Wednesday, 19 September 2012

Why Are Troponins Ignored?

Dear Bloggers

Dyspnea has a wide differential diagnosis that can potentially involve the cardiac, respiratory, abdominal, haematologic, neuromuscular, metabolic systems etc. Because of the vast number of causes of dyspnea, it is essential to take a detailed history, as much as possible, and examine carefully for various serious causes.

Performing of a chest radiograph, electrocardiogram (ECG), cardiac biomarkers, a complete blood count and an echocardiogram, etc, are essential components for the work up of the cause of the dyspnea and on occasion, there may be several overlapping causes.

Silent myocardial infarction resulting in new onset or worsening heart failure should always be considered. New ECG changes suggestive of ischemia e.g. dynamic T wave changes, should alert the physician that there is a cardiac cause.

Checking of the Troponin-I is currently regarded as the Gold Standard test to confirm a myocardial cause. Previously, it was considered that Troponin-T (TnT) was specific for cardiac muscle but studies have shown that skeletal muscle can also release TnT e.g. rhabdomyolysis. Only Troponin-I (TnI) is considered to be most specific to cardiac muscle. It is more sensitive and more specific as a cardiac biomarker than the CK-MB fraction.

Evidence Based Medicine (EBM) texts and international guidance now make mention that TnI (or TnT) should be measured and that measurement of CK-MB is no longer necessary for the diagnosis of an acute coronary syndrome. Moreover, the TnI levels stay elevated for up to 10 days, whereas CK-MB levels drop much more quickly, making it possible to still diagnose a recent myocardial infarction even if other less sensitive or specific biomarkers are negative.

TnI can be used to examine for re-infarction too. A rise of >20% from the last measurement can assist in the diagnosis of re-infarction. CK-MB is again no longer required for making this diagnosis.

It is an unfortunate situation that many Japanese medical students and junior physicians are still being taught that they should check CK-MB and that many still are uncertain about the utility of TnI. Some physicians are not inclined to check TnI or take an elevated TnI level seriously e.g. in renal failure citing that it is purely the renal failure causing the rise.

Recent evidence has actually suggested that patients with a raised troponin level without proven acute coronary aetiology actually have a worse prognosis than in patients with an obvious acute coronary syndrome. One reason for an increased mortality rate may have been the physicians did not take such a rise seriously enough, considering it unrelated to coronary heart disease and therefore, further follow-up was not performed timely enough for such patients. The American Journal of Medicine (2011) 124, 630-635

Other common causes of elevated troponins include

•aortic dissection
•cardiopulmonary resuscitation
•subarachnoid hemorrhage
•severe sepsis
•trauma / contusion
•fast atrial fibrillation
•heart failure

Stress-induced cardiomyopathy (Takotsubo) can cause heart failure, ECG changes and TnI rises. It is said that in some cases the physicians will observe the myocardial echocardiographic changes only and then (somehow) will diagnose this disorder. However, "Takotsubo Heart" cannot be diagnosed unless the patient's coronary arteries are deemed normal by angiography; thereby ruling out an acute coronary syndrome.

Essentially, we cannot ignore a potential acute coronary syndrome as evidenced by worsening dyspnea, ECG changes consistent with ischemia and a TnI rise. Although echocardiography can be useful to look for wall motion abnormalities typical of myocardial infarction, it cannot completely rule out the diagnosis especially as ultrasonographic observations have operator error and there may be poor views depending on the anatomy. In such situations emergent angiography or coronary artery computed tomography may provide the answer.

An elevated pulmonary artery pressure can be helpful to assist in the diagnosis of heart failure given a consistent history, in addition to an elevated B-Natriuretic Peptide (BNP). It is worth noting that in a recent study BNP levels were found not to be superior to physical examination of the right and left sided heart pressures by cardiology experts. The American Journal of Medicine (2011) 124, 1051-1057

Hence, it comes back to history and physical examination and understanding what common things present commonly and what important differential diagnoses should not be missed. Acute coronary syndrome is very common and Takotsubo Heart is not common at all. New onset dyspnea or worsening symptomatic heart failure should make the physician consider silent myocardial infarction in the differential diagnosis. Consistent ECG changes and elevated troponins assist in the diagnosis of this disorder.

Finally, one should not forget about pulmonary embolism (PE). This can also result in worsening heart failure and acute, sub-acute or chronic dyspnea. ECG changes can occur although they are usually right sided in origin on the ECG e.g. Tall R wave in V1 (>7mm), biphasic T waves / ST depression in V1-V3. However, a normal ECG is common and the "classic" S1Q3T3 is very unusual to see yet it seems that this is the only ECG change that students and residents seem to remember. However, BNP and TnI can both be elevated in PE, and when elevated together, they are associated with a worse prognosis.

