Akshay Dwarakanath

Variability in clinicians' opinions regarding fitness to drive in patients with obstructive sleep apnoea syndrome (OSAS).

We evaluated clinicians’ current practice for giving advice to patients with obstructive sleep apnoea syndrome. Clinicians were invited to complete a web-based survey and indicate the advice they would give to patients in a number of scenarios about driving; they were also asked what they considered to be residual drowsiness and adequate compliance following CPAP treatment. In the least contentious scenario, 94% of clinicians would allow driving; in the most contentious a patient had a 50% chance of being allowed to drive. Following treatment with CPAP, clinicians’ interpretation of what constituted residual drowsiness was inconsistent. In each vignette the same clinician was more likely to say ‘yes’ to ‘excessive’ than to ‘irresistible’ (71%±12% vs 42%±10%, p=0.0045). There was also a lack of consensus regarding ‘adequate CPAP compliance’; ‘yes’ responses ranged from 13% to 64%. There is a need for clearer guidance; a recent update to the Driver and Vehicle Licensing Agency guidance, and a statement from the British Thoracic Society, making it clear that sleepiness while driving is the key issue, may help.

Noninvasive ventilation in the management of acute hypercapnic respiratory failure

Educational aims To discuss the role of noninvasive ventilation (NIV) in the management of acute hypercapnic respiratory failure in various conditions. To discuss the common problems encountered during NIV. To provide practical considerations for setting up and delivering an optimal NIV service. Summary Noninvasive ventilation (NIV) is considered the standard of care in the management of acute hypercapnic respiratory failure secondary to chronic obstructive pulmonary disease. It can be delivered safely in any dedicated setting ranging from emergency and medical admissions departments to high-dependency and intensive care units. It reduces the demand for invasive mechanical ventilation, decreases in-hospital mortality and shortens hospital stay. The way the NIV service is delivered will depend on the model of hospital care and this varies greatly from country to country. Adequately trained staff and appropriate monitoring facilities, available around the clock, are important. A successful outcome is dependent on good patient selection and the correct implementation of NIV.

Prevalence of and treatment outcomes for patients with obstructive sleep apnoea identified by preoperative screening compared with clinician referrals.

Obstructive sleep apnoea (OSA) has implications perioperatively. We compared the prevalence of OSA and outcome with continuous positive airway pressure (CPAP) in patients diagnosed through preoperative screening and following referrals from other clinicians. Among 1412 patients (62% males) the prevalence of OSA, Epworth Sleepiness Score (ESS), the number referred for CPAP, and short and longer term use of CPAP were compared between the two groups. The prevalence of OSA was similar (62% versus 58%). There were differences in mean±sd age (61±16 versus 55±13 years; p<0.0001), ESS (11±6 versus 8±5; p<0.0001) and oxygen desaturation index (22±20 versus 19±17; p=0.039). Clinician-referred patients were more likely to be offered CPAP (p<0.0001; OR 2.84). Pre-assessment patients with mild OSA were less likely to continue CPAP long term (p=0.002; OR 6.8). No difference was seen between moderate and severe OSA patients. The prevalence of OSA was similar in both groups but pre-assessment patients were younger and less symptomatic. Preoperative screening of patients is worthwhile, independent of any effect of CPAP upon surgical outcomes; younger and less symptomatic patients are identified earlier. Pre-assessment patients with mild OSA were less likely to use CPAP; this should be considered when offering CPAP to these patients prior to surgery. Opportunistic preoperative screening identifies a high prevalence of OSA and patients are younger with fewer symptoms http://ow.ly/YKUZu

