Sitting verus supine vital capacity

Whilst working in Mt Gambier recently one of our Respiratory Physicians, Dr Borta asked me to measure a patient’s supine vital capacity which is one of our less common noninvasive respiratory function test measures.

Evaluation of diaphragm strength can be accomplished by measuring the vital capacity in an upright or sitting position followed by a measurement made in the supine position.

Here Lisa, one of our Respiratory Nurses demonstrates the supine and sitting positions.

It is well established in healthy volunteers that lung volume and vital capacity decrease after moving from the upright to supine position. This phenomenon is thought to be due to the shifting of blood to the pulmonary vasculature, changes in the position of the diaphragm, and the weight of the abdominal viscera pressing against the diaphragm. In healthy adults, the FVC falls by approximately 7.5 ± 5.7%.This change is exaggerated in many patients with severe diaphragmatic weakness, though it has not been well evaluated in Amyotrophic Lateral Sclerosis (ALS) patients, the assessment of ΔFVC has been suggested as a screening test for diaphragmatic weakness.
Interpreting an increased reduction in vital capacity in the supine position as diaphragm dysfunction should be made cautiously if the patient’s body mass index is greater than 45 kg/m² as a reduction may not indicate diaphragm dysfunction, but rather an increase in the resistance to diaphragm descent.

Lechtzin et al. studied 25 patients with ALS and demonstrated that supine FVC is an excellent measure of diaphragmatic strength in patients with ALS. It is apparent that the diaphragm becomes weak well before the upright FVC is reduced but using the supine FVC < 75% predicted as a cutoff is a highly sensitive and specific measure of diaphragmatic weakness. Longitudinal studies need to be performed to determine whether supine FVC is a better predictor of future outcomes than measures currently in use. It is not known whether early detection of respiratory muscle weakness and intervention leads to improved outcomes in ALS but it will allow interventions to be developed that target mild respiratory impairment.

Vanessa

An evening @ Portland Sleep Lab

On Monday night I had the opportunity to spend a few hours at the Portland Sleep Lab working with Gerri. I have been there many times but never when the lab has been operating.

For those who have never been to the Portland District Hospital, where the sleep lab is based, the picture provided shows the wonderful view that can be seen from some rooms in the hospital. Not a bad place to spend a night!

Apart from the great views, the Portland Sleep lab is equipped with sophisticated technology. Operating the latest version of profusion (sleep study software package). Since January this year when the E-series from compumedics was installed the communication process between Hamilton and Portland sleep labs has been streamlined.

It's fantastic for Western Victoria to boast two high quality sleep laboratories operating within this region. Next on the agenda is a sleep laboratory in Dimboola to service our patients that come from the Wimmera.

More information about this in the coming weeks.....

Jessica

Health Promotion and Education

Sometimes I give an instruction to a patient during a lung function test and am amazed when the patient does almost the opposite of what I requested. This has lead me down an interesting path of looking at the teaching-learning process in relation to adult learners.

The aim of the information and education we provide is to reducing levels of psychological distress, aid compliance and ultimately patient satisfaction (Poroch, 1995). The more informed the person is, the more likely they will have favorable health outcomes and experience less psychological stress) Joanna Briggs Institute, 2000).

Teaching is more then just imparting knowledge, as learning is more than simply listening to instructions; we want our patients to understand the information. According to O’Brien (2004), the skills required for effective health education include knowledge of the subject matter, communication skills and empathy. Barriers are time constraints, lack of resources and knowledge, disagreement with the patient regarding their expectations, powerlessness, frustration and cultural differences. These barriers of course can be overcome by a planned approach where realistic goals have been agreed upon.
We need to be able to think critically and make clinical judgments in order to meet our patients’ needs. This can be achieved by asking the patient if words are understood and welcoming questions whilst observing non-verbal cues as well as assessing a patient’s learning needs and preferred learning style whether it be visual, auditory or physical. Patient information needs are highly diverse and shaped by gender, age, socio-economic status as well as beliefs, preferences and styles of coping which are all difficult to identify and define.

