preop Flashcards
informed consent
transfer of info between physician and pt that allows the pt to make a knowledgeable decision about a particular tx
informed consent
transfer of info between physician and pt that allows the pt to make a knowledgeable decision about a particular tx
consent form
legal documentation of these discussions between the physician and the pt
surrogate decision maker
person empowered to make decisions for a patient who is not competent to do so
advance directive
a mentally capable pt/s instructions regarding his or her medical care if he or she becomes incapacitated and unable to make decisions
beta blockers
Abrupt discontinuation can increase risk of Ml;
With a sip of water a few hours before operation;
Parenteral agent until taking p.o.
atrial antiarrhythmics
With a sip of water a few hours before operation;
IV ß-blockers, diltiazem or digoxin until p.o. intake resumed
ventricular antiar
Monitor Mg, K, and Ca levels preoperatively;
With a sip of water a few hours before operation;
Parenteral amiodarone or procainamide
nitrates
Transdermal (paste, patch) may be poorly absorbed intraoperatively;
With a sip of water a few hours before operation;
Intravenous (most reliable) or transdermal until p.o. intake resumed
antihtn
Abrupt discontinuation of clonidine can cause rebound hypertension;
With a sip of water a few hours before operation;
Parenteral antihypertensives; if on clonidine, consider clonidine patch or alternative antihypertensive agents
insulin
5% dextrose solutions should be given intravenously intra- and postoperatively in patients receiving insulin;
Yi dose usual long-acting agent at the usual time preoperatively;
SSI until p.o. intake back to baseline
oral agents for DM
hold am of operation;
ssi until po intake back to baseline
metformin
Can produce lactic acidosis, particularly in the setting of renal dysfunction or with administration of IV radiographic contrast agents;
Hold for at least 1 day preoperatively;
Monitor renal function closely. Resume metformin when renal function normalizes, usually 2–3 days postoperatively. SSI until then.
aspirin, clopidogrel, ticlopidine
dc 7 days preop;
resume when diet resumed
warfarin
Hold until INR normalizes, usually 3–5 days. If anticoagulation critical, maintain anticoagulation with heparin;
Resume when diet resumed
heparin
Discontinue 4 hr preoperatively;
Resume 6–12 hr postoperatively, provided no increased risk of hemorrhage thought to exist
levothyroxine
held few days preop;
parenterally until diet resumed
estrogen
stop 4 wk prior to cases w high risk dvt
ample
allergies, medications, past medical hx, last meal, events preceding the emergency
baseline ekg
men >40 and women >50; symp cariovasc ds, htn, or dm
Dripps-American Surgical Association Classification: to quantify surgical risk
- healthy
- mild-mod systemic ds
- severe
- life threatening
- no expected to survive
cardiac risk index
high risk surgery, hx ischemic heart ds, hx chf, hx cerebrovasc ds, preop tx w insulin, preop serum cr >2
total up the number:
- 0risk
- 1 risk
- 2 risks
- more than 2 risks
METs class 1
Activity requiring >6 METs
Carrying 24 lb up eight steps
Carrying objects that weigh 80 lb
Performing outdoor work (shoveling snow, spading soil)
Participating in recreation (skiing, basketball, squash, handball, jogging/walking at 5 mph)
METs class 2
Activities requiring >4 but not >6 METs
Having sexual intercourse without stopping
Walking at 4 mph on level ground
Performing outdoor work (gardening, raking, weeding)
Participating in recreation (roller-skating, dancing fox trot)
METs class 3
Activity requiring >1 but not >4 METs
Showering, dressing without stopping, stripping, and making bed
Walking at 2.5 mph on level ground
Performing outdoor work (cleaning windows)
Participating in recreation (golfing, bowling)
METs class 4
no activity requiring >1met; can’t carry out any activities
1 met represents an oxygen consumption of
3.5ml/kg/min
(avg for resting 70kg man)
hr of 100bpm=4mets
when should smokers stop smoking before a procedure
6w
procedure related risk factors for postop pulm compl
surgical site (thoracic, upper abd), duration (3-4hr), anesthesia technique (general, spinal, and epidural)
periop mc cause of AKI is secondary to
acute tubular necrosis
goal in periop manage of pts w CKD or AKI
maintenance of euvolemia and renal perfusion
serum potassium levels should be blank before surgery
someone on ACE and angiotensin 2 for CKD should stop them when
10hrs before general anesthesia to reduce risk of post induction hypotension
what are essential records for postop CKD pts
daily weights and I&Os
when should pt be dialyzed before surgery
within 24hr of surgery
periop management of pts w diabetes
- Insulin is available in several types and is typically classified by its length of action. Rapid-acting and short-acting insulin preparations are usually withheld when the patient stops oral intake usually at midnight the day before surgery. Intermediate-acting and long-acting insulin preparations are administered two-thirds the normal evening dose the night before surgery and half the normal morning dose the morning of surgery. Long-acting oral agents are stopped 48 to 72 hours before surgery, while short-acting agents can be withheld the night before or the day of surgery.
