Ambulatory Anesthesia



5. Hospital admission by itself is not necessarily bad if it results in a better quality of care or uncovers the need for more extensive surgery.


E. Obese patients are not more likely to have adverse outcomes, but they have a higher incidence of obstructive sleep apnea (OSA). The American Society of Anesthesiologists (ASA) has published practice guidelines for the perioperative management of patients with OSA.


F. Patients who undergo ambulatory surgery should have someone to take them home and stay with them afterward to provide care.


1. After the patient has returned home, he or she must be able to tolerate the pain from the procedure, assuming adequate pain therapy is provided.


2. Patients undergoing certain procedures, such as laparoscopic cholecystectomy or transurethral resection of the prostate, should live close to the ambulatory facility because postoperative complications may require their prompt return.


II. PREOPERATIVE EVALUATION AND REDUCTION OF PATIENT ANXIETY. Each outpatient facility should develop its own method of preoperative screening to be conducted before the day of surgery (history, medications, previous anesthetics, transportation and child care needs, dietary restrictions, attire, arrival times, laboratory tests). The preoperative screening is the ideal time for the anesthesiologist to talk with the patient. Automated history taking may also prove beneficial during patient screening.


A. Upper Respiratory Tract Infection (Table 30-1)


1. Airflow obstruction has been shown to persist for up to 6 weeks after viral respiratory infections in adults. For this reason, surgery should be delayed if an adult presents with an upper respiratory infection (URI) until 6 weeks have elapsed.



TABLE 30-1 INDEPENDENT RISK FACTORS FOR ADVERSE RESPIRATORY EVENTS IN CHILDREN WITH UPPER RESPIRATORY TRACT INFECTIONS


Use of an endotracheal tube versus laryngeal mask airway


Prematurity


Reactive airway disease


Parenteral smoking


Surgery involving the airway


Presence of copious secretions


Nasal congestion


2. In the case of children, whether surgery should be delayed for this length of time is questionable. URI seems to be associated with an increased risk of perioperative respiratory events only when symptoms are present or had been present within 2 weeks before the procedure.


a. Although surgery may be canceled because a child is symptomatic, the child may develop another URI when the procedure is rescheduled.


b. Generally, if a patient with a URI has a normal appetite, does not have a fever or an elevated respiratory rate, and does not appear toxic, it is probably safe to proceed with the planned procedure.


B. Restriction of Food and Liquids Prior to Ambulatory Surgery


1. To decrease the risk of aspiration of gastric contents, patients are routinely asked not to eat or drink anything for at least 6 to 8 hours before surgery.


2. Prolonged fasting can be detrimental to patients. Infants who fast longer have greater decreases in intraoperative blood pressure.


3. No trial has shown that a shortened fluid fast increases the risk of aspiration. Gastric volumes are actually lower when patients are allowed to drink some fluids before surgery.


4. ASA practice guidelines for preoperative fasting allow a patient to have a light meal up to 6 hours before an elective procedure and support a fasting period for clear liquids of 2 hours for all patients (including taking chronic medications) (Table 30-2). Coffee and tea are considered clear liquids.



TABLE 30-2 SUGGESTED GUIDELINES TO REDUCE THE RISK OF PULMONARY ASPIRATION



a. Coffee and tea drinkers should follow fasting guidelines but should be encouraged to drink coffee before the procedure because physical signs of caffeine withdrawal (headache) can easily occur.


b. It is unclear whether rehydration during surgery is equivalent to a shorter fast before surgery in relation to postoperative nausea and vomiting.


c. ASA practice guidelines do not recommend “routine use” of gastrointestinal stimulants (metoclopramide), gastric acid secretion blockers (histamine-2 receptor antagonists), antacids, antiemetics, or anticholinergics.


C. Anxiety Reduction


1. Preoperative reassurance from nonanesthesia staff and the use of booklets reduce preoperative anxiety. However, the use of booklets is less effective than a preoperative visit by the anesthesiologist. Audiovisual instructions also reduce preoperative anxiety.


2. Much of a child’s anxiety before surgery concerns separation from the parent or parents. If the parents are calm and can effectively manage the physical transfer to a friendly and playful anesthesiologist or nurse, premedication may not be necessary.


3. Family-centered care (videotapes, pamphlets, mask practice kits) has become popular and is useful for decreasing children’s preoperative anxiety.


III. MANAGING THE ANESTHETIC: PREMEDICATION. Premedication is useful for controlling anxiety; reducing the risk of aspiration during induction of anesthesia; and controlling postoperative pain, nausea, and vomiting. Because outpatients go home on the day of surgery, the drugs given before anesthesia should not hinder their recovery.


A. Benzodiazepines


1. Midazolam is the benzodiazepine most commonly used preoperatively. For children, oral midazolam in doses as small as 0.25 mg/kg produces effective sedation and reduces anxiety. With this dose, most children can be effectively separated from their parents after 10 minutes, and satisfactory sedation can be maintained for 45 minutes. Discharge may be delayed, though, when midazolam is given before a short procedure.


2. Routine administration of supplemental oxygen with or without continuous monitoring of arterial oxygenation is recommended whenever benzodiazepines are given intravenously (IV).


3. The potential for anterograde amnesia after premedication is a concern, especially for patients undergoing ambulatory surgery.


B. Opioids and Nonsteroidal Analgesics


1. Opioids may be administered preoperatively to sedate patients, control hypertension during tracheal intubation, and decrease pain before surgery. Meperidine (but not morphine or fentanyl) is sometimes helpful in controlling shivering in the operating room or postanesthesia care unit (PACU).


2. Preoperative administration of opioids or nonsteroidal antiinflammatory drugs may be useful for controlling pain in the early postoperative period.


IV. INTRAOPERATIVE MANAGEMENT: CHOICE OF ANESTHETIC METHOD


A. General anesthesia, regional anesthesia, and local anesthesia are equally safe.


1. Even for experienced anesthesiologists, a failure rate is associated with regional anesthesia (Fig. 30-2).



FIGURE 30-2. Operating room delays are the major reasons orthopedic surgeons do not favor regional anesthesia.


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Sep 11, 2016 | Posted by in ANESTHESIA | Comments Off on Ambulatory Anesthesia

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