2.1 SELECTION OF A SURGICAL FACILITY

The surgeon must select an operating room with personnel and equipment adequate for an elective and controlled management of the patient’s airway. Preoperative preparation is intended to improve a patient’s medical status and reduce the risk of complications. The literature is insufficient to offer guidance regarding which patients can be safely managed as an outpatient as opposed to an inpatient basis or the appropriate time for discharge from the surgical facility.¹

Upper airway surgery in sleep apnea patients can temporarily worsen the sleep apnea and lead to serious and potentially fatal complications, including acute upper airway obstruction, hypoxemia, hypercarbia, myocardial infarction, cardiac arrhythmias, stroke and death. Prevention of these complications requires early detection of pending airway problems. Postoperative monitoring is performed in order to detect and prevent potential complications. While there are insufficient published data, it is assumed that patients with more severe sleep apnea are at greater risk for perioperative complications.

The determination to perform surgery as an outpatient, in an outpatient surgery center with ambulance transfer to a hospital facility, admit for a short extended recovery room stay, admit to a 23-hour unit, regular hospital room or an intensive care unit should be made with consideration of associated co-morbidities, severity of apnea, sites of airway narrowing, type of anesthesia, length of time for anesthesia, need for postoperative narcotic agents, and type of surgery being performed. This determination should be made preoperatively.¹ Confusing the matter is the use of the term ‘outpatient’ by some organizations to refer to all surgical stays less than 24 hours and by other organizations to label any stay after midnight as ‘inpatient.’ In a recent report of the American Society of Anesthesiologists,¹ consultants were surveyed using a non-validated scoring system about opinions regarding outpatient surgery in patients with OSAS. This survey suggested that a patient with mild sleep apnea undergoing uvulopalatopharyngoplasty (UPPP) or nasal surgery was not at increased risk, while a patient with moderate sleep apnea undergoing UPPP was at increased risk of complications.¹

Care should be taken in selecting patients for outpatient procedures. It is my opinion that most patients with mild or moderate sleep apnea undergoing nasal surgery only may safely be treated as an outpatient, while those with severe sleep apnea may require some observation before discharge. Similarly, most patients with mild OSAHS undergoing UPPP or other pharyngeal airway surgeries should at least be observed for several hours prior to discharge, while those with moderate or severe OSAHS should stay as an inpatient or for a longer observation period. The importance of the postoperative observation period is to document the presence or absence of sleep apnea and oxygen desaturation in the patient while sleeping without supplemental oxygen. The need for postoperative monitoring depends upon the procedure performed and associated co-morbid conditions. The quality of the hospital nursing care and skill of the anesthesiologist also have an impact on the level and type of postoperative monitoring. Some facilities can perform continuous pulse oximetry in the extended recovery unit or regular nursing unit, while others require an intensive care unit to administer this same level of care.

2.2 CHOICE OF ANESTHESIA TECHNIQUE (LOCAL, GENERAL OR MONITORED ANESTHESIA CARE)

The literature is insufficient to evaluate the effects of different anesthetic techniques on surgical outcomes after surgery for OSAS. Since airway reconstructive surgery for sleep apnea causes blood to enter the airway, it would be safest to perform these surgeries under general anesthesia, in order to control and protect the airway. When a patient with OSAS is undergoing non-airway related surgery, then a local anesthesia, or monitored anesthesia care (MAC) would be preferred. If the patient is to undergo any sedation during a non-airway surgery, then oximetry and CO₂ monitoring should be used. General anesthesia with a secure airway is preferred if the patient is going to require moderate or deep sedation.

2.3 USE OF CONTINUOUS POSITIVE AIRWAY PRESSURE (CPAP)

There is an alteration of sleep architecture and frequently sleep deprivation prior to and after surgery, including sleep deprivation due to anxiety about the surgery.^2,3 Once surgery is done and these factors are gone, however, the patient is more likely to enter deeper levels of sleep and may be predisposed to more severe sleep apnea.⁴ It would therefore seem to be beneficial to improve sleep quality as much as possible before and after surgery. When possible, a patient should be asked to use CPAP for several weeks prior to and after surgery and to bring their machine into the hospital for perioperative use. While the majority of patients are undergoing surgery because they cannot tolerate CPAP, even moderate use of CPAP preoperatively may be beneficial.

