NMS. Casos Clínicos

6

Part I ♦ Foundations

Q: How would you categorize the patient’s anesthesia risk? A: All anesthetic techniques are associated with some risk. The American Society of Anesthesiologists (ASA) has attempted to classify anesthetic morbidity and mortality based on physical status ( ASA classes 1–5 ) (Table 1-5). This patient presents an ASA 2 risk. Q: How would you decide whether to use local, spinal, or general anesthesia? A: The decision concerning the most appropriate type of anesthesia is multifaceted and should be made in consultation with an anesthesiologist. Local anesthesia is associated with fewer physiologic consequences than with regional or general anesthetics if a good anesthetic block is achieved. However, with poor local anesthesia, patients experience increased pain, which is stressful and requires large doses of intravenous (IV) medications to offset. This significantly increases the risk. Good spinal anesthesia may lead to fewer pulmo- nary complications than general anesthesia. However, it may be more dangerous in patients with coronary artery disease, mar- ginal cardiac reserve with low ejection fraction, valvular heart disease, or diabetic pe- ripheral vascular disease with neuropathy. This danger is secondary to either a loss of peripheral vasoconstriction or ability to increase cardiac output when necessary. Thus, hypotension may occur as a result of the vasodilation caused by spinal anesthesia. In addition, if a spinal anesthetic fails to provide good anesthesia, patients will require additional IV sedation or even general anesthesia, further increasing the risk. Gen- eral anesthesia allows excellent analgesia and amnesia while maintaining Table 1-5: American Society of Anesthesiologists’ Classification of Perioperative Mortality Class Definition 1 A normal healthy patient 2 A patient with mild systemic disease and no functional limitations 3 A patient with moderate to severe systemic disease that results in some functional limitation 4 A patient with severe systemic disease that is a constant threat to life and functionally incapacitating 5 A moribund patient who is not expected to survive 24 hours with or with- out surgery 6 A brain-dead patient whose organs are being harvested E If the procedure is an emergency, the physical status is followed by “E” (e.g., “2E”). 2000 From Hackett NJ, De Oliveira GS, Jain UK, Kim JYS. ASA class is a reliable independent predictor of medical complications and mortality following surgery. Int J Surg . 2015;18: 184–190 SAMPLE Class Odds Ratio for Medical Complications Odds Ratio for Mortality 1 2 3 4 5 1 2 5 1 6 33 17 60 200