Anticholinergic agent (transdermal patch); given before surgery
ENDOCRINE COMPLICATIONS
Hypoglycemia
Hypoglycemia is a potential complication of ambulatory anesthesia anytime a preoperative fasting period has been observed. Diabetics, young thin females, and the elderly are particularly at risk, but any patient may experience signs and symptoms of hypoglycemia. Minimizing the preoperative fasting period and giving IV fluids preoperatively (or having them available) may help to prevent hypoglycemia. In addition, recognizing patients who are at risk (such as diabetics) and monitoring their blood glucose via fingerstick is a very effective management strategy. Hypoglycemia may present with nonspecific signs and symptoms such as dizziness, tachycardia, hypotension, sweating, shaking, or nausea but can be easily diagnosed with a simple handheld glucometer. Hypoglycemia is easily treated with an oral or IV sugar source. In situations of severe symptomatic hypoglycemia, an injection of D50 (50% dextrose) or glucagon may be given.
Adrenal Crisis
Adrenal crisis is a rare but serious complication of suppressed adrenal release of cortisol and can rapidly cause hemodynamic collapse if the cortisol deficiency is not promptly diagnosed and rectified. Risk factors for acute adrenal crisis include both patient and procedure factors. Surgical procedures that are invasive and cause high levels of physiological stress carry the highest risk. Patients most at risk for adrenal crisis are typically those with a lengthy history of moderate‐ to high‐dose exogenous corticosteroid supplementation, though adrenal crisis has been classically associated with Addison's disease (primary adrenocortical insufficiency). Since most procedures that will be performed in an outpatient setting will be minimally invasive and of short duration, the risk of adrenal crisis is low. Patients should be screened for a history of Addison's disease or corticosteroid use, and preoperative adjunctive corticosteroid supplementation should be considered for any patient deemed to be at risk. Acutely, the management of adrenal crisis involves IV cortisol administration and supportive measures.
IMMUNOLOGICAL COMPLICATIONS
Hypersensitivity Reactions
Hypersensitivity, or allergic, reactions are common in the general population and may be produced in the ambulatory anesthesia setting by a variety of common substances. Patients with a history of allergic asthma, atopy, or autoimmune disease may be most at risk. Mild reactions include urticaria, flushing, and pruritis, while more severe reactions can be characterized by angioedema, wheezing, nausea and vomiting, or anaphylaxis. The most common complication is a localized skin reaction, frequently to an adhesive tape used to secure an IV line, for example. Some of the medications used in ambulatory anesthesia (propofol or succinylcholine) have been implicated in allergic reactions, but this is generally rare [20]. Likewise, a true allergy to local anesthetic agents is very infrequent. Most hypersensitivity reactions will be mild and can be managed symptomatically. More serious reactions involving angioedema or a skin rash covering the full body require more aggressive management such as the use of an antihistamine drug (e.g., diphenhydramine) and possibly corticosteroids. Angioedema or other acute allergic facial swelling should be carefully monitored for the development of airway compromise – an unlikely but possible sequela. Anaphylactic reaction is a life‐threatening emergency that is treated with epinephrine, corticosteroids, antihistamines, beta‐2‐adrenergic agonist inhalers, and cardiopulmonary resuscitation as needed.
PSYCHIATRIC AND EMOTIONAL COMPLICATIONS
Patient anxiety is the most commonly encountered emotional complication in ambulatory anesthesia, but patients may also experience euphoria, delirium, agitation, or hallucinations. Children and the elderly are most at risk, and certain anesthetic medications such as ketamine have been associated with a higher likelihood of emotional or cognitive disturbance. These types of complications may be distressing to the patient but are typically self‐limiting and mild. Preventing patient injury due to agitation or delirium is the primary goal of management, and close supervision remains the best strategy.
Many anesthetic medications (particularly the benzodiazepines) produce some degree of amnesia. Amnesia is often an intended effect of anesthesia and therefore not a complication per se, but the practitioner should be aware that any instructions or information given to a patient may be affected by amnesia or cognitive distortion. Patients may not be able to distinguish between dreaming and events that actually occurred during anesthesia, leading to inappropriate associations with the anesthetic experience. It is not known how often this may occur as a complication of ambulatory anesthesia, but whenever medications are given that alter a patient's consciousness and perception there is a risk of cognitive and emotional distortion.
COMPLICATIONS RELATED TO PATIENT POSITIONING
In an outpatient surgical procedure of limited duration, the risk of injury to a patient from malpositioning is relatively small. In susceptible patients, or for longer procedures, special care in patient positioning is prudent to avoid musculoskeletal injury. The provision of anesthesia causes relaxation of the musculoskeletal system that can lead to hyperextension of the joints. Also, prolonged patient immobility can contribute to venous stasis, peripheral blood pooling, and the creation of pressure points. Elderly patients, patients with a history of musculoskeletal injury or arthritis, and obese patients are at increased risk for complications related to patient positioning. Patients with Marfan syndrome, Ehlers–Danlos syndrome, or other disorders of joint hypermobility may also be at risk. Down syndrome (trisomy 21) patients have increased range of motion of the cervical spine vertebrae and are at increased risk for vertebral dislocation if the head or neck becomes hyperextended. Of specific concern to OMSs is the potential for injury to the that can occur in sedated patients due to prolonged or exaggerated opening of the mouth during surgery. Key preventive measures are positioning patients in neutral body positions, minimizing length of surgery in susceptible individuals, and ensuring that dental chairs are cushioned and sized appropriately for the patient.
COMPLICATIONS RELATED TO IV LINE PLACEMENT
Complications related to placement of an IV line are some of the most common and troubling to patients. Pain, ecchymoses, and infiltration at the IV site are the most frequently encountered and can be managed symptomatically. More serious complications include phlebitis and thrombophlebitis at the injection site and are associated with certain irritating medications (such as IV diazepam), particularly when given in a small vein or at a high concentration. Phlebitis may take several weeks to resolve completely and may necessitate analgesia and anti‐inflammatory medications. A rare but potentially serious complication involves the inadvertent intra‐arterial injection of a medication, most commonly a barbiturate, with resultant extreme pain and vascular necrosis. With careful IV placement technique and the use of a full IV setup allowing proper dilution of medications, the incidence of complications can be minimized and have a measurable impact on patient satisfaction as well as safety.
ANESTHETIC COMPLICATIONS IN PEDIATRIC PATIENTS
Complications of ambulatory anesthesia in pediatric populations are similar in many ways to those that may be encountered in adults. Higher incidences of adverse events are reported for children with higher ASA classifications, and children less than one month old and less than one year old are particularly prone to anesthesia‐related complications [22]. For pediatric and adult patients, much of the risk of complications from anesthesia can be attributed to underlying disease states and surgical risk factors. Nonetheless, there is an additional element of risk in the pediatric population due to decreased physiological reserve.
Children, far from being miniature adults, are different in fundamental anatomical and physiological ways. The