patients with obstructive sleep apnoea ( osa ) can present special challenges that must be addressed to minimise the perioperative risks . several risk factors such as obesity , male gender , age , and hereditary factors are associated with an increased prevalence of osa in the general population . among these , obesity is the strongest risk factor for sleep apnoea . the american society of anesthesiologists ' practice guidelines for the perioperative management of patients with osa recommend pre - operative initiation of continuous positive airway pressure ( cpap ) , particularly if osa is severe . there is scant data on the prevalence of osa in surgical patients and anaesthetic management in indian literature . as a result , there is no properly defined management protocol for such patients especially pre - operative use of cpap to minimise the post - operative complications . pre - operative initiation of cpap therapy along with appropriate anaesthetic planning is of paramount importance in such patients . this case report emphasises the usefulness of cpap therapy , even for a short duration , to minimise morbidity , improve recovery and hasten early discharge from the hospital after major surgery . a 36-year - old male , weighing 158 kg , body mass index of 49 kg / m , had neck pain , numbness in bilateral upper limbs and left lower limb weakness with foot drop for 1 year . magnetic resonance imaging of his cervical spine revealed prolapsed intervertebral discs at multiple levels ( c4 - 7 ) . he was posted for anterior cervical discectomy ( c5 - 7 ) with fusion . during pre - anaesthetic evaluation , the patient gave a history of snoring and daytime somnolence which was a routine feature for him for the past 6 years , to the extent that he went off to sleep during the examination . examination of cardiovascular ( including the pre - operative echocardiography ) , respiratory and other systems were unremarkable . after a detailed clinical examination , the patient was advised polysomnography , which revealed apnoea / hypopnoea index ( ahi ) of 47.7 suggestive of severe osa . during the sleep study , the patient and the surgeon were informed about the risks of anaesthesia and about the need for pre - operative cpap therapy for better outcome following surgery . in view of severe osa , the patient was advised to stop smoking and simultaneously cpap therapy ( 12 cm h2o during the night ) and incentive spirometry thrice daily for 72 h before surgery were started to optimise his respiratory functions . preoperatively , the patient had better oxygenation levels during sleep at night , lowest level of spo2 in the pre - operative period after initiating cpap being in the range of 8588% . furthermore , the patient and his relatives reported decreased episodes of waking up or choking at night during sleep . in the operation theatre , intravenous access was secured with a 16-gauge cannula and left radial artery was cannulated under local anaesthesia . anaesthesia was induced with fentanyl 1 g / kg , propofol 2 mg / kg and after having confirmed mask ventilation , rocuronium 0.8 mg / kg was administered for intubation with oral endotracheal tube ( 8.5 mm internal diameter ) with glidescope to minimise cervical spine motion . anaesthesia was maintained with o2/air 45/55% , desflurane ( minimum alveolar concentration [ mac ] 0.81.0 ) and intermittent doses of fentanyl ( 0.5 g / kg ) and atracurium ( 0.2mg / kg ) with controlled intermittent positive pressure ventilation . monitoring included electrocardiogram , oxygen saturation ( spo2 ) , invasive blood pressure , end tidal co2 ( etco2 ) core temperature and urine output . during surgery , surgical incision site was infiltrated with 10 ml 0.25% bupivacaine to achieve post - operative pain relief . urine output was 400 ml . he was extubated at the end of surgery once he became conscious , breathing spontaneously adequate tidal volume and had a satisfactory neurologic recovery . post - operative analgesia was managed with intravenous paracetamol 1 g 6 hourly and diclofenac sodium 75 mg 12 hourly . he received nasal cpap in the immediate post - operative period and during sleep ( 12 cm h2o ) for 4 days . the benefits of cpap was rewarding and included decreased nocturnal oxygen desaturation index and decreased the percentage of time with spo2 < 90% . furthermore , it was seen that the patient had reduced depression and troublesome sleep . all this helped in reducing the length of stay in the hospital and economic burden on the patient . obesity has reached epidemic proportions in india in the 21 century , with morbid obesity affecting 5% of the country 's population . india is following the footsteps of other developed countries that are steadily becoming more obese . according to the national family health survey , incidence of osa in indian population is varied from 4.4% to 13.7% , and osa hypopnoea