Early Thromboembolic Stroke Risk of Postoperative Atrial Fibrillation Following Cardiac Surgery.

OBJECTIVE: The authors aimed to study the association between postoperative atrial fibrillation (POAF) and thromboembolic stroke and to determine risk factors for thromboembolic stroke after cardiac surgery. DESIGN: The authors performed a secondary analysis from a randomized controlled trial (GRIP-COMPASS). The patients with thromboembolic stroke were compared with those without thromboembolic stroke, and the difference in the incidence of POAF between these groups was assessed. Odds ratios (OR) were calculated using logistic regression analyses. Brain imaging was studied for the occurrence of thromboembolic stroke during hospital admission, and POAF was monitored for seven days. To assess which characteristics were associated with occurrence of thromboembolic stroke, stepwise backward regression analysis was performed. PARTICIPANTS: All adult consecutive cardiac surgery patients admitted postoperatively to the intensive care unit. SETTING: Academic tertiary care medical center. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of the 910 patients included in this study, 26 patients (2.9%) had a thromboembolic stroke during hospital admission. The incidence of POAF during the first seven days after cardiac surgery in those with thromboembolic stroke was 65%, compared with 39% in those without thromboembolic stroke: adjusted OR 3.01 (95% confidence interval, 1.13-8.00). POAF, a history of peripheral vascular disease, a higher EuroSCORE, and a longer duration of surgery were associated with thromboembolic stroke. CONCLUSIONS: POAF within seven days after cardiac surgery was associated with a three-fold increased risk for a thromboembolic stroke during hospital admission. Expeditious treatment of POAF may, therefore, reduce early stroke risk after cardiac surgery.

Computer-guided normal-low versus normal-high potassium control after cardiac surgery: No impact on atrial fibrillation or atrial flutter.

INTRODUCTION: This study was designed to determine the effect of 2 different potassium regulation strategies with different targets (within the reference range) on atrial fibrillation (AF) or atrial flutter (AFL) in a cohort of intensive care unit patients after cardiac surgery. METHODS: The GRIP-COMPASS study was a prospective double-blinded interventional study in 910 patients after cardiac surgery (coronary artery bypass grafting and/or valvular surgery). Patients were assigned to either the normal-low potassium target (nLP group, 4.0 mmol/L) or the normal-high potassium target (nHP group, 4.5 mmol/L) in alternating blocks of 50 patients. Potassium levels were regulated using a validated computer-assisted potassium replacement protocol (GRIP-II). The primary end point was the incidence of AF/AFL on a 12-lead electrocardiogram during the first postoperative week. RESULTS: Of the 910 patients, 447 were assigned to the nLP group; and 463, to the nHP group, with no baseline differences between the 2 groups. The mean daily administered dose of potassium was 30 ± 23 mmol (nLP) versus 52 ± 27 mmol (nHP) (P < .001), which resulted in mean intensive care unit potassium concentration of 4.22 ± 0.36 mmol/L and 4.33 ± 0.34 mmol/L, respectively (P < .001). The incidence of AF/AFL after cardiac surgery did not differ: 38% in the nLP group and 41% in the nHP group. Also in several subgroups (eg, patients not known with prior AF/AFL or with valve surgery), there were no differences. CONCLUSIONS: There were no differences in incidence of AF/AFL with 2 potassium regulation strategies with different potassium targets and different amounts of potassium administered in patients after cardiac surgery.

The relationship between serum potassium, potassium variability and in-hospital mortality in critically ill patients and a before-after analysis on the impact of computer-assisted potassium control.