The role of Fibreoptic Bronchoscopy (FOB) in the evaluation of chronic cough

Background: Chronic cough can be debilitating and it accounts for significant number of referrals to outpatients. There is no consensus as to the best diagnostic strategy and may vary between centres. We assessed the clinical utility of FOB in the evaluation of chronic cough. Methods: Patients with chronic cough and no other clinical or radiological indications for FOB and underwent the procedure (2009-2016) were identified from the electronic records. We excluded patients who did not have a CT Thorax (CT) or had abnormal CT that could be associated with cough. Results: 56 patients (males-51%), mean age 59 years were included.24(42%) were current or ex-smokers. The median (IQR) duration of cough was 20(9-42) months. 1 patient had previous history of extra thoracic malignancy.16(28%) had evidence of obstructive spirometry. Chest radiograph was normal in 45(79%). CT was normal in 31(54%).Other CT abnormalities were lung nodules, Emphysema, atelectasis, pleural plaques, mediastinal nodes and fibrotic bands. FOB was normal in 52(91%).Other abnormalities seen were secretions, distorted vocal cords, areas of inflammation and bleeding. Bronchial washings were done in 10(18%), Transbronchial needle aspiration with EBUS and endobronchial biopsies done in 1 patient each. None of the samples showed any significant cytological, histological or microbiological abnormalities. The final diagnosis were airways disease 7(13%), acid refux-8(14%) and unexplained cough-36(63%).24(42%) required referral to specialist cough clinic. Conclusion: FOB adds little to the diagnosis of chronic cough in the context of normal or non-localising CT findings. The diagnosis and treatment of chronic cough remains a challenge.

Hypoxic challange test (HCT) in patients with interstitial lund disease (ILD)

Background: Air travel in patients with ILD poses a risk and the predictors of in-flight hypoxia remains unknown. The HCT is widely used to evaluate the need for inflight oxygen. We retrospectively evaluated the characteristics of all ILD patients who underwent the HCT and the outcome of the test. Methods: Patients who had HCT and had a diagnosis of ILD between 1993 and 2015 were identified from our HCT database. Patients were divided into Idiopathic pulmonary fibrosis group (IPF group) and Non Idiopathic pulmonary fibrosis ILD group (Non -IPF group). The HCT was performed using an inhaled gas mixture containing 15% oxygen. Patients were arbitrarily divided into two sub groups based on the baseline saturations of less than 95% and more than 95% respectively. Results: 135 patients (IPF -88, Non IPF -47), age (mean+/- SD) 67 +/-9 years were included. There was no difference in spirometry, arterial blood gases and saturations between the two groups. 65 patients (48%) had a positive HCT. The results are tabulated in Table 1. Conclusion: 37% of IPF patients and 24% of Non-IPF patients had a positive HCT despite a resting saturations of >95%. Resting oxygen saturation is a not a good determinant for the need for HCT and the subsequent outcome. Patients with ILD should be considered for HCT irrespective of resting saturations and the nature of ILD.

P65 OSAS and driving – BTS return survey to assess consistency of advice given to patients at diagnosis and after treatment– a repeat of the 2013 survey to evaluate the impact of a BTS statement and new DVLA regulations

Introduction In 2013 a BTS survey showed substantial variability in the advice that patients with obstructive sleep apnoea syndrome (OSAS) would be likely to receive from clinicians with regard to whether they were fit to drive or not. Since then the BTS has issued guidance and the DVLA changed its emphasis to sleepiness “likely to impair safe driving”, rather than sleepiness in general. The survey was divided into two parts, the first focusing on patients at presentation and the second after treatment, with the wording of the questions reflecting that used in the DVLA forms. We repeated this study in 2016 to assess whether these changes had resulted in greater consistency. Additional questions about BTS and DVLA guidance were included. Methods Web based survey of members of BTS, BSS and ARTP. Results 304 respondents. The vignettes at diagnosis are directly comparable between the surveys and the results are very similar (p = NS). In the most contentious case there remains an approximately 50:50 chance of a patient receiving opposing advice. Significant variation in the assessments of control of patient’s condition, improvement in sleepiness and compliance after treatment remains (Figure 1). 2 36% were not aware that the BTS have issued a statement 63% felt the change in emphasis from excessive sleepiness to sleepiness likely to impair safe driving helpful. 64% of respondents were not aware that DVLA had changed its guidance in January 2016. 18% of respondents advise patients to inform the DVLA when diagnosis felt to be likely based on symptoms. 57% when diagnosis confirmed following investigation, 13% when CPAP first trialled and 12% when CPAP issued to the patient. Conclusions The results of the 2016 survey confirm the results of the 2013 survey. Disappointingly the guidance from the BTS appears to have had little impact. The change in emphasis from excessively sleepy to sleepiness likely to impair safe driving was felt to be helpful by a small majority. There is a clear need for tools which are felt to be robust by clinicians and patients to help make decisions about fitness to drive and for these to be disseminated to clinicians. Abstract P65 Figure 1

