RISKS AND COMPLICATIONS OF UNDIAGNOSED OBSTRUCTIVE SLEEP APNEA FOR THE PERIOPERATIVE PATIENT. Matthew Eric Dehning, RN, BSN

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1 ..., t;., RISKS AND COMPLICATIONS OF UNDIAGNOSED OBSTRUCTIVE SLEEP APNEA FOR THE PERIOPERATIVE PATIENT By.,., July.,., Matthew Eri Dehning, RN, BSN A manusript submitted in partial fulfillment for the degree of: MASTER'S OF NURSING WASHINGTON STATE UNIVERSITY-VANCOUVER College of Nursing ,',...., ".., C;.,.

2 ., &,...., To the faulty ofwashington State University:,.. The It 16:', COMPLICAnONS OF UNDIAGNOSED OBSTRUCTIVE SLEEP APNEA members ofthe Committee appointed to examine the projet ofmatthew ERIC DEHNING find it satisfatory and reommend that it be aepted..,, Dawn Felh Rondeau, DNP, ACNP, FNP, Chair.,.,., Renee Celeste Hoeksel, PhD, RN.. Lorrie Dawson PhD, ARNP., CIf Dionetta Hudzinski MSN, RN.,,", (.,.. (..,.

3 COMPLICATIONS OF UNDIAGNOSED OBSTRUCTIVE SLEEP APNEA III RISKS AND COMPLICATIONS OF UNDIAGNOSED OBSTRUCTIVE SLEEP APNEA FOR THE PERIOPERATIVE PATIENT ABSTRACT By Matthew Eri Dehning Washington State University July 2011 Chair: Dawn Felh Rondeau Obstrutive sleep apnea (OSA) is very ommon. An estimated 82% of men and 92% of women with moderate to severe sleep apnea have not been diagnosed. This potentially leaves patients at risk for perioperative ompliations. The perioperative risk ofpatients with OSA may be redued by appropriate sreening to detet undiagnosed OSA patients. OSA is a very serious ondition that diminishes quality of life and is also assoiated with many ommon o-morbid onditions. Studies have doumented an inrease inidene of oronary artery diseases, hypertension, ongestive heart failure, erebrovasular aidents, gastroesophageal reflux disease and other potentially life threatening onditions in patients with OSA. This paper provides information that is essential for Nurse Pratitioners and other health are providers to sreen and diagnosis this very ommon and preventable heal.th ondition.

4 .,., COMPLICATIONS OF UNDIAGNOSED OBSTRUCTIVE SLEEP APNEA IV, " ABSTRACT TABLE OF CONTENTS TABLE OF CONTENTS Page III iv LIST OF TABLES V INTRODUCTION 1 STATEMENT OF PURPOSE OBSTRUCTIVE SLEEP APNEA BACKGROUND INFORMATION 1-2 & PATHOPHYSIOLOGY LITERATURE SEARCH STRATEGIES IIh.,, C " THEORETICAL FRAMEWORK LITERATURE REVIEW SIGNIFICANCE OR IMPLICATIONS FOR NURSING SUMMARY REFERENCES

5 . '" '''. "".,....'.' COMPLICATIONS OF UNDIAGNOSED OBSTRUCTIVE SLEEP APNEA LIST OF TABLES Oxyhemoglobin Dissoiation Curve, Table 1 4 v Anatomy ofnonnal Airway and Potential Airway Obstrution, Figure 1 STOP Questionnaire, Table 2 Obstrutive Sleep Apnea Signs and Symptoms, Table 3 &., e & C & C & C,,

