Renal autoregulation in experimental septic shock and its response to vasopressin and norepinephrine administration.

Evidence suggests that septic shock patients with chronic arterial hypertension may benefit from resuscitation targeted to achieve higher blood pressure values than other patients, possibly as a result of altered renal autoregulation. The effects of different vasopressor agents on renal autoregulation may be important in this context. We investigated the effects of arginine vasopressin (AVP) and norepinephrine (NE) on renal autoregulation in ovine septic shock. Sepsis was induced by fecal peritonitis. When shock developed (decrease in mean arterial pressure to <65 mmHg and no fluid responsiveness), animals were randomized to receive NE or AVP in a crossover design. Before the switch to the second vasopressor, the first vasopressor was discontinued for 30 min to ensure complete washout of the first vasopressor. Renal autoregulation was evaluated by recording the change in renal blood flow (RBF) in response to manual, stepwise reductions in renal inflow pressure. In this model, the lower limit of renal autoregulation was not significantly altered 6 h after sepsis induction (59 ± 9 vs. 64 ± 7 mmHg at baseline, P = 0.096). After development of shock, the autoregulatory threshold was lower with AVP than with NE (59 ± 5 vs. 65 ± 7 mmHg, P = 0.010). However, RBF was higher with NE both at the start of autoregulatory measurements (206 ± 58 vs. 170 ± 52 ml/min; P = 0.049) and at the autoregulatory threshold (191 ± 53 vs. 150 ± 47 ml/min; P = 0.008). As vasopressors may have different effects on renal autoregulation, blood pressure management in patients with septic shock should be individualized and take into account drug-specific effects.NEW & NOTEWORTHY Septic shock patients with chronic arterial hypertension may benefit from higher blood pressure targets due to underlying deficits in renal autoregulatory efficiency. The current study is the first to show that the choice of vasopressor agent can differentially affect renal autoregulation. These findings may contribute to more personalized blood pressure management in patients with septic shock.

Can red blood cell distribution width predict outcome after cardiac arrest?

BACKGROUND: In critically ill patients, high red blood cell distribution width (RDW) values have been associated with increased hospital mortality, but there are no data on the impact of RDW on outcomes of patients resuscitated from cardiac arrest (CA). The aim of this study was to investigate the relationship between RDW and long-term neurologic outcome in CA survivors. METHODS: We performed a retrospective analysis of an institutional database including all unconscious adult patients admitted to the intensive care unit (ICU) after non-traumatic CA between January 2007 and January 2015. Patients who survived <24 hours were excluded. The RDW (normal values 10.9-13.4%) was obtained daily from the day of admission to day 3. Patients with a cerebral performance category (CPC) score of 3-5 at 3 months were considered to have an unfavourable neurological outcome. RESULTS: Three hundred and ninety patients were included. The ICU mortality rate was 56% (N.=220) and 64% of patients (N.=251) had an unfavorable 3-month neurological outcome. The median RDW on the day of admission was 14% (13.0-15.2%) and remained stable over the observation period. Two hundred and forty-five patients (63%) had a high RDW (>13.4%) on admission. In multivariable logistic regression analysis, older age, absence of bystander cardiopulmonary resuscitation (CPR), a non-cardiac etiology of the arrest, a non-shockable initial rhythm, high adrenaline dose during CPR and high admission RDW levels were independently associated with an unfavorable outcome at 3 months. CONCLUSIONS: High RDW values are associated with poor neurological outcome among CA survivors.

Manual versus Automated moNitoring Accuracy of GlucosE II (MANAGE II).

BACKGROUND: Intravascular continuous glucose monitoring (CGM) may facilitate glycemic control in the intensive care unit (ICU). We compared the accuracy of a CGM device (OptiScanner®) with a standard reference method. METHODS: Adult patients who had blood glucose (BG) levels >150 mg/dl and required insertion of an arterial and central venous catheter were included. The OptiScanner® was inserted into a multiple-lumen central venous catheter. Patients were treated using a dynamic-scale insulin algorithm to achieve BG values between 80 and 150 mg/dl. The BG values measured by the OptiScanner® were plotted against BG values measured using a reference analyzer. The correlation between the BG values measured using the two methods and the clinical relevance of any differences were assessed using the coefficient of determination (r 2) and the Clarke error grid, respectively; bias was assessed by the mean absolute relative difference (MARD). Three different standards of glucose monitoring were used to assess accuracy. Glycemic control was assessed using the time in range (TIR). Six indices of glycemic variability were calculated. RESULTS: The analysis included 929 paired samples from 88 patients, monitored for a total of 2584 hours. Reference BG values ranged between 60 and 484 mg/dl. The r 2 value was 0.89. The percentage of BG values within zones A and B of the Clarke error grid was 99.9%; the MARD was 7.7%. Using the ISO 15197 standard and Food and Drug Administration and consensus standards, respectively, 80.4% of measurements were within 15 mg/dl and 88.2% within 15% of reference values, 40% of measurements were within 7 mg/dl and 72.5% within 10% of reference values, and 65.2% of measurements were within 10 mg/dl and 82.7% within 12.5% of reference values. The TIR was slightly lower with the OptiScanner® than with the reference method. The J-index, standard deviation and maximal glucose change were the indices of glycemic variability least affected by the measurement device. CONCLUSIONS: Based on the MARD, the performance of the OptiScanner® is adequate for use in ICU patients. Because recent standards for accuracy were not met, the OptiScanner® should not be used as a sole monitor. The assessment of glycemic variability is influenced by the time interval between BG determinations. TRIAL REGISTRATION: Clinicaltrials.gov NCT01720381 . Registered 31 October 2012.