Comparison of the accuracy of hemoglobin point of care testing using HemoCue and GEM Premier 3000 with automated hematology analyzer in emergency room.

The laboratory analysis provides accurate, but time consuming hemoglobin level estimation especially in the emergency setting. The reliability of time-sparing point of care devices (POCT) remains uncertain. We tested two POCT devices accuracy (HemoCue®201+ and Gem®Premier™3000) in routine emergency department workflow. Blood samples taken from patients admitted to the emergency department were analyzed for hemoglobin concentration using a laboratory reference Beckman Coulter LH 750 (HBLAB), the HemoCue (HBHC) and the Gem Premier 3000 (HBGEM). Pairwise comparison for each device and HbLAB was performed using correlation and the Bland-Altman methods. The reliability of transfusion decision was assessed using three-zone error grid. A total of 292 measurements were performed in 99 patients. Mean hemoglobin level were 115 ± 33, 110 ± 28 and 111 ± 30 g/l for HbHC, HbGEM and HbLAB respectively. A significant correlation was observed for both devices: HbHC versus HbLAB (r2 = 0.93, p < 0.001) and HBGEM versus HBLAB (r2 = 0.86, p < 0.001). The Bland-Altman method revealed bias of -3.7 g/l (limits of agreement -20.9 to 13.5) for HBHC and HBLAB and 2.5 g/l (-18.6 to 23.5) for HBGEM and HBLAB, which significantly differed between POCT devices (p < 0.001). Using the error grid methodology: 94 or 91 % of values (HbHC and HbGEM) fell in the zone of acceptable difference (A), whereas 0 and 1 % (HbHC and HbGEM) were unacceptable (zone C). The absolute accuracy of tested POCT devices was low though reaching a high level of correlation with laboratory measurement. The results of the Morey´s error grid were unfavorable for both POCT devices.

Fluid management guided by a continuous non-invasive arterial pressure device is associated with decreased postoperative morbidity after total knee and hip replacement.

BACKGROUND: The use of goal directed fluid protocols in intermediate risk patients undergoing hip or knee replacement was studied in few trials using invasive monitoring. For this reason we have implemented two different fluid management protocols, both based on a novel totally non-invasive arterial pressure monitoring device and compared them to the standard (no-protocol) treatment applied before the transition in our academic institution. METHODS: Three treatment groups were compared in this prospective study: the observational (CONTROL, N = 40) group before adoption of fluid protocols and two randomized groups after the transition to protocol fluid management with the use of the continuous non-invasive blood pressure monitoring (CNAP®) device. In the PRESSURE group (N = 40) standard variables were used for restrictive fluid therapy. Goal directed fluid therapy using pulse pressure variation was used in the GDFT arm (N = 40). The influence on the rate of postoperative complications, on the hospital length of stay and other parameters was assessed. RESULTS: Both protocols were associated with decreased fluid administration and maintained hemodynamic stability. Reduced rate of postoperative infection and organ complications (22 (55 %) vs. 33 (83 %) patients; p = 0.016; relative risk 0.67 (0.49-0.91)) was observed in the GDFT group compared to CONTROL. Lower number of patients receiving transfusion (4 (10 %) in GDFT vs. 17 (43 %) in CONTROL; p = 0.005) might contribute to this observation. No significant differences were observed in other end-points. CONCLUSION: In our study, the use of the fluid protocol based on pulse pressure variation assessed using continuous non-invasive arterial pressure measurement seems to be associated with a reduction in postoperative complications and transfusion needs as compared to standard no-protocol treatment. TRIAL REGISTRATION: ACTRN12612001014842.

Continuous non-invasive monitoring improves blood pressure stability in upright position: randomized controlled trial.

Intermittent blood pressure (BP) monitoring is the standard-of-care during low and intermediate risk anaesthesia, yet it could lead to delayed recognition of BP fluctuations. Perioperative hypotension is known to be associated with postoperative complications. Continuous, non-invasive methods for BP monitoring have been developed recently. We have tested a novel non-invasive, continuous monitor (using the volume clamp method) to assist with maintaining BP in safe ranges for patients undergoing surgery in a beach chair position. Forty adult patients undergoing thyroid gland surgery in an upright position were included in this prospective randomised controlled trial. Patients were equally allocated to the group with continuous monitoring of BP using the CNAP® Monitor and to the control group managed using an intermittent oscillometric BP cuff. The absolute and proportional time spent outside the range of ±20% of the target BP along with other hemodynamic and clinical parameters were evaluated. The continuous monitoring decreased the anaesthesia time spent below -20% pressure range [absolute: 12 min (4-20) vs. 27 min (16-34); p=0.001; relative to procedure length: 14% (7-20) vs. 33.5% (17.5-53); p=0.003]. No significant differences were observed in postoperative morbidity or in hospital length of stay. Continuous non-invasive BP monitoring via the CNAP® Monitor allows for better BP management in patients undergoing surgery in a beach chair position. In our randomised trial the time spent in hypotension was significantly shorter using continuous monitoring.