According to the 1992 National Adult Literacy Survey, one out of every five adults in the United States cannot understand written materials that require only basic proficiency in reading. The average adult in the United States cannot read above eight grade level. Therefore health care providers must prepare materials at the lowest possible reading level preferably the sixth grade level (age nine). People with good reading skills are not offended by simple reading material and most prefer easy-to-read material (Davis et al 1998). Lowering the reading level does not significantly alter the meaning of the text. Studies have shown that regardless of the reading ability and socio-economic status, patients are able to read a simpler brochure quicker and with better comprehension.
Seventy percent of newspapers sold in the UK have been found to be written at a reading age of 12 (Nicklin, 2002).
It is widely recognized that patients often forget things they are told during their consultation therefore written information can be used as a useful adjunct to verbal communication. Two popular formulas are used to determine the readability of written materials; the greater the number of polysyllabic words, the greater the reading difficulty; and the longer the sentences, the greater the reading difficulty.
The following data has inspired me to evaluate the information we provide to our patients. The following approaches have been found to ease patients’ reading. Using short, familiar words of one or two syllables, avoiding medical terminology whenever possible, using short sentences under ten words, using the second-person pronoun (“you”), using active rather then passive voice and using numerals rather than spelled numbers (Nicklin,2002). Information should be non-alarmist, non-patronizing and include a publication date indicating it is up to date.
Pictures apparently enhance memory, lists are easier to read than paragraphs, and in order to facilitate reading, ensure there is adequate white space on the page, set margins left-justified and ragged-right and use 12-point font (Heath, 1999). Health information is apparently accessed by 60-80% of internet users and studies show that 72% of these folk believe online information is credible. Due to the unregulated nature of the Internet we are in a fortunate position of being able to direct our patients to credible sites.
Every interaction we have with our patients and their families is an ideal opportunity to focus on risk management, health promotion and to provide teaching that can influence and affect their lives.

Vanessa

Vmax Logic Tree

Logic Tree software enables clients using Vmax software (which is what we use in our Lab) to custom design interpretation modules to run for each patient at the completion of their lung function test. It is comprised of two components; a software platform, and a development tool to design and edit modules.

Having participated in the ‘Inter-rater reliability in the interpretation of lung function tests’ study conducted by The Institute for Breathing and Sleep, Austin Health, Melbourne last year which was presented as a poster at the recent ANZSRS meeting in Brisbane it is clearly evident there is significant variation in interpretation of lung function tests across different labs.

In an effort to ensure our Lab is interpreting data according to ATS guidelines we have recently installed the Logic Tree module. We have now incorporated this quick and easy step into our post lung function test routine for each patient.
The flow chart attached gives an example of how the logic is used to report spirometry.

Not only has it been educational for me to be involved in the installation but now having had the time to look at the module in detail I can appreciate how it will be easy to custom design the interpretation if required.

This tool assists our physicians in reporting their patient’s pulmonary function tests which is not only useful from a resources point of view but also from a consistency perspective. Thus it standardises interpretative protocols and reporting phrases which leads to consistency in reporting especially helpful for referring doctors.

The Logic Tree ensures our Lab is interpreting data according to ATS guidelines and the Logic Tree will be an important aid in preparing our Lab for accreditation in the future.

Vanessa

Manse Medical

As of July 1 2010 our practice has changed names to Manse Medical. The name change is to reflect the provision of more than consultant respiratory services and reflect the enhanced commitment to providing patient services and education pertaining to sleep medicine.

The name change also represents the commitment to providing consulting services at our practice by three Melbourne based physicians Drs Camelia Borta, David Cunnington and Daniel Steinfort.

In the coming weeks you will notice the change of logo for our practice. New referral forms for lung function testing and sleep studies will be distributed shortly.

Our website address and blog will remain at the same but will also undergo a face lift to reflect the changes to the practices name.

