Wednesday 7 March, 2007

Collect blood in the serum tube first

Posted in Emergency Dept., General Practice, Michael Tam, Procedures, Wards at 22:00 by Michael Tam

Original article by: Michael Tam :: Printer friendly

Vacutainer system

This short article is relevant for those people or institutions that use vacuumed tubes for venepunction and does not apply to using a needle and syringe.

One of the disadvantages of using a vacuumed tube system for directly withdrawing blood is that there is always a possibility that the needle dislodges or that the vein collapses before all the necessary tubes are filled.

For a long time, this would involve an apology from myself to my patient and a second venepuncture to collect the necessary blood. This is actually a reason that to this day, I still prefer using a plain needle and syringe (despite the increased needlestick risk) for patients with either difficult access or who require blood in many tubes.

However, this is a trick that I learnt from experience:

Always collect blood in the serum tube first.

Read the rest of this entry »

Sunday 11 June, 2006

How to use local anaesthetic

Posted in Emergency Dept., General Practice, Michael Tam, Procedures, Surgery, Wards at 16:12 by Michael Tam

Original article by: Michael Tam :: Printer friendly

Local anaesthetic is one of the best inventions in medicine. It is difficult to imagine doing minor surgery, debridement, incision and drainage, repair of laceration, excisions, etc., without it, though we have only had infiltration local anaesthetics for about a century (with the creation of synthetic cocaine in 1891).

My first regular experience with infiltration local anaesthetics was in the emergency department. There was always a steady flow of people presenting with lacerations. At that time, I had always used whatever was available. However, there are some tricks to using “local”.

Where available and not contraindicated, use lignocaine 2% + 1:80,000 adrenaline

Simply, lignocaine 2% works better than lignocaine 1%. Adrenaline causes local tissue vasoconstriction, leading again to better and longer anaesthesia, and a less bloody field. Furthermore, as the adrenaline keeps the lignocaine in the local tissues longer, you are less likely to have systemic side-effects (meaning you can use more local anaesthetic).

Read the rest of this entry »

Friday 19 May, 2006

Blood collection from external jugular vein

Posted in Emergency Dept., General Practice, Michael Tam, Procedures, Wards at 15:00 by Michael Tam

Index: Alternatives to venepuncture :: Printer friendly

Original article by: Michael Tam

External jugular vein

If venepuncture from a limb vein is difficult or impossible, blood collection from the external jugular vein is an option to consider. Usually, the external jugular vein is large large vessel and it is a fairly easy process.

I personally do not like blood collection from the external jugular vein as it is a “gruesome” process (insofar as putting a needle into someone’s neck) and there is the (small) risk of hitting the common carotid artery. Most patients don’t like the idea very much either. Nevertheless, there are a group of patients who prefer bloods to be taken from the external jugular. In Sydney, the ex-IVDU patients who require frequent blood tests (but have extremely poor venous access) seem to like it.

Normally, I would preferentially collect blood via the radial artery but the advantage with the external jugular vein is that it is easier to collect large volumes of blood and it is less “fiddly”.

Read the rest of this entry »

Tuesday 16 May, 2006

Blood collection from radial artery

Posted in Emergency Dept., General Practice, Michael Tam, Procedures, Wards at 17:18 by Michael Tam

Index: Alternatives to venepuncture :: Printer friendly

Original article by: Michael Tam

Blood collection from the radial artery is safe, effective and quick. Learn how to do it and use it in those patients with poor venous access.

If someone has hands, then they have a radial artery. Blood runs through the radial artery under arterial pressure. You can get that blood…

The radial artery is a fantastic artery to draw blood from for a number of reasons:

  • It is a superficial artery that is easy to palpate.
  • It is a reasonable large bore vessel (e.g., some interventional cardiologists now routinely do their angiograms by feeding the catheter through the radial artery rather than femoral).
  • It isn’t an “end” artery – in most people, the radial and ulnar arteries anastomose to form the deep palmar arterial arch.
    • That means, both ulnar and radial arteries can usually completely supply the hand in isolation.
    • Even if you completely destroy the radial artery, you won’t be left with an ischaemic hand
  • You have two hands – usually at least one radial artery is easy to sample.

If you can take an arterial blood gas from the radial artery, then you should be able to collect blood for other blood tests.

Read the rest of this entry »

Monday 15 May, 2006

Blood collection from intravenous cannula

Posted in Emergency Dept., General Practice, Michael Tam, Procedures, Wards at 16:12 by Michael Tam

Index: Alternatives to venepuncture :: Printer friendly

Original article by: Michael Tam

Bloods can almost always be collected from a new cannula as long as you remember and can often be collected from an old one.

Read the rest of this entry »

Subcutaneous fluids

Posted in Medicine, Michael Tam, Procedures, Wards at 11:52 by Michael Tam

Original article by: Michael Tam :: Printer friendly

Butterfly needle

Subcutaneous fluids (i.e., parental fluid hydration through a subcutaneous line) is a fantastic option in some patients, especially those with mild dehydration, with difficult venous access or the elderly with agitation, be it from delirium or dementia.

Remember that a subcutaneous line can also be used for many medications (e.g., morphine, midazolam).

Unlike intravenous cannulation, there isn’t usually a problem with “access” with a subcutaneous line and most nursing staff are qualified in their insertion.

Fluids through a subcutaneous line in the intrascapular area is most useful in the delirious/combative elderly patient with poor oral intake. Running 500-1000 mL of 0.9% NaCl solution overnight will help prevent dehydration.

Read the rest of this entry »