Sazzadul Islam

STOP questionnaire: a tool to screen patients for obstructive sleep apnea.

Background:Obstructive sleep apnea (OSA) is a major risk factor for perioperative adverse events. However, no screening tool for OSA has been validated in surgical patients. This study was conducted to develop and validate a concise and easy-to-use questionnaire for OSA screening in surgical patients. Methods:After hospital ethics approval, preoperative patients aged 18 yr or older and without previously diagnosed OSA were recruited. After a factor analysis, reliability check, and pilot study; four yes/no questions were used to develop this screening tool. The four questions were respectively related to snoring, tiredness during daytime, observed apnea, and high blood pressure (STOP). For validation, the score from the STOP questionnaire was evaluated versus the apnea–hypopnea index from monitored polysomnography. Results:The STOP questionnaire was given to 2,467 patients, 27.5% classified as being at high risk of OSA. Two hundred eleven patients underwent polysomnography, 34 for the pilot test and 177 for validation. In the validation group, the apnea–hypopnea index was 20 ± 6. The sensitivities of the STOP questionnaire with apnea–hypopnea index greater than 5, greater than 15, and greater than 30 as cutoffs were 65.6, 74.3, and 79.5%, respectively. When incorporating body mass index, age, neck circumference, and gender into the STOP questionnaire, sensitivities were increased to 83.6, 92.9, and 100% with the same apnea–hypopnea index cutoffs. Conclusions:The STOP questionnaire is a concise and easy-to-use screening tool for OSA. It has been developed and validated in surgical patients at preoperative clinics. Combined with body mass index, age, neck size, and gender, it had a high sensitivity, especially for patients with moderate to severe OSA.

Validation of the Berlin Questionnaire and American Society of Anesthesiologists Checklist as Screening Tools for Obstructive Sleep Apnea in Surgical Patients

Background:Because of the high prevalence of obstructive sleep apnea (OSA) and its adverse impact on perioperative outcome, a practical screening tool for surgical patients is required. This study was conducted to validate the Berlin questionnaire and the American Society of Anesthesiologists (ASA) checklist in surgical patients and to compare them with the STOP questionnaire. Methods:After hospital ethics approval, preoperative patients aged 18 yr or older and without previously diagnosed OSA were recruited. The scores from the Berlin questionnaire, ASA checklist, and STOP questionnaire were evaluated versus the apnea–hypopnea index from in-laboratory polysomnography. The perioperative data were collected through chart review. Results:Of 2,467 screened patients, 33, 27, and 28% were respectively classified as being at high risk of OSA by the Berlin questionnaire, ASA checklist, and STOP questionnaire. The performance of the screening tools was evaluated in 177 patients who underwent polysomnography. The sensitivities of the Berlin questionnaire, ASA checklist, and STOP questionnaire were 68.9–87.2, 72.1–87.2, and 65.6–79.5% at different apnea–hypopnea index cutoffs. There was no significant difference between the three screening tools in the predictive parameters. The patients with an apnea–hypopnea index greater than 5 and the patients identified as being at high risk of OSA by the STOP questionnaire or ASA checklist had a significantly increased incidence of postoperative complications. Conclusions:Similar to the STOP questionnaire, the Berlin questionnaire and ASA checklist demonstrated a moderately high level of sensitivity for OSA screening. The STOP questionnaire and the ASA checklist were able to identify the patients who were likely to develop postoperative complications.

Oxygen desaturation index from nocturnal oximetry: a sensitive and specific tool to detect sleep-disordered breathing in surgical patients.

