[Featured Image: Creative Commons, danielleellis55 on Flickr.]

First off here’s a video I recorded for the CEM FOAMed network on “approach to the injecting drug user“. Be sure to subscribe on iTunes and check out the site. There’s a podcast feed and a blog feed, so be sure to get both.

httpv://vimeo.com/98215239

[Direct Download ]]

Injecting Drug User (IDUs) are frequent attenders at EDs for lots of reasons. While there is no doubt that there are a lot of social factors involved in these attendances, we can all too easily forget that these patients get really sick and often get left in the bottom of the queue of patients waiting to be seen. I think “the approach to the IDU” would make a great chapter for Rosen’s but it’s not in there yet. Harwood Nuss is the only one I’ve seen with a good chapter on it.

Complications of injection drug use

Hardwood-Nuss 5th edition p1398

I find this population of patients perhaps the most fascinating to treat. Generally ostracised by society in the way homeless people usually are. Usually undertriaged at the front door (“just another junkie”) I frequently find them in the waiting room with fairly dramatic vital signs. Without doubt injection drug use is usually not compatible with a stable and productive lifestyle and low grade criminality abounds. Certain aspects of the doctor patient relationship can be challenging here but they aren’t always drug seeking the way we expect they are.

And if your waiting room is anything like mine by the time they’ve waited 12 hrs to be seen then they’ve usually gone into withdrawal and it’s easy to blame all their symptoms and abnormal vital signs on withdrawal (even though their symptoms and abnormal vital signs all occurred prior to their withdrawal…)

All this to say that we approach them with so many cognitive biases and good old fashioned prejudices that it’s no wonder we fail to diagnose lots of the really interesting illnesses they bring with them.

Soft tissue infections

Probably higher incidence of MRSA

Most tentanus and wound botulism these days is associated with IDU

Necrotising fascitis is a much higher risk

Pyomyositis is a nice complication

Vascular

DVT

Arteriovenous malformations

Pseudo aneurysm Here’s a quote “any mass over a vascular territory may actually be a pseudo aneurysm and should be approached with caution” I know a number of people with great stories of enthusiastic junior surgeons incising and draining these with impressive and unexpected results

Associated abscess

All 4 of the above in the same leg as I saw once…

Those lovely cutaneous groin sinuses that descend to dear knows where.

Mycotic aneurysms, typically with infectious endocarditis

Pulmonary

‘Pocket shooting’: injecting into the supraclvaicular space in the hope of finding a vessel. Can result in pneumo, haemo, hydropneumo and the wonderfully titled pyopneumothorax

Dissolving tablets and injecting them can result in what I’ve heard called trash lung or talc lung. [Check out BroomeDocs podcast with @dreapadoirtas on this] This can cause granulomas in the pulmonary and even retinal vasculature (in fact looking at the retinas for talc might be better CXR or pulmonary function tests) Restrictive and obstructive dysfunction can occur. I suspect this is commoner than we suspect. I see a lot of IDUs with lowish sats and it gets blamed on something like COPD from smoking. Chronic pulmonary hypertension can result



Skeletal

Osteomyelitis and septic arthritis can be local or haematogenous

Commonest is vertebral osteomyelitis usually lumbar which may have associated disc it is with or without the even more emergent spinal epidural abscess Pain is often chronic (as has been in the cases I have seen) Don’t expect fever (unless you’re the admitting doctor in which case it can’t possibly be vertebral osteo without a fever…)

Joint involvement is axial. Think sacroiliac, sternoclavicular, hip and pubic symphysis. (Mainly fibro cartilaginous joints if you’re into the anatomy of it all) This is really important as no one will consider septic arthritis in someone with tender central chest pain.



Central nervous system

Meningitis both fungal and bacterial

Various sites for epidural abscesses

Brain abscesses

CNS aspergillosis

Cerebral murcomycosis (even when HIV negative) Headache, fever, cranial and motor deficits Apparently basal ganglia lesions on CT are the key



Fungal endophthalmitis

Decreased acuity, eye pain

White vitreal exudate on fundoscopy

Blood Born Viruses

Hep C (almost ubiquitous amongst IDU. >80% in our population)

Hep B (up to 80% become seropositive over lifetime)

HIV (about 10% in our local population)

Endocarditis

(lifetime incidence of 5%)

Classic signs are rare

Mainly right sided

Cotton fever

A brief, febrile episode following injection when the solution is filtered through cotton balls

No way to distinguish this in the ED from the other more serious occult causes of fever in the IDU

It might be easier is to think about common clinical presentations and then apply appropriate IDU pathologies

IDU with stroke

Brain abscess

Subdural empyema

Botulism

Mycotic aneurysms

Good old fashioned stroke

Groin pain

Abscess

AV fistula

DVT

Pseudo aneurysm

And I suppose it could be just a hernia

Chest pain

Pneumonia

PE (esp in groin injectors)

ACS (chronic inflammatory states like HIV lead to accelerated atherosclerosis. Never mind the cocaine use)

Sternal joint osteomyelitis

Headache

Brain abscess

Meningitis

SAH (remember all the cocaine use that goes with the heroin)

Complications of associated HIV Toxoplasmosis Lymphoma

And yes it could just be a migraine too i suppose…

Back pain

Epidural abscess

Discitis

Vertebral osteomyelitis

And yes it could just be good old fashioned back pain too I suppose

Fever

Endocarditis

Meningitis

Osteomyelitis

Cotton fever

HIV related

TB (a lot of these guys are homeless and in Dublin anyhow there are reasonably high rates of TB amongst the homeless)

Haematological malignancy

And yes I suppose it could just be a flu or the dreaded ‘viral illness’

Shortness of breath

PE

Talcosis or trash lung

Chronic pulmonary hypertension

Pneumothorax from trying to inject a neck vein

Aspiration from their recent OD, GCS 3 episode

And yes I suppose it could be a good old fashioned chest infection too

Cellulitis in IDU

necrotising fasciitis

Pyomyositis

Subcutaneous abscess

And yes I suppose it could be a simple staph or strep cellulitis

References/FOAMed Resources: