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Pre-operative evaluation - Clinical management

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  Pre-operative evaluation Surgery and anesthesia cause major perturbations to a patient’s homeostasis. The risk of potentially life-threatening complications can be reduced with appropriate pre-operative evaluation and therapy. Because cost concerns have virtually elim-inated pre-operative hospital admission, today the visit may occur just moments before the operation in the case of an emergency or a healthy outpatient, but is better managed in pre-anesthesia clinics to which patients report one or several days before their operation. Surgeons and primary-care physicians can do much to avoid operative delays and cancellations, as well as to reduce the patient’s cost and risk by identifying patients who need a pre-operative anesthesia consulta-tion and by sending all pertinent information, e.g., recent ECG, echo studies, etc., with the patient. The pre-anesthetic evaluation appears to be just another rou-tine of eliciting a history, reviewing all systems, performing a physical examina-
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History - Clinical management

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  History We begin with the “H” in “H&P,” obtaining a medical and surgical history. We are particularly concerned with the cardiopulmonary system, and exercise toler-ance is a good measure of current status. We also search for evidence of chronic diseases of other systems. For elective procedures, patients should be in the best condition possible, e.g., no exacerbation of chronic bronchitis or unstable angina. Below, we describe the pre-operative evaluation of some common medical condi-tions. When patients with these, or other rarer, conditions require an anesthetic,  a pre-anesthesia clinic visit a week or so in advance of anesthesia allows time to seek additional information, e.g., study results from the patient’s private physi-cian, perform studies, e.g., cardiac pacemaker interrogation, or obtain consulta-tion from a specialist. Such planning helps keep the operating schedule running smoothly. We inquire about any previous anesthetics, particularly any untoward events such as b
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Physical examination - Anesthesia Clinical management

  Physical examination In addition to the cardiopulmonary examination, we carefully evaluate the patient’s airway to predict whether it will be easily intubated (see Airway manage-ment). The physical examination should also seek pre-existing neurologic deficits, particularly if regional anesthesia, e.g., spinal, epidural or nerve plexus block, is considered, and any limitations to flexibility that may present difficulties with positioning the patient. If we plan on regional anesthesia, we need to inspect the anatomy, for example, does the patient have a scoliosis that would make a lumbar puncture difficult, or is his skin infected over the site where we would place the needle?
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Laboratory evaluations and studies - Anesthesia Clinical management

  Laboratory evaluations and studies Here we must ask the question, “Can the results from additional tests influence my anesthetic and post-anesthetic management?” In the majority of cases, the answer turns out to be “No,” but there are many exceptions. Among them might be a determination of serum potassium if we fear that the patient is hyperkalemic, in which case a succinylcholine-induced release of potassium would be dangerous. Coagulation studies would be needed if we plan regional anesthesia and have reason to worry about a bleeding diathesis or thrombocytopenia. Uncontrolled bleeding into the nerve plexus can cause permanent damage. In general, labora-tory and other studies should be ordered as indicated from the medical history, and only if they might have an effect on intra- or post-operative management, or perhaps if the risk analysis may suggest canceling or altering the procedure itself. For example, suppose we detect a carotid bruit during the pre-anesthetic evaluation of a
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NPO status - Anesthesia Clinical management

  NPO status During induction of general anesthesia, the gag reflex is necessarily abol-ished. Should the patient “choose” that most inopportune time to suffer gastro-esophageal reflux (or worse yet, emesis), there is a high likelihood the stomach contents could end up in the lung, causing a chemical pneumonitis or even acute suffocation from the lodging of solid particles in the bronchial tree. In addition to pharmacologic means (see Pharmacology), we minimize this risk by having the patient report for surgery with an empty stomach. Patients are asked to refrain from eating solid foods for 6–8 hours prior to elective surgery. While there is evi-dence that clear liquid ingestion is cleared rapidly and not dangerous in those patients with normal digestion (it may even  raise  the pH of the stomach con-tents above the pH 2.5 danger zone), it remains customary to tell patients who are scheduled for an elective operation in the morning not to eat or drink any-thing for at least 6 hours (fo
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Planned procedure - Anesthesia Clinical management

  Planned procedure The planned surgical, diagnostic, or therapeutic procedure influences the anesthetic management, sometimes producing problems for which we must be prepared. For example, the neurosurgeon may trigger a wild release of cate-cholamines when destroying the trigeminal ganglion in a percutaneous procedure that lasts only minutes. How are we going to protect the patient from the expected sympathetic storm? Or, how can we guard against a sudden and substantial rise in peripheral arterial resistance when the surgeon clamps the aorta in prepar-ation for the resection of an aortic aneurysm? The planned procedure also has implications for, among other things, intra-operative positioning of the patient, potential need for blood replacement, anticipated severity of post-operative pain (is a regional anesthetic an option?), and need for intensive care after surgery.
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Anesthetic choice - Anesthesia Clinical management

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  Anesthetic choice In addition to the above assessment, the anesthetic plan must consider the wishes of both patient and surgeon, as well as  our  individual skill and experience. Does the patient have special requests that need to be taken into account? For example, some patients would like to be awake (maybe the President so he doesn’t have to pass control of the US to the Vice-President), others asleep, and others do not want “a needle in the back.” Some patients present special problems, for example Jehovah’s Witnesses who do not accept blood transfusions, based on their interpretation of several pas-sages in the Bible (for example Acts 15:28, 29). A thoughtful and compassion-ate discussion with the patient usually finds the physician agreeing to honor the patient’s wishes, an agreement that may not be violated. The caring for children of Jehovah’s Witnesses brings an added concern and may require ethics consultation and perhaps even referral to a court. Again, these issues are be
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