In essence, elevated troponins should not be overlooked. Instead, further examinations should be undertaken. If silent myocardial infarction cannot be ruled out or if considered most likely, angiography is warranted. At the very least, basic cardiac treatment should be commenced for such patients on the basis that they are likely to have the problem (rather than not due to its high incidence) and that waiting is not an option especially as "time is muscle".

One should not wait for the biomarkers to become positive (which can take 4-6 hours; new highly sensitive troponin tests can provide earlier results but are still not in widespread use). Remember, and I shall say it again, "time is muscle" and the longer one waits before instituting treatment, the worse the outcome in terms of morbidity and mortality.

Remember that an essential treatment in ACS is aspirin, which reduces mortality significantly. It should never be withheld unless there is a good reason e.g. acute gastrointestinal bleeding, allergic reaction. It is said that in some institutions, some cardiologists withhold aspirin initially and proceed straight for percutaneous intervention with this drug being commenced post-procedure. This method of withholding aspirin, perhaps from the misguided belief that patients will bleed excessively during PCI, is not standard treatment according to many of the world cardiology guidelines. This needlessly puts patients at risk by delaying medical treatment of ACS.

In contrast, patients with suspicion of ACS in places such as the USA and the UK are treated more aggressively and are frequently given aspirin en route to the hospital by paramedics. In some countries e.g UK, thrombolysis by tPA for ST elevation ACS is also given en route if certain inclusion and exclusion criteria are met and they are not near to a center providing urgent PCI treatment.

It is time to take Troponins elevations more seriously and be more aggressive in the management of acute coronary syndrome in Japan rather than relying on initial PCI alone and withholding life saving drug treatment prior to such procedures.......please consider

2010 American Heart Association guidelines -- see that aspirin is given early.

2011 Summary of Guidance from the European Resuscitation Council can be obtained here

Wednesday, 17 August 2011

Evidence is to be applied not overlooked

Dear Readers

It's been a while since I last wrote on the blog. Many of you probably thought I had forgotten about it. Quite the contrary, but I have been very busy with other things though. I will continue to write on here from time to time but with no guarantees when.....sorry :-)

I wanted to talk about the use of evidence based medical practice in every day medicine.

Many physicians talk about evidence based medicine and it's importance in modern day medicine, but when it comes to actual patient care, some do not apply it stating variously that "in A country we do x,y,z treatments instead". That is not to say that the local treatment(s) is/are wrong, but without evidence to support it's use compared to well established medicines or procedures that do have a body of evidence, how can the local treatment(s) surmount evidence based treatment?

In many instances a senior has decided the treatment based on what they were taught combined with experience based practice. Hence, "if it ain't broken then why try and fix it?" Well, the use of EBM provides the best current established methods that can support the physician to provide medical therapy in the best possible manner. Of course, such treatment may be very different from local established therapy but that does not mean it should not be utilized.

Many physicians wish to remain in a comfort zone of practice of not using a new treatment method because of fear of it causing a problem, inexperience in the use of drugs or procedures, and fear that they will not get support from their fellow colleagues who may only be practicing "eminence based medicine". The fear of the unknown is a strong emotion to stop us moving forwards as physicians to provide the best possible treatment.

For example, it is said that amiodarone use in Japan is minimal for the "fear" of the side effects, which in the acute phase of use are actually minimal and in the long term can of course cause problems, but on minimal maintenance dose, such side effects can also be limited. The fear of never having used it, for example in atrial fibrillation, instead translates into the use of class I cardiac drugs that have inherent dangerous side effects such as proarrhythmia induction or class IV calcium channel blockers that can cause worsening systolic failure in patients with existing ventricular dysfunction. These decisions may not be optimal, but it is fear of the unknown that causes such paralysis in medical decision making leading to the use of treatments that may be inferior to those used in best practise.

It is also said that in episodes of benign paroxysmal positional vertigo, patients in Japan are given intravenous bicarbonate. When challenged about the evidence for the use of such treatment, some doctors can be vague and use the standard dogma of "this is standard therapy here" without being able to provide firm evidence for the benefit of such therapy. Evidence based texts e.g. UpToDate, can provide the current standard of therapy with references that one can rely on to make clinical decisions rather than resorting to old therapies that have not been critically tested in large trials.

