1.1 Preoperative Evaluation
BobbieJean Sweitzer
Inadequate preoperative evaluation and optimization are linked to perioperative mortality and morbidity (
1,
2). Health care is increasingly fragmented, medical records are not always available, and relevant information may be difficult to access. Communication failures and misunderstandings underpin many of the reported incidents. Preoperative evaluation can improve outcomes, and reduce mortality and morbidity (
2,
3).
Goals of preoperative evaluation include:
Identification of comorbid conditions
Documentation of current medications
Clarification of allergies
Elucidation of previous complications of anesthesia
Management and optimization of medical diseases
Assessment of perioperative risk
Education of patients and families
Procurement of informed consent
Interventions to lower risk (smoking cessation, preventive care)
Assessment of appropriateness for ambulatory or remote locations
Arrangement for special anesthetic techniques
Development of postoperative care plans
Instructions for medication management and fasting
Completion of regulatory requirements
Preoperative evaluation is a necessary and required component of perioperative care for all patients. However, not all patients will benefit from the same approach and matching resources to benefits is desired. Appropriate timing of the preoperative evaluation considers comorbidities, access to healthcare records, other provider relationships, and the urgency of the procedure. Some individuals will require evaluation, testing, interventions to improve health status, and intensive planning and coordination of care. These patients benefit from assessment in advance of procedures (
Table 1.1). Healthy patients having low-risk procedures can be seen on the day of their procedure immediately before anesthesia. Patients with co-existing conditions or advancing age are at increased risk (
4). The invasive nature and extent of surgery are associated with risk.
A mechanism to obtain information about the patient and triage guidelines can determine which needs to be evaluated ahead of time (
Table 1.2). The important
components of the patient history are shown in
Figure 1.1. This information is best obtained as soon as surgery is being considered. The form can be completed by the patient in person (paper or electronic version), remotely via electronic health record portals, web-based programs, or during a telephone interview. The information is used to complete the medical history and to triage services. Bolded items in
Figure 1.1 indicate medical conditions which are associated with higher risk and/or may require further testing and optimization. Gathering information and effectively triaging patients for preanesthetic assessments and ensuring adequate evaluation and optimization increases patient satisfaction, lowers risk, and improves operating room efficiency and resource utilization (
5). In addition, perioperative medicine clinics provide opportunities for behavioral modification intervention at a “teachable moment” when patients may be more receptive to change (
6).
The American Society of Anesthesiologists recommends at a minimum that the preanesthetic assessment includes the following (
7):
Patient interview
Focused examination of the airway, lungs, and heart
Review of pertinent medical records
Indicated preoperative tests
Consultations with specialists as needed
The history and physical examination, commonly referred to as the
clinical examination, is the basis for establishing diagnoses and eliminating alternative hypotheses. The history alone provides 56% of correct diagnoses in a general medical clinic and adding the physical examination increases this to 73% (
8). In patients with cardiovascular (CV) disease, the history establishes the diagnosis two-thirds of the time, and the physical examination contributes 25% (
8). Diagnostic tests, such as chest radiographs and electrocardiograms (ECGs), helped with only 3% of diagnoses, and special tests (e.g., stress testing) assisted with 6%. The history is the most important component in diagnosing respiratory, urinary, and neurologic conditions. The patient history rather than abnormal tests predict perioperative outcomes (
9). Tests should
only confirm what is already suspected by the clinical examination. The diagnostic acumen of clinicians results from the ability to integrate information gained during the clinical examination. Listening to and examining patients and assimilating their stories and outcomes of their illnesses lead to pattern recognition. Obtaining the patient’s history is not simply asking questions but asking the right questions, often in a variety of ways, and interpreting and carefully recording the answers. Rather than simply compiling facts. Providers need to develop an overall impression as the interview progresses to efficiently evaluate patients and develop next steps. Complete and thorough histories assist in planning appropriate and safe anesthesia care and are more accurate and cost-effective in establishing diagnoses than screening tests (
9).
