Preoperative Evaluation and Perioperative Care Flashcards
Increased risk factors for pulmonary morbidity include…
alcohol abuse, cigarette smoking, poor preoperative nutrition, underlying pulmonary disease, age, abdominal/thoracic incisions
What is The American College of Cardiology/American Heart Association (ACC/AHA) algorithm for perioperative cardiovascular evaluation of noncardiac surgery?
Is pre-op CXR necessary for noncardiothoracic elective surgery?
Preoperative chest radiography is of limited benefit in patients who do not have baseline dyspnea or underlying pulmonary disease.
In a 75-year-old patient with congestive heart failure who is to undergo an elective ventral hernia repair, perform an adequate history and physical examination and independently stratify perioperative cardiac risk.
- functional capacity: ask if they can climb stairs
- assess for valvular dysfunction: listen for murmurs
- assess current CHF: pts w/ CHF dx need echo or cards eval
In an 80-year-old man with chronic obstructive pulmonary disease who is undergoing an emergency inguinal hernia repair, be able to independently discuss factors to decrease perioperative pulmonary morbidity.
- improve nutrition
- IS and chest PT decrease morbidity
- selective NGT decompression can be considered
- laparoscopic approaches decrease pulm complications
What tool can be used to help guide surgeons when counseling patients and families on risks of postoperative morbidity, length of hospital stay, and risk of discharge to a skilled nursing facility?
The NSQIP risk calculator takes into account the patient’s functional status, the planned operation, and other comorbidities. It can help guide surgeons when counseling families on some general postoperative risks.
How do long-term exogenous steroids affect the adrenal glands?
Suppresses the natural corticotropin–adrenocorticotropic hormone–corticosteroid loop axis and causes adrenal atrophy. The adrenal atrophy causes a blunted response when a new stress (surgery) is present.
What is the half-life of warfarin?
40 hours
What is the half-life of apixaban?
this direct Xa inhibitor has a half-life of around 8-12 hours
What is the half-life of aspirin?
This COX inhibitor has a half-life of 2.5-4 hrs
What is the half-life of clopidogrel?
This ADP inhibitor has a half-life of about 6 hours.
In the preoperative workup of a patient for elective inguinal hernia (minor procedure), you find he has been on 2 mg/d of prednisone for 1 week. What do you do?
Stress-dose steroids are not indicated for patients on short-term steroids (< 3 weeks) or for those on low-dose (< 5 mg/d) steroids and undergoing procedures with minimal stress.
What patient populations may be on anticoagulants?
a-fib, MI, cardiac stents, vascular stents, DVT, PE, stroke, TIA, PVD
In equivocal cases, what lab test can be obtained to determine HPA axis impairment?
early-morning random cortisol <5 mcg/dL
What induction agent is contraindicated in patients with HPA axis impairment?
etomidate can further suppress HPA axis and reduce serum cortisol level
When should anticoagulants be stopped before surgery?
Stop warfarin for 5 days pre-op
Stop PO antithrombin and anti-Xas 2 days pre-op
A patient with a bare metal coronary stent can go to operating room after , and a patient with a drug-eluting stent can be operated on after .
4 weeks
6 months
How long does a pt w/ a new postop DVT need to be on anticoagulation?
12 weeks (6 months if no inciting event)
Prevent or mitigate postop pain.
- Opioids are the most widely used treatment of postoperative pain.
- Patient-controlled analgesia (PCA) benefits include decreased delay in patient access to pain medication, decreased likelihood of overdose by programming small bolus doses with a fixed lockout interval, enhanced monitoring, and ability to titrate.
- Administration of NSAIDs can reduce the dose of opioid required and decrease the occurrence of opioid-related side effects. Use caution in colorectal pts as they can increase leak. Use caution in coagulopathic, kidney failure, and ulcer pts as NSAIDs can exacerbate these issues.
Use physiologic parameters to assess the hemodynamic stability of a postoperative patient to guide ongoing resuscitation efforts.
- Heart rate (HR): Maintain between 60-100 bpm.
- Oxygen saturation: Maintain > 92 percent.
- Urine output: Maintain > 0.5 mL/kg/hr.
- Lactate and base deficit: Monitor serum lactate every 4 hours to ensure end-organ perfusion is adequate or improving with resuscitation.
Given surgical patients with hyperglycemia, understand glycemic management through appropriate therapeutic choices.
- Surgery and general anesthesia induce a neuroendocrine stress response with release of counter-regulatory hormones that result in metabolic abnormalities including insulin resistance.
- For patients who develop hyperglycemia, supplemental short or rapid-acting insulin may be administered subcutaneously, based on frequently measured capillary “fingerstick” glucose levels.