The regular visits by the three Melbourne based physician has enabled Dr. Andrew Bradbeer the opportunity to expand his sleep consulting services. Longer consultations are now available for patients with complex sleep disorders.

It is estimated that almost 90% of Australians suffer from a sleep disturbance at some time in their life, with 30% suffering a sleep disorder. Outcomes range from medical comorbidities such as hypertension and myocardial infarction from OSA to increased risk of work place and traffic accidents. This demonstrates not only a personal cost but a significant large social and economic cost. This cost is estimated to be $3-$7 billion per year.

This is a major public health issue but is still under represented on the National Health Agenda. Statistics on the Government NHMRC funding in 2002 show that sleep research received 1.1% of the pool of funding, compared with CVD 16.6%, Mental Health 23.3%, Cancer 19.2% and diabetes 6.8%.

Over the coming 6 months we aim to provide further professional and community education on sleep medicine to raise awareness of these disorders and their impact.

Jessica

What is the CAT?

The one that rules at our house is Wiggam and he’s pretty cute.
With acronyms being so common, if you go looking for CAT it may also be the Centre for Appropriate Technology or Computed Axial Tomography.

The CAT I’m going to talk about is the COPD Assessment Test.

The COPD Assessment Test is a relatively new patient -completed instrument that has been designed to provide a simple and reliable measure of health status in patients with Chronic Obstructive Pulmonary Disease (COPD). It was developed by a multidisciplinary group of international experts including Professor Paul Jones (PhD, FRCP, Professor of Respiratory Medicine, St George's Hospital Medical School, London, England) who is a world leader in the science of health status measurement in lung disease and Professor Christine Jenkins ( Clinical Professor of Medicine at the University of Sydney, thoracic physician at Concord Hospital, and head of the Airways Group at the Woolcock Institute of Medical Research in Sydney).

COPD is a progressive and largely irreversible disease characterized by emphysema and chronic bronchitis which may result in breathlessness, cough and sputum. Patients with COPD often experience an increasing deterioration of their health related quality of life (HRQL).
“Health-related quality of life, utility and productivity outcome instruments have an important role to play in the general well being of subjects with COPD. The ease with which these questionnaires can be understood and completed is pertinent to issues of compliance and therefore of accuracy in assessing the impact of this progressive, chronic disease”. (Health-related quality of life, utility, and productivity outcomes instruments: ease of completion by subjects with COPD – Stahl et al 2003.)
This 2003 study identified how subjects experienced difficulty in completing a number of well used and new questionnaires. It appeared that age, disease severity, gender and socio economic status all impacted on the ability of the COPD subjects to complete the questionnaires. This article also suggests that the indirect assessment of subject’s HRQL, via relatives, care providers or other health professionals, tends to underestimate the level of HRQL impairment.

Over the past decade, more and more research on the development and validation of questionnaires has been undertaken to quantify the impact of disease on daily life and well being from the subject’s point of view. One reason is recognising that individual patients are most concerned about their symptoms (e.g. dyspnoea) and their function (e.g. ability to perform physical tasks), rather than objective measures such as expiratory airflow (B.Gupta& S.Kant: Health Related quality of Life in COPD: The Internet Journal of Pulmonary Medicine, 2009 V11, No.1)
I found many disease specific and generic questionnaires deemed appropriate to respiratory health. Among them are the SF-12, EQ-5D, HS-COPD, EQ-5D, WPAI-COPD, SOLDQ, QLRIQ (see what I mean by acronyms). There is also the Sickness Impact Profile (SIP), Nottingham Health Profile (NHP), Quality Well Being (QWB), and the St George Respiratory Questionnaire (SGRQ) which is more complex but has a strong correlation to the CAT. Some of these have been used in research studies and looking at these assessment tools I can see why the subjects may have struggled to complete them. A number appear quite complex and time consuming. For example the SIP is a 136 item questionnaire that takes 20-30 minutes to complete.

