Peri-Operative Risk Assessment Flashcards
Airway exam
Meds to hold during surgery
- Insulin (risk of hypoglycemia)
- Oral hypoglycemics (risk of hypoglycemia, risk of lactic acidosis for metformin)
- Aspirin and other antiplatelets
- ACE inhibitors (risk of refractory hypotension)
- Herbals (hold 7-10 days prior, many interact with clotting to some degree)
Why is airway management often more difficult in pregnant patients?
- Edematous airway
- Increased risk of aspiration
- Risk of preterm labor or miscarriage
ASA status
When you do a spinal block, you have about ___ to finish the case before it wears off.
When you do a spinal block, you have about 2-3 hours to finish the case before it wears off.
Neuraxial anesthesia
- Spinal, epidural
- Lower abdomen, pelvis, lower extremities
- Childbirth
- +/- sedation
Regional anesthesia
- xxxxx
- Previous neuropathy can be worsened
Monitored anesthetic care
- Patient breathes on their own
- Medication through IV for sedation and analgesia
- Good for superficial, simple procedures
Perioperative cardiac risk for patients following coronary revascularization
Risks of perioperative cardiac deaths and/or myocardial infarctions are extremely low in patients who have undergone surgical coronary revascularization within 5 years or have undergone coronary angioplasty or stent placement from 6 months to 5 years prior, providing that the patients’ clinical conditions have normalized following the revascularization procedures.
If asymptomatic, these patients do not need further cardiac workup.
The perioperative risk for surgical patients within 5 years of surgical revascularization is extremely low, as it is for patients from 6 months to 5 years following stent placement or coronary angioplasty.
Why is the risk still high in those first 6 months?
Because there is a risk of post-surgical coronary thrombosis during this timeperiod, especially for stents.
When undergoing primary coronary stenting, patients must be on minimum 1 month of DAPT, or 3 months if the stents are drug eluting and 6 months for paclitaxel stents.
As a rule, 1 year of DAPT therapy should be considered for all of these patients.
Revised Cardiac Risk Index
- Score for perioperative cardiac risk that takes into account six factors:
- Hx ischemic heard disease
- Hx CHF
- Hx TIA or stroke
- Hx DM requiring insulin
- Serum creatinine > 2
- Major surgery (thoracic, intra-abdominal, supra-inguinal vascular surgery)
Perioperative beta blockade for patients with significant cardiovascular risk factors
In the past, this was thought to be a good idea. However, recent data has shown that this is NOT beneficial, and may in fact be harmful.
If a patient is already on a beta blocker, they should continue it at the current dose in the perioperative period, but do NOT give perioperative beta blockade based on CV risk factors alone.
Perioperative statins for patients undergoing cardiac surgery
Unlike beta blockers which carry an increased risk of stroke and other morbidity and mortality in this setting, statins have been shown to be cardioprotective in patients undergoing cardiac surgery.
ASA status classification system for patients undergoing surgery
- Healthy person
- Mild systemic disease
- Severe systemic disease
- Severe systemic disease that is a constant threat to life
- Will die in the next 24 hours if surgery is not preformed
- Deceased or declared brain-dead (as in deceased organ donors)
Low and high metabolic demand activities
Low: Getting dressed, cooking
High: Climbing two flights of stairs, walking at 6 mph
A good question to ask is: “On a good day, does climbing 2 flights of stairs make you winded or produce any chest pain?”
Echocardiography in risk assessment for surgery
LVEF < 35% is associated with more perioperative cardiac complications
It’s always 35% for LVEF.
It is believed that a large percentage of perioperative cardiac events are related to ___.
It is believed that a large percentage of perioperative cardiac events are related to diastolic dysfunction.
Especially when the operation involves significant fluctuations in intravascular volume and pressure, such as in aortic surgery with cross-clamping.
Utility of cardiac stress tests for CAD assessment and perioperative cardiac risk assessment
PPV is quite poor, but the NPV is excellent
If someone has a normal cardiac stress test, they are definitely a fine surgical candidate from a cardiac perspective.
What to do if potential surgical candidate has signs of unstable coronary disease or a major clinical predictor of risk
Defer any elective procedures until these issues are addressed by a cardiologist
Clinical predictors of cardiac risk during surgery
Strongest predictors of perioperative mortality in surgical patients over the age of 60
- ASA class
- Age
- Modified frailty index score
- Wound class
A 55-year-old man with unstable angina presents with acute abdominal pain, and he is found to have diffuse peritonitis, tachycardia, and chest pain. His ECG is consistent with a NSTEMI. Serum troponin levels are elevated. An upright CXR reveals pneumoperitoneum. Based on your history and physical findings, a perforated peptic ulcer is suspected. What is the most appropriate treatment for this patient?
Review his history, perform physical examination, order routine laboratory studies, initiate pharmacological interventions for his cardiac condition, and proceed with surgery for his perforated ulcer disease
It is conceivable that his NSTEMI is the result of increased stress related to his perforated ulcer and continued nonoperative treatment of his ulcer disease will likely lead to worsening cardiac condition; therefore, the initiation of pharmacologic treatment for his NSTEMI and surgery are the best treatments
It is best to wait __ following MI for surgery, as a general rule
It is best to wait 6 months following MI for surgery, as a general rule
(unless the surgery is to fix the MI!)