- Optimal perioperative glucose targets are between 140 and 180 mg/dL.
Presentation and dx of postop urinary retention.
- Patient risk factors include older age, male gender, and preexisting medical comorbidities such as benign prostatic hypertrophy or neuropathy.
- Procedural risk factors include anorectal surgery, inguinal/femoral hernia repair, excessive fluid administration, and the anesthetic agents used.
- Non-invasive bladder ultrasound should be used to evaluate for possible urinary retention in any patient unable to void 4 hours after surgery.
- Patients with large volume retention (>600 mL of urine) on ultrasound should have a Foley catheter kept in place to decompress the bladder.
Presentation and dx workup of postop fever
- Postoperative fever (> 38°C, 100.4°F) is common in the first few days after surgery and often resolves spontaneously. TIssue trauma causes cytokine release.
- The MC infectious causes of postoperative fever include SSI, PNA, UTI, and CLABSI.
- Basic laboratory studies, chest x-ray, urinalysis, blood and urine cultures are appropriate for initial workup of a postoperative fever. However, they are not always indicated, and their utility should be determined in the context of a thorough history and physical examination.
Evaluate and treat a patient who reports new onset lower extremity edema or pain
- Inquire about symptoms such as pain, numbness, tingling, etc. Obtain a detailed history of CV dz, PVD, or coagulopathy.
- Physical examination should focus on the CV system
- Assess extremities for pulses, motor/sensory deficits, and edema.
- Utilization of duplex US is an effective adjunct to diagnosis.
- Acute arterial thromboembolism is a surgical emergency
- Risk of VTE can be minimized with mechanical methods (graduated compression stockings) and PPX dose pharmacologic agents (i.e. heparin or lovenox).
Recognize and treat postoperative hemorrhage
- Tachycardia, hypotension, oliguria (urine output <20 mL/hr), confusion, and increasing abdominal pain may all signal postop intra-abdominal bleeding.
- Suspicion hemorrhage - resuscitation, large-bore IVs, Foley, NPO status.
- HDS patients may be managed conservatively with transfusion as indicated.
- Onset of hemodynamic instability prompts operative intervention to locate and control the source of hemorrhage.
A 65-year-old woman with a history of myocardial infarction (last year) as well as hypertension presents for an elective ventral hernia repair. What is your approach to assess her perioperative cardiac risk?
- This is an elective procedure. Emergencies go.
- Ask if she has had coronary revasc within 5 years, had a recent coronary evaluation (angio or stress test), or has new sx
- If recent revasc w/o new sx, proceed to OR
- If recent favorable w/o new sx, proceed to OR
- Ask about ability to climb stairs
- EKG and echo if no recent
- Predictors: unstable coronary sx, decompensation, arrhythmias, severe valvular dz - consider delay, med mgmt, or coronary eval
A 75-year-old man presents for his preoperative appointment for planned femoral popliteal bypass. He has a history of coronary artery disease and angina. How would you assess his cardiac risk for surgery?
- Perform a clinical assessment, including assessing for murmurs, and obtain the patient’s metabolic equivalents (METs) score.
- Ask about recent revasc, coronary eval, recurrent/new sx
- Order electrocardiogram and an echocardiogram.
- Ask about ability to climb stairs
- Refer to cards for workup if new symptoms or signs of decompensation, new coronary symptoms, arrhythmias, valve dz
What is the difference between pressure and volume controlled ventilation?
During volume-limited ventilation, inspiration ends after delivery of a set tidal volume. During pressure-limited ventilation, inspiration ends after delivery of the set inspiratory pressure.
What are some adverse pulmonary effects of positive pressure ventilation?
pulmonary barotrauma, ventilator-associated lung injury, intrinsic positive end-expiratory pressure (auto-PEEP), heterogenous ventilation, altered ventilator/perfusion mismatch, diaphragmatic muscle atrophy, respiratory muscle weakness, and diminished mucociliary motility
What are some non-pulmonary negative associations with positive pressure ventilation?
reduce cardiac output and impair hemodynamic monitoring
gastrointestinal stress ulceration, decreased splanchnic perfusion, gastrointestinal hypomotility, fluid retention, acute renal failure, increased intracranial pressure, inflammation, and disordered sleep
discuss the factors that contribute to abnormal pulmonary physiology after an operative procedure and identify patients at risk for severe postoperative respiratory failure
abdominal distention, painful upper abdominal incision, obesity, advanced age, strong smoking history with associated chronic obstructive pulmonary disease, prolonged supine positioning, and fluid overload leading to pulmonary edema
What is type 1 respiratory failure?
hypoxic failure - results from abnormal gas exchange at the alveolar level