2.4 USE OF NARCOTICS AND SEDATIVE AGENTS

Use of narcotics, sedative hypnotics and anxiolytic agents should be avoided prior to surgery in a patient with OSAS. These agents have been reported to lead to sudden death, even in the preoperative holding area.⁵ These drugs suppress respiration, blunt the arousal response and may lead to life-threatening hypoxemia. Benzodiazepine agonists affect upper airway muscle tone and worsen sleep apnea.⁶ Flurazepam has been shown to increase the Apnea Index⁷ and triazolam increased the arousal threshold to airway obstruction, apnea and hypopnea duration and oxygen desaturation.⁸ If a sleep apnea patient requires sedation or an anxiolytic, this necessitates require continuous pulse oximetry, and possibly supplemental oxygen.

2.5 REFLUX/ASPIRATION PRECAUTIONS

Obesity is common in patients with sleep disordered breath-ing, leading to an increased risk of gastroesophageal reflux^9,10 which is caused by increased intra-abdominal fat, intra-abdominal pressure and higher incidence of hiatal hernia. Ninety percent of obese patients have greater than 25 ml of gastric fluid prior to surgery, a pH under 2.5 and will be at increased risk of aspiration during induction of anesthesia¹¹ or upon extubation. In order to reduce these risks, obese patients should receive an H₂ blocker, proton pump inhibitor or esophageal motility stimulant prior to surgery.¹²

2.6 MEDICAL/ANESTHESIA/CARDIOLOGY CLEARANCE

A consultation with the primary physician, cardiologist, anesthesiologist or other specialist should be considered in patients with complicated co-morbid conditions, or in patients with multiple co-morbidities. For example, a patient with hypertension requiring three antihypertensive agents may require a consultation for medical clearance. A patient with poorly controlled diabetes may benefit from a preoperative clearance. The selection of an internist, cardiologist or anesthesiologist may be based on availability or expertise of the consultant. The purpose of the preoperative clearance is to optimize control of the co-morbidities prior to surgery and to reduce the risk of surgical complications.

Patients with OSAS are at increased risk of hypertension due to an increased sympathetic drive.^13,14 Undiagnosed hypertension is common in the sleep apnea patient. Blood pressure screening should be done at the time of initial evaluation or after initial diagnoses of OSAS. If blood pressure is elevated, these patients should be referred for treatment. Blood pressure should again be checked at a preoperative visit to be sure that hypertension is well controlled.

2.7 COMMUNICATION WITH ANESTHESIA TEAM

As the head of the surgical team, it is the responsibility of the surgeon to advise the anesthesia team about any potential difficulty with the airway. While it should be assumed that all OSAS patients may be more difficult to ventilate or intubate, there will be some with macroglossia, retrognathia or micrognathia who are going to be particularly challenging. In these patients, the surgeon may wish to have difficult airway instruments in the operating room, a tracheostomy set available or to be ready to assist with a fiberoptic intubation. I have found that patients are typically more difficult to intubate or ventilate if they have Friedman palate/tongue position IV or if the larynx is not visible with a mirror on indirect laryngoscopy.

3.1 PREPARATION FOR INTUBATION (VENTILATION)

Prior to surgery, an anti-reflux agent and anti-sialogogue should be administered to reduce the risk of aspiration and reduce saliva production.¹² It is important to maintain continuous control of the airway by the anesthesiologist. In order to ventilate the patient, the anesthetized patient will require positive pressure breathing by mask, head and neck extension, jaw protrusion, and insertion of a properly sized oral airway or long nasal airway in order to keep the tongue from falling posteriorly. A two-person ventilation approach may be needed, one for jaw positioning and mask seal and the other for ventilation.¹⁵ A 3–5 minute period of ventilation is used to increase oxyhemoglobin saturation and reduce the rate of desaturation, prior to intubation.

