Monday, May 3, 2010

Fluid Wars

It is always refreshing to find out, after 20 years or so that you have been doing things wrong.

I arrived at work early last week to find out that the nurses were no longer making up IVs until the anaesthesiologist told them exactly what solution they wanted. Further questioning revealed that one day all three anaesthesiologists in our downstairs 3 room OR had refused the normal saline offered to them and had asked for Ringer's Lactate instead. It turns out that all three had attended an evening CME event that I obviously hadn't attended at which the key message was: "SALINE KILLS PEOPLE!!!".

Now when I was a medical student, much of our very limited education in anaesthesia was provided by Dr. Kenneth Leighton, a true gentleman and excellent role model. I remember one of Dr. Leighton's aphorisms:

Doctors who use Ringer's Lactate don't know what's in it and doctors who know what's in it don't use it.

Having said that, I used RL for most of my residency and early on in as staff if only because Saline was hard to find in 1 litre bags. Early on in my career at the CofE when the province, the hospital and the department were trying to save money, someone observed that Saline cost $0.40 less than Ringers so the switch was made. We used to have great fun, trying to figure out how many bags of Saline instead of Ringers we would have to use to pay for one more liver transplant. The practice however spread to the entire region and now I believe that until recently every first bag of crystalloid in the region is saline.

One of the advantages of getting older is the opportunity to observe changes in medical practice some logical, some not not.

I remember as a student intern seeing my first case of N,V &D in paediatrics. Back then these cases were admitted for IV therapy. Later somebody figured out oral rehydration. Someone had already started the IV so one anxiety producing act was out of the way. I did however now have to write the IV orders. I had my Sick Kids blue book and was perplexedly perusing the section on fluids and electrolytes. I was trying to calculate free water, sodium and other maintenances and deficits when I felt my brain starting to explode so I punted and paged the resident. He say he would be right down and would show me how to write fluid orders. What he actually did was say: this child weights 24 kilos, is 10% dehydrated for a deficit of 2.4 litres which we will replace over 24 hours equalling 100 cc an hour plus maintenance of 40 ccs for the first 10 kg., 20 for the next and 4 for the last 4 equaling 64 ccs making a taking rate of 164 cc per hour. Now for the selection of fluid. Why don't we just use 2/3 1/3. This was done and this child is presumably now an adult somewhere.

Years later when I started as anaesthesia resident in paediatrics, 2/3 1/3 was still the maintenance fluid. Early on in my residency, I had to present an M+M on a severely dehydrated child who had come to the OR. A friend of mine who had started earlier in another program had told me that residents no matter how junior were supposed to have read up on their cases and that those who clearly hadn't were come down hard on. Not wishing a public humiliation I immersed myself in fluids and electrolytes. Everything I read told me that while children handled sodium well, they did not handle free water well which to me meant that normal saline NOT 2/3 1/3 should be the maintenance therapy in pediatrics.

2/3 1/3 however remained the standard therapy in pediatric surgery for years after. It took one very dedicated anaesthesiologist at the CofE years and hours of meetings to persuade surgeons, nurses and his fellow anaes. that saline was the way to go.

The "SALINE KILLS PEOPLE" lecture was of course sponsored by one of our local starch suppliers who would much rather we use their product at $40 for 500 cc instead of $1-2 for a litre. I actually like to use a balance of crystalloid and colloid. I used to be an enthusiastic user of albumin until we found out it too was KILLING PEOPLE. We have two starches available and about once a month or so one or the other company brings in lunch to tell us how bad the other product is. To be quite honest, one company's bag is easier to spike and I use that product.

The bottom line I seemed to have learned is that people are pretty resilient and that no matter what you pour into them within reason most of them will normalize it. There are of course exceptions and what I can get away with in 2 hours in the OR doesn't necessarily translate into 2 weeks in the ICU.

I learned another thing from Dr. Leighton in medical school. At that time VGH had 2 separate ORs, the older Heather Pavilion OR and the newer Centennial Pavilion OR. Dr. Leighton told us (and it was true) that in the Heather Pavilion OR, saline was provided while in the Centennial Pavilion OR D5W was provided. The reason? Historically Centennial Pavilion had done private patients, while Heather Pavilion had done public patients. D5W is more expensive than saline so must clearly be better. Just another example of how rich people don't necessarily get better care. Also explains why 90% of the pages I got as a student intern on surgery were for low urine output post-op although I only just figured that one out.