The fear of providing pain relief to patients is another example leading to paralysis of clinical decisions. Severe pain may not be amenable to the usual acetaminophen or NSAIDs. Sometimes the only treatment that can lead to adequate pain control can be opioids/opiates. There is again a strong fear factor that patients will become addicts or that they will stop breathing. This can sometimes translate into patients without cancer being refused adequate pain control, which may be severe, or patients with cancer being underdosed, because of physician fear.

The laws controlling the use of narcotics in Japan are very strick having been produced over 50 years ago and which need a significant overhaul for treatment of modern day patients. It is said that only patients with cancer can have opiates and even then, some physicians need a special license to prescribe it. The fact that patients in severe pain do not stop breathing with opiates is a testament that when used appropriately, they are safe. Moreover, use in the short term e.g. acute myocardial infaction and postoperatively, there is no induction of addiction. The fact that the opiate use in Japan is 1/7 that of the UK despite it having comparatively double the population, reflects the aversion of it's use in the medical community generally.

The use of EBM can help to support the physician to make difficult decisions when their experience base runs out. A physician should always recognize their limitations. If they are unable to answer the question themselves, they can ask for a specialist opinion or they can go to the books. However, the books are only as good as the time of when they were written and usually, by the time they go to print they are already out of date! Therefore, utilizing an EBM database that is updated regularly must be the best current way to answer difficult clinical questions.

One should also bear in mind that EBM texts are not just there to help with therapy. They are produced to aid the physician to consider differential diagnosis to try and prevent premature closure of diagnosis. In the early stage of an illness with few symptoms and clinical signs it can be difficult to be specific about a diagnosis. Such texts can help guide the physician about the natural history of disease and atypical manifestations and presentations. This can be very valuable as no physician can hold mountains of information in their minds ad infinitum. With the ever changing world of medicine and epidemiology of diseases over time, an updated EBM text can be a very helpful assistant.

It should never be an embarrassment to not remember something, but it is an embarrassment and sometimes negligent, if information can be checked but it is not done so because of pride of supposedly "knowing everything I need to know". From my own perspective, the more I read to keep updated, the more I realize that I know even less. I end up with more questions that when I started.

I shall no doubt be writing more on this in the future.

Essentially, there is no excuse to avoid the use of EBM at the bedside to assist in patient care. EBM can answer many of the clinical questions that come up everyday on the ward. The fear of the unknown and uncertainty is something physicians must deal with everyday. There is no escaping it by ordering more and more tests, and which "play for time", and which are unlikely to answer the questions.

As a word of warning, the use of EBM in a patient with for example, X disease, should lead to the use of that same evidence and application of it for all future patients with X disease (but by also checking to make sure the EBM recommendations are still the same or have been updated) rather than it being an isolated case or an "experimentation with EBM".

We as physicians need to keep as knowledgable as possible about the changes in medicine and by reading thoroughly we can increase our comfort zone of knowledge by applying this to patient care at the bedside rather than being fearful of the "unknown" and "personally untested". We should embrace EBM to provide the best possible patient care.

Reading EBM is good but applying it in reality is the only way to improve patient care otherwise we have a situation of "one hand clapping". Without two hands i.e. Reading and applying what was read, we will make no clapping noise and as a result, patient care will remain unchanged.

Please consider.....

Friday, 28 January 2011

Rounds around the computer are not rounds

Dear Bloggers

It's been a while since I last wrote on this blog. I'm afraid I've been very busy but I nevertheless have not forgotten about the blog.

From my experiences in Japan, patients are often discussed around computer terminals with much emphasis given to laboratory data and radiology rather than the history and examination. This is nothing new to this blog but the fact that the patients are seen for just a short time and given a cursory examination, is not what I would classify as a clinical round.

In other countries such as USA, Australia and the UK, although there is also discussion about data and scans, their emphasis is not put before the history and physical examination of the patient.

Clinical interpretations, decision making, treatments etc are based upon the combined picture of all elements including what was or was not found in the history and on the physical examination with the addition of basic tests e.g. blood tests, ECG, chest x-ray. Decisions are not based only on tests. In the emergency situation, withholding treatment while awaiting test results can end up with a dead patient. For example, a tension pneumothorax is a clinical diagnosis and sending the patient for a chest X-ray would be viewed as malpractice and even incompetence. A needle thorocotomy at the bedside is a diagnostic therapy and fully justified in such a situation.