The classic “history of present illness or
HPI” as it relates to the anesthesia evaluation starts with the planned procedure and the underlying reason for surgery. How the surgical condition developed, associated complications, and prior therapies are important. A complete listing of current and past medical conditions with delineation of severity and treatments are essential. Simply noting diseases such as hypertension or coronary artery disease (
CAD) or symptoms like shortness of breath or chest pain is not sufficient. One must explore the severity and the stability of the conditions, current or recent exacerbations, and prior treatments or planned interventions. Any activity-limiting nature of a condition is equally important. One notes previous surgical procedures, especially those on major organs, the spine and joints. The patient’s medical problems, previous surgeries, and responses to questions will elicit further inquiry to establish a complete history.
Previous experiences with anesthesia, including types of anesthetics are elucidated. Anesthesia-related complications are noted. A personal or family history of malignant hyperthermia (MH) or pseudocholinesterase deficiency is documented (see
Chapters 16.5 and
16.6). A history of difficult airway management is important (see
Chapter 16.3). Obtaining records from previous anesthetics may clarify ambiguities and can assist with planning a safe anesthetic.
A determination of the patient’s cardiorespiratory fitness or functional capacity is useful in guiding additional preanesthetic evaluation and predicting outcomes and perioperative complications. Defining exercise limits may be the single best predictor of overall perioperative risk. The easiest and most common approach is simply asking the patient to name the most strenuous activity they do regularly or have done most recently. Limiting symptomatology such as chest pain, dyspnea, or claudication should prompt further investigation. Ascertaining if patients can achieve at least an average functional capacity defined as a metabolic equivalent (
MET) of 4 by walking up a flight of stairs (at least 11 to 12 steps) predicts better outcomes (
10,
11).
Prescription and over-the-counter medications, including supplements and herbals, along with dosages and schedules are carefully recorded. Determining allergies to medicines and substances such as latex or radiographic dye with special emphasis on the specifics of the patient’s reaction to the exposure are necessary (
Chapter 13.1). Use of tobacco, alcohol, or illicit drugs is documented. Tobacco exposure using packyears (number of packs of cigarettes smoked/day × number of years of smoking) is best. For example, two packs of cigarettes daily for 10 years is recorded as 20 packyears of tobacco use.
A screening review of systems (
ROS) is especially useful to uncover symptoms that may lead to establishment of previously undiagnosed conditions. A
ROS is not a listing of medical diagnoses; those belong in the problem list or medical history sections. A general appraisal of all organ systems is ideal. For example, asking patients if they have ever had problems with their heart, lungs, kidneys, liver, nervous system, or if they have had cancer, anemia, bleeding problems, or ever been hospitalized for any reason will often prompt recall of medical problems or symptoms. A preoperative
ROS (
Table 1.3) places special emphasis on airway symptomatology, CV, pulmonary, hepatic, renal, endocrine, or neurologic symptoms. One inquires about chest discomfort (pain, pressure, tightness), duration of discomfort, precipitating factors, associated symptoms, and methodologies
of relief. Shortness of breath, with exertion or when lying flat (orthopnea), and peripheral edema are important to elicit. Patients are asked about a history of heart murmurs and what diagnostic studies have been done to evaluate a murmur. Identifying risk factors for heart disease including a family history of cardiac disease, hyperlipidemia, tobacco abuse, diabetes, and kidney or other vascular disease determines how one approaches further risk assessment. A history of heartburn, especially with associated reflux or after a period of fasting comparable to that which will occur preoperatively, is important. A personal or family history of bleeding after surgery or after tooth extraction, need for transfusion, a history of liver disease, or Ashkenazi Jewish lineage can suggest a bleeding disorder (see
Chapters 9.7,
9.8,
9.9 and
9.10) (
12). Women of child-bearing age are prompted to recall their last normal menstrual period and their likelihood of being pregnant. This history is more reliable if the female patient, especially a minor child, is interviewed in privacy. Questioning the patient about snoring and daytime somnolence may suggest undiagnosed sleep apnea (see
Chapter 4.8).
Establishing a patient’s ability to care for themselves and engage in activities of daily living ADLs (bathing, feeding, dressing) are important. An evaluation of cognition using the Mini-Cog (see
Chapter 5.13) and a formal assessment of frailty are important in elderly patients. Asking about appetite and weight loss, especially unintended loss of 10 pounds or 10% of body mass are the basis of nutritional assessment. Finally, a review of records, including notes from primary care physicians, specialists, or the hospital, and test results is important.
