Expert: Dr Ian Jackson - please note UK based - 1/24/2007

Question
Is there a formula that coorelates doses, from pill form to an IV?  I'm particularly interested in morphine.  The patient was taking 3x30mg of ms contin 3x day for chronic pain BEFORE an accident landed him in ICU.  In the event you can walk me through a formula, let's say this patient weighed 200 lbs.

Wish I could ask you about anesthetizing at sporting events or something more in the land of your personal interests ... you just seem kind and my questions are difficult for me personally.  

Answer
Hi Theresa
In someone who has stable pain control we usually work on a 3 to 1 ratio i.e. for every 30mg of morphine orally we use 10mg IV.
So someone on 90mg of morphine per day would need 30mg per 24 hours iv to manage their background pain. They would then need more for the accident though I would titrate this to effect if the patient was conscious. If patient sedated for ventillation I would use the analgesia as my first line to help achieve this and give sufficient to ensure their comfort whilst maintaining CVS stability. In UK there is increased interest in the use of remifentanil to manage patients in ITU with painful conditions. This has the advantage of being metabolised very quickly and so potentially allows better control. However that is heading into areas outside my interests.
Kind regards
Dr Ian Jackson
ps thanks for your kind words