INTRODUCTION: The relationship between potassium regulation and outcome is not known. Our first aim in the present study was to determine the relationship between potassium level and variability in (ICU) stay and outcome. The second aim was to evaluate the impact of a computer-assisted potassium regulation protocol. METHODS: We performed a retrospective before-after study including all patients >15 years of age admitted for more than 24 hours to the ICU of our university teaching hospital between 2002 and 2011. Potassium control was fully integrated with computerized glucose control (glucose and potassium regulation program for intensive care patients (GRIP-II)). The potassium metrics that we determined included mean potassium, potassium variability (defined as the standard deviation of all potassium levels) and percentage of ICU time below and above the reference range (3.5 through 5.0 mmol/L). These metrics were determined for the first ICU day (early phase) and the subsequent ICU days (late phase; that is, day 2 to day 7). We also compared potassium metrics and in-hospital mortality before and after GRIP-II was implemented in 2006. RESULTS: Of all 22,347 ICU admissions, 10,451 (47%) patients were included. A total of 206,987 potassium measurements were performed in these patients. Glucose was regulated by GRIP-II in 4,664 (45%) patients. The overall in-hospital mortality was 22%. There was a U-shaped relationship between the potassium level and in-hospital mortality (P <0.001). Moreover, potassium variability was independently associated with outcome. After implementation of GRIP-II, in the late phase the time below 3.5 mmol/L decreased from 9.2% to 3.9% and the time above 5.0 mmol/L decreased from 6.1% to 5.2%, and potassium variability decreased from 0.31 to 0.26 mmol/L (all P <0.001). The overall decrease in in-hospital mortality from 23.3% before introduction of GRIP-II to 19.9% afterward (P <0.001) was not related to a specific potassium subgroup. CONCLUSIONS: Hypokalemia, hyperkalemia and potassium variability were independently associated with increased mortality. Computerized potassium control clearly resulted in improved potassium metrics.

Effect of high-dose dexamethasone on perioperative lactate levels and glucose control: a randomized controlled trial.

INTRODUCTION: Blood lactate levels are increasingly used to monitor patients. Steroids are frequently administered to critically ill patients. However, the effect of steroids on lactate levels has not been adequately investigated. We studied the effect of a single intraoperative high dose of dexamethasone on lactate and glucose levels in patients undergoing cardiac surgery. METHODS: The Dexamethasone for Cardiac Surgery (DECS) trial was a multicenter randomized trial on the effect of dexamethasone 1 mg/kg versus placebo on clinical outcomes after cardiac surgery in adults. Here we report a pre-planned secondary analysis of data from DECS trial participants included at the University Medical Center Groningen. The use of a computer-assisted glucose regulation protocol--Glucose Regulation for Intensive care Patients (GRIP)--was part of routine postoperative care. GRIP aimed at glucose levels of 4 to 8 mmol/L. Primary outcome parameters were area under the lactate and glucose curves over the first 15 hours of ICU stay (AUC15). ICU length of stay and mortality were observed as well. RESULTS: The primary outcome could be determined in 497 patients of the 500 included patients. During the first 15 hours of ICU stay, lactate and glucose levels were significantly higher in the dexamethasone group than in the placebo group: lactate AUC15 25.8 (13.1) versus 19.9 (11.2) mmol/L × hour, P <0.001 and glucose AUC15 126.5 (13.0) versus 114.4 (13.9) mmol/L × hour, P <0.001. In this period, patients in the dexamethasone group required twice as much insulin compared with patients who had received placebo. Multivariate and cross-correlation analyses suggest that the effect of dexamethasone on lactate levels is related to preceding increased glucose levels. Patients in the placebo group were more likely to stay in the ICU for more than 24 hours (39.2%) compared with patients in the dexamethasone group (25.0%, P = 0.001), and 30-day mortality rates were 1.6% and 2.4%, respectively (P = 0.759). CONCLUSIONS: Intraoperative high-dose dexamethasone increased postoperative lactate and glucose levels in the first 15 hours of ICU stay. Still, patients in the dexamethasone group had a shorter ICU length of stay and similar mortality compared with controls. TRIAL REGISTRATION: ClinicalTrials.gov NCT00293592 . Registered 16 February 2006.

Prognostic value of admission glycosylated hemoglobin and glucose in nondiabetic patients with ST-segment-elevation myocardial infarction treated with percutaneous coronary intervention.

BACKGROUND: In nondiabetic patients with ST-segment-elevation myocardial infarction, acute hyperglycemia is associated with adverse outcome. Whether this association is due merely to hyperglycemia as an acute stress response or whether longer-term glycometabolic derangements are also involved is uncertain. It was our aim to determine the association between both acute and chronic hyperglycemia (hemoglobin A(1c) [HbA(1c)]) and outcome in nondiabetic patients with ST-segment-elevation myocardial infarction. METHODS AND RESULTS: This observational study included consecutive patients (n=4176) without known diabetes mellitus admitted with ST-segment-elevation myocardial infarction. All patients were treated with primary percutaneous intervention. Both glucose and HbA(1c) were measured on admission. Main outcome measure was total long-term mortality; secondary outcome measures were 1-year mortality and enzymatic infarct size. One-year mortality was 4.7%, and mortality after total follow-up (3.3 ± 1.5 years) was 10%. Both elevated HbA(1c) levels (P<0.001) and elevated admission glucose (P<0.001) were associated with 1-year and long-term mortality. After exclusion of early mortality (within 30 days), HbA(1c) remained associated with long-term mortality (P<0.001), whereas glucose lost significance (P=0.09). Elevated glucose, but not elevated HbA(1c), was associated with larger infarct size. After multivariate analysis, HbA(1c) (hazard ratio, 1.2 per interquartile range; P<0.01), but not glucose, was independently associated with long-term mortality. CONCLUSIONS: In nondiabetic patients with ST-segment-elevation myocardial infarction, both elevated admission glucose and HbA(1c) levels were associated with adverse outcome. Both of these parameters reflect different patient populations, and their association with outcome is probably due to different mechanisms. Measurement of both parameters enables identification of these high-risk groups for aggressive secondary risk prevention.