When reviewing patients on the ward rounds, clinical signs need to be re-elicited to determine if there is a worsening or an improvement. It is not often necessary to keep repeating laboratory data daily (unless the patient is very unwell) or 'following the X-ray' or perhaps more commonly, 'following the CT'. One must remember that patient signs e.g. crackles of pneumonia, can disappear before the radiograph resolution. Hence, following a scan may prove to be less accurate than the physical examination. One must actually 'follow the patient' and not waste time with unnecessary, costly, tests when simply percussing, palpating and listening can tell you if there is an improvement or not and without cost.

On ward rounds, unwell patients need daily physical examination or even more frequently if the clinical need arises. A simple few words and a wave is not sufficient. It does not tell you what is going on with the patient. Moreover, laying on of hands is invaluable as it tells the doctor sometimes more information than a blood test or an xray. In addition, patient satisfaction is better because it shows that the medical staff are actually interested in finding the problem.

There have been situations when a full physical examination of the patient has resulted in the patient developing a 'welling look' and comments including 'I have never been examined in such detail before. Thank you.', 'I've been in hospital for many weeks and this is the first time I have been examined properly'. Family members are also highly satisfied if the medical staff show real interest and examine.

In addition, although it is not commonplace for medical staff to ask many questions as it is viewed as a kind of 'rudeness' to inquire and can be embarrassing, that kind of way will result in diagnoses being missed as the question(s) was/were never posed. Better to ask more questions by asking 'why' than be scolded by a senior doctor later with them asking you 'why not !'

Hence, ward rounds done on paper / electronically of course have their place, but they should not be the only component of a ward round. Patients need to asked more questions to help narrow down the current problems and physical examination should be performed for reassessment.

All conversation information and physical examination needs to be properly noted (under subjective and objective in the SOAP format of notation) at the time it takes place and not hours later. Remember that such information is the basis of a legal document and if not written down immediately, essential information can be and is often missed. This can lead to inaccuracies and wrong tests / treatments being ordered or not ordered at all.

Treatments need to always be re-evaluated. Antibiotics, dose, frequency, side effects, and the patient response to such therapy needs to always be considered. Moreover, rather than just starting antibiotics and forgetting about the stop-date, such treatment always needs to be revisited to decide on when to complete the course. If the patient does not respond appropriately, there can be several reasons which need to be considered:

1) The antibiotic is not covering the organism(s) e.g. anaerobic bacteria
2) The dose / frequency is too low
3) The patient has immune suppression
4) The bacteria has resistance to the antibiotic
5) A non-bacterial cause is present e.g. pulmonary embolism, vasculitis, fungal infection
6) A collection has formed e.g. lung abscess, valve ring abscess, sub-phrenic abscess
7) There may be a drug-fever; patients need to always be asked if they have ever had a reaction to drugs with antibiotics being a particularly common problem
8) There is a line infection e.g. prolonged use of central lines causing candida bacteremia

Hence, simply switching to a 'napalm-kill everything' carbapenem that kills indiscriminately is not always the answer. The bacteria may be very sensitive to the original antibiotic e.g. penicillin, but it may be one or more of the above elements that is resulting in failure of resolution. Switching to a 'penem' will of course be useless if there is candidemia, abscess formation, PE.

Carbapenem usage should not be first line except in certain situations e.g. neutropenic sepsis. Because antibiotics are strictly managed by microbiologists, pharmacists and infectious disease doctors in places such as the UK, Australia and the USA, carbapenem use is far less. In many situations, it is 3rd or 4th line but almost never first line.

Hence, evaluating where infection may be coming from rather than pumping in a 'penem' and hoping for the best is essential to ensure that the patient is receiving appropriate care.

As I have mentioned, commencing antibiotics needs deep consideration but stopping them is also a very important thing.

The usual way of stopping antibiotics is when the clinical features and (e.g. symptoms and signs), vital signs improve e.g. fever resolution, the patient feeling better, and with the hematologic parameters returning towards normal, which is sometimes not practiced in some institutions. Patients are sometimes maintained on intravenous antibiotics for weeks on end even though the patient is well, mobilising, eating and drinking for the mere fact that the C-reactive protein (CRP) is still elevated. I have heard of a case in a university hospital, whereby a patient who was well post-surgery had an elevation of the CRP and which was the sole clinical indication to re-operation. This way is not advocated. The CRP is indeed a better indicator that the laboratory is open.

When making clinical decisions, all elements must be taken into account and not a non-specific lab test.