Respiratory induced dynamic variations of stroke volume and its surrogates as predictors of fluid responsiveness: applicability in the early stages of specific critical states.

Respiratory induced dynamic variations of stroke volume and its surrogates are very sensitive and specific predictors of fluid responsiveness, but their use as targets for volume management can be limited. In a recent study, limiting factors were present in 53 % of surgical patients with inserted arterial line. In the intensive care unit (ICU) population the frequency is presumably higher, but the real prevalence is unknown. Our goal was to study the feasibility of dynamic variations guided initial volume resuscitation in specific critical states. We have performed a 5 year retrospective evaluation of patients admitted with diagnosis sepsis, polytrauma, after high risk surgery or cardiac arrest. Occurrence of major (sedation, mandatory ventilation and tidal volume, open chest and arrhythmias) and minor limiting factors (PEEP level, use of vasopressors and presence of arterial catheter) was screened within the first 24 h after admission. In the study period 1296 patients were hospitalized in our ICU with severe sepsis (n = 242), polytrauma (n = 561), after high risk surgery (n = 351) or cardiac arrest (n = 141). From these patients 549 (42.4 %) fulfilled all major criteria for applicability of dynamic variations. In our evaluation only limited number of patients admitted for polytrauma (51 %), sepsis (37 %), after cardiac arrest (39 %) or surgical procedure (33 %) fulfil all the major criteria for use of dynamic variations at the ICU admission. The prevalence was similar in patients with shock. Occurrence of minor factors can pose further bias in evaluation of these patients. General use of dynamic variations guided protocols for initial resuscitations seems not universally applicable.

Clinical and microbiological efficacy of continuous versus intermittent application of meropenem in critically ill patients: a randomized open-label controlled trial.

INTRODUCTION: Meropenem bactericidal activity depends on the time when the free drug concentrations remain above the minimum inhibitory concentration of pathogens. The goal of this study was to compare clinical and bacteriological efficacy of continuous meropenem infusion versus bolus administration in critically ill patients with severe infection, and to evaluate the safety of both dosing regimens. METHODS: Patients admitted to the interdisciplinary Intensive Care Unit (ICU) who suffered from severe infections and received meropenem were randomized either in the Infusion group (n = 120) or in the Bolus group (n = 120). Patients in the Infusion group received a loading dose of 2 g of meropenem followed by a continuous infusion of 4 g of meropenem over 24 hours. Patients in the Bolus group were given 2 g of meropenem over 30 minutes every 8 hours. Clinical and microbiological outcome, safety, meropenem-related length of ICU and hospital stay, meropenem-related length of mechanical ventilation, duration of meropenem treatment, total dose of meropenem, and ICU and in-hospital mortality were assessed. RESULTS: Clinical cure at the end of meropenem therapy was comparable between both groups (83.0% patients in the Infusion vs. 75.0% patients in the Bolus group; P = 0.180). Microbiological success rate was higher in the Infusion group as opposed to the Bolus group (90.6% vs. 78.4%; P = 0.020). Multivariate logistic regression identified continuous administration of meropenem as an independent predictor of microbiological success (OR = 2.977; 95% CI = 1.050 to 8.443; P = 0.040). Meropenem-related ICU stay was shorter in the Infusion group compared to the Bolus group (10 (7 to 14) days vs. 12 (7 to 19) days; P = 0.044) as well as shorter duration of meropenem therapy (7 (6 to 8) days vs. 8 (7 to 10) days; P = 0.035) and lower total dose of meropenem (24 (21 to 32) grams vs. 48 (42 to 60) grams; P < 0.0001). No severe adverse events related to meropenem administration in either group were observed. CONCLUSIONS: Continuous infusion of meropenem is safe and, in comparison with higher intermittent dosage, provides equal clinical outcome, generates superior bacteriological efficacy and offers encouraging alternative of antimicrobial therapy in critically ill patients.

Increasing abdominal pressure with and without PEEP: effects on intra-peritoneal, intra-organ and intra-vascular pressures.

