For example, repeated episodes of sleep microarousal can cause sleep fragmentation, daytime fatigue, daytime sleepiness, memory loss, etc., and increase the sympathetic system tension, blood pressure, pulse rate, heart rate volume, and decrease in blood oxygen saturation can directly lead to cardiac arrhythmia, myocardial ischemia, stroke and sudden death. Surgery to relieve upper airway obstruction and improve patients’ quality of life is one of the most important means of treating OSAHS at present, but there are great risks during and after surgery, and life-threatening complications can occur (1). Xiaolan Cai, Department of Otorhinolaryngology, Qilu Hospital, Shandong University Perioperative risks are high in patients with OSAHS, and sleep fragmentation and hypoxemia are two of the major factors (2). Currently, Apnea Hypopnea Index (AHI) is the main index for diagnosing OSAHS and determining the severity of patient’s condition. Some studies have confirmed that patients with AHI >70 beats/h and Lowest Saturation (LSaO2) <80% have a higher risk of postoperative complications (3).Safe perioperative treatment of patients with OSAHS requires special attention to the pre- and post-surgery period, as OSAHS patients are often accompanied by other diseases such as hypertension, gastroesophageal reflux, diabetes mellitus Coronary artery disease and obesity; studies have shown that hypertension is present in about 45%-48% of OSAHS patients, cardiac arrhythmias are present in about 58% of OSAHS patients (4), and the prevalence of occult diabetes mellitus can be as high as 80% (5). The above risk factors suggest that the persistence of occult underlying health conditions in OSAHS patients significantly increases the risk of serious complications in the perioperative period (6). The presence of certain anatomical structural abnormalities in patients with OSAHS, such as mandibular retraction, mandibular shortening, lingual hypertrophy, tonsil and uvula hypertrophy, nasal obstruction, abnormal position of epiglottis, anterior laryngeal body, and prolonged airway extension can lead to difficulties in endotracheal intubation and intraoperative ventilation, which can in turn lead to tissue edema and aggravation of postoperative upper airway stenosis. And postoperatively, the use of anesthetics, analgesics, and sedatives reduces the microarousal response, prolonging respiratory events and further aggravating sleep apnea and hypoxemic hypercapnia. A growing number of studies have shown that OSAHS is a risk factor for high incidence of complications and mortality during anesthesia, with perioperative complications around 10%-20% (7), especially in upper airway surgery, and that it must be given high priority before, during, and after surgery in order to minimize the risks and associated disorders, and that early detection and management of outstanding issues of all types is beneficial in preventing complications. In this article, we review and analyze the potential complications associated with OSAHS surgery and strategies to avoid them. I. Preoperative treatment 1. Selection of surgical procedure The selection of surgical procedure mainly involves whether the patient should undergo outpatient surgery or inpatient surgery, which needs to take into account the relevant comorbidities, severity of apnea, upper airway stenosis and type of surgery, anesthesia mode, anesthesia time, and the use of postoperative analgesic and many other factors. The American Society of Anesthesiologists has developed a relevant assessment system (8), which concludes that: in patients with mild OSAHS, laser palatoplasty or nasal surgery does not increase the risk of associated complications, and in general, for most patients with mild OSAHS non-airway surgery or nasal surgery can be performed as an outpatient, with a minimum of 2 hours of observation in the recovery room after the outpatient procedure; however, patients with moderately severe disease are at a significantly increased risk, and palatoplasty or pharyngoplasty is not recommended for patients with moderate-to-severe disease, but for patients with moderate-to-severe disease. plication or pharyngeal airway surgery should be admitted to the hospital and kept under observation for at least 24 hours after surgery and for at least a few hours before discharge, with extended observation in patients with severe OSAHS, which should especially include observation of sleep time. Before discharge from the hospital after surgery, it should be known how well the patient sleeps under normal conditions (e.g., normal lying or habitual lying position, no