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Impaired cerebrovascular autoregulation in patients with severe sepsis and sepsis-associated delirium

Patrick Schramm, Klaus Klein, Lena Falkenberg, Manfred Berres, Dorothea Closhen, Konrad J Werhahn, Matthias David, Christian Werner, Kristin Engelhard
2012 Critical Care  
Sepsis-associated delirium (SAD) increases morbidity in septic patients and, therefore, factors contributing to SAD should be further characterized. One possible mechanism might be the impairment of cerebrovascular autoregulation (AR) by sepsis, leading to cerebral hypo-or hyperperfusion in these haemodynamically unstable patients. Therefore, the present study investigates the relationship between the incidence of SAD and the status of AR during sepsis. Methods: Cerebral blood flow velocity was
more » ... measured using transcranial Doppler sonography and was correlated with the invasive arterial blood pressure curve to calculate the index of AR Mx (Mx>0.3 indicates impaired AR). Mx was measured daily during the first 4 days of sepsis. Diagnosis of a SAD was performed using the confusion assessment method for ICU (CAM-ICU) and, furthermore the predominant brain electrical activity in electroencephalogram (EEG) both at day 4 after reduction of sedation to RASS >-2. Results: 30 critically ill adult patients with severe sepsis or septic shock (APACHE II 32 ± 6) were included. AR was impaired at day 1 in 60%, day 2 in 59%, day 3 in 41% and day 4 in 46% of patients; SAD detected by CAM-ICU was present in 76 % of patients. Impaired AR at day 1 was associated with the incidence of SAD at day 4 (p = 0.035). Conclusions: AR is impaired in the great majority of patients with severe sepsis during the first two days. Impaired AR is associated with SAD, suggesting that dysfunction of AR is one of the trigger mechanisms contributing to the development of SAD.
doi:10.1186/cc11665 pmid:23036135 pmcid:PMC3682283 fatcat:aqvupsk25vdvffa5v6upwom7am

Cerebrovascular autoregulation in critically ill patients during continuous hemodialysis

Patrick Schramm, Dorothea Closhen, Janosch Wojciechowski, Manfred Berres, Klaus Ulrich Klein, Marc Bodenstein, Christian Werner, Kristin Engelhard
2013 Canadian Journal of Anesthesia  
Purpose In chronic renal failure, intermittent hemodialysis decreases cerebral blood flow velocity (CBFV); however, in critically ill patients with acute renal failure, the effect of continuous venovenous hemodialysis (CVVHD) on CBFV and cerebrovascular autoregulation (AR) is unknown. Therefore, a study was undertaken to investigate the potential effect of CVVHD on CBFV and AR in patients with acute renal failure. Methods This cohort study investigated 20 patients with acute renal failure who
more » ... quired CVVHD. In these patients, the CBFV and index of AR (Mx) were measured using transcranial Doppler before and during CVVHD. Results The median Mx values at baseline were 0.33 [interquartile range (IQR): 0.02-0.55], and during CVVHD, they were 0.20 [0.07-0.40]. The differences in Mx (CVVHD -baseline) was (median [IQR]) -0.015 [-0.19-0.05], 95% confidence interval (CI) -0.16 to 0.05. The Mx was [ 0.3 in 11/20 patients at baseline measurement. Six of these patients recovered to Mx \ 0.3 during CVVHD. The CBFV was (median [IQR]) 47 [36-59] cmÁsec -1 at baseline and 49 [36-66] cmÁsec -1 during CVVHD. The difference of CBFV was 0.0 [-4 -2.7], 95% CI -2.5 to 4.2. Conclusion Compared with patients with intermittent hemodialysis, CVVHD did not influence CBFV and AR in critically ill patients with acute renal failure, possibly due to lower extracorporeal blood flow, slower change of plasma osmolarity, and a lower fluid extraction rate. In a subgroup of patients with sepsis, the AR was impaired at baseline in more than half of the patients, and this was reversed during CVVHD. The trial was registered at ID: NCT01376531.
doi:10.1007/s12630-013-9912-z pmid:23536386 fatcat:bkbpg5nrezblhmvhszrd4eo2hy