No life ever grows great until it is focused, dedicated and disciplined." ~Harry E. Fosdick
NOVEMBER 2009.
Announcement: MedTutor takes a break till December 20th 2009. There may be no updates until that time.
Presentations:
1. A girl with chest pain and hemoptysis
2. Chronic kidney disease
Articles:
1. Initiating anticoagulation (from BMJ Learning)
Anticoagulants can cause serious harm to patients if not properly handled. The risk of major bleeding is greatest during the first three months of treatment with oral anticoagulants. Hence it is always better to initiate anticoagulation slowly in non-urgent situations like thromboprophylaxis in atrial fibrillation. Rapid anticoagulation with warfarin carries another risk, that is, the risk of paradoxical thrombosis because of rapid depletion of Protein C.
Anticoagulant drugs can be divided into two categories: oral and injectable. Oral anticoagulants interfere with the action of vitamin K and reduces the biological activity of clotting factors II, VII, IX, and X as well as the anticoagulant proteins C and S.
.
Extracts from my book: Academic Adventures
.
GESTATIONAL DIABETES
When Prof Sandy and the students came to Mrs Singh’s room, she was in the bathroom. They had to wait awhile before they heard the sound of the flush and the door opened. Mrs Singh came out, wiping her hands on a towel.
“Sorry to make you wait,” she said.
Sandy told her that it was all right.
“I always have this urge to go to the bathroom. Is it because of the diabetes?” she asked as she settled into her bed and pulled the covers up over her feet.
“I don’t think so. Your diabetes is very mild. Many pregnant women do experience this same sensation like you. It is not because of diabetes,” Sandy told her.
After a quick examination of her charts, he listened to her chest with his stethoscope, Then Sandy turned to the students and asked, “If I tell you that Mrs Singh has gestational diabetes, what do you understand from that?”
Chandra said, “Her diabetes started during her pregnancy.”
“And by diabetes, do you mean a fasting plasma glucose of more than 7mmol/L and a two-hour postprandial plasma glucose of more than 11.1mmol/L?”
“Yes that is right.”
Sandy pursed his lips and shook his head.
“Anyone else has anything to say?” he asked.
No one answered. So he told them that the term gestational diabetes did not necessarily mean diabetes as defined in the non-pregnant state. “The term gestational diabetes is used even for pregnant women with glucose intolerance.”
“Why is that? Why is glucose intolerance considered as diabetes in a pregnant woman?” Benny asked.
“The threshold is lower in pregnancy because of the risk hyperglycemia poses to the fetus and to the mother during pregnancy. In the non-pregnant state, we define 7mmol/L as the fasting glucose level to diagnose diabetes because it is from that level upwards that epidemiological studies have shown a risk for diabetic complications. In the pregnant state, the fasting level of 5.3mmol/L similarly marks a threshold of risk. That is why we apply the label gestational diabetes from that point upwards.”
“Is the two hour postprandial glucose value similarly lower for the diagnosis of gestational diabetes?” Arif asked.
“Yes,” Sandy answered. “In a pregnant women without gestational diabetes we expect the two hour postprandial plasma glucose to be below 6.7mmol/L.”
“In the non-pregnant state, it can be 7.8mmol/L or lower, isn’t it?” Benny asked.
“Yes.”
“Did Mrs Singh have a glucose tolerance test done?” Diane asked.
Mrs Singh spoke before Sandy could reply. “Yes. It was quite annoying really to have blood taken so many times.”
Sandy smiled at her. He asked the students, “Is there any difference between the oral glucose tolerance test in pregnancy and that in others?”
“The glucose tolerance test for a pregnant woman is a three hour test while for others it is a two hour test,” Diane said.
Sandy agreed with her. “The target values for the diagnosis of diabetes are also different. In pregnancy the values to remember are: fasting 5.3mmol/L, first hour 10mmol/L, second hour 8.6mmol/L and third hour 7.8mmol/L. Values above these indicate diabetes. In the non-pregnant state the corresponding values are: fasting 7.0mmol/L, first hour 10mmol/L and the second hour 11.1mmol/L.”
Benny had a doubt. He asked, “But isn’t 5.6mmol/L the upper limit of normal for fasting blood in the non-pregnant state?”
Sandy told him, “Below 5.6mmol/L is normal according to the American Diabetic Association, as you say, but a value above 5.6mmol/L does not make a non-pregnant person a diabetic. I want you to be very clear about this. We should only label a person as diabetic in the non-pregnant state when the fasting plasma glucose is 7mmol/L or more. The same holds true for the value of 11.1mmol/L in the two hour postprandial state.”
The students digested the information for a while.
“That means the threshold for diagnosis of gestational diabetes is lower than in the other case,” Chandra said.
“Correct. That is because the term gestational diabetes also includes what is called glucose intolerance in the non-diabetic state. In pregnancy, there is only normal and gestational diabetes. In the non-pregnant state, there is normal, impaired glucose tolerance and diabetes.”
“I think I have got the concept,” Arif said. “It is because hyperglycemia is teratogenic and damaging to the mother and fetus.”
Sandy nodded his agreement. Then he asked,
“So what are the dangers of hyperglycemia to the mother and fetus?”
Arif answered, “It can increase the incidence of preeclampsia and pregnancy induced hypertension in the mother. It can cause stillbirth and large babies. And it can also increase the risk of hypoglycemia in the newborn.”
Sandy agreed with him. He said, “In the first trimester of pregnancy hyperglycemia can be teratogenic. That is why it is better to control high blood sugar before the woman becomes pregnant.”
“Can the usual oral drugs like the sulphonylureas and Metformin be used in pregnancy?” Diane asked.
(To be continued)
Dr Vela Menon, MD
Faculty of Medicine, International Medical University, Malaysia
To join MedTutor or to give a feedback, please write to moc.liamg|todikiwrotutdem#moc.liamg|todikiwrotutdem. Membership is free.
Please create an account and/or sign in first.
|
if you already have a Wikidot.com account |
or |
it is worth it and is free |
