Relative Blood Volume Monitoring during Renal Replacement Therapy in Critically Ill Patients with Septic Shock: A Preliminary Report.

BACKGROUND: Volume management during renal replacement therapy (RRT) in septic shock is always in the conflict between aggravating hypovolemia by undue ultrafiltration (UF) and insufficient reduction of fluid overload which is associated with adverse outcome. Relative blood volume (RBV) monitoring could be helpful for timely transition from fluid resuscitation to fluid removal. METHODS: Data of RBV were continuously monitored and used for guidance of UF and fluid resuscitation in 21 consecutive patients with severe septic multiple organ failure. RRT was applied with extended daily hemodiafiltration for median 11 h (range 6-23). Changes in RBV were analyzed during the first 4 treatment sessions. RESULTS: During 26 treatments, RBV monitoring revealed an internal volume loss substituted by a median infusion volume of 2.38 l (maximum 8.07 l) per treatment to keep the RBV constant. In the remaining 40 sessions, a median net-UF of 1.00 l (range 0.40-4.40) was achieved. In the first 2 days predominantly substitution was necessary whereas from the third day UF became increasingly possible. The 28-day survival rate was 81%. CONCLUSION: Blood volume monitoring proved to be an easy and feasible tool for safe guidance of fluid management maintaining the balance between UF and vascular refilling. Video Journal Club 'Cappuccino with Claudio Ronco' at http://www.karger.com/?doi=433415

Extended daily on-line high-volume haemodiafiltration in septic multiple organ failure: a well-tolerated and feasible procedure.

BACKGROUND: The outcome of patients with septic multiple organ failure (MOF) remains poor. There are experimental and clinical data indicating a beneficial effect of high-volume haemofiltration. Delivering high-volume therapy is only cost effective using on-line devices because of high costs for additional solution bags in conventional continuous renal replacement therapy (CRRT). We investigated feasibility and effectiveness of extended daily on-line high-volume haemodiafiltration (HDF) with technically maximum convective volume in patients with septic MOF in a pilot study. METHODS: We included 21 consecutive critically ill patients with septic MOF having a mortality risk >50% (SAPS II >50, APACHE II >25). Renal replacement therapy (RRT) was applied with extended daily HDF for 6-23 h using the AK 200 Ultra S dialysis machine in the ultracontrol pre-dilution mode. Dialysate and substitution fluid were prepared on-line. Patients underwent 289 treatments. RESULTS: The mean convective volume was 17.8 ± 3.7 L/h and 208 ± 66 mL/kg/h, respectively, median treatment time was 10:15 h/day. Seventeen of 21 patients survived 28 days (81%). The 90-day survival rate was 52% (11/21) versus 19% compared to the survival rate predicted by APACHE II (33.6 mean) and SAPS II (68.6 mean) scores. Haemodynamics improved significantly during the treatment procedures. Material costs per treatment amounted to 35 €. CONCLUSIONS: Extended daily on-line HDF using maximum convective volume seems to improve the outcome of septic MOF, especially in the early phase. The investigated mode of treatment proved to be feasible, well tolerated and highly cost effective compared to conventional CRRT. At present, this procedure would be applicable at every ICU facility with nephrological support.

Quantification of anandamide and 2-arachidonoylglycerol plasma levels to examine potential influences of tetrahydrocannabinol application on the endocannabinoid system in humans.

The effects of tetrahydrocannabinol (THC) and endogenous cannabinoids (endocannabinoids, ECs) are both mediated by activation of the cannabinoid receptors CB1 and CB2. Exogenous activation of these receptors by THC could therefore alter EC levels. We tested this hypothesis in healthy volunteers (n = 25) who received a large intravenous dose of THC (0.10 mg/kg). Effects on the EC system were quantified by serial measurements of plasma ECs after THC administration. Eleven blood samples were drawn during the first 5 h after THC administration and two more samples after 24 and 48 h. THC, its metabolites THC-OH (biologically active) and THC-COOH (non-active), and the ECs anandamide and 2-arachidonoylglycerol (2-AG) were quantified by liquid chromatography-mass spectrometry. EC-plasma levels showed a biphasic response after THC injection reaching maximal values at 30 min. Anandamide increased slightly from 0.58 ± 0.21 ng/ml at baseline to 0.64 ± 0.24 ng/ml (p < 0.05) and 2-AG from 7.60 ± 4.30 ng/ml to 9.50 ± 5.90 ng/ml (p < 0.05). After reaching maximal concentrations, EC plasma levels decreased markedly to a nadir of 300 min after THC administration (to 0.32 ± 0.15 ng/ml for anandamide and to 5.50 ± 3.01 ng/ml for 2-AG, p < 0.05). EC plasma concentrations returned to near baseline levels until 48 h after the experiment. THC (0.76 ± 0.16 ng/ml) and THC-OH (0.36 ± 0.17 ng/ml) were still measurable at 24 h and remained detectible until 48 h after THC administration. Although the underlying mechanism is not clear, high doses of intravenous THC appear to influence endogenous cannabinoid concentrations and presumably EC-signalling.