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Biomedical subjects

R L Blair

Publications and source records attributed to R L Blair.

At least 19 recordsLinked to original sources
PubMed2005

Clinical predictors in obstructive sleep apnoea patients with calibrated cephalometric analysis--a new approach.

AIM: Utilization of a new method to accurately quantify differences in cephalometric parameters between obstructive sleep apnoea (OSA) and normal patients, and to identify good predictors for OSA. To illustrate the ethnic differences in cephalometry. METHOD: This prospective study involves 106 South-east Asians. A calibrated catheter is inserted into the upper airway during standard cephalometry to obtain the precise magnification and allow exact measurement of anatomical parameters of cephalometry in both erect and supine positions. RESULTS: The OSA patients have longer lower-facial length, narrower skull base, shorter and receding mandible, smaller posterior airway space (PAS), narrower retropalatal space, longer and thicker soft palate, smaller hard and soft palate angles longer tongue length and more inferiorly displaced hyoid. For the palatal level, retropalatal distance of 11.2 mm cut-off/predictive value for male (receiver operating characteristics (ROC) = 0.8414 with PPV = 77.46, NPV = 90.00) and 5.5 mm for female (ROC = 0.9180 with PPV = 100.00, NPV = 84.21) at erect position were selected. For retrolingual level, erect PAS of 10.1 mm cut-off/predictive value for male (ROC = 0.7000 with PPV = 78.38, NPV = 37.78), 5.3 mm for female (ROC = 0.7227 with PPV = 75.00, NPV = 75.00) were selected. Our study showed that South-east Asians have different cephalometric values compared with White people, Black people and Hispanics. CONCLUSION: This new method of cephalometry using a calibrated catheter provides an accurate and simple method of obtaining precise cephalometric measurements. There is no cephalometric data on OSA from South-east Asia available. These results suggested that surgeons managing OSA patients and using cephalometry as a diagnostic method should have a set of normative and OSA cephalometric values that apply to their local populations.

Adult↗
PubMed2005

10th Yahya Cohen Memorial Lecture: Clinical predictors in obstructive sleep apnoea patients with computer-assisted quantitative videoendoscopic upper airway analysis.

AIM: To identify the clinical predictors and assist surgeons in their clinical management of obstructive sleep apnoea (OSA) - a prospective study with a new approach to analyse the static and dynamic upper airway morphology between patients with OSA and normal subjects. To introduce a new method of assessment for surgical outcome. MATERIALS AND METHODS: Quantitative computer-assisted videoendoscopy (validated with upper airway magnetic resonance imaging) was performed in 49 (43 males, 6 females) patients with OSA and compared with 39 (22 males, 17 females) controls (apnoea-hypopnoea index <5). Absolute cross-sectional areas, transverse and longitudinal diameters at the retro-palatal and retro-lingual levels were measured during end of quiet respiration and during Mueller's manoeuvre in the erect and supine positions, allowing us to study static and dynamic morphology (collapsibility) of the upper airway. We analysed 3744 parameters. RESULTS: In males, retro-palatal and retro-lingual areas during Mueller's manoeuvre in the supine position of 0.7981 cm2 [receiver operating characteristics (ROC) = 0.9284, positive predictive value (PPV) = 86.05%, negative predictive value (NPV) = 84.62%] and 2.0648 cm2 (ROC = 0.8183, PPV = 76%, NPV = 83.33%), respectively, were found to be good predictors/ cut-off values for OSA. Retro-palatal area measured in the supine position during Mueller's manoeuvre (AS1M) and collapsibility of retro-palatal area in the supine position calculated (CAS1) were found to have significant correlations with severity of OSA. In females, areas measured during Mueller's manoeuvre in the supine position of 0.522 cm2 at retropalatal level (ROC = 1, 100% PPV and NPV) and transverse diameter at retro-lingual level during erect Mueller's manoeuvre of 1.1843 cm (ROC = 0.9056, PPV = 100%, NPV = 83.33%) were found to be predictive. All measurements at the retro-palatal level and in the supine position had higher predictability. Area measurements obtained during Muller's manoeuvre were more predictive (ROC >0.9910) than resting measurements (ROC >0.8371). Several gender and anatomical-site specific formulas with excellent predictability (ROC close or equal to 1) were also devised. Examples of surgical outcome assessment were introduced. CONCLUSION: Upper airway Mueller's studies are predictive and useful (independent samples t-test/Mann Whitney U test, ROC) in identifying patients with OSA. With these gender and anatomical-site specific OSA predictors/formulas and this innovative clinical method, we hope to assist other surgeons with quantitative clinical diagnosis, assessment, surgical planning and outcome assessment tools for OSA patients.