INTRODUCTION: It is impractical to perform polysomnography (PSG) in all surgical patients suspected of having sleep disordered breathing (SDB). We investigated the role of nocturnal oximetry in diagnosing SDB in surgical patients. METHOD: All patients 18 years and older who visited the preoperative clinics for scheduled inpatient surgery were approached for study participation. Patients expected to have abnormal electroencephalographic findings were excluded. All patients underwent an overnight PSG at home with a portable device and a pulse oximeter. The PSG recordings were scored by a certified sleep technologist. The oximetry recordings were processed electronically. RESULT: Four hundred seventy-five patients completed the study: 217 males and 258 females, aged 60 ± 11 years, and body mass index 31 ± 7 kg/m2. The apnea-hypopnea index (AHI), the average number of episodes of apnea and hypopnea per hour of sleep, was 9.1 (2.8 to 21.4) [median (interquartile range)] and 64% patients had AHI >5. There was a significant correlation between oxygen desaturation index (ODI, hourly average number of desaturation episodes) and cumulative time percentage with SpO2 <90% (CT90) from nocturnal oximetry, with the parameters measuring sleep breathing disorders from PSG. Compared to CT90, ODI had a stronger correlation and was a better predictor for AHI. The area under receiver operator characteristics curve for ODI to predict AHI >5, AHI >15, and AHI >30 was 0.908 (CI: 0.880 to 0.936), 0.931 (CI: 0.090 to 0.952), and 0.958 (CI: 0.937 to 0.979), respectively. The cutoff value based on the maximal accuracy for ODI to predict AHI >5, AHI >15, and AHI >30 was ODI >5, ODI >15, and ODI >30. The accuracy was 86% (CI: 83%–88%), 86% (CI: 83%–89%), and 94% (CI: 92%–96%), respectively. The ODI >10 demonstrated a sensitivity of 93% and a specificity of 75% to detect moderate and severe SDB. CONCLUSIONS: ODI from a high-resolution nocturnal oximeter is a sensitive and specific tool to detect undiagnosed SDB in surgical patients.

Postoperative Oxygen Therapy in Patients With OSA: A Randomized Controlled Trial

BACKGROUND: Surgical patients with OSA are at increased risk for perioperative complications. Postoperative supplemental oxygen is commonly used, but it may contribute to respiratory depression in patients with OSA receiving opioids. The objective of the study is to investigate the effect of postoperative supplemental oxygen on arterial oxygen saturation (Sao2), sleep respiratory events, and CO2 level in patients with untreated OSA. METHODS: Consented patients with an apnea hypopnea index (AHI) > 5 events per hour on a preoperative polysomnography were randomized (1:1) to oxygen (O2 group) or no oxygen (control group). The O2 group received oxygen at 3 L/min via nasal prongs for three postoperative nights. The primary outcomes were polysomnographic parameters measuring Sao2, sleep respiratory events, and Pco2 measured by transcutaneous CO2 monitor (PtcCO2) on nights 1 through 3. The intention‐to‐treat and per protocol analysis were completed. RESULTS: There were 123 patients randomized (O2 group: n = 62; control group: n = 61). On night 3, the O2 vs control group had a higher average Sao2 (95.2% ± 3% vs 91.4% ± 4%, respectively; P < .001) and lower oxygen desaturation index (median, 2.3; 25th‐75th percentile, 0.2–13.8 vs median, 18.5; 25th‐75th percentile, 8.2–45.9 events per hour, respectively; P < .0001). The O2 group had a decreased AHI (median, 8.0; 25th‐75th percentile, 2.1–19.9 vs median, 15.6; 25th‐75th percentile, 9.5–45.8, respectively; P = .016), hypopnea index (P < .001), and central apnea index (P = .026) and a shortened longest apnea hypopnea duration (P = .002). Although time percentage with PtcCO2 ≥ 55 mm Hg ≥ 10% on postoperative night 1, 2, or 3 was found in 11.4% patients, there was no difference in PtcCO2 between the groups. CONCLUSIONS: Postoperative supplemental oxygen was found to improve oxygenation and decrease the AHI without increasing the duration of apnea‐hypopnea event or PtcCO2 level. A small number of patients had significant CO2 retention while receiving supplemental oxygen. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT01552304; URL: www.clinicaltrials.gov

Postoperative Oxygen Therapy in Patients with Obstructive Sleep Apnea: A Randomized Controlled Trial.

