Thursday 7 May 2009

Translation of Pathology into Questions for History Taking

Dear Bloggers

I have often focused my blog articles on how to take a history. However, many junior residents come from medical school and are still uncertain how to ask the 'right' questions. It is not an easy thing being faced with a sick patient and then, miraculously knowing which questions to ask. However, in order to understand what questions we should ask in the very first place we need to fundamentally turn things upside down and think about the disease first and then work out what questions can stem from such diseases.

For example, a patient may present with chest pain. This should immediately make us consider the causes of chest pain that should never be missed, for example, acute coronary syndrome (ACS), aortic dissection, pulmonary embolism, pneumonia, pneumothorax, oesophageal rupture, to name but a few.

The direction of questions to the patient is totally dependent on the presenting complaint. Hence, when we consider ACS, we know that it causes crushing, severe chest pain with pain radiating to the neck, jaw, arms. There can be sweating, nausea, vomiting, collapse, palpitations etc. The duration of pain is usually defined as lasting more than 20 minutues.

Now, we need to translate such information into questions.

For example,
'Please tell me what the pain feels like' [open question]
'Does it feel like a heavy pressing feeling? Like an elephant sitting on your chest?' [closed question]
'Does the pain travel anywhere else?' [semi-open question]
'Does it travel to your neck, jaw or down your arm or arms?' [closed question]
'What time did the pain start? What were you doing at the time?' [open question]
'How long do you think you have had the pain?' [open question]
'On a scale of 1 to 10, 1 being almost no pain and 10 being the worst pain imaginable, where would you put this pain on that scale?' [visual analogue scale -- very important!]
'Have you had any other symptoms with this pain?' [open question]
'Have you had any nausea, vomiting, palpitations or loss of consciousness ?' [closed question]
'Have you had a pain the same as this before?' [open question]

The above example is a string of 'stock' questions for defining possible Acute Coronary Syndrome which then makes us consider the investigations and treatment even before the laying on of a stethoscope.

On the hand, the patient may say that the pain feels sharp when breathing, which takes us down the route of ALSO asking about causes of pleuritic chest pain. We still ALWAYS ask about the ACS, aortic dissection, oesophageal rupture questions as well. We DO NOT miss them out just because the pain sounds pleuritic. We go back to these other screening questions AFTER dealing with the specific questions for pleuritic chest pain.

Hence, 'Please tell me what the pain feels like' [open question] -- SHARP, WHEN I BREATH IN
'Do you have a cough or phelgm?' -- YES, I COUGHED UP SOME PHELGM
'What colour was the phelgm?' -- I AM NOT SURE.....
'Was it white, yellow, green, brown or red like blood?' -- ACTUALLY, IT WAS RED LIKE FRESH BLOOD
'Do you feel feverish or chilly?' -- NO
'Have you got any other symptoms?' -- YES, I FEEL A BIT BREATHLESS
'Can you tell me when it happened?' -- MMM, IT WAS SUDDEN, WHEN THE CHEST PAIN CAME ON
'Can you tell me how severe your breathlessness is? For example, are you breathless talking to me now or just when you walk?' -- I AM BREATHLESS WHEN I WALK
'Do you normally get breathless?' -- NO, I AM USUALLY OKAY TO WALK ANYWHERE WITHOUT A PROBLEM
'Do you feel any other symptoms?' -- SUCH AS?
'Well, do you have any palpitations of your heart? Does it feel irregular, fast or slow?' -- IT FEELS FAST AND IRREGULAR
'Have you noticed this problem in the past?' -- NO, I HAVE ALWAYS BEEN HEALTHY
'Have you been unwell recently?' -- NO
'Have you taken any recent long-haul flights?' -- YES, I FLEW TO AUSTRALIA FOR A SHORT HOLIDAY. THE FLIGHT TOOK 18 HOURS. I CAME BACK 3 DAYS AGO.
'Do you have any leg swelling? Any pain or redness of either leg?' -- YES, I NOTICED IT THIS MORNING. MY RIGHT LEG SEEMS SWOLLEN AND PAINFUL.
'Have you been diagnosed with any cancer recently? Or do you take any hormone replacements such as the contraceptive pill?' --NO
'Do any of your family have any history of blood clotting problems?' YES, MY MOTHER HAD A CLOT IN HER LEG IN THE PAST. SHE HAD TO TAKE WARFARIN FOR THE REST OF HER LIFE. THE DOCTORS DID NOT KNOW WHAT CAUSED IT IN HER DAY.

