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Postoperative delirium and defibrillation
802
LETTERS TO THE EDITOR
REFERENCES
1. Scheinman M, Sullivan R, Hutchinson J, et al: Clinical significance of changes in serum magnesium in patients undergoing cardiopulmonary bypass. J Thorac Cardiovasc Surg 61:135-140, 1971 2. Wistbacka J, Koistinen J, Karlquist K, et al: Magnesium substitution in elective coronary artery surgery: A double-blind clinical study. J Cardiothorac Vasc Anesth 9:140-146, 1995
3. Brookes C, Fry C: Ionized magnesium and calcium in plasma from healthy volunteers and patients undergoing cardiopulmonary bypass. Br Heart J 69:404-408, 1993 4. Gomez MN: Magnesium and cardiovascular disease. Anaesthesiology 89:222-240, 1998
Postoperative Delirium and Defibrillation To the Editor: A patient developed delirium after a reoperative coronary artery bypass revascularization, but the delirium resolved after he was defibrillated for ventricular fibrillation. A 65-year-old man was admitted to the hospital for coronary revascularization. He had undergone a coronary artery bypass operation 15 years previously. He was a heavy drinker, consuming three glasses of hard liquor per day, and was suffering from depression, but he was not taking any drugs for the depression. Preoperative physical examination and laboratory workup were normal. On the morning of the surgery, the patient received diazepam, 10 mg PO, and fentanyl, 3 lag/kg intravenously, for sedation and analgesia during the insertion of the invasive monitoring catheters. Anesthesia was induced with thiopental and fentanyl. Pancuronium bromide was used for neuromuscular blockade. Anesthesia was maintained with 50% oxygen, 50% air, and 0.6% isoflurane and fentanyl. A bubble oxygenator and intermittent cold blood cardioplegia were used during the operation. Cardiopulmonary bypass was instituted at a flow rate of 2.4 L/min/m z, and mean arterial pressure was kept at 50 to 70 mmHg. The patient was cooled to 30°C. The distal anastomosis was performed to the left anterior descending artery, right coronary artery, OM1 and OM2. The duration of cardiopulmonary bypass was 120 minutes, and the aortic ischemic time was 80 minutes. Total operation time was 200 minutes. The patient was extubated after 8 hours in the intensive care unit. The patient was hemodynamically and psychologically stable until the end of the first 24 hours, then he became increasingly confused (motor restlessness, transient hallucinations, disorientation). He was treated with haloperidol, 16 mg, and diazepam, 20 rag, intramuscularly over 14 hours, which reduced the agitation and kept him sedated. In the early hours of postoperative day 2, the patient suddenly became agitated again with visual hallucinations and had an episode of ventricular fibrillation. Before the ventricular fibrillation, he had not had an arrhythmia or hypotension. He was defibrillated with 200 J and converted to sinus rhythm. All the laboratory values and blood gas analyses were normal before and after the ventricular fibrillation. The patient remained confused for 15 minutes after the defibrillation, then his mental status returned to the preoperative level. The patient was discharged from the hospital on postoperative day 8 without any further problems. The incidence of postoperative delirium for patients who underwent cardiac surgery was reported to be 38.5%. 1 The cause is divided into preoperative, intraoperative, and postoperative stages. Preoperative factors are aging, cerebrovascular disease, polypharmacy, alcohol withdrawal, depression/dementia/anxiety, and gender, futraoperative factors are type of surgery and anesthetic drugs. Postoperative factors are hypoxia, hypocarbia, and sepsis. 1 In this case, the symptoms that appeared 24 hours after the operation could be related to any of the factors listed. Because the symptoms of the delirium were worse before the development of the ventricular fibrillation and the psychiatric symptoms improved after the defibrillation, this effect may be related to the defibrillation because no drugs were given before the defibrillation. It may be possible in this situation that there is a relationship between neurotransmitter levels of the central nervous system and defibrillation. No information could be found in the literature on the effects of defibrillation and electroconvulsive therapy.