oxygen or intravenous or intramuscular analgesics). Is sleep apnea worse than preoperatively, etc.? Postoperative monitoring is limited by environmental factors that do not exactly mimic the home environment, and certain conditions, such as raised head of the bed, postoperative oxygen, steroidal corticosteroid use, frequent checkups or sounds that disturb sleep and cause deep sleep, and a decrease in Rapid Eye Movement (REM), may result in an improvement or decrease in sleep apnea (AHI) compared to supine sleep. Analgesic use exacerbates it, so it is important to document the presence or absence of sleep apnea during postoperative observation, as well as the patient's oxygen saturation during sleep without oxygen. Hospital policies and care models directly influence the level and manner of postoperative monitoring, e.g., some hospitals use continuous pulse oximetry monitoring, while others require ICU implementation of postoperative monitoring. 2. Choice of anesthesia technique (local anesthesia, general anesthesia, or cardiac monitoring) Currently, most clinicians believe (7,8) that, because airway reconstruction surgery in patients with OSAHS can cause bleeding and access to the upper airway, general anesthesia is beneficial to the control and protection of the upper airway and ensures the safety of ventilation during the surgery. At the same time, controlled hypotension can be adopted to reduce intraoperative bleeding, which is conducive to calm intraoperative operation and complete hemostasis, preventing postoperative primary hemorrhage and obtaining satisfactory analgesia; at the same time, local soft tissue trauma can be avoided, preventing long-term complications such as pharyngeal lumen scarring and stenosis. Therefore, general anesthesia should be the preferred method for surgery involving the airway in patients with OSAHS. Local anesthesia can be considered under strict cardiac monitoring and oxygen inhalation only for non-airway procedures performed in patients with OSAHS, but sedation should be used cautiously to keep the patient awake and maintain an open airway, and blood oxygen and carbon dioxide levels can be monitored appropriately, and general anesthesia is more favorable for maintaining airway safety in patients who require moderate or deep sedation.General anesthesia for OSAHS surgery, especially during endotracheal Intubation, intraoperative controlled hypotensive state to observe the fluctuation of blood pressure and blood oxygen, as well as the mastery of the indication of extubation at the end stage of anesthesia, etc., have higher requirements for the practice level of anesthesiologists. According to T.Y. Li (8), all patients with OSAHS should be regarded as having a difficult airway, and the degree of difficulty of tracheal intubation should be objectively assessed, with a preference for slowly induced, transnasal tracheal intubation under mucosal surface anesthesia and conscious sedation. In addition, because obesity is very common among patients with OSAHS, the risk of gastroesophageal reflux should be alerted during the induction of anesthesia and extubation phase to prevent the occurrence of aspiration (7). 3. Use of Continuous Positive Airway Pressure (CPAP) preoperatively As the tolerance of OSAHS patients to surgery and anesthesia medication is significantly reduced, especially when accompanied by hypertension, asymptomatic cerebral embolism and so on, the risk of surgery is greater. And the more severe the disease, the greater the potential danger of surgery, and predicts difficulties in tracheal intubation and airway maintenance. Prone to intraoperative and postoperative hemodynamic instability, in which REM rebound in patients with severe OSAHS is thought to be a potentially important factor contributing to postoperative hemodynamic instability (6). The night before surgery, patients often suffer from insomnia due to anxiety about the upcoming surgery, and in addition, sleep deprivation can persist if CPAP is not well tolerated by the patient (9). Once the surgery is completed, patients can mostly enter deep and REM sleep. Therefore, sleep apnea can be more severe after surgery than preoperatively (10). Any preoperative measures to improve sleep quality may reduce postoperative deep sleep rebound. Perioperative CPAP treatment reduces postoperative deep sleep and REM sleep rebound, enhances respiratory drive, reduces pharyngeal edema, and makes anesthesia management easier and safer by improving the patient's sleep structure, correcting sleep apnea disorders and hypoxemia, which is of positive significance in promoting the