Article Text


Respiratory physiology: new tools, old concepts
P138 Evaluation of the need for a comprehensive assessment of lung function pre operatively in the morbidly obese
  1. A Renton,
  2. D A Lonsdale,
  3. G V Miller,
  4. J S White
  1. York Teaching Hospital NHS Foundation Trust, York, UK


Introduction and Objectives Chronic morbid obesity has been shown to impinge on normal respiratory function and can ultimately result in respiratory failure. Lee et al (2010) concluded that a more physiological assessment of individuals in this group is required when they are investigated clinically. Accordingly, the clinical pathway of patients referred for bariatric surgery at York Hospital was changed to include comprehensive Pulmonary Function Tests (PFT's), as well as the current standard Overnight Pulse Oximetry. The objective was to evaluate the revised clinical service and distinguish if the additional measurements are appropriate for morbidly obese patients as part of their surgical pre-assessment.

Methods Data were collected from patients undergoing bariatric pre-surgical assessment, between January 2011 and June 2011. PFT's undertaken included dynamic lung volumes, static lung volumes and transfer factor for carbon monoxide (TLCO), using a Medgraphics Plethysmograph system in accordance with recognised standards. Overnight oximetry was performed using Minolta 300i pulse oximeters. Abnormalities of lung function were determined using the BTS (1997) guidelines. Obstructive sleep apnoea (OSA) was diagnosed using the Scottish Intercollegiate Guidelines Network, (2003) guidelines.

Results A total of 59 patients were included in the study with demographics and measurements summarised in Abstract P138 table 1. 28.8% had normal lung function and no evidence of OSA, 39% had evidence of OSA but normal lung function. 6.8% had abnormal lung function but no OSA and 25.4% had both abnormal lung function and evidence of OSA.

Abstract P138 table 1

Summary of demographic and respiratory data for pre bariatric surgery patients

Conclusions Va and FRCPleth are reduced in all groups but is more significant in both groups with abnormal lung function. Those with combined abnormalities are on average 14.8 and 6 years older than those with no abnormalities or just OSA respectively suggesting the development of these co-morbidities with age. We feel that the finding that 32.2% of bariatric referrals were found to have abnormal lung function justifies the inclusion of these measurements when assessing this category of patient. Also, further assessment following weight loss in order to establish the underlying nature of deficient lung function would be useful.

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.