We were taught as students the method of collection of midstream collection of urine for microbiologic studies. The idea was that the bacteria contaminating the distal urethra would be washed away with the stream of urine in the early part, and a noncontaminated sample of urine would be available. We teach our students and residents the same thing, and get our patients to give their urine samples that way.
When I was an undergraduate student, I had seen our Professor of Surgery dress a patient's wound. When the time came for application of antiseptic cream over the cleaned wound, he got a resident doctor to squeeze the tube of the antiseptic craem, discard the first portion that came out and then used the subsequent portion. He did not explain why he did so, but it appeared he wanted to not use the part near the opening of the tube because it could be contaminated.
That day we were taking round of our emergency ward. On the bedside table of a patient, there was a syringe loaded with amber colored solution. It was on the unsterile surface of the table. Its nozzle was open.
"What injection is that?" I asked. No one knew. "It could be sodium thiopentone" I said. "It used to look like that when I was a House Officer. I could be urine too. The may have kept it for testing for proteinuria."
"Sir, it must be antibiotic" the Registrar said.
"But how will they use it? Its nozzle is open. The injection must be contaminated." Then I thought of my erstwhile Professor of Surgery. "Perhaps they will discard the first couple of drops and inject the remaining part which won't be contaminated."
My Assistant Professor got the joke and expanded on it. "Midstream injection!" he said.
When I was an undergraduate student, I had seen our Professor of Surgery dress a patient's wound. When the time came for application of antiseptic cream over the cleaned wound, he got a resident doctor to squeeze the tube of the antiseptic craem, discard the first portion that came out and then used the subsequent portion. He did not explain why he did so, but it appeared he wanted to not use the part near the opening of the tube because it could be contaminated.
That day we were taking round of our emergency ward. On the bedside table of a patient, there was a syringe loaded with amber colored solution. It was on the unsterile surface of the table. Its nozzle was open.
"What injection is that?" I asked. No one knew. "It could be sodium thiopentone" I said. "It used to look like that when I was a House Officer. I could be urine too. The may have kept it for testing for proteinuria."
"Sir, it must be antibiotic" the Registrar said.
"But how will they use it? Its nozzle is open. The injection must be contaminated." Then I thought of my erstwhile Professor of Surgery. "Perhaps they will discard the first couple of drops and inject the remaining part which won't be contaminated."
My Assistant Professor got the joke and expanded on it. "Midstream injection!" he said.
