A red flag for diagnosing brain death: decompressive craniectomy of the posterior fossa

PURPOSE

Brain death/death by neurologic criteria (BD/DNC) may be determined in many countries by a clinical examination that shows coma, brainstem areflexia, and apnea, provided the conditions causing reversible loss of brain function are excluded a priori. To date, accounts of recovery from BD/DNC in adults have been limited to noncompliance with guidelines.

CLINICAL FEATURES

We report the case of a 72-yr-old man with a combined primary infratentorial (hemorrhagic) and secondary global (anoxic) brain lesion in whom decompressive craniectomy of the posterior fossa and six-hour therapeutic hypothermia (33-34°C) followed by 8-hour rewarming to ≥ 36°C were conducted. Thirteen hours later, clinical findings of brain function loss were documented in addition to guideline-compliant exclusion of reversible causes (arterial hypotension, intoxication, depressant drug effects, relevant metabolic or endocrine disequilibrium, chronic hypercapnia, neuromuscular disorders, and administration of a muscle relaxant). Since a primary infratentorial brain lesion was present, German guidelines required further ancillary testing. Doppler ultrasonography revealed some preserved cerebral circulation, and BD/DNC was not diagnosed. Approximately 24 hr after rewarming to ≥ 36°C, the patient exhibited respiratory efforts. He continued with assisted respiration until final asystole/apnea, without regaining additional brain function other than mild signs of hemispasticity. Follow-up computed tomography showed partial herniation of the cerebellum through the craniectomy gap of the posterior fossa, alleviating caudal brain stem compression.

CONCLUSIONS

Therapeutic decompressive craniectomy of the posterior fossa may allow for delayed reversal of apnea. In these patients, proof of cerebral circulatory arrest should be mandatory for diagnosing BD/DNC.

[Remifentanil analgesia for aspiration of follicles for oocyte retrieval]

Remifentanil is an esterase-metabolized ultra-short acting mu-agonist opioid with a rapid clearance. The aim of this study was to determine the efficacy of remifentanil infusion for the short-lasting, but painful, transvaginal puncture for oocyte retrieval. Eighty consenting adult women (ASA I and II) aged 30.5 +/- 5 years and with a body weight of 69.1 +/- 9.1 kg were enrolled in this prospective study. After an oral premedication with 7.5 mg midazolam, all patients received 3 l/min oxygen. Subsequently, the remifentanil infusion was started with a rate of 0.3 microg/kg/min. Remifenanil doses were adjusted as needed for painless puncture and sufficient oxygen saturation in steps of 0.05 microg/kg/min. Dosage requirements, blood pressure, heart rate, oxygen saturation (pulse oxymetry, SaO2) and the level of analgesia were recorded every 3 minutes. Follicular aspiration lasted 11.8 +/- 4.1 min and the time of remifentanil infusion was 18.7 +/- 4.6 min. Dosage requirements of remifentanil were 0.3 microg/kg/min in 48.7% of all patients, but 27.8% needed only 0.25 microg/kg/min and 16.6% needed only 0.2 microg/kg/min. However, 4.2% of patients needed 0.35 microg/kg/min and 2.7% of all cases needed 0.4 microg/kg/min. Vital parameters remained nearly unchanged. Oxygen saturation decreased significantly from 99.2 +/- 0.7% to 98.2 +/- 2.4% after 3 min and to 94.9 +/- 7.2% after 10 min. Nine women showed motoric reactions to puncture. In many cases, the infusion of remifentanil after premedication with midazolam provided a suitable and satisfying anaesthesia for oocyte retrieval. Some patients, however, showed motoric reactions to vaginal puncture, while in other cases significant and clinical relevant decreases in Hb-oxygen saturation occurred. Therefore, we no longer carry out remifentanil infusion for transvaginal oocyte retrieval. We now prefer a remifentanil infusion of 0.2 microg/kg/min and propofol (1 mg/kg initially with intermittent doses of 0.5 mg/kg) combined with assisted ventilation by mask.

[Total intravenous anesthesia with propofol and sufentanil for resection of pheochromocytoma]

Various anaesthesiological procedures have been described for resection of phaeochromocytoma. In this case report total intravenous anaesthesia with propofol and sufentanil is presented. The patient showed a smooth haemodynamic course. A short hypertensive phase during tumour preparation responded well to small amounts of an alpha blocker. A drop in blood pressure after tumour removal, not uncommon in phaeochromocytoma surgery, was rectified by fluid replacement guided by pulmonary capillary wedge pressure and by inotropic drugs in medium doses for a short period. At the end of the operation the patient was haemodynamically stable and the postoperative course was uneventful. It can be concluded that total intravenous anaesthesia with propofol and sufentanil seems to be a suitable anaesthetic technique for phaeochromocytoma resection, providing great haemodynamic stability and allowing easy adjustment to intraoperative requirements.

Total intravenous anaesthesia using propofol, gamma-hydroxybutyrate or midazolam in combination with sufentanil for patients undergoing coronary artery bypass surgery

Total intravenous anaesthesia (TIVA) using propofol, gamma-hydroxybutyrate (GHB) or midazolam in combination with sufentanil was investigated in 45 patients undergoing coronary artery bypass grafting (CABG). Anaesthesia was induced with sufentanil, etomidate and pancuronium. After endotracheal intubation, anaesthesia was continued with sufentanil (2 micrograms kg-1 h-1) for all patients. Patients were randomized to receive supplementary propofol (2 mg kg-1 h-1, n = 15), gamma-hydroxybutyrate (20 mg kg-1 h-1, n = 15) or midazolam (0.06 mg kg-1 h-1, n = 15). Haemodynamic measurements were performed after induction and at various times in the pre-bypass period. In the propofol group, a significant decrease in heart rate (HR 12% +/- 3%), cardiac index (CI 23% +/- 4%), mean arterial pressure (MAP 16% +/- 3%) and left ventricular stroke work index (LVSWI 17% +/- 4%) occurred until sternotomy was performed. With the exception of cardiac index, both midazolam and gamma-hydroxybutyrate produced similar haemodynamic effects: cardiac index was temporarily decreased (19% +/- 4%) by midazolam and remained unchanged after gamma-hydroxybutyrate. In both groups, sternotomy was followed by temporary hypertension, associated with a significant rise in systemic vascular resistance. No electrocardiographical signs of ischaemia were observed in any patient. In the case of propofol and midazolam, gamma-hydroxybutyrate showed adequate haemodynamic stability especially after induction of anaesthesia and may also be a suitable agent for total intravenous anaesthesia in patients with coronary artery disease. However, during sternotomy, supplementary administration of opioids was required.