Determinants of renal potassium excretion in critically ill patients: the role of insulin therapy.

OBJECTIVES: Insulin administration lowers plasma potassium concentration by augmenting intracellular uptake of potassium. The effect of insulin administration on renal potassium excretion is unclear. Some studies suggest that insulin has an antikaliuretic effect although plasma potassium levels were poorly controlled. Since the introduction of glycemic control in the intensive care unit, insulin use has increased. We examined the relation between administered insulin and renal potassium excretion in critically ill patients under computer-assisted glucose and potassium regulation. DESIGN: Prospective observational study. SETTING: Twelve-bed surgical intensive care unit of a university teaching hospital. PATIENTS: Consecutive intensive care unit patients. INTERVENTIONS: Potassium and glucose levels were regulated by a computer-assisted decision support system. Both potassium and insulin were continuously administered by syringe pump. MEASUREMENTS AND MAIN RESULTS: Renal potassium excretion was measured daily in the 24-hr urine collections. The 24-hr urinary samples of patients with kidney failure or on renal replacement therapy were excluded. Multivariate analysis with potassium excretion as the dependent variable was performed. In 178 consecutive patients, 1,456 24-hr urinary samples, were analyzed. Mean ± SD plasma potassium was 4.2 ± 0.3 mmol/L, with 79 ± 46 mmol/d of potassium administered and a mean insulin dose of 53 ± 38 U/day. Renal potassium excretion was 126 ± 51 mmol/day. After multivariate analysis correcting for relevant variables (including diuretics, pH, potassium levels and renal sodium excretion), insulin administration was independently and positively associated with renal potassium excretion. Other significant variables were potassium levels, potassium administration, renal sodium and chloride excretion, creatinine clearance, diuretic therapy, pH, known diabetes and intensive care unit admission day (R = .52; p <. 001). CONCLUSION: Insulin administration is associated with an increase in the renal potassium excretion in critically ill patients.

Guidelines for Perioperative Care for Liver Transplantation: Enhanced Recovery After Surgery (ERAS) Recommendations.

BACKGROUND: Enhanced Recovery After Surgery (ERAS) is a multimodal, evidence-based, program of care developed to minimize the response to surgical stress, associated with reduced perioperative morbidity and hospital stay. This study presents the specific ERAS Society recommendations for liver transplantation (LT) based on the best available evidence and on expert consensus. METHODS: PubMed and ClinicalTrials.gov were searched in April 2019 for published and ongoing randomized clinical trials on LT in the last 15 y. Studies were selected by 5 independent reviewers and were eligible if focusing on each validated ERAS item in the area of adult LT. An e-Delphi method was used with an extended interdisciplinary panel of experts to validate the final recommendations. RESULTS: Forty-three articles were included in the systematic review. A consensus was reached among experts after the second round. Patients should be screened for malnutrition and treated whenever possible. Prophylactic nasogastric intubation and prophylactic abdominal drainage may be omitted, and early extubation should be considered. Early oral intake, mobilization, and multimodal-balanced analgesia are recommended. CONCLUSIONS: The current ERAS recommendations were elaborated based on the best available evidence and endorsed by the e-Delphi method. Nevertheless, prospective studies need to confirm the clinical use of the suggested protocol.

Metabolic and neurologic sequelae in a patient with long-standing anorexia nervosa who presented with septic shock and deep hypoglycemia.