S25 Establishing a normal range in driving simulator performance using standard deviation of lane position (SDLP) in an advanced PC –based driving simulator (MiniUoLDS)

Introduction Some patients with OSAS are at higher risk of being involved in road traffic accidents. No objective tests have been shown to predict reliably whether an individual is safe to drive or not and there is significant variation in the advice given by the clinicians. Using a continuously measured variable (SDLP) on an advanced PC-based driving simulator the at risk patients can be identified with a high degree of accuracy. We have now compared driving performance based on SDLP in controls and untreated OSAS patients and have established a normal range. Methods 129 untreated male OSAS patients (Age 53+/-12, ESS 14+/-5, ODI 41+/-26, BMI 36+/-8,) and 79 male controls (Age 56+/-15, ESS 4+/-3, BMI 28+/-8) were recruited in the study. All performed a simulator run after initial acclimatisation. The simulator run consisted of eight epochs and on average needed 7 min to complete one epoch driving at 70 miles per hour. The simulator layout was designed in line with the UK highways agency road standards. The mean SDLP in epoch-3 (SDLP3) was compared between the two groups using unpaired T-test. The SDLP3 in the patient group was evaluated and this was compared with the mean and 95th centile values of SDLP 3 among the controls. Results There was a significant difference in SDLP3 between OSAS patients and controls (0.44 v/s 0.39, P = 0.03). 10% of patients had worse SDLP3 than the 95th centile among controls (Figure 1).Abstract S25 Figure 1 Conclusions Worse SDLP is a marker of poor driving performance and this is significantly worse in untreated OSAS patients as compared to controls. The choice of 95% is arbitrary but is consistent with the approach taken to establish a normal range. Establishing where a patient lies in comparison to controls may be useful in advising patients whether they are at increased risk of an accident due to OSAS. Defining a normal range based on continuously measured variable in MiniUoLDS holds promise and is a step ahead towards developing an objective test in evaluating the at risk OSAS patients.

P251 Prevalence and treatment outcome of Obstructive Sleep Apnoea (OSA) diagnosed following preoperative screening compared with GP or other clinician referral

Introduction OSA is very prevalent and has potential implications perioperatively. Preoperative screening may identify high risk patients and treatment with CPAP may reduce perioperative complications, though this is unproven. We evaluated the treatment outcome and long term compliance with CPAP in patients diagnosed through preoperative screening and compared it with patients diagnosed with OSAS following GP or other clinician referral. Method Over 2 years (October 2009–2011) 1412 patients (males-62%) had sleep studies (oximetry or respiratory variable). 44% were referred from the preassessment clinic following screening for possible OSA. The prevalence of sleep disordered breathing, the Epworth Sleepiness Score (ESS) and among those referred for a CPAP trial the outcome, long-term compliance and average use per night were compared between preassessment and clinician referred patients. Results The prevalence of OSA was 62% and 58% in the clinician referred and preassessment patients respectively. There was a significant difference in age (61 +/-16 v/s 55 +/-13, P = <0.0001) and ESS (11 +/-6 v/s 8 +/-5, P = <0.0001) between the two groups. Clinician referred patients were more likely to be commenced on CPAP (P = <0.0001, OR- 2.79). Preassessment patients with mild OSA who were prescribed CPAP were more likely to fail the CPAP trial (P = 0.01, OR- 3.02) and were less likely to continue CPAP treatment after one year (P = 0.02, OR-2.1). No difference was seen between the groups in patients with moderate or severe OSA. There was a significant difference in the median CPAP usage, 5.5 hours v/s 4 hours (Mann Whitney, P = 0.0053, figure-1). Both groups reported a significant improvement in ESS with CPAP (Δ ESS-5 and Δ ESS-4, P = <0.0001) between the clinician referred and preassessment patients respectively. Abstract P251 Figure 1. Conclusions The prevalence of OSA was similar in patients referred following preoperative screening or from another clinician, but preassessment patients were younger and less symptomatic. There was no difference in short or long term CPAP use in patients with moderate or severe OSA, but preassessment patients with mild OSA were less likely to use CPAP in the short or longer term. Opportunistic screening of patients awaiting surgery is worthwhile, independently of any effect of CPAP upon surgical outcomes.

