Mariana Mogos

Ketamine Alleviates Fear, Depression, and Suicidal Ideation in Terminally Ill Patients

Dear Editor: There are many terminally ill patients who suffer from anxiety, fear of death, severe depression, and often suicidal ideation. In the last 20 years, in the intensive care unit (ICU) at Kenneth Norris Cancer Hospital we have used ketamine and narcotic combinations successfully. We have observed that terminally ill patients who received ketamine did not suffer of the above symptoms in comparison to those who were treated conventionally with opiates and benzodiazepines. Ketamine, a phencyclidine derivative, has analgesic, amnesic and anesthetic effects. Its mechanism of action is predominantly mediated by N-methyl-d-aspartic acid (NMDA) receptors as noncompetitive antagonist for glutamate. Recent clinical studies suggest that ketamine rapidly relives symptoms of major depressive illness. Based on our experience we recommend that patients with severe anxiety, depression, and suicidal ideation receive ketamine as part of their treatment. References

Mediastinal haemorrhage mimicking tamponade during en-bloc oesophagectomy.

EDITOR: Concealed mediastinal haemorrhage is rare during oesophagectomy procedures. It may occur in patients with major chest trauma following aortic injury. Occasionally patients undergoing aortic arch surgery may present with postoperative mediastinal bleeding. We report a case in which concealed mediastinal haemorrhage complicated an en-bloc oesophagectomy procedure in the early stages of the operation. The diagnosis was not clear because the bleeding was not obvious, as it involved the posterior mediastinum. The mediastinal haemorrhage mimicked cardiac tamponade and was unresponsive to fluid replacement. A 60-yr-old male, ASA III, with oesophageal cancer, was scheduled to undergo en-bloc oesophagectomy and colon interposition. Past medical history included hypertension, chronic obstructive pulmonary disease, reflux disease and smoking. The surgical plan included initial exploration of the right chest for mobilization of the oesophagus, followed by abdominal and left-sided neck explorations for completion of en-bloc oesophagectomy. The transverse colon would then be mobilized and interposed in place of the oesophagus. Preoperative preparation included blood gas analysis and pulmonary function tests, which were within normal limits. A dobutamine stress echo was negative for cardiac disease. Following induction of anaesthesia, a 39-G double lumen tube was placed uneventfully. Proper placement was confirmed with auscultation and fibreoptic bronchoscopy. Anaesthesia was maintained with isoflurane and intermittent boluses of fentanyl. In addition to the standard anaesthesia monitors, a radial arterial line and pulmonary artery catheter were placed. Initial pulmonary artery pressures were within the normal range (30/15–32/17 mmHg, pulmonary artery occlusion pressures 12–14 mmHg, central venous pressure (CVP) 8–10 mmHg). Initial blood gases were also in the normal range and pulse oximetry showed a saturation of 100% breathing 50% oxygen. The patient was placed in the left lateral decubitus position, one-lung ventilation was initiated and a right thoracotomy was performed in order to mobilize the stomach and oesophagus. This portion of the procedure lasted for the first 3 h of surgery, during which time blood gases remained in the normal range and the patient required only 50% oxygen to maintain adequate oxygenation. After completion of the mobilization, the thoracotomy incision was closed and the patient turned supine. Blood loss at this portion of the procedure was approximately 250–300 mL. Haemodynamic parameters remained in the normal range. Shortly after turning the patient, the patient became haemodynamically unstable, accompanied by a slowly developing fall in oxygen saturation (99–88%). There was no significant change in peak inflation ventilatory pressures. Auscultation of the lungs revealed no abnormalities. The patient was given 100% oxygen. There was minimal drainage from the right-sided chest tube. The blood pressure (BP) ranged from 60/30 to 70/40 mmHg, and heart rate was 120–130 beats min 1. The oxygen saturation continued to deteriorate in spite of 100% oxygen and ventilation of both lungs. Fibreoptic bronchoscopy revealed no abnormal findings. The hypotension was treated with crystalloid and blood. The patient received 3000 mL crystalloid and albumin 5% 500 mL without any significant improvement in haemodynamics. BP was maintained in the 80/40–90/50 mmHg range with 10 μg kg 1min 1 of dopamine. There was no evidence of any bleeding at this time, however, haemoglobin analysis revealed a decrease in haemoglobin from 14.0 to 12.0. The patient received three units of packed red blood cells but there was no response. Pulmonary artery pressures were slightly elevated despite the hypotension. There was no evidence of pericardial tamponade (CVP was 12–15 mmHg, pulmonary capillary wedge pressure was 15–17 mmHg). There was no evidence of ischaemic changes on the electrocardiogram. Cardiac output varied from 4.4 to 5.5 L min 1. The patient continued to require increasing inotropic support and fluids to maintain BP. The surgeon was asked to inspect the mediastinum for any signs of mediastinal bleeding via the upper abdominal incision, as the chest incision was already closed. Inspection of the base of the heart did not show any distension and therefore direct tamponade was excluded. An immediate intraoperative chest X-ray showed widening of the mediastinum with an enlarged upper mediastinal opacity extending to the upper zone of the lung. Initially this opacity was diagnosed as upper lobe collapse. The repeat bronchoscopy showed Correspondence to: Duraiyah Thangathurai, Department of Anesthesiology, LAC/USC Medical Center, USC/Kenneth Norris Cancer Hospital, 1441 Eastlake Avenue, Rm 4341, Los Angeles, CA 90033, USA. E-mail: thangath@usc.edu; Tel: 1 323 865 3441; Fax: 1 323 865 0084

Caution with Epidural Opioid Use in Sleep Apnea Patients

Dear Editor, Epidural opioids are now routinely used in surgical patients for postoperative pain relief. Opioids commonly used include morphine and hydromorphone (dilaudid). Sleep apnea patients are prone to developing respiratory depression with the use of opioids. Over the last 10 years in our institution …

Excessive Use of Phenylephrine by the Perfusionist and Hemodynamic Instability

oval and pushing in, the J-tip got entangled by multiple turns round the chordae. With modern devices in interventional radiology, intravasular foreign bodies can be retrieved easily under fluoroscopic uidance. In this patient, because the guidewire was entrapped ith multiple loops around the chordae, any forceful attempt ould have torn it and may have resulted in severe tricuspid egurgitation. In 1 case report by Hoda et al,8 there was possible ntanglement of the guidewire at the tricuspid valve, but the ontinuous flow of blood and the dynamic movement of the ricuspid valve might have subsequently freed the entrapped uidewire by gentle traction. This complication can be preented by standardizing guidewire distance markings, adhering o the safe length during insertion, and choosing a catheter kit ithout guidewire length discrepancies.

Doxapram revisited in patients with cancer.

Dear Editor: Terminally ill patients often request not to be intubated or placed on ventilators. However, the aggressive opioid therapy required for optimal pain control in patients with cancer may result in respiratory depression and carbon dioxide retention. Doxapram is a nonspecific central respiratory stimulant that can increase minute ventilation by enhancing both respiratory rate and tidal volume with a concomitant fall in Paco2 and rise in Pao2, without reversing the analgesic effects of opioids. To maintain the respiratory rate within the normal range, doxapram is delivered by continuous infusion, at a rate of 0.25 to 0.5 mg=min. In the last 15 years at USC Norris Cancer Hospital we have not experienced any side effects, such as anxiety and agitation, at the dosage range described. Doxapram’s short half-life allows tight control and the dose is titrated according to respiratory rate. It has proven to be effective in patients requiring high doses of narcotics, such as morphine or dilaudid. Doxapram was not used in patients with brain metastases or with a history of seizures because it lowers the seizure threshold.