Thursday, 21 February 2008

History Can Be Better Than CT !!

Dear Bloggers

I want to tell you about another real patient case that has been anonymised to show you how history can give the diagnosis better than a CT scan !

An elderly patient was admitted into hospital with a 3-day history of increasing dyspnoea and cough. The patient was normally wheelchair bound following an episode of Stevens-Johnson Syndrome several years before although she was able to walk a few steps to visit the toilet. However, in the 3-day period, because of breathlessness the patient was unable to walk at all.

The cough was productive and the sputum was said to be clear and there was no apparent bloody tinge to the sputum or any haemoptysis.

However, prior to admission, the patient developed a high fever of over 39 degrees which prompted the admission into the hospital.

The patient admitted that she had been losing weight and had a reduced appetite for at least 6 months.

The patient was a heavy smoker and had been so for many years.

The patient denied any chest pain (pleuritic) or bone pain.
There were no shaking chills or night sweats.
There were no upper or lower gastrointestinal symptoms, no joint or muscle pains, no genitourinary problems and no cardiac symptoms such as palpitations.

Previous Medical History included the above in addition to type 2 diabetes and hypertension.

The patient was being treated with glimepiride, metformin, enalapril and aspirin.

The was no family history of note and the patient lived with her husband in an apartment block and the elevator was working and they had good family support.

On examination

The patient looked slightly unwell and was sweaty (perspiration on the forehead and a drenched hospital gown) but was conscious and alert. The patient was hot to the touch.

Hands revealed tar staining of the fingers on the right hand consistent with heavy, prolonged cigarette smoking but there was no finger clubbing. There was some mild palmar erythema but no CO2 retention flap.

The pulse was regular, bounding in nature and tachycardic at 110/min. Skin turgor was reduced.
BP was 110/60 supine- a sitting blood pressure to assess for hypovolaemia was not performed.

JVP was not elevated and there were no palpable lymph nodes in the neck or axillae.

Eyes were normal and there was no anaemia, jaundice and no Horner's Syndrome.

Mouth examination revealed a bone-dry tongue and coagulated blood around the gums.

CVS: heart sounds were normal 1 + 2 and no murmurs or added sounds. There was no peripheral oedema.

RESP: respiratory rate was 14 per minute, the chest was hyper-expanded and the trachea revealed the 'tug'-sign consistent with chronic lung disease but it was not deviated.
Percussion was resonant throughout anteriorly and posteriorly.
Auscaultation in fact revealed coarse, wet crackles at the left base and reduced air entry on that side.

ABDO: Abdominal examinaion was soft, non-tender, no hepatosplenomegaly, no renal angle tenderness. A 4-5 cm abdominal aortic aneurysm was identified in the epigastric region- there was an added bruit. The bowel sounds were normal.

Peripheral pulses were normal.

CNS examination was grossly normal.

PNS examination revealed proximal muscle wasting although there was some wasting of the small muscles on the dorsum of both hands.
Tone was within normal limits.
Power was approximately 4/5 throughout.
Reflexes were present in the upper limbs but absent in the lower limbs. There was no muscle fasculation.
Coordination and sensation testing had not been performed.
Babinski examination was normal on the right and equivocal on the left.


From the history and examination it was clear that this patient had an acute illness and a bacterial pneumonia was highly likely.

However, the preceding 6 months of weight loss and reduced appetite plus the evidence of a proximal myopathy made a bronchogenic carcinoma also likely. Ca lung is well established to result in paraneoplastic proximal myopathy.

Examination of the chest Xray on the PACS (electronic radiology) was unrevealing.

Bloods revealed a raised WBC and inflammatory markers plus a raised BUN and normal creatinine which respectively indicated infection and dehydration that were already found through the history and examination.

A senior doctor was not content with the PACS radiograph and asked to see the hard copy plain film because experience showed that more can be seen on the plain film.

Indeed, on looking a the hard copy CXR it was clear that there were several ununited rib fractures, an odd shadow at the hilum on the left side around the area of the aortic knuckle and looking behind the heart shadow there was consolidation.

To the senior physician, it made the suspicion of a bronchogenic carcinoma even more likely.

Review of the CT earlier by the junior doctor had suggested only a consolidation was evident but on review by the senior doctor, with the idea that a malignancy was likely, indeed a malignant neoplasm was identified around the region of the aortic arch.

