A 50-year old 70 kg man is scheduled for emergency portal-caval shunt for bleeding from esophageal varices. He has received twelve units of packed cells in the past 36 hours. He has a history of alcoholism and chronic obstructive lung disease. Blood pressure is 85/60 mmHg, pulse is 110 bpm, respirations are 20, hemoglobin is 14 gm/dl, and temperature is 36 degrees centigrade.
I. Blood volume status
1. Should he receive more blood? Why or why not?
2. Should he receive other component therapy? If so, explain.
3. What are your endpoints of therapy?
II. Consequences of liver disease
1. How does severe liver disease contribute to anesthetic risk?
2. How do you assess coagulation status?
3. How do you identify patients who may have abnormal bleeding?
A history of medications like anticoagulants, nonsteroidal anti-inflammatory agents, or aspirin is significant, as is a history of bleeding problems in the patient or in the family, of needing transfusions for prior cases not associated with major blood loss, or of having a disease associated with coagulopathy. Exam of the mucous membranes shows petechial hemorrhages associated with platelet disorders, and clotting factor disorders present with hemorrhages to the joints, muscles, gastrointestinal system, or cerebrum.
3. What is the significance of ascites, if present?
4. What are other signs of importance?
III. Chronic obstructive pulmonary disease
1. How do you assess lung function?
2. What value do pulmonary function tests have to you?
3. What value do arterial blood gases have to you?
4. The paO2 is 70 mmHg when Venturi mask oxygen is in place, giving a FIO2 of 28%. What is your interpretation?
I. Selection and placement of monitors
1. Which are required, and why?
2. If a pulmonary artery catheter is deemed necessary, give reasons.
3. The cardiac index is 1.6 liters. What other data is needed?
4. What is your management?
5. The mixed venous pO2 is 30 mmHg. What is your management?
II. Selection and management of anesthesia
1. What are your major concerns regarding induction?
2. If a rapid sequence were needed, would you use succinylcholine? Explain.
3. Discuss other options and give reasons for your rationale.
4. Discuss inhaled vs narcotic maintenance.
5. Would you avoid nitrous oxide? Explain.
6. What are the effects of various drugs on hemodynamics?
7. What are the effects of various drugs on renal function?
8. Which relaxant would you use for maintenance? Explain.
9. Relaxation appears inadequate despite no twitch monitor response. What is your management?
III. Assessment and maintenance of circulatory adequacy
1. The blood pressure is now 70/50 mm Hg, pulse is 120 bpm during the procedure. Why?
2. What is your treatment?
3. What are your choices for fluid replacement?
4. What ratio of crystalloid, colloid, and packed cells do you use?
Using the "4-2-1" rule, baseline fluid requirements correlate closely with metabolic rate and the need for water, and the patient needs 110 cc/hr. Blood loss estimates should be replaced with packed red blood cells, and a hematocrit of 30% should be maintained.
Crystalloid replacement is three times that of estimated blood loss, and colloid replacement is a replacement volume equal to that of lost blood.
5. What are your end points of therapy?
6. How do you assess adequacy of coagulation intraoperatively?
IV. Significance of hemoglobinuria
1. The urine color is now red. What is the significance of this?
2. What is your differential diagnosis?
3. What is your management?
I. Assessment of oliguria
1. For the first two hours in the recovery room, urine output is 10ml/hr. What is your differential diagnosis?
2. What is your management?
II. Ventilatory care
1. Is this patient certain to remain intubated? Why or why not?
2. How long will the patient remain intubated?
3. What are your ventilatory orders?
4. Two hours after arrival, paCO2 is 50 mmHg. What other data do you need?
5. What is your management?
6. How do you decide when to extubate?
III. Postoperative analgesia
1. Would epidural narcotics be appropriate? Why or why not?
2. What are your drug choices?
3. What are the hazards of these choices?
4. How would you manage these hazards?
5. Is patient-controlled analgesia appropriate?