6 COMPLICATIONS OF UNDIAGNOSED OBSTRUCTIVE SLEEP APNEA 1 Obstrutive sleep apnea (OSA) is a disorder haraterized by repetitive episodes of apnea or redued inspiratory airflow due to upper airway obstrution during sleep (Olson 2011)., &., & Obstrutive sleep apnea is the most ommon sleep-related breathing disorder and is widely reognized as a publi health problem. In the United States OSA is more prevalent than asthma and is as ommon as diabetes mellitus (Krieger & Caples 2007). When sleep is disrupted in OSA by arousals, apneas, and hypopneas, the onsequenes inlude ardiovasular morbidity, exessive sleepiness, depressed mood, ognitive impairment, and diminished quality of life (Hirshkowitz 2008). Aording to Stierer, Wright, George, Thompson, Wu and Collop (2010) OSA has been I;;...i'...,, reognized as a potential independent risk fator for adverse perioperative outomes. Although the prevalene of OSA in the general population has been estimated to be between 2% and 4%, there is a higher inidene in ertain subpopulations suh as males and obese subjets. Many people with OSA have not been diagnosed. The atual prevalene of OSA in the general population may be as high as 80% to 90% of all patients.. & ompliations.",. "".\..... C1 e, ",, Despite its high prevalene and signifiant adverse effet on a patients funtioning and quality of life, exessive sleepiness often goes unreognized in the primary are setting. The from OSA an negatively affet a surgial outome. The inidene of perioperative ompliations (ie, preoperative, intraoperative and postoperative ompliations olletively) is inreased among patients with OSA (Olson 2011). The Joint Commission has suggested that a National Patient Safety Goal should be the redution of perioperative ompliations in patients with OSA.

7 s C, It C C., The in COMPLICATIONS OF UNDIAGNOSED OBSTRUCTIVE SLEEP APNEA 2 Statement of Purpose fir & $. & ",! and an integrated team approah to perioperative management (Olson 2010). $ e II;. Amerian Soiety of Anesthesiology and Amerian Aademy of Sleep Mediine has developed a linial pratie guideline for the perioperative management of patients with OSA. Common among the guidelines is an emphasis on maintaining a high index of suspiion for OSA, areful use of mediations, vigilant monitoring for evidene of upper airway obstrution, Nurse pratitioners and other primary are providers need to be autely aware that exessive sleepiness is a ommon problem. There are assoiated problems whih stem from OSA suh as medial, neurologi, and psyhiatri disorders that are seen in the primary are setting. The purpose of this paper is to determine the symptoms that lead to a diagnosis of OSA the primary are setting and how to best provide a treatment plan to redue the assoiated risks during the perioperative period ofare.., Pathophysiology Apnea is the essation of airflow at the nose and mouth for more than ten seonds and ontinued respiratory effort despite airflow essation. In entral sleep apnea (CSA) the brains' respiratory ontrol enters are imbalaned during sleep. CSA is a rare type of sleep apnea. In CSA, the area ofthe brain that ontrols breathing doesn't send the orret signals to the breathing musles. As a result, there is no effort to breath at all for brief periods. In people with indiates omplete obstrution of the upper airway. Apnea is onsidered obstrutive if there is.,.,,,, CSA, snoring does not typially our (Pollard & Rie 2006).

8 " COMPLICATlONS OF UNDIAGNOSED OBSTRUCTIVE SLEEP APNEA 3,. Ii &...' Hyperpnea is defined as a 50% redution in airflow for at least 10 seonds15 or more times per hour of sleep assoiated with snoring and a 4% derease in oxygen saturation (Paje & Kremer 2006). Blood levels ofarbon dioxide and the neurologial feedbak mehanism do not reat quikly enough to maintain an even respiratory rate, with the entire system yling between apnea and hyperpnea, even during wakefulness. Sleep abolishes proprioeptive feedbak from thorai and upper airway reeptors and suppresses hemial feedbak, whih inreases neural output to the pharyngeal musles. At sleep onset, all or any ofthese mehanial, neural, and strutural fators ontribute to upper airway ollapse that either fully eliminates or substantially redues ventilation. During airway obstrution hypoxemia, hyperapnia, and a derease in ph development auses a progressive inrease in ventilator drive to the respiratory pump and upper airway musles (Paje & Kremer 2006). The patient stops breathing and then starts again. There is no effort made to breathe during the pause in breathing; there are no hest movements., oxyhemoglobin After an episode of apnea, breathing may be faster (hyperpnea) for a period oftime. During this time several fators an hange a relationship between P02 and S02, ausing the dissoiation urve to shift to the right or left. A shift to the right depits hemoglobin's dereased affinity for oxygen or an inrease in the ease with whih oxyhemoglobin disassoiates and oxygen moves into the ells. A shift to the left depits....'"" hemoglobin's inreased affinity for oxygen, whih promotes assoiation in the lungs and inhibits dissoiation in the tissues. The oxyhemoglobin dissoiation urve is shifted to the right by aidosis (low ph) and hyperapnia (inreased PaC02) (MCane & Huether 2006)..,