The moral of the story is that there were two process in play here. Firstly, the acute deterioration with symptoms and signs of a pneumonia. Yes, pneumonia is very common in the elderly but in a chronic smoker, one must always think about malignancy. With the more chronic component of weight loss and appetite loss, a hunt for the malignancy was imperative.

Using a PACS system is excellent as it can be used throughout the hospital and films almost never get lost! However, it depends upon which type of computer screen and resolution whether you can see the problems. If it is a high-tec radiologist high resolution screen then there is usually no problem to identify changes. However, if it is an old LCD screen with poor resolution, covered in dust and finger print marks then I would suggest looking at the plain film every time because otherwise, you will miss important problems.

In this case, the patient had a pneumonia secondary to a malignant tumour that had metastasized to bone. This malignancy had been initially missed, although later picked up by the senior doctor, because the CXR could not be adequately read on the PACS system and moreover, because the history of weight and appetite loss had not been fully appreciated by the junior physician.

The clinical suspicion came from the history and physical examination and the odd shadow around the aortic knuckle confirmed the suspicion. CT gave nicer pictures but did nothing to aid in the diagnosis.

A bit of advice is, try to hold the plain xray film at an angle when looking at the heart shadow because you can sometimes see areas of consolidation show up that had previously been unseen when looking head on. Also, try not to stand so close to the Xray. Sometimes, standing back, you will see the consolidated area literally jump out at you and you will wonder how you missed it in the first place. Lastly, remember that the lungs extend below the upper level of the diaphragm shadows on the CXR-- hence, pneumonia can sometimes be hiding below the diaphragm. CXR reading is an art and it is not simply done before doing a CT !! If you can read the CXR properly, in most cases, you don't need to do a CT especially for pneumonia.

Repeating tests to give you the same answer makes little logical sense and increases radiation exposure and cost.

Please consider not using CT scans when they are not clinically necessary. It should be enough with taking a thorough history, physical examination and a plain Xray film unless there are unusual features that cannot be easily determined or that require more detailed examination.

So, next time you see a smoker with pneumonia, find out if they have symptoms of malignancy e.g. bone pain, weight / appetite loss, symptoms of hypercalcaemia etc and bear that in mind when you look at the CXR !

Have a great weekend!!!

How to make the transition from medical student to doctor?

Dear Bloggers

Today's discussion is slightly different. I would like to discuss my opinion on the transition from medical student to becoming a doctor.

I remember being a medical student and attending lectures to learn about diseases, pharmacology, anatomy, biochemistry and so on and so forth. The information in those lectures was excellent and provided the foundation of my knowledge of common diseases.

In part, I was also allowed to go to different locations for training outside the university for specialties such as surgery, paediatrics, obstetrics and gynaecology, general medicine, general (family) practice to name but a few.

In so doing, I was able to learn as a student how the information in the lectures and in the books bore relevance in the hospital system. As such, I soon learnt that the rare diagnoses such as Zollinger-Ellison Syndrome from gastrinoma are very rare, but of course, such rare diagnoses are what everyone remembers. However, the common things such as heart failure, its presentation, investigation and therapy may have only been covered in a single lecture with no emphasis on this being an important thing to know.

Hence, using the basic knowledge from medical school and seeing how it is applied in the real life scenario of the hospital system is really essential how to understand and make the transition from medical student to doctor.

One thing I always say is Common Things Are Common, and I often hear from medical students and junior doctors alike, rare diagnoses, which albeit are correct, are not the commonest presenting illness for the symptoms and signs.

How did I make the transition from medical student to doctor??

Well, I was always advised by my mentor, a famous Professor in Infectious Disease medicine, to see the patient and obtain the history and physical examination and then read about the problems in the textbooks, thereby reinforcing the medical problems with literature. This indeed was useful and I use such a method to this day. In fact, the patients are the best teachers. Going to the bedside and going through a detailed history in the correct order of how things occurred will in fact teach you a lot about the illness by itself. In so doing, the information obtained can then allow you to concentrate on areas of the physical examination that cause concern.

Then, by drawing together the positive elements of the clinical picture along with the pertinent negative symptoms e.g. no chest pain, no sputum, in a body systems review, allowed me to understand which diseases were not likely to be causing the problem.

By having a problem list from history and physical examination alone, I was then taught to consider the likeliest diagnoses from these problems e.g. central crushing chest pain, dyspnoea, diaphoresis, nausea and vomiting are more likely to be an AMI or unstable angina rather than Bornholm's disease from coxsackie virus.

