A randomized, controlled, double-blind crossover study on the effects of isoeffective and isovolumetric intravenous crystalloid and gelatin on blood volume, and renal and cardiac hemodynamics.

BACKGROUND & AIMS: Blood volume expanding properties of colloids are superior to crystalloids. In addition to oncotic/osmotic properties, the electrolyte composition of infusions may have important effects on visceral perfusion, with infusions containing supraphysiological chloride causing hyperchloremic acidosis and decreased renal blood flow. In this non-inferiority study, a validated healthy human subject model was used to compare effects of colloid (4% succinylated gelatin) and crystalloid fluid regimens on blood volume, renal function, and cardiac output. METHODS: Healthy male participants were given infusions over 60 min > 7 days apart in a randomized, crossover manner. Reference arm (A): 1.5 L of Sterofundin ISO, isoeffective arm (B): 0.5 L of 4% Gelaspan®, isovolumetric arm (C): 0.5 L of 4% Gelaspan® and 1 L of Sterofundin ISO (all B. Braun, Melsungen, Germany). Participants were studied over 240 min. Changes in blood volume were calculated from changes in weight and hematocrit. Renal volume, renal artery blood flow (RABF), renal cortex perfusion and diffusion, and cardiac index were measured with magnetic resonance imaging. RESULTS: Ten of 12 males [mean (SE) age 23.9 (0.8) years] recruited, completed the study. Increase in body weight and extracellular fluid volume were significantly less after infusion B than infusions A and C, but changes in blood volume did not significantly differ between infusions. All infusions increased renal volume, with no significant differences between infusions. There was no significant difference in RABF across the infusion time course or between infusion types. Renal cortex perfusion decreased during the infusion (mean 18% decrease from baseline), with no significant difference between infusions. There was a trend for increased renal cortex diffusion (4.2% increase from baseline) for the crystalloid infusion. All infusions led to significant increases in cardiac index. CONCLUSIONS: A smaller volume of colloid (4% succinylated gelatin) was as effective as a larger volume of crystalloid at expanding blood volume, increasing cardiac output and changing renal function. Significantly less interstitial space expansion occurred with the colloid. TRIAL REGISTRATION: The protocol was registered with the European Union Drug Regulating Authorities Clinical Trials Database (https://eudract.ema.europa.eu) (EudraCT No. 2013-003260-32).

Development of a telehealth monitoring service after colorectal surgery: A feasibility study.

AIM: To evaluate the feasibility of a text-messaging system to remotely monitor and support patients after discharge following elective colorectal surgery, within an enhanced recovery protocol. METHODS: Florence (FLO) is a National Health Service telehealth solution utilised for monitoring chronic health conditions, such as hypertension, using text-messaging. New algorithms were designed to monitor the well-being, basic physiological observations and any patient-reported symptoms, and provide support messages to patients undergoing colorectal surgery within an enhanced recovery after surgery protocol for 30 d after discharge. All interactions with FLO and physiological readings were recorded and patients were invited to provide feedback. RESULTS: Over a four-week period, 16 out of 17 patients used the FLO telehealth service at home. These patients did not receive telephone follow-up at three days, as per our standard protocol, unless they reported being unwell or did not make use of the technology. Three patients were readmitted within 30 d, and two of these were identified as being unwell by FLO prior to readmission. No adverse events attributable to the use of the technology were encountered. CONCLUSION: The utilisation of telehealth in the early follow-up of patients who have undergone major colorectal surgery after discharge is feasible. The use of this technology may assist in the early recognition and management of complications after discharge.