This brings us back to the CAT. According to the user guide (GlaxoSmithKline 2009) it is a validated, short and simple patient-completed questionnaire which has been developed for use in routine clinical practice. Its development involved literature reviews and consultation with physicians and patients. It is not a diagnostic tool (unlike FEV) but rather a tool to measure health status which may give a better understanding to the patient and clinician as to the impact and progression of their COPD. The CAT consists of 8 questions that are easy to understand and that patients should be able to complete independently. Each response attracts a score between 0-5 which is then added to produce a total score. Further research is currently being conducted to define ranges of CAT score severity and to better understand the clinical relevance in a CAT score from one visit to the next. The Cat Development Steering Group has proposed some potential management considerations according to a patient’s score, correlated to impact level and a broad clinical picture (based on appropriate items from the previously mentioned SGRQ). But the scenarios given are for illustrative purposes only as individual patients will vary in the way COPD affects them. For example a score over 30 rates a very high impact level, over 20 is high, 10-20 medium and less than 10 rates a low impact level.
The CAT score needs to be considered in relation to an individuals disease though there is not always a strong relationship between disease stage and health status score (Jones PW. Health status measurement in chronic obstructive pulmonary disease Thorax 2001; 56 880-7).
Its usefulness may be in initial assessment of and monitoring the progression of COPD in patients (perhaps even identifying specific areas of impairment), or possibly to assess the degree of recovery following an acute exacerbation. Its use in assessing whether an individual patient has had a worthwhile response to specific therapy is limited (but it is more reliable for assessing response to therapy in groups of patients). Recommended use of the CAT is every 3-6 months.

Why might we use the CAT?
It is simple and quick to complete (a few minutes).
It provides a framework for discussion with the patient.
It may help identify where COPD has the greatest effect on a patients life.
It may assist in better informed management decisions of the disease.

Used in conjunction with other COPD clinical assessment tools (e.g. spirometry) it can help to ensure a patient is optimally managed. It is recognized that how the CAT is used will vary according to a particular healthcare setting (and country) and we will need to consider if and how we can incorporate it into our practice to ensure it is useful and relevant.

The use of generic questionnaires versus disease specific questionnaires is a discussion in itself.

Irene

Pulmonary Rehabilitation

Recently I have performed lung function tests for patients who have attended a Pulmonary Rehabilitation (PR) program since their previous testing, which has prompted me to look further into the effectiveness of Pulmonary Rehabilitation on persons with COPD.
Whilst the research has found that Pulmonary Rehabilitation improves health status and quality of life by improving exercise tolerance and shortness of breath, a study by Carone et al (2007) looked into its effectiveness in the most severe category of COPD, i.e. patients with chronic respiratory failure (CRF). They found that PR is equally effective in the most severe category of COPD, i.e. patients with chronic respiratory failure (CRF), and supports the prescription of PR also in these patients.
In another study Riario-Sforza et al (2009)looked at a group of patients with COPD undergoing PR, and evaluated the number needed to treat (NNT) to achieve an increase in physical capacity, as defined by a significant improvement in the six-minute walk test (6MWT). The NNT in the overall study group was 2 and the same NNT was obtained in GOLD stages of COPD 2, 3, and 4, but was 8 in stage 1. They found therefore that PR is highly effective in improving the exercise capacity of patients with COPD, as demonstrated by a valuable NNT, with better results in patients with a more severe disease.
The objective of a third study by Di Meo et al (2008) was to identify predictors of improvement in the 6-minute walked distance (6MWD) in elderly COPD patients after PR. Although they could not develop a model accurately predicting the response to rehabilitation, they concluded from their study that "among elderly patients with COPD, a comprehensive PR programme can significantly improve the 6MWD even in the presence of chronic hypoxemia, and that the most physically impaired patients achieve the greatest benefit from rehabilitation."
This is great news for people with COPD, and especially for those whose condition is worse. Participating in the course will provide improvement in breathlessness, ability to exercise, and quality of life, and the worse the condition is the greater improvement that can be achieved.

Heather