- large molec means it cannot cross placenta hence can be given to pregnant lady
- can b given eithe sc or iv
- work as co factor -> heparin bind to antithrombin -> antithrombin change it configuration -> AT bind to thrombin -> making thrombin inact due to AT n heparin complex
- 2 types - low molec weight LMW n high molec weight HMW
- LMW -> high DOA , inhibit xpecially factor Xa, example enoxaparin
- HMW -> increase AT actvt n inhibit xpecially fact IIa n Xa
- adverse effect -> haemorrhage (antidote=protamine)/hypersensitivity/trombocytopenia
be nice & click me
Saturday, July 24, 2010
anticoagulant 1 :heparin:
anticoagulant 1 :heparin:
- large molec means it cannot cross placenta hence can be given to pregnant lady
- can b given eithe sc or iv
- work as co factor -> heparin bind to antithrombin -> antithrombin change it configuration -> AT bind to thrombin -> making thrombin inact due to AT n heparin complex
- 2 types - low molec weight LMW n high molec weight HMW
- LMW -> high DOA , inhibit xpecially factor Xa, example enoxaparin
- HMW -> increase AT actvt n inhibit xpecially fact IIa n Xa
- adverse effect -> haemorrhage (antidote=protamine)/hypersensitivity/trombocytopenia
Friday, July 23, 2010
child-pugh score ...
- assess the prognosis of chronic liver disease, mainly cirrhosis.
- predict mortality during surgery
- required strength of treatment and the necessity of liver transplantation.
Child class: A: 5 - 6, B: 7 - 9, C: > 9.
Measure | 1 point | 2 points | 3 points | units |
Bilirubin (total) | <34> | 34-50 (2-3) | >50 (>3) | μmol/l (mg/dl) |
Serum albumin | >35 | 28-35 | <28 | g/l |
INR | <1.7 | 1.71-2.20 | > 2.20 | no unit |
Ascites | None | Mild | Severe | no unit |
Hepatic encephalopathy | None | Grade I-II (or suppressed with medication) | Grade III-IV (or refractory) | no unit |
Thursday, July 1, 2010
see one, do one, teach one
If you are part of the same educational lineage of most physicians in the history of Western medicine, you are familiar with the "See one, Do one, Teach one" approach to learning medical procedures. The idea is that you watch one procedure before you do one, and then you are prepared to teach the next person how to do it. Simple, right? But anyone learning to intubate or to place a central line knows this is easier said than done, especially when you are one of the most junior members of the medical team. How many of you have been a part of a conversation akin to the following?
"Hello, I'm student doctor Chen. I'll be draining that fluid in your belly for you today."
"Nice to meet you. Doctors are so young these days! How many times have you done this?"
"Well, to be honest, you are my first. But I've watched videos about it, practiced on a mannequin, and watched my resident do it on a patient down the hall yesterday!"
Imagine yourself as the patient. You would expect the best person available to do the paracentesis. That a fresh medical student wants to stick a giant needle into your belly is a reasonable source of anxiety. This situation stresses the student as well. You want to do the right thing for the patient and are worried about complications; all the while, you know you need to learn these skills to succeed in your future career. There is a reason medicine follows the apprenticeship model of clerkship and residency: it is best learned by practicing on humans! Here are some strategies to help you succeed with more procedures as a medical student.
- Placement. If you want to learn procedures, sign up for rotations and clerkship sites known to encourage medical student participation. Anesthesia, emergency medicine blocks, surgical subinternships, and busy county hospitals are often good options. Rotations in clinical settings where there are few residents are also an option, because you may learn directly from present attendings, making the patient at more ease. After you've secured a procedure-rich rotation, make sure you "show up." This means going out of your way to be present when procedures are being done. Stay late, delay your lunch, and put away your mobile device!
Once you work with a resident, that person will be more comfortable with you doing the task. Keep in mind that it's helpful, but often not sufficient, to say that you watched so-and-so do the procedure before. Different people have different styles and skill levels. Channel any frustration about not putting your hands on the patient to enthusiasm for your supervisors' willingness to teach; you can always learn something from watching. (Gently remind them later that you are the kind of person who learns by doing! But this will check off the "See one"" step in learning techniques. - Preparation. As the medical student dutifully concerned about the welfare of the patient on which you are about to complete a procedure, you owe it to the team and the patient to be prepared. At the beginning of rotations where you might be doing interventions, read books like Roberts and Hedges' Clinical Procedures in Emergency Medicine, watch videos on The New England Journal of Medicine Website, and look up procedure descriptions on eMedicine.
Test yourself by writing down the steps and going through the motions with your supervisor. Another way to prepare is to get your hands on an educational ultrasound machine. Visualizing anatomy today will help you do the procedure tomorrow. Increasingly, more interventions are done under ultrasound guidance. Learning to use the machine is vital to doing such procedures. - Practice. There are different ways to practice procedures before you get to the real thing, ranging from poking needles through cardboard boxes to intubating a recently deceased patient. Many schools provide training with computerized simulators such as SimMan® to help students and residents develop the manual dexterity needed for interventions. In addition, pig tracheas are used to teach tracheostomy, fellow medical students are useful for intravenous line placement, and freshly dead (not preserved) educational cadavers can be used for central line placement. And you may have attending physicians in the intensive care unit or emergency department who call you over to "practice" cardiopulmonary resuscitation or intubation on patients who just died.
With regard to practicing on newly dead patients, the Council on Ethical and Judicial Affairs of the American Medical Association recommends that physicians request permission from the family of the deceased prior to performing procedures on recently deceased patients.[1] My experience and the literature[2] suggest otherwise; this important vestige of an older tradition for learning procedures only occasionally follows these guidelines. When confronted with such an opportunity, you have to be prepared to learn from it. Keep in mind that use of mannequins or simulators to teach procedures may be helpful to reinforce the steps learned in reading about the procedure or watching a video, but rehearsals are not a replacement for interventions on living patients.[3] - Confidence. Whether you are scared out of your wits, it is important to exude cool confidence in front of the patient. And if you feel ready to try a new procedure, make sure your supervisor knows it. At the same time, don't be foolhardy in your approach. (You have no right to be confident without completing the previous 3 steps.) Know when to step back and say, "This isn't working for me. I think you should take over." Your resident will be quick to help you out, whether that means guiding your hand or taking over completely. Some fields and training sites require residents to be signed off after 3 procedures; for patient safety, the "Do one" step has evolved to "Do three!"
- Graciousness. After your successful procedure -- or even an attempt -- be sure to express your graciousness to the patient for permitting your doing the procedure, and your supervisor for helping you through it. Both people will be more likely to let you or future trainees "practice" their procedures with them. Pretty soon you will be in a position to "Teach one."
Like many other things in medicine, learning procedures requires study and hands-on practice. And if after giving it a shot, you are bored by, never get comfortable with or cannot stand doing procedures, consider exploring disciplines in which physicians need not stick tubes in vessels or cavities. For me, the gratification of hearing the "pfffft" of a needle decompressing a pneumothorax or the relief patients feel after being drained of 7 L of ascitic fluid is enough to keep at it.