It is all very good to use a medical list of causes, the one which I constructed is DIET IN HIM, an example case that I published last year maps out the different causes from the DIET IN HIM list for a particular patient problem. However, this is just the start!! One has to know the epidemiology of disease such as the age of onset, the likelihood in female or males e.g. SLE, how the disease usually presents and the salient features for diagnosis. Then one has to produce the differential diagnosis based on which is the best diagnosis to fit all the features and with less common ones below this.

Remember, this is based solely on history and physical examination alone.

In the UK, most patients admitted will been seen by the junior doctors who takes the history and physical at the bedside. There may be an ECG available and rarely have any blood tests been taken except if it is a referral from the Accident and Emergency (ER) department or another team. Then the junior doctor takes the blood tests and orders the radiological tests.

However, in the interim, whilst awaiting the results, treatment is usually commenced in anticipation of the results. Hence, treatment is not delayed waiting to see if you are right or wrong. How can this be done??

Well, it comes back to interpreting the history and physical examination. Patients with signs of heart failure get furosemide before the chest xray is performed with oxygen therapy. Patients with chest pain consistent with an ST elevation MI on ECG get the aspirin, heparin, oxygen, morphine, and thrombolysis before the CK and Troponins are available. Patients with signs of a tension pneumothorax get the needle inserted into the 2nd intercostal space in the mid-clavicular line before the CXR is taken. The patient with a good history of PE e.g. sudden onset pleuritic chest pain, cough, dyspnoea, hypoxaemia and a clear chest examination and Xray get heparin before the D-Dimer or spiral CT are performed.

The fact is, making a diagnosis based on history and physical examination is imperative. Without the proper history and poor physical examination skills, the ability to make a diagnosis can be delayed and then the reliance on machines to make the diagnosis for you increases and treatment for severe illnesses can be delayed resulting in adverse outcomes.

Problem Based Learning (PBL) using common presenting illnesses to teach how to understand differential diagnoses and which common diagnoses to consider is very important. This type of teaching is used for the famous MRCP exams in which limited data is provided and the likeliest diagnosis needs to be selected. The USMLE exams are similar in format as well. You see, patients do not present to you and say I have all of these symptoms and my diagnosis can only be X disease. There are many diseases that have overlap of symptoms and signs and the only thing that can separate them can be the timing of onset, epidemiology, sex predominance, location in the world, sexual history, so on and so on.

However, PBL is a classroom based idea and sets the mental framework about how to go about thinking of the patient problems. It is an entirely different scenario being tired and on-call at 4am and to be called to the ER to see a sick patient. This is where the use of bedside teaching comes in to play. By knowing which salient questions to ask as a discriminator to quickly get to the likely diagnosis can speed up the history taking and allows the doctor to already consider what treatments the patient is likely to require.

For example, the patient with the classical history of ischaemic chest pain is going to be questioned about the elements of the pain, its severity, its radiation, to ascertain if it is truly ischaemic or related to for example a dissecting aortic aneurysm because the treatments are different, the former being medical in most cases and the latter being emergency surgery!!

It is my opinion that training as a doctor is a vocation. When you become a doctor for the first time, you have just started on the long road to learning about diseases, their diagnosis and treatment. Medical school does not adequately prepare you for real life medicine. It neither prepares students about how to talk to patients or their families.

The best way to really make the transition is to see as many patients as possible as a student and really try and take a decent and comprehensive history including the Body Systems Review. The teaching of physical examination is really very much reliant on your teachers but you can also learn from some very good books that are available these days.

Try and practise Problem Based Learning. One UK book I would recommend is Rapid Review of Clinical Medicine (for MRCP) by Sharma and Kaushal and published by Manson Publishers. This book is available from Amazon.

Then, with this background of patients cases from real examples plus PBL examples, when you see a similar patient case in future, you should go through a similar process for the differential diagnosis and scale according to likelihood the most likely diagnosis and consider what further tests you would do and more importantly, what emergency treatments you will start.

Learn, learn, learn your medical emergencies e.g. treatment of AMI, PE, COPD, Asthma, Seizure etc.... There are many books available to do this, but I would strongly suggest you use one based on current evidence rather than on opinion.....

The ability to solve medical problems come from many years of experience and even senior doctors get it wrong on occasion because patients don't write the textbooks and doctors are human.

Good luck with your quests!

Extension for Case Result

Dear Bloggers

As you are aware, I posted a case for you to attempt to answer last week. In view that there have yet to be any replies to the case, as a consequence, I will therefore extend revealing the answers for a further week to allow you more time.

Please feel free to send in your answers anonymously.

Have a great day!