blood and oxygen supply to the heart, brain, and other vital organs, improving the patient's tolerance for surgery and anesthesia, and preventing the occurrence of perioperative complications (6,7).OSAHS patients mostly suffer from chronic pharyngitis due to long-term open-mouth breathing during sleep.Long-term inflammatory stimulation leads to poor vasodilatation of the mucous membrane and intraoperative bleeding, which is unfavorable for operation. Therefore, for OSAHS patients with a long course of disease, serious condition, hypertension and other complications, glucocorticoids and antimicrobials can be applied before surgery, and localized nebulization of the pharyngeal cavity can be performed. Combined with noninvasive positive pressure ventilation therapy such as CPAP, it can effectively eliminate patients' open-mouth breathing during sleep and improve the chronic inflammatory state of the pharyngeal cavity mucosa. Therefore, most scholars recommend (11) the use of CPAP treatment preoperatively to ensure the safe use of anesthesia and analgesic drugs in the perioperative period in patients with OSAHS. Although, most patients who choose upper airway surgery refuse to use CPAP or have poor CPAP tolerance, moderate preoperative CPAP still has some positive significance, and if possible, patients should be asked to use CPAP for several weeks before and after surgery, and bring their own ventilator to the hospital for perioperative treatment. 4. Use of analgesics and sedatives Sedatives, anxiolytics, and analgesics should be avoided if possible in patients with OSAHS prior to surgery, as they have been reported to cause sudden preoperative death in patients with OSAHS (12). Sedatives inhibit respiratory drive, impair the microarousal response, and can lead to life-threatening hypoxemia. Benzodiazepine P203 hypnotics (sedatives) can affect upper airway dilator muscle tone, increase apnea index, decrease oxygen saturation and the microarousal response, and prolong the duration of respiratory events (13). If a patient with OSAHS requires sedative or anxiolytic medication, it should be administered immediately before the start of the procedure, with adjunctive oxygenation and continuous oximetric pulse monitoring. 5. alert reflexes and aspiration Obesity is very common in patients with OSAHS, leading to accumulation of abdominal fat, increased intra-abdominal pressure, and elevated risk of gastro-esophageal reflux. since obese patients are characterized by a large volume of gastric fluid and a low pH value, in order to minimize this type of complication during the induction of anesthesia and extubation phase, H2-receptor antagonists, proton-pump blockers, or esophageal prokinetics should be administered preoperatively (14); and postoperatively, suction should be applied to the gastric contents. 6. Preoperative medical consultation system Physicians, cardiovascular physicians, anesthesiologists, and related specialists should be Comprehensive consideration should be given to the complications associated with OSAHS patients, and they should be treated promptly. For example, complicated hypertension should be treated with triple antihypertensive therapy, and diabetes mellitus comorbidities that are not well controlled may benefit from preoperative medical consultation. The aim is to optimize the treatment of complications in OSAHS patients preoperatively and to reduce the risks associated with surgery. Due to the increased sympathetic drive in patients with OSAHS, the risk of hypertension is significantly increased, and undiagnosed hypertension is more common (15, 16). Therefore, preoperative blood pressure monitoring is mandatory. 7.Communication with the anesthesiologist As a surgeon, it is the responsibility to discuss with the anesthesiologist the potential risks and difficulties that may be triggered during the surgery.The anesthesiologist should be aware of the severity of sleep apnea, which challenges the maintenance of airway safety due to the presence of hypertrophy of the tongue, retrusion of the mandible, and a small jaw in some patients with OSAHS, which consequently leads to difficulties in mechanical ventilation or intubation and extubation. Such patients should be prepared for tracheotomy in the operating room, and fiberoptic tracheoscopy can also be used to assist intubation. Endotracheal intubation should preferably be performed in the awake state in moderate and severe patients, thus avoiding the risk of asphyxiation in case of difficult intubation. Postoperative monitoring Several studies have shown (17) that the severity of sleep apnea on the