Preoperative cardiac evaluation tests
Everyone gets an ECG
If you have a history of CAD or CHF, you get an echo and a stress test vs catheterization
What is the biggest pulmonary risk during surgery, from an anesthesia perspective?
Carbon dioxide clearance / ventilation
Remember, the anesthesiologist can always just give extra oxygen if a patient has low sats. But they can’t necessarily clear that CO2 if the patient has crappy lungs
Preoperative pulmonary evaluation prior to surgery
Nothing is required for a healthy individual without risk factors.
However, if lung disease is suspected, PFTs are indicated. Also, on the day-of, an ABG can provide useful information.
Smoking and surgery
-
Smoking is bad. Patients who are active smokers have greater morbidity and mortality associated with surgery and anesthesia. They should be instructed to (at least temporarily) cease smoking prior to surgery.
- HOWEVER, immediately following cessation, mucosal secretions increase.
- So, they need to stop at least 8 weeks before. They will need a nicotine patch or similar therapy in the meantime to help with cravings.
Liver function scores for surgical evaluation
- MELD-Na is for general status and liver transplant list
-
Childs-Pugh is the one most surgeons use for functional status/risk stratification
- Childs-Pugh A means they are good to go
- Childs-Pugh C means they are on the door of death
Childs-Pugh score
Risk of perioperative death increases dramatically as you go up on this scale. Even with just one of these your risk of perioperative death is 40%.
Patients at risk of poor post-surgical healing
- Those who lost 20% of body weight in last 3 months (think cachectic cancer patients or patients with GI obstruction)
- Those w/ albumin < 3 g/dL
- Those who fail a skin anergy test (TB antigen, do you have sufficient antibodies to mount a response?)
If hypoalbuminemic, malnutrition can be further investigated with prealbumin and CRP. If these are low, you should strongly suspect malnutrition. If they are normal, you should suspect liver pathology.
Note: Prealbumin is not a precursor to albumin. It is what comes before albumin on gel electrophoresis.
Treatment: Oral refeeding. 10 days is optimal.
Absolute contraindications to same-day elective surgery
- DKA
- Very high blood sugar
Hypoalbuminemia is an indication for pre-operative. . .
. . . CXR
Age-based preoperative testing indications
Everybody over 40 gets a BMP
Everybody over 60 gets a CXR
Perioperative management of antihypertensives
Most can be continued except as below, which must be discontinued 1 day prior to surgery:
- ACEi’s
- ARBs
- Diuretics
Antiepileptics in the perioperative period
All can and should be continued intraoperatively, unless there is some other medical contraindication
Oral contraceptives in the perioperative period
Most can continue oral contraceptives in the perioperative period while receiving antithrombotic medications, except for those with a high risk of VTE. These individuals must discontinue 1 month prior to surgery.
Psychiatric drugs in the perioperative period
- Most common drugs (like SSRIs) are on a case by case basis. Pertinent other psychiatric drugs include:
- Lithium: Discontinue 3 days prior to surgery
- Tricyclics: Discontinue intraoperatively
- Nonselective irreversible MAOis (basically just tranylcypromine): Discontinue 2 weeks prior to surgery
- Benzos: Fine in most patients, but must be discontinued in patients with cardiac risk factors by tapering several days before surgery.
Levothyroxine in the perioperative period
Discontinue during surgery and resume postoperatively
NSAIDs in the perioperative period
Short-acting: Discontinue 2-3 days prior to surgery
Long-acting: Discontinue 1 week prior to surgery
Antianginal medications in the perioperative period
Should absolutely be continued
Statins, which often go together, should also be continued.
Antibiotic ppx or surgery
- When indicated, cefazolin is always first-line
- If allergic, clindamycin or vancomycin
- Add metronidazole if it is a GI/abdominal operation
Post-surgical pressure ulcers
Caused by prolonged compression of a certain area during surgery or in the post-surgical period.
Post-surgical stress ulcers
- These are specifically peptic ulcers that occur in very sick patients seemingly spontaneously
- Most likely if there is mechanical ventilation (especially without enteral nutrition) or if there is hepatic dysfunction, renal dysfunction, sepsis, or shock
- PPIs or H2 blockers are given as ppx for at-risk patients
Etiologies of secondary hemorrhage (post-operative hemorrhage) by timeframe
Indications for specific pre-operative cardiac tests based on RCRI
-
ECG: >1 RCRI risk factor and one of:
- Arrhythmias
- COPD
- Age >65
- PVD
- Echo: Exacerbation or new onset cardiac Sx, patients with VHD who have not had an echo in the past year
-
Stress test OR radionuclide myocardial perfusion imaging (if unable to perform strenuous exercise):
- RCRI 0-1 with low risk procedure, not necessary
- RCRI >1 with good functional capacity, not necessary
- RCRI >1 with poor or unknown functional capacity, indicated
Appropriate adult urine output
0.5 mL/kg/hr
Flow volume loops
Operating on patients with liver problems
- In all but the most emergent surgeries, cirrhotic patients should have such complications corrected before proceeding to surgery in order to minimize the risk of surgical morbidity.
- If they have ascites, paracentesis