syndrome varies from 2.4% to 2.8% . acceptance of nasal cpap in indian osa patients is low , the cost of the circuit , being the major impediment . discontinuation of cpap was observed in 25% with leakage from the nasal mask being the major cause . however , there is a paucity of indian data on the prevalence of patients with osa presenting for surgical procedures . on literature search , on 204 surgical patients where they observed that 24.5% subjects were at high risk for osa ( stop - bang > 3 ) with a male predominance . this high - risk group of patients had a higher prevalence of associated cardiorespiratory and endocrinal disorders . they had further observed a concordance among the surgical population in india with that of the western population pertaining to the risk of osa . the authors concluded that a high degree of suspicion and knowledge of association of osa and medical diseases may help in detection of such cases and decrease the rate of perioperative complications thus improving patients ' safety . nevertheless , a significant number of indians suffers from osa , so it is prudent to optimise them with pre - operative cpap so as to avoid post - operative complications . there are case reports that have illustrated the use of post - operative cpap or high flow oxygen therapy to treat post - operative hypoxemia . ours is probably the first case report that highlights the pre - operative use of cpap to help improve the patient outcome , following major surgery . in a study carried out by liao et al . , patients received arbitrary auto - titrated positive airway pressure treatment for three pre - operative days before surgery and had reduced post - operative ahi and improved oxygen saturation in the patients with moderate and severe osa . in our patient , we had used cpap ( 12 cm h2o only in the night ) for 3 days before surgery . however , whether initiation of cpap 3 days preoperatively is optimal is unknown and needs to be further evaluated . we used cpap ( 12 cm h2o only in the night ) for 3 days before surgery . obesity and particularly central adiposity can increase sleep apnoea susceptibility by increasing upper airway mechanical loads and/or decreasing compensatory neuromuscular responses . thick and short neck , limitation of cervical extension , reduction of thyromental distance , reduction of the calibre of the airways and increased neck circumference are common in these patients which may pose hindrance in securing the airway . three - minute pre - oxygenation and use of positive pressure in the airways during induction improves oxygenation and prevents airway obstruction . further , it has been reported that the difficulty in securing the airway in these patients is up to 8 times more frequent than the control group . therefore , it is mandatory to have a difficult airway cart ready in the operating room . as our patient had cervical myelopathy , glidescope was used for facilitating endotracheal intubation to limit cervical spine movement . other options for intubation in such cases include awake fibreoptic intubation , video - assisted devices ( c - trach ) and intubating laryngeal mask airway . difficulties faced during pre - operative mask ventilation and tracheal intubation should be kept in mind before deciding to extubate such patients . an airway exchange catheter should be left in situ if reintubation is expected . a supraglottic airway device or nasopharyngeal airway should be within reach as well . these patients are sensitive to central nervous system depressant drugs , hence minimal doses of sedatives and narcotics are advisable . our patient also needed low dose fentanyl and propofol for induction of anaesthesia despite his increased body weight . residual effects of inhalational anaesthetic agents may be harmful in these patients for which , our patient was maintained at a mac of 0.8 . to ensure complete reversal from neuromuscular blockade , we used atracurium to provide muscle relaxation after the initial intubating dose of rocuronium . a minimum of 3 days of cpap therapy in morbidly obese patients with osa in the pre - operative period can be helpful which has to be continued in the post - operative period and help in achieving good recovery from major spine surgery and early discharge from the hospital .
morbidly obese patients with clinical features of obstructive sleep apnoea can present a myriad of challenges to the anaesthesiologists which must be addressed to minimise the perioperative risks . 
 initiation of continuous positive airway pressure ( cpap ) therapy early in the pre- and post - operative period along with appropriate anaesthetic planning is of paramount importance in such patients . 
 this case report emphasises the usefulness of cpap therapy , even for a short duration , to minimise morbidity , improve recovery and hasten early discharge from the hospital after major surgery .