The needle went into my patient’s arm but stayed empty. “That vein has gone flat,” I said to him and to our nursing student, who was watching. “We need you to help him,” I said to the vein. Our RN had already made one unsuccessful attempt.
“I know why it’s happening,” said our patient. “I made an affirmation that I wouldn’t bleed this morning.” He had a history of problems with bleeding.
“Well, we need you to bleed today, so that we can learn. Tell your vein something different now, please. It’s for the greater good of your body,” I smiled, tightening the tourniquet, gently feeling with my fingertips for a cooperative vein in his brown forearms.
We learn so much from blood. The pathologists in their labs (and even some machines we have here in our remote clinic) can give us measurements that speak to the health of the red and white blood cells, the happy functioning of a liver or kidneys, the history of bacteria or viruses encountered or the damage done to a breaking heart. The key that unlocks all this information is a fine needle (but not so fine it breaks up the blood cells) that can draw blood from a friendly spot in the patient’s vein. The procedure is called venepuncture.
Cannulation is sort of the opposite procedure: it involves inserting a small plastic tube into someone’s vein – we call it gaining access – so that we can put medicine or restorative fluids in. A cannula is a plastic device with a needle inside it. The needle’s bevelled edge enters a vein, introducing the plastic tube. The needle is then retracted with a snap into a plastic housing. You need dexterity, calm and perhaps a little X-ray vision – sometimes veins can be felt but not seen.
My nursing colleagues make it look easy but my own memory of learning to cannulate is lost in a sea of failures: the needle going through a vein and out the other side of the vein; filling a syringe with salt water that went into the wrong place and caused the patient pain.
We practiced on plastic dummy arms scarred with needle marks from previous students. The more adventurous of my colleagues practised on each other – no doubt an impressive learning experience.
In the late 80s and early 90s I was learning to perform these procedures at a time when HIV was high in the consciousness of all health-workers. People talked about wearing two pairs of gloves. Many of us had experienced near misses – almost getting pricked with a contaminated needle or getting pricked with a needle but blessedly remaining disease-free. Once, after I pricked myself with an acupuncture needle I was removing from my HIV-positive patient, I experienced the slow burn of waiting to see if I had contracted the virus.
Despite this, despite having friends living with HIV, when I learned to cannulate I sometimes didn’t want to wear gloves. Sometimes it was impossible to find the vein without touching the patient’s skin.
The nub of cannulation is finding that big, helpful vein in a patient’s arm (or foot or scalp, if you get desperate enough). The vein needs to be big and resilient enough to take the cannula without collapsing or breaking. There needs to be a straight stretch of a vein, without a valve in it. Knocking a valve with a needle is painful for the patient. Putting a straight needle into a curved or curly vein will result in the needle coming out the other side. Either way, the fluid or medicine that your patient needs in their bloodstream will not go where it needs to.
When a client needs intravenous therapy, it’s an important and often urgent, situation. She or he might be dehydrated or shocked (with all their blood going deep inside the body to sustain internal organs). They might have an infection that necessitates medicine getting directly into the system. Hey, no pressure.
As a junior doctor, cannulation is part of your routine hospital work. At night, you are asked to cannulate all the most difficult patients that your colleagues were unable to access during their workday – the alcoholics with their fragile veins, the ladies with big soft arms and tiny veins. I feel grateful for my patients who allowed me to learn. I still feel for their suffering.
There are skills that nurses are trained to excel in but doctors are not encouraged to. It’s partly snobbery, this idea that nurses have to work hard at what comes to doctors naturally. Midway through my first year as an intern I found that there was a course on venepuncture and cannulation for nurses. It went over three days and I stuck my head in when I could, sat in during my lunch break and drank up the teaching. The teaching nurse gave me a copy of the theoretical notes. I pored over them.
Back in the clinic, I felt grateful to her for allowing me, all those years ago, to slip in and out of her classroom to learn more about the art and science of slipping sharp needles into people’s veins. Now our own nursing student, sweet-natured and bright, watched me intently as I used my fingers to find where our patient’s veins ran. “You can sit down, if you like,” I told her. “Oh no, I’m happy standing,” she said, eyes shining.
Finally the blood flowed freely, and we were able to take multiple exquisite vials of it. They will travel hundreds of kilometres to the lab and tell us interesting things.
An hour later, our student came to my room with a broad smile. She had just taken blood successfully for the first time, working on another patient. “I did it!” our student said and gave me a hug. Her first blood. It was indeed a rite of passage.
Thumbnail photo of blood orange by Eric Hill.