Adult↗
PubMed2004

Quantitative computer-assisted digital-imaging upper airway analysis for obstructive sleep apnoea.

This was a prospective study of a new objective method which quantitatively analyses the upper airways in patients with obstructive sleep apnoea (OSA). Video-nasopharyngoscopic examinations of the upper airways of 45 patients were carried out with an endoscopic calibrator. Images of the upper airway during quiet respiration and Mueller's manoeuvre in erect and supine positions were digitized by computer to generate the actual dimensions of obstructive sites. Measurements by the new method were validated by comparing 90 pairs of videoendoscopic images with upper airway magnetic resonance imaging (MRI) measurements at two identical levels. Quantitative precision is 100% for the retropalatal level and 95.6% for the retrolingual level with a tolerance of 0.5 cm(2) between the two methods. The absolute mean of the difference between the two methods of measurement is 0.08 cm(2) at the retropalatal level and 0.18 cm(2) at the retrolingual level. The agreement between the digital-imaging videoendoscopic and MRI measurements was 93.3% for the retropalatal level and 95.6% for the retrolingual level. Quantitative computer-assisted digital imaging is a reliable, cost-effective clinical method of upper airway evaluation in OSA patients. This method allows us to examine the dynamic and static morphology objectively, measure surgical outcomes of upper airway, opening up new avenues for OSA management.

Body Mass Index↗
PubMed1999

Surgical simulation: an animal tissue model for training in therapeutic and diagnostic bronchoscopy.

A series of surgical simulation exercises has been developed using an animal model to allow trainees to practise basic instrument handling and develop psychomotor skills in bronchoscopy, without risk to patients. A pig model was found to be most suitable. After suitable preparation the model can be used for diagnostic and therapeutic exercises in bronchoscopy, including lavage, biopsy and the removal of various foreign bodies. The model is a safe, inexpensive and convenient means of bronchoscopic training for otolaryngology trainees. For the trained specialist who has to remove bronchial foreign bodies infrequently, the model is a useful way of maintaining skills.

Animals↗
PubMed1998

Lipomatosis of the minor salivary glands.

Lipomatosis has not previously been reported in minor salivary glands. Its occurrence in the parotid gland is well recognized. We present the first reported case of lipomatosis of the minor salivary glands in the nasal cavity. We also review the tumours of the minor salivary glands, lipomas and lipomatosis of the parotid, and the few reported cases of lipomas of the sinonasal tract.

Adult↗
PubMed1996

The management of unilateral vocal cord palsy by augmentation using autologous fat.

Augmentation of the vocal cord with Teflon paste has been one of the mainstays of treatment of a unilateral vocal cord palsy. Recently the licence for Teflon in the UK has been withdrawn, creating the need for an alternative. Over the last 2 years we have been using autologous fat harvested from the abdominal wall for this purpose. Fat is more difficult to work with than Teflon and we have developed a modified injection gun in order to facilitate the injection of the fat. The technique has been used in 14 patients with improvement of the voice in eight.

Adipose Tissue↗
PubMed1996

The Scottish tonsillectomy audit. Audit Sub-Committee of the Scottish Otolaryngological Society.