Of course, infection causes inflammation, and even after the bacteria have been eliminated, the inflammation may persist for several days or even several weeks thereby elevating the CRP. But if the patient is feeling better, fever, signs of sepsis have resolved and other parameters are returning to normal, there is no indication to continue intravenous antibiotics. They can be switched to short-course oral treatment or even discontinued depending on the clinical situation. Exceptions are for chronic or difficult to treat infections such as osteomyelitis and endocarditis that require many weeks of antibiotics. However, for an uncomplicated pneumonia or a urinary tract infection which are exceedingly common, short course antibiotics with clinical reevaluation and early de-escalation is best to avoid prolonged hospital stay, reduce antibiotics pressure on bacteria and to reduce cost to the patient.

Remember that if a patient is on drugs that could be causing worsening of their condition e.g. ACE inhibitors, anti-psychotic drugs etc, they should be stopped to evaluate if they are the cause and to observe for resolution. An excellent resident recently keenly noted that in a patient with an FUO for 6 months, that all investigations offered up no cause. Only on instituting a 'drug holiday' of stopping all drugs, did the fever abate, inflammatory markers rapidly dropped and patient could eat and mobilize!

I can't emphasize enough the importance of bedside history taking, re-evaluation by physical examination, and re-evalautuon of drug treatments etc. Clinical examination can avoid the 'follow the CT' reflex and avoid radiation. Your patients will be much more satisfied that you've taken the time to lay hands on them to evaluate them than sending them into the 'tube of truth' to come out empty handed.

However, as a word of warning, if you do find an abnormal clinical examination e.g. unequal pulses and BPs in a patient with central tearing chest pain, the physical exam directs the physician to obtain appropriate scans and institute life saving treatment.

Without the tools of history and physical examination, we as doctors are shooting in the dark and using a sledgehammer to crack a walnut with routine CT scanning for simple pneumonias that can be diagnosed simply by traditional methods and a simple X-ray. Without the basic tools and over-reliance on the 'machine', we end up slaves to the machine and practicing defensive medicine when no such defense is necessary or warranted.

In the end, it comes down to clinical reasoning which can only be learned from experienced staff adept in managing the many conditions that medicine throws at us on a daily basis. The PC is not a patient and cannot speak or elicit signs. Better to go to the bedside. The patient will tell you more than any book or webpage.

Please consider.....

Tuesday, 17 August 2010

Japanese Medicine Should Use the iPad at the Bedside

Dear Bloggers

Yes, it's been 6 months since I last put finger tips to keys to write on this blog. I have been busy with many things :-)

Since I last wrote, the iPad and the iPhone 4 have come on to the market.

The iPad is a really neat device albeit somewhat heavy. The screen is a nice size but grainy unlike the new iPhone 4 retina display. But, it makes a great eBook reader, word processor, newspaper reader etc. However, I think it has many more uses including within medicine.

It can potentially be used to 'clerk' patients. That means it can be used to record the patient interview and physical findings etc. Basically, a portable electronic patients records device that can upload to the main system for synchronising data. From my experience of seeing Japanese patient record softwares, they are cumbersome and complicated. Also, you either have to have a PC desktop or a laptop. Use of a laptop even at the patient bedside is cumbersome and the battery last about 4 hours if you are lucky ! Usually, it's about an hour in reality as someone else has used the machine without plugging it in.

The iPad has a 10 hour battery after a four hour charge and it much lighter than a laptop. With the touch screen technology, you can tap boxes referring to positive or negative findings, draw diagrams, add voice notes etc This cannot be down so easily or so cheaply on the current PC technology. The iPad is cheap enough and advanced enough to take medicine into a new era where the doctor can be freed up to see the patients at the bedside rather than being tied to the nurse station where the PCs are.

In the 'good old days' the papers notes meant that you could write the patient notes directly at the bedside and define an immediate plan and decide on your tests. But, there was never a way to make that information immediately known to relevant members of the team if they were in another location. Also, it meant that in order to see something relevant in the notes everyone would have to crowd around the patient notes. With the iPad, if every member of staff had such a device, all team members could read the notes simultaneously, check the lab data and radiology on the move from patient to patient so that problems are not missed.

Taking an iPad to the bedside and clerking the patient melds the old with the new and allows immediate updates for the patient care.

Now all that is needed is for some clever software makers to liaise with what physicians need and to make a package in Japanese to allow the doctors to be freed up to practice medicine at the bedside. Such software could also include the 'Review of Systems' with check boxes that would then organise the data later on to auto generate problem lists so that the physician does not overlook the information.

Integration with other software packages that could generate a differential diagnosis would be the next step but let's get 'denshi kalte' made portable first and bring medicine into the new age of technology the way it should have always been!