BACKGROUND: Intra-organ and intra-vascular pressures can be used to estimate intra-abdominal pressure. The aim of this prospective, interventional study was to assess the effect of PEEP on the accuracy of pressure estimation at different measurement sites in a model of increased abdominal pressure. METHODS: Catheters for pressure measurement were inserted into the stomach, urinary bladder, peritoneal cavity, pulmonary artery and inferior vena cava of 12 pigs. The pressures were recorded simultaneously at baseline, during 10 cm H20 PEEP, external abdominal pressure (7 kg weight) plus PEEP, external abdominal pressure without PEEP, and again under baseline conditions. RESULTS (MEAN +/- SD): PEEP alone increased diastolic pulmonary artery and inferior vena cava pressure but had no effect on the other pressures. PEEP and external abdominal pressure increased intraperitoneal pressure from 6 +/- 1 mm Hg to 9 +/- 2 mm Hg, urinary bladder pressure from 6 +/- 2 mm Hg to 11 +/- 2 mm Hg (p = 0.012), intragastric pressure from 6 +/- 2 mm Hg to 11 +/- 2 mm Hg (all p

Intraoperative fluid optimization using stroke volume variation in high risk surgical patients: results of prospective randomized study.

INTRODUCTION: Stroke volume variation (SVV) is a good and easily obtainable predictor of fluid responsiveness, which can be used to guide fluid therapy in mechanically ventilated patients. During major abdominal surgery, inappropriate fluid management may result in occult organ hypoperfusion or fluid overload in patients with compromised cardiovascular reserves and thus increase postoperative morbidity. The aim of our study was to evaluate the influence of SVV guided fluid optimization on organ functions and postoperative morbidity in high risk patients undergoing major abdominal surgery. METHODS: Patients undergoing elective intraabdominal surgery were randomly assigned to a Control group (n = 60) with routine intraoperative care and a Vigileo group (n = 60), where fluid management was guided by SVV (Vigileo/FloTrac system). The aim was to maintain the SVV below 10% using colloid boluses of 3 ml/kg. The laboratory parameters of organ hypoperfusion in perioperative period, the number of infectious and organ complications on day 30 after the operation, and the hospital and ICU length of stay and mortality were evaluated. The local ethics committee approved the study. RESULTS: The patients in the Vigileo group received more colloid (1425 ml [1000-1500] vs. 1000 ml [540-1250]; P = 0.0028) intraoperatively and a lower number of hypotensive events were observed (2[1-2] Vigileo vs. 3.5[2-6] in Control; P = 0.0001). Lactate levels at the end of surgery were lower in Vigileo (1.78 +/- 0.83 mmol/l vs. 2.25 +/- 1.12 mmol/l; P = 0.0252). Fewer Vigileo patients developed complications (18 (30%) vs. 35 (58.3%) patients; P = 0.0033) and the overall number of complications was also reduced (34 vs. 77 complications in Vigileo and Control respectively; P = 0.0066). A difference in hospital length of stay was found only in per protocol analysis of patients receiving optimization (9 [8-12] vs. 10 [8-19] days; P = 0.0421). No difference in mortality (1 (1.7%) vs. 2 (3.3%); P = 1.0) and ICU length of stay (3 [2-5] vs. 3 [0.5-5]; P = 0.789) was found. CONCLUSIONS: In this study, fluid optimization guided by SVV during major abdominal surgery is associated with better intraoperative hemodynamic stability, decrease in serum lactate at the end of surgery and lower incidence of postoperative organ complications. TRIAL REGISTRATION: Current Controlled Trials ISRCTN95085011.

Esophageal Doppler-guided fluid management decreases blood lactate levels in multiple-trauma patients: a randomized controlled trial.

INTRODUCTION: Esophageal Doppler was confirmed as a useful non-invasive tool for management of fluid replacement in elective surgery. The aim of this study was to assess the effect of early optimization of intravascular volume using esophageal Doppler on blood lactate levels and organ dysfunction development in comparison with standard hemodynamic management in multiple-trauma patients. METHODS: This was a randomized controlled trial. Multiple-trauma patients with blood loss of more than 2,000 ml admitted to the intensive care unit (ICU) were randomly assigned to the protocol group with esophageal Doppler monitoring and to the control group. Fluid resuscitation in the Doppler group was guided for the first 12 hours of ICU stay according to the protocol based on data obtained by esophageal Doppler, whereas control patients were managed conventionally. Blood lactate levels and organ dysfunction during ICU stay were evaluated. RESULTS: Eighty patients were randomly assigned to Doppler and 82 patients to control treatment. The Doppler group received more intravenous colloid during the first 12 hours of ICU stay (1,667 +/- 426 ml versus 682 +/- 322 ml; p < 0.0001), and blood lactate levels in the Doppler group were lower after 12 and 24 hours of treatment than in the control group (2.92 +/- 0.54 mmol/l versus 3.23 +/- 0.54 mmol/l [p = 0.0003] and 1.99 +/- 0.44 mmol/l versus 2.37 +/- 0.58 mmol/l [p < 0.0001], respectively). No difference in organ dysfunction between the groups was found. Fewer patients in the Doppler group developed infectious complications (15 [18.8%] versus 28 [34.1%]; relative risk = 0.5491; 95% confidence interval = 0.3180 to 0.9482; p = 0.032). ICU stay in the Doppler group was reduced from a median of 8.5 days (interquartile range [IQR] 6 to16) to 7 days (IQR 6 to 11) (p = 0.031), and hospital stay was decreased from a median of 17.5 days (IQR 11 to 29) to 14 days (IQR 8.25 to 21) (p = 0.045). No significant difference in ICU and hospital mortalities between the groups was found. CONCLUSION: Optimization of intravascular volume using esophageal Doppler in multiple-trauma patients is associated with a decrease of blood lactate levels, a lower incidence of infectious complications, and a reduced duration of ICU and hospital stays.

