Correlation of nasal symptoms with objective findings and surgical outcome measurement

Thesis submitted for the degree of Master of Surgery, University of London, 1993.
Published (excluding Chapter 9) 1996.
Recompiled HTML format June 2007
© 1993 – 2016 JW Fairley

Mr James W Fairley BSc MBBS FRCS MS
Consultant ENT Surgeon

Abstract

Contents

Recent diagnostic and therapeutic advances using rigid nasendoscopy are diffusing into clinical ENT practice without good scientific evidence of benefit.

There is diagnostic confusion over rhinosinusitis, and a lack of reliable and valid outcome measures for the results of treatment.

Surgical attention has turned from the maxillary antrum to the anterior ethmoid and middle meatus. There is a risk that variants of normal may be interpreted as being the cause of symptoms, and result in unnecessary, ineffective and potentially dangerous surgical treatment. If the ostiomeatal complex has been ignored in the past, there may be too much uncritical acceptance of its importance now.

Outcome measures for treatment of rhinosinusitis are difficult to establish because subjective symptoms correlate poorly with clinical findings and measurements of nasal function. To help develop suitable outcome measures, subjective symptoms of rhinosinusitis were correlated with clinical findings and measurements of nasal function.

In a series of physiological experiments, clinical observations and surgical trials, statistically significant associations were found between subjective nasal obstruction and nasal inspiratory peak flow, between facial pain / headaches and nasendoscopic abnormalities, and between rhinorrhoea, cough and impaired mucociliary function.

In all clinical studies, predictive value of objective measurements was poor, the relationships accounting for around 7% of the variation in subjective symptoms. Subjective post nasal drip appeared unrelated to any objective measurement.

Outcome measurement for sinus surgery must therefore be based primarily on subjective symptoms. A 12-item self-scored nasal symptom questionnaire was shown to be a convenient, reliable and valid outcome measure for treatment of rhinosinusitis. It was used in a randomized controlled trial of endoscopic middle meatal antrostomy versus conventional inferior meatal intranasal antrostomy. Interim results have not revealed any significant difference between conventional and endoscopic sinus surgery.

Statement of Originality of Thesis as a Contribution to Surgical Science

“There is nothing new under the sun” (Ancient Chinese proverb)

This thesis consists of a series of 8 related studies, reported as separate chapters. There are 2 basic physiological experiments on healthy volunteers (Chapters 2 & 3), 1 validation study on general ENT outpatients (Chapter 4), 3 sets of systematic clinical observations and measurements on patients attending a nasal research clinic (Chapters 5, 6 & 7), and 2 surgical trials, one being a randomized controlled design (Chapters 8 & 9).

Chapter 2

The idea of measuring nasal inspiratory peak flow repeatedly in the same subject, with the aim of determining individual “calibration curves” for the relation between subjective and objective patency, was original. The resulting concept, that each individual’s nose is calibrated for his or her personal range, is useful to remember when attempting to assess the objective results of surgery designed to improve the nasal airway. It implies that the only valid way of using objective measures of nasal patency is to compare results before and after in the same patient. The concept of a “normal range” for NIPF is probably invalid.

Chapter 3

A new device was invented to determine the sensitivity of the nasal mucosa to pressure as a cause of pain. I was responsible for the design concept; Dr. J.C. Stevens (Medical Physicist, Royal Hallamshire Hospital) realised the physical design. This type of study was originally performed in the 1940’s but has not been repeated since.

Chapter 4

The content of the nasal symptom questionnaire is based on Lund’s work (1988). The self-scored sheet was original, as were the validation studies. This questionnaire, if adopted widely, may form the basis for proper comparative evaluation of surgical treatment for rhinosinusitis. This will facilitate meta-analysis both for clinical research and for audit – a fundamental contribution to future surgical studies.

Chapters 5,6 & 7

Systematic clinical observations and measurements of function are correlated with subjective symptoms. This is not an original idea, but has been done with greater precision than usual. The results are remarkably similar in all three studies. Although statistically significant relationships can be demonstrated between subjective and objective findings in the nose, their predictive value for the individual patient is poor, objective findings accounting for around 7% of the variation. The conclusion is that objective measurements are of very limited value in the assessment of surgical outcome in rhinosinusitis. The implication for future studies, and for surgical audit, is that we need to use outcome measures based on the patient’s subjective opinion, such as the questionnaire validated in Chapter 4.

Chapter 8

This surgical trial, using strict selection criteria on well documented patients – provides further new evidence that mucosal pressure contact zones can cause facial pain and headaches, and that their removal can relieve such symptoms. This is helpful to surgical practice in this controversial area.

Chapter 9

This randomized controlled trial (RCT) is an extremely rare event in studies of the surgical treatment of rhinosinusitis. I am aware of only two other published studies to date. It is recognized that the RCT is the gold standard for proper evaluation of a new treatment, it is also recognized that such studies are very difficult to organize. Although my study has not yet provided a definitive answer, I hope that it may serve as a model for a multi-centre trial, and/or provide data for meta-analysis.