Have a good week :-)

Friday, 19 February 2010

A Friday Rant On Infection

Dear Bloggers

When we do invasive procedures, we should consider whether we are doing the procedure for the right reason, that the right equipment is used, and in an aseptic manner and maintained correctly.

Should we regard urinary catheterisation as a procedure less important than let's say, central line insertion? Should we be any less careful?

Well, the UK Department of Health figures from 2001 showed that about 25% of patients end up being catheterised during their inpatient stay. The risk of developing bacteriuria is about 5% per day and of those who develop it, about 4% will develop bacteraemia. The death rate from such bacteraemia can be as high as 30%. Clearly, the numbers of patients developing infection are not insignificant at all with the knock on effects of increased morbidity, increased hospital stay, increased cost and even death.

In a review of awareness of catheterisation, the attending was the least likely to know that their patient had been catheterised and up to 22% of residents were also unaware! Unawareness led to an increase in the inappropriate use of catheters. Documentation of the reason for catheterisation was also shown to be poor. In several studies based on the appropriateness of catheterisation, up to 50% of such procedures were deemed inappropriate!

Hence, when we perform urinary catheterisation, we need to appreciate why we are doing it and is there another option. Patients should NOT be catheterised to just 'help the staff'. It is an unfortunate practice in some institutions to place a catheter in elderly patients who are otherwise continent because of mobility problems such that the staff need not toilet the patient regularly. This is not a good reason to catheterise a patient.
Even patients with low urine output do not always need to be catheterised. A bladder volume scanner can be used to estimate the amount instead of passing a catheter.

If we do decide to catheterise, the right equipment should be used including sterile gloves, a sterile sheet (with a circle cut in the middle for exposure of the genitalia) and sterile 'one use' lidocaine gel. All equipment should be prepared in advance of putting on the gloves.

There is no excuse for using non-sterile gloves or previously opened gel, as this increases the risk of transferring bacterial infection into an otherwise sterile environment and which bacteria may be potentially highly resistant to antibiotics e.g. pseudomonas.

A basic but important thing to do is Wash Your Hands before the procedure. Medical staff are not immune from carrying infection. Far from it. Use of a sterilising hand wash is ideal.

There are several instructive formats available for teaching the Global Standard of urinary catheterisation and they include the New England Journal of Medicine videos of the procedure for men and women and the new ABC of Practical Procedures, BMJ Press 2010.

  • In the following explanations, the doctor has a 'clean hand' for using the sterile equipment and a 'dirty hand' for holding the penis or preparing the female labia. After placing on sterile gloves, and a sterile drape over the groin to expose only the genitalia, in men, the dirty hand pulls the penis is a vertical direction. If there is a foreskin present, it should be retracted with the dirty hand and the glans cleaned with sterile water using the clean hand. There is no reduction in bacterial infection from using a sterilising agent on the glans. Likewise, in female catheterisation, the labia should be parted with the dirty hand and the urethral area cleaned using the clean hand.
  • Following this, 10ml of STERILE lidocaine 'one use' gel should be injected down the male urethra via a prepared syringe until all of it has been instilled. The tip of the penis is then pressed to maintain the gel inside the urethra for about 1 minute to allow the lidocaine to take its anaesthetic effect. Then, the pre-opened 12F-14F male catheter is placed down the urethra. The use of such gel is to reduce trauma, patient discomfort and infection.
  • When the prostate is reached the patient should be told to take deep breaths which can relax the bladder neck and the catheter can be twisted slightly which can help entry of it into the bladder. In female catheterisation, as the urethral is very short, the gel can be placed on the shorter female catheter after which it can then be inserted. Once inside the bladder, the catheter is pushed in to the full extent and sterile water (usually 10ml) is injected into the balloon port and the catheter is pulled back. Urine should flow out into a prepared kidney dish and then, the collection bag can be attached. In men, the foreskin should then be return to its usual position to prevent the glans from swelling.
  • The catheter bag should be placed on a stand by the bed and it should NOT touch the floor. It should NOT be placed above the level of the bladder to avoid reflux of urine from the bag into the bladder. The bag should be in a place which avoids the lower exit tubing coming into contact with footware e.g. when staff come to review the patient.
In this closed system, unless the bag needs to be drained, it should not be touched. Taking Catheter Specimens of Urine should be avoided unless necessary. Routine change of the catheter is not recommended.

The procedure should always be documented in the patient notes in addition to why it was necessary to place the catheter in the first place. Another important thing is to document the residual volume to know if the patient has outflow obstruction.