9 COMPLICAnONS OF UNDIAGNOSED OBSTRUCTIVE SLEEP APNEA 4 Table 1 Oxyhemoglobin Dissoiation Curve 100 ioo so 'ii" S lj 50.E 40 i :I 30 20, 10 0 Sl1ff. to nght +P"COz +Temp,eraturo,-pH '10 :zo 3iO AO 54) flo } 100 P,,02 (mm HU). The pathogenesis of OSA is multi-fatorial. Contributing fators inlude airway anatomy, upper airway dilator musles, and ventilator stability. The site of upper airway obstrution typially lies in the pharynx. The pharyngeal luminal area during inspiration reflets a balane between ollapsing intra-pharyngeal negative sution pressure and dilating fores provided by the pharyngeal musles. In onsious individuals, the pateny of the retropalatal, retroglossal, and retroepiglotti pharynx is maintained by the entral nervous system's ontinually mediated ontration of the tensor palatine, the genioglossus, and the hyoid bone musles. These dilator musles oppose the negative ollapsing fore developed during inspiration. This ativation of musle tone is typially redued during sleep and, in many individuals, leads to ompromised pateny of the upper airway with turbulent airflow and snoring. In obese patients, more adipose tissues in the pharyngeal strutures inrease the likelihood that relaxation of the upper airway musles will ause ollapse of the soft walled oropharynx between the uvula and the epiglottis.

10 COMPLICAnONS OF UNDIAGNOSED OBSTRUCTIVE SLEEP APNEA 5 Extraluminal pressure is inreased by superfiially loated masses and the upper airway is ompressed externally (Paje & Kremer 2006). Figure 1 Anatomy ofnormal Airway Potential Airway Obstrution 1 f A 0: 3 A '" \II 3 \/I '" fl a.jpg Literature Searh Strategies A ombination of searh strategies was utilized related to the topi of interest. The initial searh inluded websites suh as GoogleSholar.om, Uptodate.om, and Medline.om. The Portland Veteran's Administration's databases were utilized. The one database that was the most useful was Pubmed.om. Searh terms utilized inluded "Primary Care", "OSA", and "Perioperative OSA". Only soures that were available in full text were utilized. There were literally hundreds of artiles on the topi. Beause OSA was not on the forefront of medial researh prior to the early 90's, resoure materials that were no older than five years were utilized. The information provided the most reent and up to date materials available. The materials utilized inluded retrospetive studies, surveys, self administered questionnaires,

11 e., It soures.,...';)., Ii. Review COMPLICATIONS OF UNDIAGNOSED OBSTRUCTIVE SLEEP APNEA 6 sientifi reviews, sreening protools, literature reviews, and random sample studies. Of the fifty or so artiles that were reviewed, they were further narrowed to eight of the most pertinent of information. The riteria for this paper was developed from a ombination of soures taking into onsideration primary are patients and also those patients in the perioperative period of are. The main fous of this paper lies in the assessment and diagnosis of OSA in the general population, and the assoiated risks for patients during the perioperative period of are, whether diagnosed previously with OSA or not. of Literature Stierer, Wright, George, Thompson, Wu, and Collop (2010) onduted a study utilizing a self-administered questionnaire, with a previously validated predition model, evaluating the probability for OSA. Conseutive patients 18 years and older ompleted a self administered questionnaire to assess demographis (age, gender, rae, body mass index [BMI] and sleep.., /e.., disturbane symptoms. History of angina, myoardial infartion, stroke, heart failure, and oronary artery revasularization was reorded based on self-report. The frequeny of sleep related symptoms (e.g., snoring, witnessed apneas) was reorded on a 6-point Likert Sale (never, rarely, sometimes, often, usually, and always). Patients with >70% propensities were onsidered to be at high risk of having the disorder. The Amerian Soiety of Anesthesiology (ASA) advoates the use of the STOP questionnaire (see table 2) whih asks about snoring, daytime sleepiness, falling asleep while relaxing, waking up at night with a feeling of shortness of breath or hoking, waking up in the morning still feeling tired or with a headahe, hroni

