Single electroencephalographic patterns as specific and time-dependent indicators of good and poor outcome after cardiac arrest.

OBJECTIVE: To evaluate the prognostic value of single EEG patterns recorded at various time-frames in postanoxic comatose patients. METHODS: This retrospective study included 30-min EEGs, classified according to the definitions of continuity of background activity given by the American Clinical Neurophysiology Society. Isoelectric pattern was distinguished from other suppressed activities. Epileptiform patterns were considered separately. Outcome was dichotomised based on recovery of consciousness as good (Glasgow Outcome Scale [GOS] 3-5) or poor (GOS 1-2). RESULTS: We analysed 211 EEGs, categorised according to time since cardiac arrest (within 12h and around 24, 48 and 72h). In each time-frame we observed at least one EEG pattern which was 100% specific to poor or good outcome: at 12h continuous and nearly continuous patterns predicted good outcome and isoelectric pattern poor outcome; at 24h isoelectric and burst-suppression predicted poor outcome; at 48 and 72h isoelectric, burst-suppression and suppression (2-10µV) patterns predicted poor outcome. CONCLUSIONS: The prognostic value of single EEG patterns, defined according to continuity and voltage of background activity, changes until 48-72h after cardiac arrest and in each time-frame there is at least one pattern which accurately predicts good or poor outcome. SIGNIFICANCE: Standard EEG can provide time-dependent reliable indicators of good and poor outcome throughout the first 48-72h after cardiac arrest.

Absent SEP during therapeutic hypothermia did not reappear after re-warming in comatose patients following cardiac arrest.

BACKGROUND: Early prediction of neurological outcome for patients resuscitated from cardiac arrest (CA) is a challenging task. Therapeutic hypothermia (TH) has been shown to improve neurological outcome after CA. Two recent studies indicated that somatosensory evoked potentials (SEP) recorded during TH retains high prediction value for poor neurological outcome. It remains unclear whether TH can influence the recovery of bilaterally absent (BA) N20 after re-warming. The primary endpoint of the present study was to evaluate if patients with BA SEPs during TH can recover cortical responses after re-warming. The secondary endpoint was to evaluate whether BA SEPs recorded during TH retains its prediction value for poor neurological outcome as in normothermic patients. METHODS: A single centre prospective cohort study including comatose adults resuscitated from in/out-of-hospital CA treated with TH. SEPs were recorded during TH (6-24 hours after CA) and after re-warming in those patients who remained comatose. Neurological outcome was assessed 6 months after CA using the Glasgow Outcome Scale. RESULTS: Sixty patients were included. In patients with preserved SEP, no significant differences were found between N20 mean amplitude during TH and after re-warming. During TH, 24 patients showed bilaterally absent N20 but none of these recovered cortical responses after re-warming. All patients with absent SEPs during TH did not recover consciousness. CONCLUSIONS: In a single centre cohort of comatose CA patients, our results showed that all patients with absent SEPs during early recording (6-24 hours) during TH showed bilaterally absent SEPs after re-warming. As a secondary result we confirmed previous data that BA SEPs during TH retains its prognostic value for poor neurological outcome, as in normothermic patients.

Low-dose dopamine in kidney transplantation.

BACKGROUND: The use of low-dose dopamine (LDD; 0.5-2.5 mug/kg/min) in kidney transplant recipients seeks to increase urine output, prevent arterial vasospasm, and reduce the incidence of acute tubular necrosis. The aim of this study was to evaluate the effect of LDD in the early postoperative period (12 hours) among kidney transplant recipients. METHODS: We studied all kidney transplant recipients admitted to the Intensive Care Unit (ICU) in the early postoperative period from January 2004 to December 2008. A total of 105 patients were retrospectively assigned to two groups: group A (n = 57) was treated with LDD and group B (n = 48), not treated with LDD. All patients otherwise received the same therapy. Blood sample analysis and kidney function were recorded at 0, 6, and 12 hours after admission. For each patient, we collected the following data: donor and transplant kidney features, recipient demographics, intraoperative events, hemodynamic and kidney function parameters in the ICU, and outcomes. Patients were followed for 6 months after ICU discharge. RESULTS: Hourly diuresis and kidney function parameters showed no significant difference between the groups. Significant differences between group A and group B were observed in heart rate (92.63 +/- 14.18 vs 82.87 +/- 13.5, respectively), hours of ICU length of stay (29.0 +/- 17.42 vs 20.43 +/- 7.35, respectively), and 6-month mortality rate (8.8% vs 0%, respectively; P < .05). CONCLUSION: LDD prescription in kidney transplantation neither improved kidney function during the postoperative period nor short-term outcomes, but was associated with an increased heart rate, ICU length of stay and 6-month mortality.

Skin temperature during sympathetic block: a clinical comparison of bupivacaine 0.5% and ropivacaine 0.5% or 0.75%.

Measurement of skin temperature can be used as an indicator of sympathetic blockade induced by neuraxial anaesthesia. The aim of the study was to test the skin temperature response to epidural administration of bupivacaine and different concentrations of ropivacaine. Forty-eight ASA class I-II patients undergoing herniorraphy were enrolled into a prospective, randomized, double-blind clinical trial. Patients were randomly allocated to receive epidural anaesthesia with a single dose of 18 ml of bupivacaine 0.5% (n=16); ropivacaine 0.5% (n=16), or ropivacaine 0.75% (n=16). A temperature probe was positioned on the skin of the thigh and skin temperature registered before epidural anaesthesia, every 10 minutes for the first hour after the epidural injection and every hour for the following four hours. Sensory blockade was assessed by pinprick and motor blockade using the Bromage scale. No significant difference was observed in sensory or motor blockade. A skin temperature rise of 1 to 1.8 degrees C compared with basal values was observed in all patients within the first hour. Temperature returned to basal values within four hours in the ropivacaine 0.5% group, within five hours in the ropivacaine 0.75% group, and remained 1 degrees C higher after five hours in the bupivacaine 0.5% group (P<0.01). The duration of sympathetic block is significantly shorter with ropivacaine than with bupivacaine.