Obstetrical anesthesia- toxemia
1. What specific issues are involved in providing analgesia for labor in an uncomplicated pre-eclamptic patient?
2. What is your recommendation for analgesia?
3. The patient has a platelet count of 70,000. How would you now proceed?
A normal platelet count is between 150,000-440,000, and this patient is thrombocytopenic at a count of below 150,000. At a count of between 40,000-70,000, intraoperative bleeding can be severe.
4. What is your differential diagnosis for thrombocytopenia?
Qualitative vs quantitative defects can be the cause of bleeding. Qualitative defects include aspirin or nonsteroidal use, ethanol use, cirrhosis, uremia, or inherited defects like von Willebrand disease. Quantitative defects are seen after massive blood transfusion, malignant infiltration from aplastic anemia or multiple myeloma, drugs like chemotherapeutic agents, cytotoxic drugs, ethanol, hydrochlorothiazide, radiation exposure, or bone marrow depression. It can also be seen with destruction from hypersplenism, disseminated intravascular coagulation, burns, autoimmune disease, idiopathic thrombocytopenic purpura, or drugs like heparin.
5. What are general indications for platelet transfusion?
Thrombocytopenia or qualitative defect with significant bleeding, prophylaxis for patients with thrombocytopenia, and after massive transfusion with diffuse coagulopathy present.
5. How are platelets prepared?
Fresh whole human blood is centrifuged, and the plasma is recentrifuged to produce 30-50 ml of plasma. At room temperature, it lasts five days.
6. How much platelet replacement should be given for a platelet count of 50,000, if you want to increase it to 150,000?
One unit of platelets should increase the count by 5000-8000/mm3. It is okay to use ABO-incompatible platelets, and a 170-mcm filter should be used.
5. Is a bleeding time useful?
There is a lack of correlation between bleeding time and increased intraoperative bleeding. However, a normal value is between four and nine minutes, with a time more than 1.5 times normal being significantly abnormal.
Methods to measure anesthetic system gases
1. How can one measure inspired or end-tidal concentrations of halothane?
2. What is the accuracy of these methods?
3. How can one measure inspired or end-tidal concentrations of nitrous oxide?
4. Is mass spectroscopy worth the additional cost over just oxygen and CO2 monitoring? Why or why not?
Management of the alcoholic patient
A 60-year old man is a chronic alcoholic is to undergo a colon resection.
1. What are the special anesthetic concerns in this patient?
2. How would you prepare to manage these concerns?