first and second days after UPPP does not improve significantly, and is even more severe than before surgery, and that the 24-hour period after surgery is the most dangerous time period for surgical complications other than sudden death due to the cumulative effects of sleep deprivation, anesthesia application, and rebound in the PEM period and other potential risk factors (18). , 19). Studies have shown (9) that the majority of patients, even those with remarkable outcomes 3 months after surgery, do not show significant improvement in apnea index, respiratory disturbance index, minimum oxygen saturation, and minus oxygen index for at least two days after surgery compared with the preoperative period; there is no literature available that confirms how long postoperative monitoring should be continued, but that postoperative monitoring is a favorable measure for the early detection or prevention of complications,. Among them, continuous pulse oximetry is the simplest and most reliable method for early detection of postoperative alveolar hypoventilation, which can alert healthcare professionals to pending respiratory complications that have not yet occurred. Continuous pulse oximetry monitoring can be combined with an audible alarm and can be applied to all OSAHS patients undergoing upper airway surgery or non-airway surgery. Intermittent monitoring of oximetry is not significant because placement of the oximetry probe may awaken the patient, and although there is no consistent endorsement of the significance of continuous cardiac monitoring, its use should be considered in patients with significant cardiac disease or arrhythmia. It has been suggested that ICU monitoring has implications for minimizing the risk of postoperative complications in patients with OSAHS. A large body of early literature recommended monitoring of oxygen saturation and cardiac arrhythmias in the ICU unit because, the incidence of serious airway complications after UPPP surgery is as high as 13%-25%. Recent analysis of the literature has shown (20, 21) that airway complications have been significantly reduced to about 1.4% due to the current improved techniques of perioperative treatment, reduction of soft tissue edema in the upper airway, and avoidance of sedative drug abuse. Most surgeons and anesthesiologists have developed a standard model of preoperative and postoperative nursing supervision (23) to ensure that OSAHS patients are treated in an orderly manner in the ward, operating room, and recovery room, and that the patient's respiratory rate, respiratory depth, the presence or absence of snoring apnea, hypoventilation, respiratory effort, and other important signs are monitored and recorded. 2. Post-surgical position of patients In OSAHS patients sleeping in lateral, prone or head-high position, respiratory disorders such as apnea, hypoventilation and hypoxemia are improved, while in supine position, apnea and hypoventilation are aggravated due to the fall of the tongue root backward. Due to the lack of venous valves of the veins in the head and neck region, the flat position can cause the venous pressure to increase, which aggravates the edema of soft tissues. Therefore, the head of the bed should be elevated after surgery to reduce the edema of the soft tissues of the head and face and the nasal cavity, to improve frequent breathing, and to avoid the supine position (8). 3.Postoperative analgesia All opiate analgesics can cause dose-dependent decreases in respiratory drive, respiratory rate, and tidal volume, causing alveolar hypoventilation, hypoxemia, and hypercapnia (23,24).The frequency and severity of respiratory disturbances are significantly increased after use in patients with OSAHS, which should be of special concern. However, what makes it difficult for healthcare professionals is that after upper airway reconstruction, patients often have significant pain and require 10-14 days of appropriate analgesia (17). Currently, there is no adequate literature evaluating the effectiveness of analgesics used by different routes, such as oral, intramuscular or intravenous. In conclusion, analgesics should be used with caution and should be considered only when pain is severe and other medications are ineffective; the choice of strong analgesics should be considered when weaker analgesics are ineffective; and oral opiate therapy is preferred for mild-to-moderate pain to reduce respiratory depression. Non-steroidal anti-inflammatory drugs also have a role to play, but one must be wary of the potential danger of increased bleeding. Mucosal surface anesthesia also has a certain auxiliary pain-reducing effect. 