12 .... snorting., s, COMPLICATIONS OF UNDIAGNOSED OBSTRUCTIVE SLEEP APNEA 7 nasal ongestion, as well as reports of witnessed behaviors suh as sleepiness, gasping, hoking, or the absene of breathing while asleep (Olson 2010). Table 2 STOP Questionnaire STOP Questionnaire.. 2. Chung,, Aording 1. Snoring: Do you snore loudly (louder than talking or loud enough to be heard through losed doors)? Tired: Do you often feel tired, fatigued, or sleepy during the daytime? 3. Observed: Has anyone observed you stop breathing during your sleep? 4. Blood Pressure: Do you have or are you being treated for high blood pressure? *High risk of OSA, answering yes to two or more questions. Low risk of OSA, answering yes to less than two questions. F. & Elsaid, H. (2009). Sreening for obstrutive sleep apnea before surgery: why is it important? Current Opinion in Anesthesiology, 22: , Berlin & In..,', to Seet & Chung (2010), patients with OSA may have an inrease in postoperative adverse respiratory events, sustained arrhythmias, hypertension, and other ardiovasular events. The gold standard for the diagnosis of OSA is polysomnography. The Questionnaire and the Amerian Soiety of Anesthesiologists OSA heklist are useful sreening tools, while the STOP and the STOP-BANG Questionnaires are easy to use in adults (Seet and Chung 2010). a study by Stierer, Wright, George, Thompson, Wu and Collop (2010), relevant perioperative data and ompliations were traked and reorded. This study also inluded a self '

13 COMPLICATIONS OF UNDIAGNOSED OBSTRUCTIVE SLEEP APNEA 8 administered questionnaire using a Likert Sale. Differenes in median estimated propensities for OSA were onsidered by this data. The preoperative survey was ompleted by 3,553 onseutive subjets. A total of2,139 patients had perioperative data and estimated propensity sores. Ninety-four of the 2,139 (4.4%) patients gave a self-reported prior diagnosis of OSA. One hundred three (4.8%) patients were found to be at high risk ofosa based on the survey. Seventy-five perent of the patients with >70% propensity for OSA had not been diagnosed. 94 of the 2,139 (4.4%) patients gave a self-reported prior diagnosis of OSA. The study results reported that undiagnosed sleep apnea is very ommon in the ambulatory surgery setting. The questionnaires used in this investigation are not 100% preditive, and may fail to identify patients with OSA, partiularly in those who are young, thin, or female. Greenberg-Dotan, Reuveni, Simon-Tuval, Oksenberg, Tarasiuk (2007) onduted a quantitative study to explore gender differenes in o-morbidities and total health are utilization five years prior to diagnosis of OSA. The study mathed 289 male patients with 289 female patients who had ompleted a polysomnographi (PSG) test whih resulted in a diagnosis of OSA. The polysomnography test has been shown to be the most speifi for diagnosing OSA (Stierer, et ai., 2010). The study utilized a two-way analysis of variane to determine the signifiane ofthe total 5-year osts between all women and men in the study. It was determined that ompared to men with similar OSA severity, women were more frequent users of health are resoures. Women with OSA reported atypial OSA symptoms, whih may lead to other diagnosis suh as depression, insomnia, and hyperthyroidism. Little is known regarding differenes in morbidity and health are utilization prior to OSA diagnosis

14 ., COMPLICATIONS OF UNDIAGNOSED OBSTRUCTIVE SLEEP APNEA 9 based on gender. Women with typial symptoms may fail to get feedbak from their partners and thus be unaware of the need to seek are or if aware, may feel unomfortable about seeking help for a "male" problem. Also liniians who are unaware that OSA is ommon in women will e ;".'j inreased.. evaluation likely fail to reognize the problem, and women without typial symptoms will also be missed (Greenberg-Dotan, et.al 2007). Gali, Whalen, Gay, Olson, Shroeder, Plevak, and Morgenthaler (2007) onduted a quantitative study reporting that the presene ofundiagnosed OSA inreased the perioperative morbidity and mortality for patients in perioperative are. Following surgery, patients were monitored in the Post Anesthesia Care Unit (PACU) for signifiant respiratory events: apnea, supplemental oxygen requirements, sedation, or episodes of desaturation (Whalen, et ai., 2007). Initiation of the protool began with sreening of patients in the preoperative lini to determine a sleep apnea linial sore (SACS). A SACS was generated for eah patient and patients of sores of 15 or higher were ategorized as "high risk". A total of. perioperative information or anellation of surgery. Ofthese, 1923 had a low SACS and 251." 2206 patients were sreened, and data from 22 were exluded from analysis due to missing had a high SACS. The frequeny of unplanned ICU admission for low sores was 0.5%, ompared with 8.8% for those with a high SACS sore. Thus, a higher SACS sore may be able to predit those patients who may require a unplanned ICU admission. " vitally important to develop risk-stratifiation methods so that resoures may be used wisely to The ability to identify those individuals who are at risk for perioperative risks for OSA was determined to be the major problem with this study. Sine OSA is not unommon, it is