Regional specialist societies offer a valuable mechanism for the conduct of medical audit. The experience of the audit sub-committee of The Scottish Otolaryngological Society in conducting an audit on laryngeal cancer encouraged us to undertake a larger audit of tonsillectomy practice in Scotland. Although the number of tonsillectomies performed has declined over the last 10 years, they still account for about 20 per cent of all operations performed by otolaryngologists and as such are a major consumer of resources (Personal communication--Directorate of Information Services, Information and Statistics Division. NHS in Scotland, Management Executive, Edinburgh). The Scottish tonsillectomy audit was devised to define current practice, review indications for surgery and recommend such modifications in practice as may be necessary to optimise patient care and the use of resources. Funding was obtained from the Clinical Resource and Audit Group (CRAG) of the Scottish Home and Health Department. Data on current practice was collected during the period February 1992 to January 1993. Proformas were completed by medical, administrative and secretarial staff in all participating hospitals, collected by an audit secretary and passed to the relevant data collection centre. Data was then entered into a specially designed database before being forwarded to the audit co-ordinator based in Dundee for collation. Six and 12 months following surgery, all inpatients were sent a questionnaire to obtain data on the efficacy of the operation. Data were obtained from a total of 9,773 patients. Two thousand and seventy-nine of these were seen as both outpatients and inpatients, 4,309 were outpatients only and 3,385 were inpatients only. Four thousand, one hundred and one patients returned at least one follow-up questionnaire. The topics audited included source and reason for referral, indications for surgery, grade of staff involved, type of surgery and length of stay in hospital. In agreement with previous studies (H.M.S.O., 1989), differences were found in the rates of tonsillectomy performed in different Health Boards. Although the highest referral and operation rates were found in the Highland region, referral and operation rates did not correlate in all other areas. Recurrent tonsillitis was the most frequent principal reason for the decision to operate although there were differences between Health Boards for other indications including obstructive symptoms. Most patients had symptoms for two to three years although some patients had been affected for 40 years prior to being listed for tonsillectomy. Some area ENT services were consultant-based while others involved more junior staff. The grade of staff involved did not appear to affect the decision made at the Outpatient Department (OPD) or the outcome of the operation. Ninety-eight per cent of patients who returned the questionnaire were glad that the operation had been performed. Recommendations regarding changes in tonsillectomy practice are given.

Adenoidectomy↗
PubMed1996

The Scottish tonsillectomy audit. The Audit Sub-Committee of the Scottish Otolaryngological Society.

Regional specialist societies offer a valuable mechanism for the conduct of medical audit. The experience of the audit sub-committee of The Scottish Otolaryngological Society in conducting an audit on laryngeal cancer encouraged us to undertake a larger audit of tonsillectomy practice in Scotland. Although the number of tonsillectomies performed has declined over the last 10 years, they still account for about 20 per cent of all operations performed by otolaryngologists and as such are a major consumer of resources (Personal communication-Directorate of Information Services, Information and Statistics Division. NHS in Scotland, Management Executive, Edinburgh). The Scottish tonsillectomy audit was devised to define current practice, review indications for surgery and recommend such modifications in practice as may be necessary to optimise patient care and the use of resources. Funding was obtained from the Clinical Resource and Audit Group (CRAG) of the Scottish Home and Health Department. Data on current practice was collected during the period February 1992 to January 1993. Proformas were completed by medical, administrative and secretarial staff in all participating hospitals, collected by an audit secretary and passed to the relevant data collection centre. Data was then entered into a specially designed database before being forwarded to the audit co-ordinator based in Dundee for collation. Six and 12 months following surgery, all inpatients were sent a questionnaire to obtain data on the efficacy of the operation. Data were obtained from a total of 9,773 patients. Two thousand and seventy-nine of these were seen as both outpatients and inpatients, 4,309 were outpatients only and 3,385 were inpatients only. Four thousand, one hundred and one patients returned at least one follow-up questionnaire. The topics audited included source and reason for referral, indications for surgery, grade of staff involved, type of surgery and length of stay in hospital. In agreement with previous studies (H.M.S.O., 1989), differences were found in the rates of tonsillectomy performed in different Health Boards. Although the highest referral and operation rates were found in the Highland region, referral and operation rates did not correlate in all other areas. Recurrent tonsillitis was the most frequent principal reason for the decision to operate although there were differences between Health Boards for other indications including obstructive symptoms. Most patients had symptoms for two to three years although some patients had been affected for 40 years prior to being listed for tonsillectomy. Some are ENT services were consultant-based while others involved more junior staff. The grade of staff involved did not appear to affect the decision made at the Outpatient Department (OPD) or the outcome of the operation. Ninety-eight per cent of patients who returned the questionnaire were glad that the operation had been performed. Recommendations regarding changes in tonsillectomy practice are given.