4. Continuous positive pressure ventilation (CPAP) and assisted oxygenation After surgery, it is very important to maintain appropriate blood oxygen. Decreased oxygen saturation can lead to cardiac arrhythmia or serious cardiac and central nervous system complications. Adjunctive postoperative oxygenation in patients without sleep apnea can maintain oxygen saturation above 90%. In general, continuous assisted oxygenation is not necessary when the patient's baseline oxygenation is stably maintained above 90% while breathing room temperature air in the awake state; however, in patients with OSAHS, the purpose of oxygenation is not only to keep oxygenation stable during wakefulness, but also to prevent fluctuations in oxygenation in the event of respiratory disturbances in the sleep state. Preoperative noninvasive ventilation should be carried out in all OSAHS patients who can tolerate CPAP therapy, and CPAP application is also safe and reliable after upper airway surgery in the majority of OSAHS patients.Effective CPAP pressure support is equally important in OSAHS patients after surgery, especially within 2 days after palatopharyngoplasty, when airway stenosis is more pronounced than preoperatively (25). Most scholars recommend (6,7) the use of CPAP therapy preoperatively and resuming its use shortly after postoperative extubation to reduce the risk of gastroesophageal reflux (26) and to ensure the safe use of anesthetics and analgesics in patients with OSAS. In patients with concomitant hypertension, postoperative CPAP therapy in conjunction with intravenous antihypertensive medications can achieve short-term stabilization of blood pressure reduction, thereby reducing the incidence of perioperative hypoxemia and hypertensive crises (27). The therapeutic pressure for postoperative CPAP can be either the preoperative pressure or a higher pressure to counteract postoperative soft tissue edema and persistent hypoxemia during sleep, or a lower therapeutic pressure to accommodate an enlarged upper airway after surgery or to prevent the patient from being unable to tolerate CPAP therapy. Another option for noninvasive ventilation therapy is an autoregulated CPAP ventilator, which presets the therapeutic pressure and automatically regulates it based on the presence of respiratory events such as respiratory disturbances and airflow limitation. Postoperative CPAP therapy is limited by potential subcutaneous interstitial edema after maxillary and mandibular anterior migration; and by nasal congestion, edema, or bleeding after nasal surgery, but an oral-nasal full face mask can be chosen instead of a nasal mask or nasal pillows after nasal surgery. 5. Reduce postoperative airway edema Various types of upper airway surgery, even after laser or radiofrequency ablation therapy, as well as difficult tracheal intubation and other treatments can lead to respiratory edema, especially after severe apnea and multiplanar airway surgery. Administration of systemic steroid hormone therapy is a reliable means of reducing upper airway edema, and a commonly used drug is dexamethasone because it causes less sodium retention. For best results, it is usually given once preoperatively and in divided doses postoperatively at a dose of 10-15 mg/d of dexamethasone in adults, and can be given locally with cold ice packs or gargles to reduce soft tissue edema and pain. Within 1 hour after surgery, topical Dobelle's solution gargle or systemic antimicrobials are given to reduce the risk of infection and help reduce pain and local edema. Postoperative nasal obstruction can cause or aggravate sleep apnea and should be avoided. Nasal sprays and decongestants are effective in relieving nasal obstruction after nasal surgery or nasal cannula. 6. Use of postoperative sedatives Many patients complain of insomnia after surgery, and the use of sedative sleeping pills to help patients fall asleep is very common. However, sedative hypnotics and anxiolytics should be avoided in patients with OSAHS because they have the ability to raise the microarousal threshold, prolong the duration of apnea, and increase the severity of apnea and hypovolemia. If sleep-promoting agents must be used, it is safer to choose short-acting nonbenzodiazepines with a half-life of 1-2.5 hours. Among them, ZALEPLON and ZOLPIDEM TARTRATE. had no significant effect on the apnea hypoventilation index in patients with mild-to-moderate OSAHS compared with placebo (31, 32).ZALEPLON had no significant effect on oxygen saturation, but ZOLPIDEM decreased the minimum oxygen saturation and increased the total number of hours of oxygen saturation below 90% and below 80% of the total time. 7. Preventing the formation of deep vein thrombosis Obesity, advanced age, prolonged surgical procedures, prolonged bedtime and other factors are likely to lead to the formation of deep vein thrombosis and pulmonary embolism. The use of continuous compression stockings, compression stockings or subcutaneous injection of heparin, getting out of bed as early as possible and avoiding prolonged bed rest can reduce the risk of deep vein thrombosis. 