ball functions manually within hours of surgery and is able to accept nutrients promptly Nasoduodenal or percutaneous jejunal feeding catheters. Stomach emptying occurs after 24 hours.
What is a concern in starting total parenteral nutrition in a malnourished patient?
Refeeding syndrome – when given IV glucose, insulin levels rise and electrolytes are shifted back intracellularly – Hypokalemia, hypomagnesemia, hypophosphatemia, Hyperglycemia, hyperchloremic acidosis, volume overload with resultant heart failure.
When does a cirrhotic patient with abnormal coagulation studies require a transfusion of fresh frozen plasma to minimize risk of bleeding due to surgery?
On call to the operating room. The timing of transfusion is dependent on the quantity of each factor delivered and it’s half life. The half-life of the most stable clotting factor, factor seven is 4 to 6 hours
What is the most common nosocomial infection postoperatively?
Urinary tract infection
Name the factors that predispose to fistula formation.
Friends
Foreign body Radiation Inflammation Epithelialization of the tract Neoplasm Distal obstruction Steroids
Definition of a high output fistula
More than 500 mL per day output, usually proximal and unlikely to close
Fever, chills, pain and redness along the infused vein, losing from IV sites, respiratory distress, anxiety, hypertension, oliguria
Hemolytic transfusion reaction– Peptides from the compliment, released into the blood as the red cells are destroyed rapidly, cause hypotension, activate coagulation, and lead to disseminated intravascular coagulation
In the setting of severe hemophilia A, what is the best option for preventing or treating a bleeding complication?
Desmopressin (DDAVP) + e–Aminocaproic acid
Desmopressin is a synthetic analogue of antidiuretic hormone that increases levels of factor 8 and von Willebrand factor
A patient is about to undergo a coronary bypass. He is also taking NSAIDS. When should he stop taking this medication to minimize his risks of bleeding?
Stop 3 to 4 days before surgery. NSAIDs cause A reversible defect that lasts three or four days and platelets will be functional for surgery
Next step in management for a suspected ureteral injury
Intravenous pyelogram
What is hydronephrosis?
Water inside the kidney
Treatment for severe, symptomatic hypocalcemia?
Intravenous calcium infusion.
Calcium supplementation, up to 1–2 g every four hours is sufficient in patients with mild symptoms