A variety of methods are available to maintain ventilation in a difficult airway (Table 14.1). The simplest approach is to insert a long nasopharyngeal airway that extends inferior to the base of tongue. A laryngeal mask airway (LMA) is another excellent way to stabilize the airway and allow ventilation.^16,17 The LMA is inserted blindly, and keeps the base of tongue and epiglottis from collapsing posteriorly. Other options require additional equipment and expertise such as use of a rigid ventilating bronchoscope, an esophageal–tracheal combitube, or the placement of a 14 gauge angiocath into the cricothyroid membrane followed by transtracheal jet ventilation.

Table 14.1 Available methods for difficult ventilation

3.2 INTUBATION TECHNIQUES

The sleep apnea patient can be a challenge to intubate due to the combination of skeletal deficiency, a long airway, excessive oropharyngeal and hypopharyngeal soft tissue, and a relatively anterior larynx. If easily ventilated, then short-acting paralyzing agents such as succinylcholine may be used. Oral intubation may not be feasible if the larynx cannot be visualized. Alternative methods (Table 14.2) are available for difficult intubations. The safest approach is an awake oral or nasal intubation as the patient continues breathing. A more comfortable approach for the patient is a planned awake transnasal fiberoptic intubation performed with the patient in a sitting or semi-sitting position. Another simple option is the use of a light wand (lighted stilet) inserted into the endotracheal tube, with transcutaneous guidance into the trachea, in a darkened room. If the patient is ventilated through an LMA, then the easiest intubation approach is through the LMA. One of the newest approaches is the use of a video laryngoscope, which has a small video camera on the end, allowing the anesthesiologist to visualize the larynx on a screen. As a result, the endotracheal tube can be guided through the vocal cords, by visualizing the video screen.

Table 14.2 Available methods for difficult intubation

A patient may also require a planned temporary or skinned lined tracheostomy. Planned tracheostomy should be considered in those with severe sleep apnea and failure of CPAP, those with life-threatening cardiac arrhythmias or severe oxygen desaturation,¹⁸ or in those with a failed intubation at a prior surgery. Temporary tracheostomy should also be considered if significant postoperative edema is expected. An emergency tracheostomy or cricothyrotomy may be needed if a patient cannot be ventilated or intubated.

3.3 EXTUBATION

Extubation is another critical time due to potential airway obstruction. Full reversal of neuromuscular block should be verified prior to extubation. The patient should have purposeful movement, recovery of neuromuscular activity, sustainable head lift for at least 5 seconds, and an adequate voluntary tidal volume. Whenever possible, the patient should be in the semi-upright or lateral position. In addition, it is generally accepted that patients should be extubated awake.^1,19 Most anesthesiologists prefer not to extubate ‘deep’ as the airway may obstruct. However, if extubated light or awake, the patient may cough or buck on the tube and cause bleeding into the airway. As a result, there are certainly medical and surgical contraindications to awake extubation. In children, postobstructive pulmonary edema may occur with deep extubation due to negative pressure breathing against a closed airway. In general, if the patient was easy to ventilate with induction, there should be no difficulty ventilating after extubation. The patient should only be extubated with appropriate personnel and equipment present so as to be able to replace the tube if necessary.

It is unclear whether adjunctive local anesthetic agents improve operative safety. Use of long-acting local anesthetics at the conclusion of surgery may reduce the need for narcotic analgesics but may worsen apnea due to blockage of airway mechanoreceptors that contribute to the arousal stimulus and apnea termination.²⁰ Narcotic agents should be minimized during surgery, as their effect may persist postoperatively and lead to postoperative complications.

3.4 SURGEON AVAILABILITY

The surgeon and anesthesiologist should both be in the operating room at time of induction, intubation, and extubation for all sleep apnea patients.