15 " COMPLICATIONS., 10 OF UNDIAGNOSED OBSTRUCTIVE SLEEP APNEA safeguard patients undergoing surgial proedures. Death and ardio respiratory ompliations have been assoiated with OSA during the postoperative period, it is neessary to advoate for intensive monitoring for OSA patients during this period (Gali, et. al 2010)..,.. In a retrospetive hart review, patients undergoing hip and knee replaements without a previous diagnosis of OSA were found to have a 24% inidene of ompliations, ompared with 9% ofthose without OSA, inluding ardia events, ompliations requiring,. an transfer to an ICU, and respiratory events requiring support suh as CPAP or intubation (Gali, et.al. 2007). Tait, Voepel-Lewis, Burke, Kostrzewa and Lewis (2008) onduted a qualitative study of Two-thousand twenty-five hildren between the ages of2-18 who were undergoing nonardia eletive proedures. The hildren were lassified as being overweight or obese, utilizing. age and sex adjusted body mass index. Although the definition of adult obesity based on BMI (30kg/m2) is well established, there is no universally aepted riterion for use in hildren. This is beause hildhood BMI hanges signifiantly as a funtion of age and sex. The Centers for " If Disease Control and prevention riteria define overweight hildren as BMI of greater than 85 th perentile to less than 95 th perentile and obesity is defined as having a BMI in the 95 th perentile $ or greater. The inidene and severity of perioperative adverse events were olleted prospetively. The study onluded that obesity in hildren and a history of OSA were strongly suggestive for perioperative ritial adverse respiratory events in hildren. Respiratory events inluded: oxygen desaturation, oughing, breath holding, airway obstrution, laryngospasm,

16 diffiult mask ventilation, and bronhospasm. These events are greater than ten perent of COMPLICATIONS OF UNDIAGNOSED OBSTRUCTIVE SLEEP APNEA 11 l- baseline for obese hildren. e;;.." Mador, Khamis, Nag, Mreyoud, Jallu and Mehboob (2010) onduted a quantitative retrospetive study to determine whether OSA inreases the risk of ardio-respiratory ompliations in patients who are undergoing endosopi proedures. Proedures were.. rate.. performed in 639 patients: olonosopies 68.5%, upper endosopies 20.2%, and ombined proedures 11.3%. The main study onlusion is that patients with OSA do not have a higher of ardio-respiratory ompliations when they undergo endosopi proedures under onsious sedation as ompared to those without OSA. In those patients undergoing endosopi proedures with onsious sedation there appears to be no inreased risk of ardiorespiratory ompliations (Mador, et. ai201o). Signifiane to Nursing. hypertension,., Nurses and health are providers need to be aware of the symptoms and ontributing fators of OSA. OSA is assoiated with obesity, systemi hypertension, pulmonary ardia arrhythmias, oronary artery disease, stroke, and heart failure. These omorbidities ontribute to the inreased risk ofperioperative ompliations in patients with OSA (Olson 2011). The need for primary are providers to be very diligent in the diagnosis and treatment of OSA is very important. See Table 2 for a list of signs and symptoms of GSA whih indiates a need for further diagnosti studies speifially a sleep study (polysomnography).

