Limitations of computed tomographic angiography in the diagnosis of brain death.

OBJECTIVE: To evaluate the accuracy of cerebral computed tomographic angiography (CT-a) for the diagnosis of brain death (BD). DESIGN AND SETTING: Prospective observational study in intensive care units. PATIENTS: Twenty-one clinically BD patients enrolled over 12 months. MEASUREMENTS AND RESULTS: All clinically BD patients were evaluated by electroencephalography (EEG) and CT-a after exclusion of hypothermia and drug intoxication. Data collected included: demographic characteristics, cause of BD, delay between in-hospital admission and BD diagnosis and between EEG and CT-a, occurrence of cardiac arrest, administration of vasoactive agents, results of EEG and CT-a. We evaluated the sensitivity of EEG and CT-a and their agreement. Groups were compared according to BD diagnosis by EEG and CT-a (E+C+), or only by EEG (E+C(-)). Statistical analysis were performed by Mann-Whitney test and Fisher's exact test. BD was confirmed by EEG in all cases (sensitivity 100%) whereas only 11 patients of 21 had no cerebral perfusion during CT-a (sensitivity 52.4%). No agreement was documented between EEG and CT-a for the diagnosis of BD (kappa = 0). Patients' characteristics did not differ between E+C+ and E+C(-) groups. In the E+C(-) group arterial opacification was observed in 100% of patients, but opacification of the internal cerebral veins was achieved in only 30%. CONCLUSIONS: In clinically BD patients with no electroencephalographic activity CT-a documents opacification of the intracerebral vessels in a significant percentage of the cases. Therefore CT-a cannot be recommended as a means of BD diagnosis.

Risk and protective factors for major complications after pneumonectomy for lung cancer.

Pneumonectomy carries a high-risk for postoperative complications. The aim of the study was to identify factors that may predispose to the development of major postoperative complications after pneumonectomy for lung cancer. All consecutive patients from January 2000 to December 2005 were retrospectively studied. Major postoperative complications were defined by respiratory failure, pulmonary embolism, pneumonia, shock, cardiogenic pulmonary oedema, myocardial ischaemia or symptomatic cardiac arrhythmia. One hundred and twenty-nine patients were included. The overall hospital mortality rate was 10.8%, and complications occurred in 42.6%. Multivariate analysis revealed that patients with American Society of Anesthesiologist (ASA) class >2 [odds ratio (OR) 8.26; 95% confidence interval (CI), 3.19-36.55] and liberal fluid administration during surgery (OR, 1.96 for each litre; 95% CI, 1.45-3.16) to be risk factor for major cardiopulmonary complication or mortality. Preoperative haemoglobin > or =10 g/dl (OR, 0.19; 95% CI, 0.01-0.91) and low tidal volume administrated during surgery (< or =7.35 ml/kg; OR, 0.36; 95% CI, 0.10-0.92) were identified as protective factors. Pneumonectomy remains a high-risk surgery. Postoperative complications may be influenced by the comorbidities but also the management of fluid infusion and mechanical ventilation during the surgical procedure.

The effect of clonidine on the minimum local analgesic concentration of epidural ropivacaine during labor.

UNLABELLED: On the basis of the determination of minimum local analgesic concentration (MLAC), ropivacaine has been demonstrated to be less potent than bupivacaine during the first stage of labor. In this study we assessed the effect of clonidine on the MLAC of ropivacaine. Seventy-seven parturients of mixed parity requesting epidural analgesia for labor (cervical dilation, 3-7 cm) were included in the study. They received an epidural bolus of either ropivacaine (n = 30), ropivacaine plus clonidine 30 microg (n = 28), or ropivacaine plus clonidine 60 microg (n = 19) in the second part of the study. The concentration of the ropivacaine solution was determined by the response of the previous parturient in that group by using an up-down sequential allocation. A visual analog pain score of < or =10 mm within 30 min after the epidural bolus (20 mL) was considered an effective response. An effective result directed a 0.01% wt/vol decrement for the next patient. An ineffective result directed a 0.01% wt/vol increment. The MLAC of ropivacaine was 0.097% wt/vol (95% confidence interval, 0.085%-0.108%). It was unaffected by a 30-microg dose of epidural clonidine (0.081% [0.045%-0.117%]) but was significantly decreased by a 60-microg clonidine dose (0.035% [0.024%-0.046%]) (P < 0.001). This study documents a decrease in the MLAC of ropivacaine by clonidine, significant for a 60- microg dose. IMPLICATIONS: Epidural ropivacaine potency in labor can be increased by the addition of epidural clonidine. This study demonstrates that 60 microg of epidural clonidine significantly decreases the minimum local analgesic concentration of ropivacaine during the first stage of labor but is associated with sedation.