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Mr FF is an 80 year old man living with minimal assistance in country South Australia. He was reviewed prior to a total hip replacement.
The following case is intended to stimulate discussion regarding the investigation and management of perioperative anaemia and perioperative anticoagulation strategies.
•Past Medical History
1.
- Mixed mitral valve disease. Minimally invasive mitral valve repair in August 2010. Post operative echocardiogram shows persisting moderate regurgitation but normal left ventricular function.
- Atrial fibrillation.
- COAD
- Osteoporosis
- Gout
- Chronic Renal Failure
- Septic arthritis right knee. September 2010 ;3 months of IV antibiotic therapy. Admission complicated by ATN and a right groin collection requiring incision and drainage.
•Medication list:
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- Risedronate/Calcium 1 tablet weekly
- Colchicine 0.5mg daily
- Warfarin 2mg daily
- Frusemide 40mg daily
- Ferrogradumet 1 tablet daily
- Oxycontin 40mg bd
- Ezetimibe/Simvastatin 10mg/40mg daily–
- Seretide 50/500 1 puff bd
- Tiotropium 1 puff daily
Mr F describes ongoing right knee pain as well as progressively worsening right hip pain. He has lost over 20kg of weight in the last year and has had poor appetite. This is associated with variable bowel habit with periods of alternating loose stools and constipation. He has never noted any frank blood or melaena bowel actions. He has been increasingly fatigued in the last three months but denies shortness of breath as he is unable to walk far due to hip and knee pain. Relevant examination findings include : mild pallor , marked pitting oedema but no other signs of cardiac failure. Chest auscultation was unremarkable and there was no organomegaly. His right knee had restricted range of movement , there was ongoing swelling which the patient reports as unchanged but no erythema or warmth. Urinalysis was unremarkable.
CBE: Showed a microcytic anaemia : Hb 81 (progressively falling) MCV 75
Biochemical abnormalities included hypoalbuminaemia (Alb 20-25) , persistently elevated creatinine since his previous admission (150-170).
His inflammatory markers were also persistently elevated: CRP consistently 100
Iron studies :
Could you make some comments primarily regarding how you would manage the following:
- His anaemia and interpretation of his iron studies
- His anticoagulation strategy
- Other issues you would like to discuss (of which there are many)
- Other issues you would like to discuss (of which there are many)
Although it's not listed in his meds, I'd want to double check he's not sneaking in some NSAIDs on the sly.
ReplyDeleteThe microcytic anaemia would support iron deficiency but his ferritin is inconsistent with this...
Issues:
ReplyDelete1. anaemia with what seems like Fe deficiency even in the presence of Fe tablets (MCV is the low end of normal i believe. low transferrin saturation would support fe deficiency however previously high ferritin and now normal would suggest inflammation which in addition to liver disease could mask a true iron deficiency
----few red flags of alternating bowel habits, weight loss and anaemia ^.. need to perform a PR examination and investigate for GI malignancy with colonoscopy, I do not believe that a faecal occult blood test is indicated in this patient as he is symptomatic and that is a screening test
2. hypoalbuminaemia
----? d/t decreased synthetic function - ? metastatic infiltration, would like to see the remainder of his LFTS
----? inflammatory state especially with the consistently elevated CRP - ?site of ongoing infection, ? chronic arthritis in the knee, given spread of infection in last admission ? osteomyelitis.
----? malnutrition, need to take a dietary history
----? d/t loss of protein e.g. nephrotic syndrome, protein losing enteropathy. a 24 hour urine albumin collection may be considered as he has peripheral oedema (one of the criteria for nephrotic syndrome) especially as he had no other indicators of heart failure , would also like to see his lipid profile although he is on lipid therapy
----impact on morbidity and mortality - higher in patient's who have hypoalbuminaemia therefore cause needs to be addressed prior to proceeding with surgery
3. chronic renal impairment
would like to see the rest of his electrolytes
4. anticoagulation strategy - with valvular heart disease + AF he requires warfarin
also why is he on oxycontin?
this may well be the tip of the iceberg....
thanks for your comments to date :
ReplyDelete- Kalima : No NSAIDS were taken on the sly
- Regarding the issues above:
Anaemia: the initially low transferrin which is now recovering would suggest to me that inflammation /chronic disease may have been the cause but I agree, his symptoms were concerning enough for a colonoscopy to be arranged which was normal.
- Here are a few other additional questions you may wish to address regarding his anaemia :
1. What is the significance of perioperative anaemia?
2. Should his Hb be normalised before planned surgery?
3. Is parenteral iron indicated? What about the role of erythropoiesis stimulating agents?
With regard to his anticoagulation: I think you stress an important point about valvular heart disease. With CHADS2 scores widely used, many forget that this risk assessment tool is for non-rheumatic atrial fibrillation. So, assuming that warfarin is indicated for this patient, here are some further issues to consider (particularly in a long case setting)
1. how would you manage perioperative anticoagulation?
2. would this patient require 'bridging' therapy and if so with what?
3. what concerns would you have about 'bridging' therapy in this particular case.
Briefly regarding the other issues:
- remainder of the LFTs were unremarkable
- 24 hour urine albumin was not elevated
- statin therapy was being used as primary prevention (is there a role for statins in perioperative optimisation?)
- oxycontin had been prescribed for chronic knee and hip pain (how does this impact on his perioperative analgaesia requirements?)
Having an a go at the preoperative anticoagulation questions:
ReplyDeleteThis patient is at high risk of thromboembolism in the absence of anticoagulation, because of AF and mitral valve repair. Also, prosthetic mitral valve is more thrombogenic than aortic valve. Therefore bridging therapy would be required.
The choice is between Unfractionated heparin or LMWH
LMWH is not suitable for this patient with renal impairment.
Given he is a country patient I would admit him pre-operatively to cease warfarin and commence on intravenous unfractionated heparin. The main concern would be postoperative bleeding.
Addit - after looking up articles I read there is an argument to use heparin at dose for prophylaxis against venous thromboembolism, rather than full dose, in order to minimise the bleeding risk. This is excluding patients with embolic event the last 12 months who are at very high risk.
Thanks for your comments : The last guidelines from 2008 are currently being revised but are stated here : http://chestjournal.chestpubs.org/content/133/6_suppl
ReplyDeleteFor bridging therapy, LMWH could still be potentially used at 50% dose reduction but anecdotally, you may find that joint replacement surgeons are particularly cautious about full anticoagulation. It would be reasonable to discuss with the orthopaedic team the rationale for bridging therapy. Also bear in mind that if spinal/epidural anaesthesia is being considered in this patient, the use of LMWH (especiallywith renal impairment) makes timing of cathether insertion and removal problematic on the ward (consider this issue also when using clopidogrel)
At the risk of sounding like a noob, isn't a mitral valve repair different to a mitral valve replacement, i.e. the thrombogenic potential from a repair is much less than an MVR.
ReplyDeleteAlthough, as already stated, she is at high risk because of her mitral valvulopathy and AF.
Does anyone know if a mitral valve repair in itself would convey any added risk?!
The latest guidelines are available from chest this year.
ReplyDeleteMitral valve repair was not listed as an added risk factor though perhaps it was omission .
CHADS2 goes out the window in the presence of rheumatic AF ; this is listed arbitrarily as 'high risk' for thrombotic events in the latest guidelines with an estimated risk of >10% annual risk of stroke/emoblic events.Bridging anticoagulation is therefore warranted and probably fits the bill for this patient.