8. Maintenance of blood pressure Hypertension is extremely common in patients with OSAHS, and the risk of postoperative hypertension in these patients is significantly increased after surgery due to increased sympathetic tone (15, 16). More than half of OSAHS patients who undergo upper airway surgery require antihypertensive therapy during the postoperative recovery period to maintain postoperative blood pressure below 160/90 mmHg. Control of blood pressure stabilization is the most important therapeutic measure after maxillomandibular plasty surgery because healing of postoperative traumatic bone tissue is associated with high and low blood pressure. Blood pressure control is important to reduce postoperative bleeding, hematoma and secondary soft tissue edema. 9. Indications for Discharge of OSAHS Patients After Surgery There is no literature available to provide guidance on the appropriate timing of postoperative discharge of patients with OSAHS, and physicians of the American Society of Anesthesiologists have concluded (8) that patients may be considered for discharge when their oxygen saturation returns to the preoperative baseline in the absence of stimuli, while breathing room air, and there is no hypoxemia or upper airway obstruction after 7 hours of monitoring. Such recommendations, although of some value, are not practical for many patients. Most patients with OSAHS who opt for surgical treatment are unable or unwilling to use CPAP, and surgery is not always completely successful for all patients, with apnea persisting in many postoperatively. Therefore, more practical indications for discharge are: no significant worsening of respiratory events and hypoxemia at discharge compared with preoperative sleep baseline; some patients with persistent sleep disturbances require assisted oxygenation at home or elevation of the head of the bed during sleep and minimization of soft tissue edema; and discharge to home should only be considered when the patient is able to swallow appropriately, consume water, and maintain nutrition, and oral rinses of analgesia may be appropriate for pain control. Pain. Important vital signs, such as temperature, pulse, blood pressure, and respiratory rhythm, should be maintained stable before discharge. Summary: Surgical management of patients with OSAHS poses special challenges to surgeons, anesthesiologists, and nursing staff. The risk of surgical and post-anesthetic complications, including upper airway obstruction, myocardial ischemia, stroke, cardiac arrhythmia, and sudden death, is significantly increased and can be reduced by high vigilance before and after surgery. Safe perioperative treatment, as an important concept, includes careful use of analgesics and sedatives, reduction of upper airway edema, prevention of aspiration and deep vein thrombosis, control of blood pressure, use of noninvasive positive pressure ventilation such as CPAP whenever possible, and appropriate postoperative monitoring. REFERENCES 1. Editorial Committee of Chinese Journal of Otorhinolaryngology, Chinese Society of Otorhinolaryngology, Chinese Medical Association. Diagnostic basis and efficacy evaluation criteria for obstructive sleep apnea hypoventilation syndrome and indications for uvulopalatopharyngoplasty (Hangzhou)[S]. Chinese Journal of Otolaryngology,2OO2,37(6):403-4O4. 2. Kryger M H, Roth T, Dement W C. Principles and practice of sleep medicine. 4th ed. Philadelphia: Elsevier. 2005:1287- 1296. 3. 1296. 3. Esclamando R, Glenn M, Mcculloch T, et al. Perioperative complications and risk factors in the surgical treatment of obstructive sleep apnea syndrome. Laryngoscope, 1989, 99: 1125-1129. 4. Hoffstein V, Mateika S. Cardiac arrhythmias, snoring and sleep apnea. Chest. 1994,106(2): 466-471. 5. Peltier AC, Consens FB, Sheikh K, et al. Autonomic dysfunction in obstructive sleep apnea is associated with impaired glucose regulation. Sleep Med. 2007, 8(2):149-155. 6. Kezirian EJ, Weaver EM, Yueh B, et al. Risk factors for serious complication after uvulopalptopharyngoplasty[J]. Arch Otolaryngol Head Neck Surg, 2006, 132: 1091-1098. 