Ayda Tiirkrz, MD Riza Tiirkrz, MD Oner Giilcan, MD Ozcan Ersoy, MD Infnti University School of Medicine Malatya, Turkey REFERENCE
1. Parikh SS, Chung F: Postoperative delirium in the elderly. Anesth Analg 80:1223-1232, 1995
LETTERS TO THE EDITOR
REFERENCES
1. Scheinman M, Sullivan R, Hutchinson J, et al: Clinical significance of changes in serum magnesium in patients undergoing cardiopulmonary bypass. J Thorac Cardiovasc Surg 61:135-140, 1971 2. Wistbacka J, Koistinen J, Karlquist K, et al: Magnesium substitution in elective coronary artery surgery: A double-blind clinical study. J Cardiothorac Vasc Anesth 9:140-146, 1995
3. Brookes C, Fry C: Ionized magnesium and calcium in plasma from healthy volunteers and patients undergoing cardiopulmonary bypass. Br Heart J 69:404-408, 1993 4. Gomez MN: Magnesium and cardiovascular disease. Anaesthesiology 89:222-240, 1998
Postoperative Delirium and Defibrillation To the Editor: A patient developed delirium after a reoperative coronary artery bypass revascularization, but the delirium resolved after he was defibrillated for ventricular fibrillation. A 65-year-old man was admitted to the hospital for coronary revascularization. He had undergone a coronary artery bypass operation 15 years previously. He was a heavy drinker, consuming three glasses of hard liquor per day, and was suffering from depression, but he was not taking any drugs for the depression. Preoperative physical examination and laboratory workup were normal. On the morning of the surgery, the patient received diazepam, 10 mg PO, and fentanyl, 3 lag/kg intravenously, for sedation and analgesia during the insertion of the invasive monitoring catheters. Anesthesia was induced with thiopental and fentanyl. Pancuronium bromide was used for neuromuscular blockade. Anesthesia was maintained with 50% oxygen, 50% air, and 0.6% isoflurane and fentanyl. A bubble oxygenator and intermittent cold blood cardioplegia were used during the operation. Cardiopulmonary bypass was instituted at a flow rate of 2.4 L/min/m z, and mean arterial pressure was kept at 50 to 70 mmHg. The patient was cooled to 30°C. The distal anastomosis was performed to the left anterior descending artery, right coronary artery, OM1 and OM2. The duration of cardiopulmonary bypass was 120 minutes, and the aortic ischemic time was 80 minutes. Total operation time was 200 minutes. The patient was extubated after 8 hours in the intensive care unit. The patient was hemodynamically and psychologically stable until the end of the first 24 hours, then he became increasingly confused (motor restlessness, transient hallucinations, disorientation). He was treated with haloperidol, 16 mg, and diazepam, 20 rag, intramuscularly over 14 hours, which reduced the agitation and kept him sedated. In the early hours of postoperative day 2, the patient suddenly became agitated again with visual hallucinations and had an episode of ventricular fibrillation. Before the ventricular fibrillation, he had not had an arrhythmia or hypotension. He was defibrillated with 200 J and converted to sinus rhythm. All the laboratory values and blood gas analyses were normal before and after the ventricular fibrillation. The patient remained confused for 15 minutes after the defibrillation, then his mental status returned to the preoperative level. The patient was discharged from the hospital on postoperative day 8 without any further problems. The incidence of postoperative delirium for patients who underwent cardiac surgery was reported to be 38.5%. 1 The cause is divided into preoperative, intraoperative, and postoperative stages. Preoperative factors are aging, cerebrovascular disease, polypharmacy, alcohol withdrawal, depression/dementia/anxiety, and gender, futraoperative factors are type of surgery and anesthetic drugs. Postoperative factors are hypoxia, hypocarbia, and sepsis. 1 In this case, the symptoms that appeared 24 hours after the operation could be related to any of the factors listed. Because the symptoms of the delirium were worse before the development of the ventricular fibrillation and the psychiatric symptoms improved after the defibrillation, this effect may be related to the defibrillation because no drugs were given before the defibrillation. It may be possible in this situation that there is a relationship between neurotransmitter levels of the central nervous system and defibrillation. No information could be found in the literature on the effects of defibrillation and electroconvulsive therapy.
Ayda Tiirkrz, MD Riza Tiirkrz, MD Oner Giilcan, MD Ozcan Ersoy, MD Infnti University School of Medicine Malatya, Turkey REFERENCE
1. Parikh SS, Chung F: Postoperative delirium in the elderly. Anesth Analg 80:1223-1232, 1995