For example one can write the following in the notes, DATE / TIME: Mr Jones not passed any urine for 12 hours. Complaining of pain in the lower abdomen. Examination revealed a large distended bladder than was dull to percussion up to his umbilicus. Prostate examination: enlarged, no central sulcus, smooth and non-tender ; likely BPH. Likely urinary outflow obstruction from BPH. Need to rule out UTI. Hence, need for insertion of Foley Catheter.

Procedure explained to patient with his verbal consent to proceed. Aseptic technique carried out. 10ml of 'instillgel' inserted down the penis. A 12F Foley catheter passed with ease into the bladder. Free flow of clear urine observed. 1200ml of residual urine in the bag post-catheterisation. Sample of urine sent for MC&S [microscopy, culture and sensitivity]. Foreskin returned to usual position post-catheterisation. Collection bag placed on bedside stand. Patient now much improved with relief of pain.

The need for the patient to continue using the catheter should be reviewed on a daily basis. It should not be kept in place just for the staffs' convenience. If the patient needs to toilet at night then it is the ward staffs' job to assist the patient rather than getting the doctor to come at 2am to put in a catheter for incontinence. Moreover, a diaper can be used instead of inserting a catheter. However, there will be some occasions when placing a catheter may be necessary e.g. try to heal decubitus ulcers and avoiding urinary contamination of the sores. However, such sores should usually be covered to aid healing with water-proof dressings. The need for a 'Foley' should be assessed on an individual basis rather than carte blanche' insertion of catheters.

We should also be aware that if we decide to remove the catheter, it should be done in the morning as a Trial With Out Catheter (TWOC). Hence, if the patient goes into obstruction, it will usually be during the daylight hours when the usual team are present and a catheter can be reinserted. It is not good etiquette to expect the on-call doctor to perform a chore that the daytime team can easily do.

Condom Catheters for men who are incontinent can be used in place of a Foley catheter. There is also Intermittent Catheterisation which can be taught to competent patients, which may avoid the need for a long term catheter.

Essentially, we must try and cut down on nosocomial infection. We must take all procedures seriously and use due care and attention to maintain aseptic technique. Just because we regard good aseptic technique important for CV line insertion, it does not mean that it is unimportant for Foley catheter insertion.

Please consider.

Tuesday, 9 February 2010

A Flurry of Endocarditis

Dear Bloggers

There have been two recent cases of infective endocarditis in young adults -- both aged below 30 years with 3rd degree mitral valve prolpase, both growing streptococcal spp from blood cultures and both with previous valvular abnormalities. One had a 'floppy' mitral valve and suspected endocarditis several years before and the most recent patient had confirmed endocarditis in the past.

In the latter case, the patient had a history of preceding tooth extraction prior to the original onset of endocarditis. In this recurrence, the patient had lost the cap to a repaired tooth several months previously. There was no complaint about tooth pain or current problems on direct questioning.

However, on examination, using a simple spatula and a pen light to inspect the teeth, it soon became clear that the base of a previous tooth [the one that lost the cap] was fully exposed and tender to touch. This was the probable site of bacterial entry.

Inspection of the nails revealed two fresh splinter haemorrhages which had occurred since the admission and whilst using antimicrobial agents at the appropriate dose and fully sensitive for the organisms identified.

Bedside fundoscopy examination revealed no abnormalities.

In the former case, there was no evidence of tooth problems. However, in view that the patient also presented with a 'pounding' headache, despite the lack of neurological signs, a mycotic aneurysm needed to be excluded. An MRA indeed revealed an early mycotic aneurysm.

Interestingly, both patients' original chief complaint was fever. Both patients had upper respiratory tract symptoms e.g. rhinorrhoea in the former case and cough with sputum in the latter case. In both instances, the patients were misdiagnosed with conditions such as a 'common cold'. How could this be?

Making a diagnosis of a relatively uncommon infection can be difficult for the uninitiated. More often than not, such symptoms are due to a common cold. Although I do not support such practice, for convenience, it is quick and easy to prescribe 'cold' medications and antibiotics for 'fever' after a cursory look, without appreciating the importance of doing a thorough work up e.g. full history, physical examination and labs, which are time consuming in a hectic outpatient clinic where patients are lucky to get 5 minutes with the doctor. In the season of H1N1 influenza, it is easy to consider everyone has possible flu or a 'common cold'. Hence, without a full workup, endocarditis can be missed and was missed - twice.....

