A 5-year old 20 kg boy is scheduled for closure of an atrial septal defect detected by echocardiography. He has repeated bouts of pneumonia, and is a hemophiliac with past episodes of soft tissue bleeding and hemarthrosis related to minor trauma. Blood pressure is 90/60 mm Hg, heart rate is 90 bpm, temperature is 37.8 degrees centigrade, and the hemoglobin is 11.8
I. Cardiac status
1. Does it matter to you if this is a primum vs a secundum atrial septal defect? Why or why not?
2. Is cardiac catheterization indicated?
3. How would you use this data?
1. Is the fever of concern? Why or why not?
2. Is it safe to proceed with antibiotic coverage and corrective surgery if the surgeon attributes the mild fever to pneumonia?
Preparation of hemophiliac for elective operation
1. How would you evaluate factor VIII deficiency?
In von Willibrand disease, there is a decrease in factor VIII antigen, and in factor VIII: vWF.
What is factor VIII?
It is a large protein of two factors, von Willibrand factor, or factor VIII:vWF, and factor VIII antigen, which is an anticoagulant. Each is under separate genetic control. Platelet adhesion and formation of a plug requires factor VIII: vWF.
3. What products would you want to have available to correct any deficiency? 4. What is your choice, and why?
5. Would you strive for a normal factor VIII concentration preoperatively? Why or why not?
6. How does coagulation stay localized to the tissue site?
The liver clears activated coagulation factors, and the natural anticoagulants antithrombin III acts as protease scavenger, and protein C inactivates factors V and VIII.
1. Is a central venous catheter indicated?
2. What information would you obtain from it, which would affect your management?
3. Would a pulmonary artery catheter offer any advantages?
4. What do you anticipate will happen to pulmonary artery pressures after closure of an atrial septal defect?
1. Is an intravenous induction or an inhalation induction preferable?
2. Would you prefer a volatile anesthetic, or a narcotic for maintenance? Explain.
3. Would you use nitrous oxide? Explain.
4. Is a muscle relaxant needed?
5. Which muscle relaxant would you use? Explain.
1. How will you monitor factor VIII vs heparin?
2. Does this matter for cardiopulmonary bypass?
3. Would you give fresh frozen plasma prophylactically?
4. Would you give platelets or cryoprecipitate? Explain.
5. How is cryoprecipitate formed?
It comes from fresh frozen plasma that undergoes controlled thawing.
6. What does it contain?
Factors VIII and XIII, von Willebrand factor, fibrinogen, and fibronectin.
7. For what conditions is it indicated?
Von Willebrand's disease, hemophilia A, factor XIII deficiency, and after massive transfusion to replace factor VIII and fibrinogen.
1. You are infusing fresh whole blood after bypass. The blood pressure falls from 90/60 mm Hg to 50/30 mm Hg. What is your immediate therapy?
2. Hives and erythematous blotches appear. What is the etiology?
3. What is the treatment?
4. The central venous pressure is 2 mm Hg. Would you stop the transfusion?
5. Would you start another unit of fresh whole blood from a different donor?
6. If no blood were available, what would you use?
1. Will you plan immediate extubation, or will you leave the patient intubated? Explain.
1. Are spinal opioids effective after cardiac operations?
2. Where do spinal opioids act?
3. Are they appropriate for a 5-year old child?
4. Do abnormal factor VIII levels have a bearing on their use?
5. What are the alternatives for pain management?
6. Should you avoid intramuscular injections in this patient?