- The ideal method of providing insulin in the perioperative period is debatable. Any regimen should however (1) maintain adequate glycemic control to avoid hyperglycemia or hypoglycemia; (2) prevent metabolic disturbances; (3) be easy to understand and administer. The patient should receive a continuous infusion of 5% dextrose to provide 10 g glucose/hour. Fingerstick glucose levels are monitored intraoperatively and followed postoperatively at least every 6 hours. The goal is to maintain a glucose level of between 120 and 180 mg/dL. It is generally considered preferable to have the patient at the higher end of this range because of the adverse consequences of hypoglycemia. Sliding scale use of subcutaneous insulin has been the standard method of glucose control in surgical patients. Alternatively, intravenous insulin can be used with a continuous infusion of 1 to 3 units/hour of intravenous insulin being given. This approach is particularly helpful in the brittle diabetic. In the postoperative period, close attention should be paid not only to the patient’s blood sugar, but also to the patient’s carbohydrate intake.
- Diabetic ketoacidosis (DKA) can develop in patients with either type I or type II diabetes. DKA is deceptively easy to overlook because it can mimic postoperative ileus. It may present as nausea, vomiting, and abdominal distension, or in association with polyuria (which is commonly mistaken for mobilization of intraoperative fluids). For this reason, patients with type I diabetes (and many with type II diabetes) should have their urinary ketone level monitored by dipstick. This method is faster and much less costly than following serum ketone levels, and it gives a fairly accurate picture of developing ketoacidosis. A glucose level that is
consent form
legal documentation of these discussions between the physician and the pt
surrogate decision maker
person empowered to make decisions for a patient who is not competent to do so
advance directive
a mentally capable pt/s instructions regarding his or her medical care if he or she becomes incapacitated and unable to make decisions
beta blockers
Abrupt discontinuation can increase risk of Ml;
With a sip of water a few hours before operation;
Parenteral agent until taking p.o.
atrial antiarrhythmics
With a sip of water a few hours before operation;
IV ß-blockers, diltiazem or digoxin until p.o. intake resumed
ventricular antiar
Monitor Mg, K, and Ca levels preoperatively;
With a sip of water a few hours before operation;
Parenteral amiodarone or procainamide
nitrates
Transdermal (paste, patch) may be poorly absorbed intraoperatively;
With a sip of water a few hours before operation;
Intravenous (most reliable) or transdermal until p.o. intake resumed
antihtn
Abrupt discontinuation of clonidine can cause rebound hypertension;
With a sip of water a few hours before operation;
Parenteral antihypertensives; if on clonidine, consider clonidine patch or alternative antihypertensive agents
A 28-year-old man is undergoing an operation for right inguinal hernia. The anesthesiologist notices that his end-tidal CO2 value rises abruptly, and the patient’s jaw is stiff. The patient’s temperature is 41 °C, his heart rate is 130 beats/minute, and his blood pressure (BP) is 130/75 mm Hg. Which of the following abnormalities would be expected if a sample of his blood were tested at this point in the operation?
A. Hyperkalemia
B. Hypocalcemia
C. Alkalosis
D. Anemia
E. Hypoalbuminemia (Lawrence 31-32)
Lawrence. Essentials of General Surgery, 5th Edition. Lippincott Williams & Wilkins, 09/2012. VitalBook file.
Answer: A
This is a classic description of malignant hyperthermia. The typical electrolyte picture is that of rhabdomyolysis, with hyperkalemia, hypercalcemia, and acidosis. Malignant hyperthermia is not known to affect red cell mass or albumin levels. The patient should be given 100% oxygen, the operation should be stopped and the wound closed, and dantrolene should be administered. (Lawrence 32)
Lawrence. Essentials of General Surgery, 5th Edition. Lippincott Williams & Wilkins, 09/2012. VitalBook file.
oral agents for DM
hold am of operation;
ssi until po intake back to baseline
metformin
Can produce lactic acidosis, particularly in the setting of renal dysfunction or with administration of IV radiographic contrast agents;
Hold for at least 1 day preoperatively;
Monitor renal function closely. Resume metformin when renal function normalizes, usually 2–3 days postoperatively. SSI until then.
aspirin, clopidogrel, ticlopidine
dc 7 days preop;
resume when diet resumed
warfarin
Hold until INR normalizes, usually 3–5 days. If anticoagulation critical, maintain anticoagulation with heparin;
Resume when diet resumed
heparin
Discontinue 4 hr preoperatively;
Resume 6–12 hr postoperatively, provided no increased risk of hemorrhage thought to exist
levothyroxine
held few days preop;
parenterally until diet resumed
estrogen
stop 4 wk prior to cases w high risk dvt