Learning Points and Pearls in Endocarditis

  • Take a thorough history ! That includes previous medical history, medications, allergies, sexual history, travel history etc. If there is any hint of possible valvular disease, ask about dental treatment, rheumatic fever, previous murmurs etc. Don't make assumptions as you may get caught out.
  • Examine the patient with focus on the potential areas that might be affected by what comes to light from the history e.g. cough and sputum = thorough chest examination; fever and previous endocarditis = look for peripheral signs and listen to the heart sounds.
  • Use the modified Duke's Criteria for diagnosis of endocarditis.
  • If there is a suspicion of endocarditis, ask about the patient's dental history. Even if there is no complaint of current problems, nevertheless, inspect the teeth and gums. Do not merely look. Tap them gently with a sterile instrument. A painful tooth / teeth raises the suspicion up a notch. If dentists merely looked at our teeth without touching and prodding them, they might never find the tooth decay!
  • Get into the habit of doing bedside fundoscopic examination. It provides an immediate answer and saves time and money instead of sending the patient to the opthalmologist. The technique requires practice but is invaluable. It is especially important to do if the patient cannot be moved. Patients may not complain of visual loss especially if the peripheral retina is affected so again, we should not make assumptions that there are normal eyes just because the patient has no eye symptoms.
  • Blind prescribing of antibiotics for 'common colds' is not justifiable without a firm assessment and can lead to unwanted side effects and bacterial resistance. Such treatment can result in culture-negative endocarditis thereby making treatment much more difficult to tailor later.
  • Suspected endocarditis patients need 3 sets of blood cultures and an echocardiogram; trans-esophageal if possible. Remember that 'vegetation-negative' endocarditis exists and that trans-esophageal echo is not 100% sensitive. Newer modalities are coming to the fore such as PET-CT for identifying infected valves in 'vegetation-negative' endocarditis. If you are interested in further reading, please see A Bright Spot: Infective Endocarditis and PET/CT. Huyge et al. The American Journal of Medicine, Vol 123, No 1, January 2010
  • A pulsatile headache in a patient with fever and a heart murmur or other peripheral signs suggesting endocarditis, should make one consider a mycotic aneurysm. It is reasonable to undertake further investigations e.g. contrast CT or MRI.
  • Embolisation whilst using appropriate antibiotics is a possible indication for urgent surgery as is a vegetation >10mm. Definite indications for surgery include heart failure (moderate-severe), severe aortic or mitral valve incompetence with evidence of abnormal blood flow, fungal endocarditis or a highly resistant organism and perivalvular infection with abscess or fistula formation. UpToDate support surgical intervention after a second episode of embolisation whilst on antimicrobial agents.
  • Inflammatory markers play very little role of when surgery should be undertaken. Making a decision to operate or not based on the level of CRP is nonsensical as any decision should be based on the degree of haemodynamic instability. Moreover, severe aortic or mitral valve incompetence is usually associated with some heart failure and this condition may further decompensate. Hence, aggressive treatment with early surgery should be considered in such situations. Even in asymptomatic severe valvular incompetence without heart failure, early surgery may show benefit. In a paper by Habib et al on native valve endocarditis and optimal surgical timing, it is stated that 'Patients with severe aortic leaflet destruction and congestive heart failure, patients with perivalvular extension or uncontrolled infection, and patients with high embolic risk have poor outcome under medical therapy. Early surgery is necessary in all such patients with 'complicated' endocarditis unless severe comorbidity is present'. Curr Opin Cardiol. 2007 Mar;22(2):77-83.

Wednesday, 20 January 2010

A Classic Bedside Physical Sign - Asterixis

Dear Bloggers

Above is the classic sign of Flapping Tremor, also termed Asterixis, commonly seen in hepatic encephalopathy and CO2 retention. It is also seen in uraemia. The clues for the cause in this patient were the obvious jaundice and palmar erythema. Smelling the breath also revealed the classic Fetor Hepaticus -- sadly there is no current technological means to purvay this smell across the internet! Abdominal palpation revealed hepatomegaly.

The technique for asterixis is performed by asking the patient to extent their arms so that they are straight at the elbow. The patient is then instructed to extend the wrists and spread the fingers wide. This will allow asterixis to be uncovered.

Pearl: When you see a jaundiced patient ask them to perform the test for asterixis. A positive test suggests encephalopathy e.g. Grade 2 Hepatic Encephalopathy. If the patient has known COPD, e.g. the archetypcal chronic bronchitic 'blue bloater' and a positive asterixis sign, checking a blood gas for rising CO2 levels is justified. Remember that Type 1 respiratory failure patients e.g. emphysematous 'pink puffers' can also develop type 2 respiratory failure on occasion!