17 .i.,., Table II COMPLICATIONS OF UNDIAGNOSED OBSTRUCTIVE SLEEP APNEA 12 3 Obstrutive Sleep Apnea Signs and Symptoms Major signs and symptoms of OSA: Loud and hroni snoring Choking, snorting, or gasping during sleep Long pauses in breathing Daytime sleepiness, no matter how muh time you spend in bed Other ommon signs and symptoms of OSA inlude: Waking up with a dry mouth or sore throat Morning headahes C Restless or fitful sleep Insomnia or nighttime awakenings Going to the bathroom frequently during the night Waking up feeling out of breath Forgetfulness and diffiulty onentrating Moodiness, irritability, or depression C. C Aording to Olson, OSA is a prevalent disorder and most individuals who have OSA are undiagnosed. Thus, all preoperative medial histories, and physial examinations should look for symptoms and signs of OSA, not just a diagnosis history of OSA. This information may need to ome from others (suh as a parent or spouse) who are aware that the patient is sleepy or &.';: "., gasps, hokes, snorts, or stops breathing while asleep. In the primary are setting during the preoperative evaluations patients who do not have diagnosed OSA may need to defer eletive surgery for a sleep study to determine the risk for the patient. The primary method for diagnosing OSA at present is to have the patient undergo a sleep study known as polysomnography. OSA is diagnosed if the patient has an apnea index greater than 5, meaning more than five apnei episodes per hour, or a respiratory disturbane ',.'C,>

18 COMPLICAnONS OF UNDIAGNOSED OBSTRUCTIVE SLEEP APNEA 13. index (RDI) whih is the ombination of apneas and hypopneas, greater than 10 per hour. In the appropriate linial setting, sleep apnea an be diagnosed by an RDI between 5 and 10. Beause polysomnography is expensive and labor intensive, efforts are underway to find improved methods of diagnosing and sreening for OSA. At this time the only alternative is overnight oximetry, whih measures a patient's oxygen saturations throughout the night... " Overnight oximetry is not onsidered ompletely adequate as a sreening test, beause the oxygen levels in the blood of many patients with OSA do not provide the information needed to understand their ondition (Swierzewski 2011). Unfortunately, studies using overnight oximetry.". as a sreening tool for OSA have shown good speifiity and positive preditive value, but poor sensitivity and negative preditive value. This means overnight oximetry may miss subjets with & OSA who do not desaturate (Ryan Pl, Hilton MF, Boldy DA, et al 1995). & Summary OSA is a very ommon ondition in the ommunity that often goes undiagnosed until there is a ompliation related to OSA. Sending a patient to have a surgial proedure using., mortality general anesthesia is putting both the provider and the patient at a high risk. Moderate-to-severe sleep apnea was assoiated with 33% mortality over 14 years ompared to 6.5% and 7.7% in people with mild or no sleep apnea (Marshall et ai., 2008). Beause the age of the population is inreasing and obesity is on the rise, the likelihood that a patient having a surgial., proedure who is not diagnosed with OSA may our more often. A national researh study needs to be onduted on how to best sreen patients for OSA and how to best are for patients inluding eduation and treatment follow-up both in the primary are setting and during the

19 .. COMPLICATIONS., OF UNDIAGNOSED OBSTRUCTIVE SLEEP APNEA 14 perioperative period of are. Aording to Olson, the impat of preoperative treatment of OSA.,. on patient outomes has been sarely studied. There is moderate to high quality evidene from non-surgial patients that the treatment of OSA improves physiologial outomes that may be risk fators for perioperative ompliations. This provides the rationale for initiating therapy.,., preoperatively, and also the need for ontinued researh. Patients with OSA are at high risk for perioperative ompliations and pose multiple hallenges, inluding diffiult airway management and inreased inidene of postoperative ompliations. Beause undiagnosed OSA is ommon, a foused history and physial examination followed by the administration ofa sreening tool would help to identify patients at risk Utilizing for OSA (Adesanya et ai., 2010). There are many different sreening tools used in health are for OSA, the most sensitive and speifi tool for determining the risks for OSA is not lear. an easy to use tool suh as the STOP or the STOP-Bang Questionnaire provides neessary information in sreening for possible OSA. Sreening for OSA during a primary are/family pratie appointment will help in identifying and treating patients who may have OSA prior to undergoing surgial and medial proedures. Additional researh in this area is., &.. needed, to prevent operative ompliations related to OSA.., I