BACKGROUND: Surgical patients with OSA are at increased risk for perioperative complications. Postoperative supplemental oxygen is commonly used, but it may contribute to respiratory depression in patients with OSA receiving opioids. The objective of the study is to investigate the effect of postoperative supplemental oxygen on arterial oxygen saturation (Sao2), sleep respiratory events, and CO2 level in patients with untreated OSA. METHODS: Consented patients with an apnea hypopnea index (AHI) > 5 events per hour on a preoperative polysomnography were randomized (1:1) to oxygen (O2 group) or no oxygen (control group). The O2 group received oxygen at 3 L/min via nasal prongs for three postoperative nights. The primary outcomes were polysomnographic parameters measuring Sao2, sleep respiratory events, and Pco2 measured by transcutaneous CO2 monitor (PtcCO2) on nights 1 through 3. The intention‐to‐treat and per protocol analysis were completed. RESULTS: There were 123 patients randomized (O2 group: n = 62; control group: n = 61). On night 3, the O2 vs control group had a higher average Sao2 (95.2% ± 3% vs 91.4% ± 4%, respectively; P < .001) and lower oxygen desaturation index (median, 2.3; 25th‐75th percentile, 0.2–13.8 vs median, 18.5; 25th‐75th percentile, 8.2–45.9 events per hour, respectively; P < .0001). The O2 group had a decreased AHI (median, 8.0; 25th‐75th percentile, 2.1–19.9 vs median, 15.6; 25th‐75th percentile, 9.5–45.8, respectively; P = .016), hypopnea index (P < .001), and central apnea index (P = .026) and a shortened longest apnea hypopnea duration (P = .002). Although time percentage with PtcCO2 ≥ 55 mm Hg ≥ 10% on postoperative night 1, 2, or 3 was found in 11.4% patients, there was no difference in PtcCO2 between the groups. CONCLUSIONS: Postoperative supplemental oxygen was found to improve oxygenation and decrease the AHI without increasing the duration of apnea‐hypopnea event or PtcCO2 level. A small number of patients had significant CO2 retention while receiving supplemental oxygen. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT01552304; URL: www.clinicaltrials.gov

A Perioperative Smoking Cessation Intervention With Varenicline, Counseling, and Fax Referral to a Telephone Quitline Versus a Brief Intervention: A Randomized Controlled Trial

BACKGROUND: The effectiveness of perioperative interventions to quit smoking with varenicline has not been compared with brief interventions. Our objective was to determine the efficacy of a comprehensive smoking cessation program versus a brief intervention for smoking cessation. METHODS: In this prospective, multicenter study, 296 patients were randomized to participate in a smoking cessation program (one 10- to 15-minute counseling session, pharmacotherapy with varenicline, an educational pamphlet, and a fax referral to a telephone quitline); or brief advice and self-referral to a telephone quitline. The primary outcome was the 7-day point prevalence (PP) abstinence at 12 months after surgery. Secondary outcomes included abstinence at 1, 3, and 6 months. Multivariable generalized linear regression was used to identify independent variables related to abstinence. RESULTS: The 7-day PP abstinence for the smoking cessation program versus brief advice group was 42.4% vs 26.2% (relative risk [RR], 1.62; 95% confidence interval [CI], 1.16–2.25; P = .003) at 12 months. The 7-day PP abstinence at 1, 3, and 6 months was higher in the smoking cessation group versus the brief advice group: 45.7% vs 25.5% (RR, 1.79; 95% CI, 1.29–2.49; P < .001), 46.4% vs 26.9% (RR, 1.72; 95% CI, 1.25–2.37; P< .001), and 45.0% vs 26.2% (RR, 1.72; 95% CI, 1.24–2.38; P < .001), respectively. Participating in the smoking cessation group predicted abstinence at 12 months (RR, 1.58; 95% CI, 1.12–2.21; P = .0087). CONCLUSIONS: A perioperative smoking cessation program with counseling, pharmacotherapy with varenicline, an educational pamphlet, and a fax referral to a quitline increased abstinence from smoking 1, 3, 6, and 12 months after surgery versus a brief intervention.

OSA Questionnaire: A new tool for screening obstructive sleep apnea

Frances Chung, University of Toronto, University Health Network, Toronto, ON, Canada; Balaji Yegneswaran, University of Toronto, University Health Network; Sharon Chung, University of Toronto, University Health Network; S Islam, University of Toronto, University Health Network; A Khajehdehi, University of Toronto, University Health Network; C Shapiro, University of Toronto, University Health Network;

What is the best screening questionnaire for obstructive sleep apnea

Balaji Yegneswaran, University of Toronto, University Health Network, Toronto, ON, Canada; Balaji Yegneswaran, University of Toronto, University Health Network; Sharon Chung, University of Toronto, University Health Network; A Khajehdehi, University of Toronto, University Health Network; S Islam, University of Toronto, University Health Network; C Shapiro, University of Toronto, University Health Network; F Chung, University of Toronto, University Health Network;