4.1 PATIENT POSITIONING

Sleep apnea severity and hypoxemia tend to improve when adult OSAS patients are tested in the sleep laboratory in the lateral, prone, or sitting positions rather than supine. Elevation of the head of the bed after surgery reduces soft tissue edema and turbinate engorgement, and improves the nasal airway. Since there are no valves in the veins of the head and neck, lying flat increases venous pressure and increases tissue edema. While the literature is insufficient to provide guidance for the postoperative period, most physicians agree that after airway surgery, the head of the bed should be elevated and the supine position should be avoided.¹

4.2 PATIENT ANALGESIA

Reconstructive surgery for sleep apnea is often painful, requiring narcotic agents for adequate pain control.²³ All opiate agents including morphine, meperedine, hydromorphone and fentanyl cause dose-dependent reduction of respiratory drive, respiratory rate, and tidal volume and can lead to hypoventilation, hypoxemia and hypercarbia.^24,25 The literature is insufficient to evaluate the effects of different analgesic techniques and there is no agreement about the safety of nurse-administered versus patient-controlled analgesia with systemic opioids.¹

In general, narcotic agents should be titrated for pain severity and used only as needed. Stronger narcotic agents should be used only when weaker analgesic agents are not adequate. Mild to moderate pain should be treated with oral opioid agents such as codeine, hydrocodone, oxycodone and propoxyphene, as these agents have only mild respiratory suppressing effects. Non-narcotic options include centrally acting agents such as tramadol hydrochloride and acetominophen, which is often used in combination with opioid agents. Non-steroidal anti-inflammatory agents (ibuprofen, naproxen, ketorolac, tromethamine) may also be helpful but should be used with caution due to the potential for increased bleeding. Newer COX-2 non-steroidal antiinflammatory agents (celocoxib) probably have minimal bleeding risk. Topical anesthetics such as benzocaine may also be helpful for pain control.

4.3 OXYGENATION

Maintaining adequate oxygenation is mandatory following surgery. Supplemental oxygen should be continued in order to maintain the oxygen saturation above 90%. Supplemental oxygen may be discontinued when the patient is able to maintain their baseline oxygen saturation while breathing room air. CPAP can be safely used after most upper airway surgeries to prevent desaturation during sleep²⁶ and should be used as soon as feasible after surgery in patients who were using it prior to surgery. Following surgery, CPAP may also reduce the risk of gastroesophageal reflux.²⁷ Patients should be instructed to bring their own PAP machine to the surgery facility for postoperative use during sleep at the preset pressure. The CPAP pressure may be changed if needed: higher due to tissue edema or muscle relaxation; lower due to enlargement of the airway. CPAP should be avoided after maxillary advancement due to the risk of subcutaneous emphysema. After nasal surgery, CPAP can be used with a full face mask instead of a nasal mask or nasal pillows.

4.4 REDUCING AIRWAY EDEMA

Despite surgical correction of the upper airway, edema caused by surgical trauma or difficult intubation may cause airway compromise, especially in those with severe apnea, multiple sites of airway compromise, and multiple airway surgeries. Tissue edema occurs even after laser and radiofrequency (RF) procedures.^28,29 Systemic steroids can reduce edema in the upper airway.³⁰ Dexametasone (10–15 mg/dose in adults) is the preferred corticosteroid agent due to the limited effect on sodium retention. I administer steroids prior to surgery and several doses postoperatively.

Soft tissue edema may be reduced by tissue cooling. Tissue precooling reduces edema in thermal wounds from lasers³⁰ or cautery units. Application of external ice packs or sucking on ice chips may also reduce swelling. Topical or systemic antibiotic prophylaxis may also reduce edema by reducing bacterial contamination of the surgical wound. Perioperative use of a broad-spectrum antibiotic agent with anaerobic coverage is recommended with oral or nasal surgery and topical chlorhexidine oral rinse has been shown to reduce bacterial counts in the oral cavity.

Nasal obstruction may cause or worsen sleep apnea³¹ while improving the nasal airway can improve sleep apnea.³² Nasal packing should be avoided in patients undergoing nasal surgery. Alternatives to packing include use of quilting septal sutures, septal splints, nasal tubes such as Doyle splints, or nasopharyngeal airways sewn into place. Use of a decongestant nasal spray (oxymetazoline) or a systemic decongestant postoperatively is also helpful following nasal surgery or nasal intubation.