20 COMPLICATIONS OF UNDIAGNOSED OBSTRUCTIVE SLEEP APNEA Referenes '" Adesanya A.O., Lee, W., Greilih, N.B., & Joshi G.P. (2010). Perioperative management of obstrutive sleep apnea. Chest 138 (6), Chung, F. & Elsaid, H. (2009). Sreening for obstrutive sleep apnea before surgery: why is it Gali, e important? Current Opinion in Anesthesiology, 22: B., Whalen, F.X., Gay, P.., Olson, E.1., Shroeder, D.R., Plevak, D.1., & Morgenthaler, T.1. (2010). Management plan to redue risks in perioperative are of patients with presumed obstrutive sleep apnea syndrome. Journal ofclinial Sleep Mediine, 3 (6), Greenberg-Dotan, S., Reuveni, H., Simon-Tuval, T., Oksenberg, A., & Tarasiuk, A. (2007). Gender differenes in morbidity and health are utilization among adult obstrutive sleep apnea patients. Sleep, 30 (9) ,. ' :4_ Helpguide.org. (2011). Obstrutive Sleep Apnea Signs and Symptoms. Retrieved June 10,2011 from Hirshkowitz, M.(2008). The linial onsequenes of obstrutive sleep apnea and assoiated exessive sleepiness. The Journal offamily Pratie, Vol. 57, No.8 Suppl: S9-S 16. Krieger, S. & Caples, S. M. (2007). Obstrutive sleep apnea and ardiovasular disease: impliations for linial pratie. Cleveland Clinial Journal ofmediine, De;74(12):853-6, 858, 861-2

21 ..." COMPLICAnONS $ OF UNDIAGNOSED OBSTRUCTIVE SLEEP APNEA 16 Krames, Christy (1999). Illustration. Retrieved June 10, 2011 from t;; '", Health i'.,'ii" $.. fla.jpg Marshall, N.S., Wong, K.H., Liu, P.Y. Cullen, R.J., Knuiman, M.W., & Grunstein, R.R. (2008). Sleep apnea as an independent risk fator for all-ause mortality: The Busselton Study. Sleep, 31(8) MCane, K.L., & Huether, S.E. (2006). Pathophysiology. The Biologi Basis for Disease in Adults and Children. S1. Louis, MO: Elsevier Mosby. Modemmediine.om (2011). Oxyhemoglobin Dissoiation Curve. Retrieved June 10,2011 from Pollard, J.M., & Rie, C.A. (2006). Sleep apnea an underdiagnosed disorder. Health Hints, (10) No.4. Paje, D.T., & Kremer, M.J. (2006). The perioperative impliations ofobstrutive sleep apnea. Orthopaedi Nursing, 25 (5), Mador, J.M., Khamis, M.A., Nag, N., Mreyoud, A., Jallu, S., & Mehboob, S. (2010). Does sleep I; apnea inrease the risk of ardiorespiratory ompliations during endosopy proedures? Sleep Breath. Original artile..,., e Olson, E. (2010). Surgial risk and the preoperative evaluation and management ofadults with obstrutive sleep apnea. Retrieved Marh 20, 2011 from

22 Ryan..,..., apnea/hypopnea COMPLICATIONS OF UNDIAGNOSED OBSTRUCTIVE SLEEP APNEA PJ., Hilton MF, Boldy DA, Evans A., Bradbury S., Sapiano S., Prowsek., Clayton R.M., Validation of British thorai soiety guidelines for the diagnosis of the sleep syndrome: an polysomnography be avoided? Thorax, 50(9): Seet, E., & Chung, F. (2010). Management of sleep apnea in adults-funtional algorithms for the Ii ambulatory perioperative period: Continuing Professional Development. Canadian Journal of Anesthesiology, 57: Stierer, T.L. Wright, C. George, A., Thompson, R.E., Wu,.L., Collop, N. (2010). Risk assessment of obstrutive sleep apnea in a population of patients undergoing surgery. Journal ofclinial Sleep Mediine, 6 (5), Swierzewski, S.W. (2011). Sleep apnea diagnosis. Retrieved May 31, 2011 from Tait, A.R., Voepel-Lewis, T., Burke, C., Kostzewa, A., Lewis, I. (2008). Inidene and risk fators for perioperative adverse respiratory events in hildren who are obese. Anesthesiology, 108(3), *,,,