Adolescent↗
PubMed1994

The Scottish Otolaryngology Audit--laryngeal cancer audit.

Regional otolaryngological societies offer a valuable mechanism for the conduct of medical audit. The experience of the audit subcommittee of the Scottish Otolaryngological Society over the last few years is reviewed and a description is given of the findings of an audit of the management of laryngeal cancer in Scotland. The data collection infrastructure currently employed is described and emphasis is placed on the importance of 'ownership' of audit by those participating.

Aged↗
PubMed1991

An assessment of the incidence of iron deficiency in paediatric otolaryngology inpatients.

The aims of this study were: to determine whether there is an increased incidence of iron deficiency in paediatric otolaryngology inpatients compared with other surgical controls; and to establish whether preoperative screening of haemoglobin level is warranted in such patients. Children aged 1-10 years admitted electively for ENT surgery or for general surgical procedures had blood taken for haemoglobin level, mean cell volume and serum ferritin. Their age, weight, socioeconomic class and ethnic background were recorded. A total of 100 patients entered the study, in a six-month period. The mean ages and weights for the two groups were statistically different, so allowance was made for this in calculations. Social class was not significantly different. No relationship could be established between haemoglobin level and ferritin level for individual patients. Multiple regression analysis for haemoglobin level, mean cell volume and for ferritin level showed that allowing for the age and weight differences these variables were not significantly different for the two groups. This study has therefore shown no increased incidence of iron deficiency in paediatric ENT inpatients. Each Department should formulate its own policy on pre-operative haemoglobin screening, based on local considerations.

Child↗
PubMed1989

Laryngeal electromyography.

Over the last 40 years sporadic reports have appeared in the otolaryngological and neurological literature describing techniques and applications of laryngeal electromyography. Despite considerable refinements in methodology and instrumentation over that time laryngeal electromyography has not been widely adopted in routine clinical practice. This paper describes a simple, reliable and reproducible technique which has been employed by the author over a 15-year period. The indications for laryngeal electromyography are reviewed and the technique currently used is briefly described with reference to alternative techniques. The usefulness of the information obtained by this examination is discussed.

Electromyography↗
PubMed1988

Thermal myringotomy (an alternative to grommet insertion in childhood secretory otitis media?).

Thirty-six children with bilateral secretory otitis media were treated by thermal myringotomy and middle ear aspiration in one ear, and conventional myringotomy, middle ear aspiration and Shepard grommet insertion in the other ear. All children underwent adenoidectomy. Comparing the effectiveness of the two different procedures over a three-month review period, our main findings are as follows. All thermal perforations were closed by 42 days. Elimination of middle ear fluid was achieved in 81 per cent of the thermal myringotomy group, and in 100 per cent of the grommet group. While there was no significant difference in the hearing improvement between the procedures, conventional myringotomy and grommet insertion provided significantly better sustained middle ear ventilation.

Adenoidectomy↗