Comparison of absolute fluid restriction versus relative volume redistribution strategy in low central venous pressure anesthesia in liver resection surgery: a randomized controlled trial.

BACKGROUNDː Lowering central venous pressure (CVP) can decrease blood loss during liver resection and it is associated with improved outcomes. Multiple CVP reducing maneuvers have been described, but direct comparison of their effectiveness and safety has never been performed. METHODSː Patients undergoing resections of two or more liver segments were equally randomized to absolute fluid restriction (AR, N.=17) or relative volume redistribution group (RR, N.=17). The ease of reaching low CVP, blood loss, morbidity and mortality were assessed. Besides, the effect of Pringle maneuver and utility of stroke volume variation (SVV) were analyzed. RESULTSː Both methods of CVP reduction were equally effective (0.7±0.9 vs. 0.9±1.0 protocolized steps in the AR and RR group; P=0.356) and safe (no difference in observed blood loss, intraoperative hemodynamic parameters, lactate levels, morbidity and mortality). Patients in the AR group received smaller amount of fluids in the pre-resection period (120 (100-150) vs. 600 (500-700) mL; P<0.001), and had slightly longer hospital stay (10 [8-14] vs. 8 [7-11]; P=0.045). Low CVP was predicted by SVV>10% with 81.4% sensitivity and 77.1% specificity. Reduced blood loss and transfusion rate was observed when Pringle maneuver was used. CONCLUSIONSː In our study, absolute fluid restriction and relative volume redistribution seemed to be equally effective and safe methods of lowering CVP in patients undergoing liver resection. According to our data high SVV might be considered as a low CVP replacement. Pringle maneuver reduced blood loss and transfusion requirement.

Splanchnic vasoregulation during mesenteric ischemia and reperfusion in pigs.

We evaluated the hepatic arterial buffer response (HABR) to portal vein (PV) occlusion during 2 h of reduced superior mesenteric arterial blood flow (median 2 mL min(-1) kg(-1), range of 1-3 mL min(-1) kg(-1)) and 1 h of reperfusion in seven pigs and in seven controls. In animals with reduced mesenteric blood flow, celiac trunk blood flow (Qtr) increased during mesenteric hypoperfusion from 4 +/- 1 mL min(-1) kg(-1) (mean +/- SD) to 16 +/- 3 mL min(-1) kg(-1) (P = 0.028), and hepatic arterial blood flow (Qha) increased from 2 +/- 1 to 10 +/- 4 mL min(-1) kg(-1) (P= 0.018). The extra-hepatic fraction of Qtr (Qtr-Qha) also increased (P = 0.028). In controls, Qtr and Qha also increased, but to lower levels. At baseline, acute PV occlusion increased Qha by 5.0 +/- 2.8 mL min(-1) kg(-1) (P < 0.001), whereas Qtr-Qha decreased by 1.6 +/- 1.6 mL min(-1) kg(-1) (P = 0.007). After 120 min of reduced mesenteric blood flow, the HABR was exhausted (change in Qha to PV occlusion of 0.7 +/- 1.6 mL min(-1) kg(-1) [P= 0.27]). The efficacy of the HABR was also reduced in controls animals. Despite increased cardiac output, all flows from the celiac trunk decreased during reperfusion (P = 0.028) and the HABR partially recovered. We conclude that reduced mesenteric perfusion impairs the HABR, which recovers only partially after reperfusion. The distribution of the increased celiac trunk flow secondary to PV occlusion ranges from increased HABR and decreased non-hepatic blood flow (a steal) to decreased hepatic arterial blood flow and increased non-hepatic blood flow (an inverse steal).