S5 VARIABILITY IN CLINICIAN'S PERCEPTION REGARDING FITNESS TO DRIVE IN PATIENTS WITH OBSTRUCTIVE SLEEP APNOEA SYNDROME (OSAS)- ON BEHALF OF THE BRITISH THORACIC SOCIETY SLEEP APNOEA SAG.

Introduction Advice about driving is a key component of the management of OSAS patients. No objective tests have been shown to predict reliably whether an individual is safe to drive or not and therefore the advice given will depend upon the opinion of clinicians. We evaluated the current practice of advice given regarding fitness to drive in OSAS patients. Methods Clinicians were invited to participate in a web-based survey. The questionnaire included six clinical vignettes describing a variety of OSAS patients. For each the respondent chose from options ranging from driving without restriction to advising not to drive at all. For ease of presentation the data are summarised as whether would allow driving or not. Results 467 respondents completed the survey. The advice given by the respondents to various clinical vignettes was variable (figure-1). In the least contentious scenario (vignette-1) there was 1 in 14.6 chance and in the most (vignette-4) there was a 1 in 2 chance of an individual being told whether they could drive or not. Respondents were more likely to advise patients to refrain from driving if the AHI was worse (P- < 0.0001, OR-3.9), if the Epworth sleepiness score was high (P-< 0.0001, OR-23.5) and if the patient admitted to any problems at all while driving (P- 0.0098, OR-1.6). Males were more likely to allow OSAS patients to drive. Consultants without an interest in sleep medicine and respondents seeing less than 5 patients per month were more likely to advise against driving. The advice given was not related to the age of the clinician. Abstract S5 Figure 1. Conclusions This survey has shown that there is considerable variability in the advice given by clinicians, with in some situations a patient having an even chance of receiving opposite advice, depending on who they see. Restriction of driving has major implications for an individual, both social and financial. Allowing someone to drive who is not safe to do so has potentially disastrous consequences for them and others. The issue of how to improve consistency of advice needs to be addressed.

S47 Comparing Coping Strategies While Driving in Patients with Obstructive Sleep Apnoea Syndrome (OSAS) and in Healthy Controls

Introduction Tiredness while driving is potentially fatal and it is recommended that a driver who starts to feel tired should stop and have a rest, but some may use various strategies to try to stay alert. We devised a questionnaire that assessed various commonly used coping strategies and explored whether there is a difference between patients with OSAS and normal controls. We also hypothesised that patients might admit to utilising such strategies more readily than to sleepiness while driving and asked about sleepiness while driving in various situations. Method 133 (52±10 yrs, ESS 12±6, ODI 31± 24) untreated OSAS patients and 49 healthy controls (45±17 yrs, ESS 3±2) were included in the study. The coping strategy section included ten questions about various strategies they adapt in order to stay awake. They were asked to rate on a 3-point scale, from “never” to “frequently”. The questionnaire was scored by adding up the ratings for the ten questions, and the highest possible score was 30. Comparisons were made using one way ANOVA. Results There was a significant difference in the total coping strategy score between the patients of different severities (mild, moderate, severe, as per ODI) and the healthy controls. However there was no difference when different severities of OSAS were compared against each other (Table 1). There was strong correlation between the coping strategy score & ESS (Spearman r=0.53, p<0.0001). 81% (38/47) of patients and 77% (23/30) of controls who did not admit to feeling sleepy while driving admitted using coping strategies. Conclusion OSAS patients report using significantly higher number of coping strategies compared to healthy individuals irrespective of the severity of disease. It also correlated strongly with marker of day time sleepiness (ESS). Asking about such coping strategies may be a better way identifying who are at risk of an accident than asking directly about problems with sleepiness while driving. Abstract S47 Table 1 Controls (n = 50) Mild OSAS [ODI 5 –15] (n = 44) Moderate OSAS [ODI 16 – 30] (n = 41) Severe OSAS [ODI >30] (n = 48) Bonferroni’s Multiple comparison testOne way ANOVA Is p<0.05? P value Control vs Mild Control vs Moderate Control vs Severe Mild vs Moderate Mild Vs Severe Moderate vs Severe Coping Strategy Score 3.5(2.5) 6.9(4.1) 6.8(4.4) 6.6(5.2) <0.0001 Yes Yes Yes No No No ESS 3(2) 12(5) 10(5) 11(6) <0.0001 Yes Yes Yes No No Yes