At this point, the diagnosis of deep vein thrombosis causing pulmonary embolism is pretty well established just from the history. The history also tells us that the patient has at least two risk factors -- remember Virchow's Triad? She has poor flow from a long-haul flight and a familial tendency to form clots [hence a change in blood viscosity]. Two out of 3 of Virchow's Triad predisposes to thrombosis. Again, from the history, it makes us consider the investigations and treatment even before laying on of the stethoscope.

After this history of the main problem, we still go on to ask about the other causes of pleuritic pain such as 'Do you have any history of tuberculosis?' 'Any recent history of a common cold e.g. running nose, earache, headache' -- remember Tb, typical pneumonia, viral infections etc, can cause pleural reactions and localised chest pain.

We also still ask about the diagnoses that should not be missed and hence, the previous ACS questions
'Does the pain feel like a heavy pressing feeling? Like an elephant sitting on your chest?' [closed question] -- NO
'Does the pain travel anywhere else?' [closed question] -- NO
'Does it travel to your neck, jaw or down your arm or arms?' [closed question] -- NO
'What time did the pain start? What were you doing at the time?' [open question] -- 8:30 THIS MORNING, I WAS WASHING THE DISHES.
'How long do you think you have had the pain?' [open question] -- AT LEAST 2 HOURS
'On a scale of 1 to 10, 1 being almost no pain and 10 being the worst pain imaginable, where would you put this pain on that scale?' [visual analogue scale -- very important!] -- 5/10
'Have you had any nausea, vomiting, palpitiations, loss of consciousness ?' [closed question] -- YES, PALPITATIONS ONLY BUT NONE OF THE OTHER SYMPTOMS
'Have you had a pain the same as this before?' [open question] -- NO, NEVER

Hence, the response of the above questions takes us away from ACS as the cause and keeps us pointing towards DVT-PE.

The specific questions for aortic dissection, oesophageal rupture and other pathologies still need to be asked so that they are not missed. It is best to be thorough. Sometimes, patients present with TWO pains, and both could be life threatening so it is only with the history being taken methodically that the cause of the different pains can be elucidated.

As can be appreciated, it is the presenting complaint that stems the follow-on stock questions in order to identify serious pathology so that a rapid diagnosis can be made and the correct treatment can be instituted.

From the above history, we are soon able to narrow down the diagnosis to DVT-PE by changing from open to closed specific questions. Once the critical diagnosis is considered, the physician seeks to establish the cause and risk factors for the problem. In doing so, when performing the physical examination, the physician would focus the examination on the cardiorespiratory system by looking for tachycardia, raised JVP, pleural effusions, crackles, signs of DVT in the lower limbs.

In view of the family history, the patient would be screened for familial coagulopathies, a D-Dimer would be checked and the patient would have an ECG to screen for ACS and ECG abnormalities associated with PE.
The patient would receive a chest radiograph to look for a widened mediatinum (screen for dissection), consolidation, effusions etc.
The patient would receive a spiral CT of the chest and a doppler ultrasound of the lower limbs and pelvis to look for thrombosis whilst receiving full treatment dose of heparin as soon as possible.

Hence, in summary, when we hear the chief complaint, we must immediately begin to think of diagnoses that fit the initial pattern. We must consider life threatening diagnoses first. When thinking of the pathology, consider how the disease can manifest. Then consider how those manifested problems can be explained by symptoms. Then pose those questions to the patient.

Explore all the serious pathologies before moving down the list on to the less severe and non-acute causes of the symptoms.

In the end, you will have taken a very detailed history and have many pertinent positive and negative symptoms and hopefully, a very focused history of the disease you have already considered at the very first mention of the chief symptoms. It is important though to take the history rapidly in the case of life threatening problems such as ACS. In such situations, it is often the case that the doctor takes the history whilst examining the patient :-o

At first it may be difficult to think in this way but with practice, being able to take a history will become easier in time. Remember though, read about your patients conditions and remember what they tell you. It will help you make diagnoses in your future patients too.

Please consider....

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