4.5 POSTOPERATIVE MONITORING

The first 24 hours after surgery are probably the most critical time for complications, though deaths from complications have also occurred later, potentially from the accumulated effects of sleep deprivation, narcotic agents and REM rebound.^33,34 Unfortunately, the literature is insufficient to offer guidance regarding the impact of telemetry monitoring, ICU or stepdown units versus routine hospital ward settings, or the appropriate duration of monitoring.¹

Postoperative monitoring is performed in order to detect and prevent potential complications. Continuous pulse oximetry is the easiest and most reliable method for early detection of postoperative hypoventilation as it can alert the nursing staff and physician to a pending airway complication, and should be used for all OSAS patients following upper airway surgery. Intermittent spot checking of oxygen saturation typically has no benefit since the patent will usually be awakened by putting on the oximetryprobe. Some surgical facilities can perform continuous pulse oximetry in the extended recovery unit or hospital ward setting while others require an intensive care unit to administer continuous monitoring. While there is no consensus about whether cardiac monitoring affords any protection to the patient after sleep apnea surgery, it should be used in patients with a history of significant cardiac disease or cardiac arrhythmias.

Monitoring in the ICU has been recommended as a measure to decrease the risk of complications after OSAS surgery.^35,36 Some older publications have recommended ICU monitoring to monitor oxygen saturation and cardiac arrhythmias^21,22 while others have advocated ICU monitoring due to the high incidence of serious airway complications (13–25%) in patients undergoing UPPP.^36,37 Newer publications have noted a much lower complication rate, likely due to more aggressive perioperative precautions to avoid tissue edema and excessive sedation.^38,39 Other authors⁴⁰ used the precautions listed in this chapter and reported an overall complication rate of 4% (1.4% airway issues, 1.4% bleeding) in 347 consecutive patients.

4.6 USE OF SEDATIVES POSTOPERATIVELY

Sedative hypnotics are frequently administered after surgery for complaints of insomnia. As discussed earlier in this chapter, sedative hypnotics and anxiolytics should be avoided due to the adverse effects on arousal thresholds, as well as apnea duration and severity. For patients with OSAS, short-acting non-benzodiazapine hypnotic agents may be safer than benzodiazepine hypnotics. Zaleplon (half-life 1 hour) and zolpidem tartrate (half-life 2.5 hours) have no significant effect on the Apnea/Hypopnea Index compared to placebo in mild to moderate sleep apnea patients.⁴¹ However, while zaleplon had no effect on the oxygen saturation, zolpidem reduced the lowest oxygen saturation compared to placebo as well as the total time with SaO₂<90% and 80%, compared to the placebo group.

4.7 DVT PROPHYLAXIS

Obesity, advanced age, long surgical procedures and prolonged bed-rest can predispose to deep vein thrombosis (DVT) and pulmonary emboli. Methods to reduce the risk of this complication include application of sequential compression stockings, elastic stockings and subcutaneous heparin. DVT prophylaxis is indicated for the majority of patients undergoing surgery for sleep apnea.

4.8 BLOOD PRESSURE CONTROL

Patients with OSAS have a higher prevalence of hypertension and are at increased risk of postoperative hypertension due to an increased sympathetic tone.^13,14 To maintain a postoperative systolic blood pressure below 160 mm Hg and diastolic below 90 mm Hg, over half of the patients undergoing upper airway surgery for OSAS will require an antihypertensive agent in the recovery room (unpublished observations, S. Mickelson MD). Blood pressure control during and after surgery is imperative in order to reduce the risk of postoperative bleeding and tissue edema. Blood pressure control is most important after osseous surgeries, since postoperative bleeding from bone is blood pressure dependent.

4.9 GENERIC PATIENT CARE PROTOCOLS

Physician and hospital patient care protocols for preoperative instructions and postoperative orders are often utilized for surgery.⁴² Institution protocols should be examined to be sure that routine recovery room, surgical ward, or extended recovery unit orders are appropriate for the sleep apnea patient (see Tables 14.3 and 14.4). Nursing checks should be more frequent than for the non-OSAS patient, in order to visually check the patient’s breathing status and be sure there is no labored breathing.

Table 14.3 Standard preop orders for sleep apnea surgery

Table 14.4 Standard postop orders after sleep apnea surgery