Preanesthesia assessment is the process of clinical evaluation prior to the delivery of anesthesia in patients undergoing both surgical and nonsurgical procedures. This process includes interviewing the patient, reviewing the patient’s medical records, performing a physical examination, including an airway examination, ordering and/or reviewing relevant medical tests, and consulting other medical subspecialists as necessary. The goals of preanesthesia evaluation include familiarizing the provider with the patient’s medical conditions, determining the severity of illness, and confirming optimization of all identified issues.
Anesthesia providers should, at a minimum, perform a pulmonary, cardiovascular, and an airway evaluation. The patient’s vital signs should also be noted. Evaluation of other organ systems may be necessary depending on the patient’s current comorbidities.
Evaluate for presence of peripheral venous sites; for regional blocks, examine the extremity or the back for presence of infection or distorted anatomy.
Assess baseline level of consciousness and deficits if the patient has had prior neurologic disease (stroke, neuropathies, etc).
Auscultate for heart rate, rhythm, and presence of murmurs; note baseline heart rate and blood pressure.
Auscultate for rales, rhonchi, and wheezing, especially in patients with known pulmonary disease. Note baseline respiratory rate and O2 saturation at room air.
Look for clinical signs that predict difficult airway management. Evaluation of the airway includes, but is not limited to assessing the thyromental distance and cervical spine flexion/extension, examining the oral cavity (Table 64-1) and assigning a Mallampati Classification (Figure 64-1 and Table 64-2). If a difficult airway is anticipated, additional assistance and alternative equipment should be readily available.
TABLE 64-1Elements of Airway Examination ||Download (.pdf) TABLE 64-1 Elements of Airway Examination
|Airway Examination ||Non-reassuring Finding |
|Teeth ||Edentulous |
|Length of upper incisors ||Relatively long |
|Relation of maxillary and mandibular incisors during normal jaw closure ||Prominent overbite, inability to demonstrate underbite |
|Relation of maxillary and mandibular incisors during voluntary protrusion of mandible ||Patient cannot bring mandibular incisors anterior to maxillary incisors |
|Interincisor distance ||< 3 cm |
|Visibility of uvula ||Not visible with tongue protruded and with patient sitting up |
|Shape of the palate ||Highly arched or very narrow |
|Compliance of mandibular space ||Stiff, indurated, occupied by mass |
|Thyromental distance ||Less than three finger breadths |
|Thickness of neck ||Thick neck |
|Length of neck ||Short neck |
|Range of motion of head and neck ||Patient cannot touch tip of chin to chest or limited neck extension |