Epidural analgesia and postoperative orthostatic haemodynamic changes: observational study.

CONTEXT: In thoracic and abdominal surgery, epidural analgesia provides excellent pain relief, but associated postural hypotension can delay mobilisation. OBJECTIVES: To assess postoperative orthostatic haemodynamic changes in patients receiving epidural analgesia after major surgery. DESIGN: Prospective observational study. Physiological intervention. SETTINGS: Montreal General Hospital tertiary teaching hospital. PATIENTS OR OTHER PARTICIPANTS: Patients scheduled for thoracic or abdominal surgery with thoracic epidural analgesia using a mixture of bupivacaine 0.1% and fentanyl 3 µg ml(-1). INTERVENTION(S): Arterial blood pressure and heart rate were measured in supine, sitting and standing position before surgery and daily for the first 3 postoperative days. MAIN OUTCOME MEASURE: Orthostatic hypotension, defined as a drop in SBP of more than 20  mmHg during the orthostatic tests, was investigated as a predictor of inability to mobilise during the postoperative period. RESULTS: One hundred and sixty-one patients were enrolled in the study. Hypotension was detected in 59 (37%) of the patients on postoperative day 1, 20 (12%) on day 2 and four (2.5%) on day 3. On day 1, 43% of the patients walked, 39% only sat and 17% were bedridden. Supine SBP less than 90  mmHg, haemodynamic changes during the orthostatic tests, dizziness or nausea, did not predict inability to walk. Only blood loss more than 500  ml and supine mean BP less than 70  mmHg were negative predictors of mobilisation on day 1. CONCLUSION: Epidural analgesia is associated with arterial hypotension in the postoperative period. However, haemodynamic assessment does not predict inability to walk after thoracic and abdominal surgery. Early mobilisation should be tried irrespective of BP or orthostatic changes in postoperative patients with epidural analgesia.

A multidrug-resistant Acinetobacter baumannii outbreak in intensive care unit: antimicrobial and organizational strategies.

PURPOSE: Multidrug-resistant Acinetobacter baumannii (MRAB) is an emerging cause of intensive care unit (ICU) outbreaks. Patients are the main reservoirs, inducing cross transmission. We describe an MRAB outbreak that occurred in the Prato Hospital ICU in June to August 2009. MATERIALS AND METHODS: The ICU consists of 2 separated 4-bed rooms (rooms A and B). The MRAB-positive patients were included in our study. During the outbreak, infection control measures were enhanced; patients and environmental screenings were performed. A 6-month follow-up was carried out. RESULTS: Four of 26 patients admitted during the outbreak were MRAB positive. All patients were located in room A; no case was detected in room B either in the hospital or during the follow-up. Management included closure to new admissions, reinforcement of infection control measures, patient and environmental screenings, discharge of room B MRAB-negative patients for at least 5 days after the first case identification. All isolates were carbapenems resistant and tigecycline and colistin susceptible. All patients received tigecycline: 2 were successfully treated, 1 died because of preexisting illness, and 1 developed resistance and recovered after colistin therapy. CONCLUSIONS: Enhanced infection control measures and adequate antibiotic strategy limited the outbreak. Tigecycline allowed rapid recovery. Nevertheless, resistance ensued; so colistin remained the only therapeutic option. However, pan-drug resistance has been reported.

Neuroprotective effects of propofol in models of cerebral ischemia: inhibition of mitochondrial swelling as a possible mechanism.

BACKGROUND: Propofol (2,6-diisopropylphenol) has been shown to attenuate neuronal injury in a number of experimental conditions, but studies in models of cerebral ischemia have yielded conflicting results. Moreover, the mechanisms involved in its neuroprotective effects are yet unclear. METHODS: The authors evaluated the neuroprotective effects of propofol in rat organotypic hippocampal slices exposed to oxygen-glucose deprivation, an in vitro model of cerebral ischemia. To investigate its possible mechanism of action, the authors then examined whether propofol could reduce Ca2+-induced rat brain mitochondrial swelling, an index of mitochondrial membrane permeability, as well as the mitochondrial swelling evoked by oxygen-glucose deprivation in CA1 pyramidal cells by transmission electron microscopy. Finally, they evaluated whether propofol could attenuate the infarct size and improve the neurobehavioral outcome in rats subjected to permanent middle cerebral artery occlusion in vivo. RESULTS: When present in the incubation medium during oxygen-glucose deprivation and the subsequent 24 h recovery period, propofol (10-100 microM) attenuated CA1 injury in hippocampal slices in vitro. Ca2+-induced brain mitochondrial swelling was prevented by 30-100 microM propofol, and so were the ultrastructural mitochondrial changes in CA1 pyramidal cells exposed to oxygen-glucose deprivation. Twenty-four hours after permanent middle cerebral artery occlusion, propofol (100 mg/kg, intraperitoneal) reduced the infarct size by approximately 30% when administered immediately after and up to 30 min after the occlusion. Finally, propofol administered within 30 min after middle cerebral artery occlusion was unable to affect the global neurobehavioral score but significantly preserved spontaneous activity in ischemic rats. CONCLUSIONS: These results show that propofol, at clinically relevant concentrations, is neuroprotective in models of cerebral ischemia in vitro and in vivo and that it may act by preventing the increase in neuronal mitochondrial swelling.

Erythropoietin attenuates post-traumatic injury in organotypic hippocampal slices.

Recent experimental evidence indicates that erythropoietin (Epo), in addition to its hormonal role in regulating red cell production, operates as a neuroprotective agent. So far, the neuroprotective effect of human recombinant Epo (rhEpo) has been mainly demonstrated in models of cerebral ischemia/hypoxia and in selected in vivo studies of traumatic neuronal injury. To further investigate the potential role of this multifunctional trophic factor in post-traumatic cell death, we examined the protective effects of rhEpo in a newly developed model of mechanical trauma in organotypic hippocampal slices. Organotypic rat hippocampal slices were subjected to traumatic injury by allowing a stylus to impact on the CA1 area with an energy of 6 microJ. Hippocampal damage was identified and measured 24 and 48 h later with the fluorescent dye propidium iodide (PI). In untreated slices, the impact induced a significant increase in the mean hippocampal PI fluorescence, co-localized with the area of impact at 24 h (primary post-traumatic injury) and progressively spread to the whole slice between 24 and 48 h (secondary post-traumatic injury). Addition of rhEpo (1-100 UI/mL) or of the NMDA antagonist MK-801 (30 microM) immediately after the traumatic injury reduced hippocampal damage by approximately 30% when observed 24 h later. At 48 h after trauma, the protective effect of rhEpo was greater (by about 47%) and significantly more pronounced than that of MK-801 (28%). Our results suggest that the neuroprotective activity of rhEpo is particularly effective against delayed, secondary post-traumatic damage. This well tolerated agent could provide a therapeutic benefit in pathologies involving post-traumatic neurodegeneration.