7. Practice guidelines for the perioperative management of patients with obstructive sleep apnea. apnea. a report by the American Society of Anesthesiologists Task Force on perioperative management of patients with obstructive sleep apnea. Anesthesiology 2006;104:1081-1093. 8. Li TY. Anesthetic management in uvulopalatopharyngoplasty. Chinese Journal of Otolaryngology, Head and Neck Surgery, 2007, 42(2):157-160 9. Rosenberg J, Rosenberg-Adamsen S, Kehlet H. Post-operative sleep disturbances; causes, factors and effects on outcome. Eur J Anaesthesiol 1995;10 (Suppl):28-30. 10.Cullen DJ. Obstuctive sleep apnea and postoperative analgesia: a potentially dangerous combination. J Clin Anesth 2001; 13:83-5. 11.Kaw R, Michota F, Jaffer A, et a1.Unrecognized sleep apnea in the surgical patients implications for the peri-operative setting[J].Chest, 2006,129(1): 198-205. 12.Fairbanks DNF. Uvulopalatopharyngoplasty complications and avoidance strategies. Otolaryngol Head Neck Surg 1990; 102: 239-45 13.Berry RB,Kouchi K, Bower J, et al. Triazolam in patients with obstructive sleep apnea. Am J Respir Crit Care Med 1995; 151: 450-4. 14.Warwick JP, Mason DG. Obstructive sleep apnoea in children. Anaesthesia 1998;53: 571-9. 15.Worsnop CJ, Pierce RJ. Naughton M. Systemic hypertension and obstructive sleep apnea. Sleep 1993; 16: S148-9. 16.Bonsignore MR, Marrone O, Insalaco G, et al. The cardiovascular effects of obstructive sleep apnoeas: analysis of pathogenic mechanisms. Eur Respir J 1994; 7: 786-805. 17.Troell TJ, Powell NB, Riley TW, et al. Comparison of postoperative pain between laser assisted uvulopalatoplasty, uvulopalatopharyngoplasty and radiofrequency volumetric tissue reduction of the palate. Otolaryngol Head Neck Surg 2000; 122: 402-9. 18.Rosenberg J, Rasmussen GI, Wojdemann KR, et al. Ventilatory pattern and associated episodic hypoxaemia in the late postoperative period in the general surgical ward. Anaesthesia 1999; 54: 323-8. 19. Skinner MI, et al. Anesthesia with abdominal surgery leads to intense REM sleep during the first postoperative week. Anesthesiology 1990; 73:52-61. 20. Hathaway B, Johnson JT. Safety of uvulopalatopharyngoplasty as outpatient surgery. Otolaryngol Head Neck Surg 2006; 134(4):542-4. 21.Kezirian EJ, Weaver EM, Yueh B, et al. Incidence of seious complications after uvulopalatopharyngoplasty. Laryngoscope 2004; 114(3):450-3. 22. Hakim I. Is post operative intensive care monitoring necessary after uvulopalatopharyngoplasty? Otolaryngol Head Neck Surg 1998; 119(4):352-6. 23. Mickelson SA. Perioperative and anesthesia management in obstructive sleep apnea surgery. Fairbanks DNF, Mickelson SA, Woodson BT, et al. Snoring and obstructive sleep apnea, 3rd edition. Philadelphia: Lippincott Williams & Wilkins; 2003. p. 223-32. 24. Bailey PL, Egan TD, Stanley TH. Intravenous opioid anesthetics. In: Miller RD, editor. Anesthesia.5th edition. Philadelphia: Churchill Livingstone; 2000. p. 273-376. 25.Terris D J, Clerk AA, Norbash A M, et al. Norbash A M, et al. Characterization of postoperative edema following laser-assisted uvulopalatopharyngoplasty using MRI and polysomnography. Implications for the outpatient of obstructive sleep apnea syndrome. Laryngoscope, 1996,106(2 Pt 1): 124-128. 26.Kerr P, Shoenut JP, Millar J, et al. Nasal CPAP reduces gastroesophageal reflux in obstructive sleep apnea syndrome. Chest 1992;101(6):1539-44. 27.Sanner B M, Tepel M, Markmann A, et al. Effect of continuous positive airway pressure therapy on 24-hour blood pressure in patients with obstructive sleep apnea syndrome. Am J Hypertens,2002 ,15(3):251-257. 28.Terris DJ, Clerk AA, Norbash AM, et al. Characterization of postoperative edema following laser-assisted uvulopalatoplasty using MRI and polysomnography: implications for the outpatient treatment of obstructive sleep apnea syndrome. Laryngoscope 1996; 106:124-128. 29. Powell NB, Riley RW, Troell RJ, et al. Radiofrequency volumetric reduction of the tongue: a porcine pilot study for the treatment of obstructive sleep apnea syndrome. apnea syndrome. Chest 1997;111: 1348-55. 30.Sheppard LM, Werkhaven JA, Mickelson SA. The effect of steroids or tissue pre-cooling on edema and tissue thermal coagulation after CO2 laser impact. Lasers Surg Med 1992; 12: 137-46. 31.George CFP. Perspectives on the management of insomnia in patients with chronic respiratory disorders. Sleep 2000; 23(Suppl 1):S31-5. 32.Mickelson SA. Avoidance of complications in sleep apnea patients. In: Terris DJ, Goode RL, editors. Goode RL, editors. Surgical management of sleep apnea and snoring. Boca Raton(FL):Taylor & Francis Group;2005.p.453-64.