I had not thought there would be any confusion about operative steps that have been described in books. Now I realize time and again that I was wrong. The steps are often not learnt from text books, but from what a senior resident teaches the juniors. It is a chain in which one link goes out at the end of residency, and another one enters at the beginning. The knowledge base of the chain is carried forward, sometimes changed like Chinese whispers. When some of these residents become faculty, the science of Obstetrics and Gynecology changes.
The most recent example of this is as follows. A woman was undergoing an endocervical curettage and cervical biopsy under paracervical block. I had taught them how to administer that block, and I was secure in that knowledge. Unfortunately it had not been learned at all or had been unlearned. The woman was grimacing and moaning and was in pain. I investigated the cause and found that they had administered only half the dose and that too at not very appropriate place. I got the problem corrected and she settled down. That prompted me to conduct an in OT survey of how all of my people administered a paracervical block. The results are shown below.
All of them used 1% lignocaine, which was OK. Only one Assistant Professor used 20 ml, all other fell short by 50%, which was not OK. Only one person used correctly 3 and 9 o'clock position. Why the others were stuck on 4 and 8 o'clock positions is explained by my theory elaborated at the beginning of this post. One was set on covering all bases and injected the drug at 12 and 6 o'clock too. All of them thrust the needle like swordsmen, deep enough to make a good job of it. Luckily no one thrust it right up to the hilt. I asked the same question to another resident doctor from another unit, to make sure that it was a phenomenon restricted to people in my unit. Her answer was similar, except that she thrust the needle for half its length.
"So it will be half an inch if the needle is 1 inch long, and 6 inches if the needle is 1 foot long" I said.
She made a face and settled on 2-3 cm.
"The right answer is1% lignocaine, 10 ml each at 3 and 9 o'clock positions, or 5 ml each at 4, 5, 7, and 8 o'clock positions, at a depth of 2-3 mm under the vaginal mucosa of the lateral fornix. Less drug or wrong position would not stop the pain, more than 3 mm depth would possibly puncture the uterine vessels and cause local bleeding and/or intravascular injection and complications like cardiac arrhythmia" I told them.
The most recent example of this is as follows. A woman was undergoing an endocervical curettage and cervical biopsy under paracervical block. I had taught them how to administer that block, and I was secure in that knowledge. Unfortunately it had not been learned at all or had been unlearned. The woman was grimacing and moaning and was in pain. I investigated the cause and found that they had administered only half the dose and that too at not very appropriate place. I got the problem corrected and she settled down. That prompted me to conduct an in OT survey of how all of my people administered a paracervical block. The results are shown below.
Position of doctor
|
Volume
|
Position of injection
|
Depth of injection
|
1st year 1
|
10
|
4 and 8 o’ clock
|
2 cm
|
1st year 2
|
10
|
4 and 8 o’clock
|
2-3 cm
|
1st year 3
|
10
|
4 and 8 o’clock
|
2
|
2nd year 1
|
10
|
4 and 8 o’clock
|
Up to just below pelvic peritoneum
|
2nd year 2
|
10
|
4 and 8 o’clock
|
2-3 cm
|
2nd year 3
|
10
|
3 and 9 o’clock
|
2-3 cm
|
3rd year 1
|
10
|
3, 6, 9, 12 o’clock
|
2-3 cm
|
3rd year 2
|
10
|
4 and 8 o’clock
|
2-3 cm
|
Assistant Professor 1
|
10
|
4 and 8 o’clock
|
By judgment, varying from case to case, finally committed to 2-3 cm on forcing the answer.
|
Assistant Professor 2
|
20
|
4 and 8 o’clock
|
2.5 cm
|
All of them used 1% lignocaine, which was OK. Only one Assistant Professor used 20 ml, all other fell short by 50%, which was not OK. Only one person used correctly 3 and 9 o'clock position. Why the others were stuck on 4 and 8 o'clock positions is explained by my theory elaborated at the beginning of this post. One was set on covering all bases and injected the drug at 12 and 6 o'clock too. All of them thrust the needle like swordsmen, deep enough to make a good job of it. Luckily no one thrust it right up to the hilt. I asked the same question to another resident doctor from another unit, to make sure that it was a phenomenon restricted to people in my unit. Her answer was similar, except that she thrust the needle for half its length.
"So it will be half an inch if the needle is 1 inch long, and 6 inches if the needle is 1 foot long" I said.
She made a face and settled on 2-3 cm.
"The right answer is1% lignocaine, 10 ml each at 3 and 9 o'clock positions, or 5 ml each at 4, 5, 7, and 8 o'clock positions, at a depth of 2-3 mm under the vaginal mucosa of the lateral fornix. Less drug or wrong position would not stop the pain, more than 3 mm depth would possibly puncture the uterine vessels and cause local bleeding and/or intravascular injection and complications like cardiac arrhythmia" I told them.