OBJECTIVE: To report the case of a 48-year female with chronic remitting anorexia nervosa who was found comatose at home and admitted to our hospital with a deep hypoglycemia (glucose level 0.6 mmol/L; 11 mg/dL) and septic shock secondary to a bilateral pneumonia. METHOD: Case report. RESULTS: After admission to the critical care unit, she further displayed a number of pronounced complications known to be associated with anorexia, including hypophosphatemia, disturbed liver functions and depression of all three hematological cell lines. The neurological recovery of the patient was complicated by encephalopathy and transient tetraparesis. With initial deep hypoglycemia at presentation and persisting coma, magnetic resonance imaging performed 5 days later did not demonstrate characteristic post-hypoglycemic abnormalities. Neuroradiological examination did however reveal the presence of extensive calcifications in the basal ganglia known as Fahr's syndrome. DISCUSSION: The potential relation between anorexia nervosa and Fahr syndrome has not been described before. The fact that this patient survived a glucose level that is usually associated with a very poor outcome is probably related to its special origin.

Clinical correlates of arterial lactate levels in patients with ST-segment elevation myocardial infarction at admission: a descriptive study.

INTRODUCTION: Blood lactate measurements can be used as an indicator of hemodynamic impairment and relate to mortality in various forms of shock. Little is known at the moment concerning the clinical correlates of systemic lactate in patients with ST-segment elevation myocardial infarction (STEMI). METHODS: To assess the relation of systemic arterial lactate levels in STEMI patients with clinical correlates at presentation in the catheterization laboratory, we measured arterial lactate levels with a rapid point-of-care technique, immediately following femoral sheath insertion. The study population (n = 1,176) was divided into tertiles with lactate levels ≤ 1.1 (n = 410), 1.2 to 1.7 (n = 398) and ≥ 1.8 mmol/l (n = 368). We compared both baseline characteristics and outcome measures of the three lactate groups. RESULTS: Factors independently associated with higher lactate levels were hypotension, heart rate, thrombolysis in myocardial infarction (TIMI) flow 0 to 1, diabetes and non-smoking. Mortality at 30 days in the three groups was 2.0%, 1.5% and 6.5%. The latter group also showed lower blush grades and greater enzymatic infarct sizes. An intra aortic balloon pump (IABP) was used more frequently in patients with higher lactate levels (4.2%, 7.6% and 14.7%). CONCLUSIONS: In STEMI patients, impaired hemodynamics, worse TIMI flow and non-smoking were related to increased arterial lactate levels. Higher lactate levels were independently related with 30-day mortality and an overall worse response to percutaneous coronary intervention (PCI). In particular, acute mortality was related to admission lactates ≥ 1.8 mmol/L. Point-of-care measurement of arterial lactate at admission in patients with STEMI has the potential to improve acute risk stratification.

Trial design: Computer guided normal-low versus normal-high potassium control in critically ill patients: Rationale of the GRIP-COMPASS study.

BACKGROUND: Potassium depletion is common in hospitalized patients and can cause serious complications such as cardiac arrhythmias. In the intensive care unit (ICU) the majority of patients require potassium suppletion. However, there are no data regarding the optimal control target in critically ill patients. After open-heart surgery, patients have a strongly increased risk of atrial fibrillation or atrial flutter (AFF). In a novel trial design, we examined if in these patients different potassium control-targets within the normal range may have different effects on the incidence of AFF. METHODS/DESIGN: The "computer-driven Glucose and potassium Regulation program in Intensive care Patients with COMparison of PotASSium targets within normokalemic range (GRIP-COMPASS) trial" is a single-center prospective trial in which a total of 1200 patients are assigned to either a potassium control-target of 4.0 mmol/L or 4.5 mmol/L in consecutive alternating blocks of 50 patients each. Potassium levels are regulated by the computer-assisted potassium suppletion algorithm called GRIP-II (Glucose and potassium regulation for Intensive care Patients). Primary endpoint is the in-hospital incidence of AFF after cardiac surgery. Secondary endpoints are: in-hospital AFF in medical patients or patients after non-cardiac surgery, actually achieved potassium levels and their variation, electrolyte and glucose levels, potassium and insulin requirements, cumulative fluid balance, (ICU) length of stay, ICU mortality, hospital mortality and 90-day mortality. DISCUSSION: The GRIP-COMPASS trial is the first controlled clinical trial to date that compares potassium targets. Other novel methodological elements of the study are that it is performed in ICU patients where both targets are within the normal range and that a computer-assisted potassium suppletion algorithm is used. TRIAL REGISTRATION: NCT 01085071 at ClinicalTrials.gov.

Implementation and evaluation of a nurse-centered computerized potassium regulation protocol in the intensive care unit--a before and after analysis.

BACKGROUND: Potassium disorders can cause major complications and must be avoided in critically ill patients. Regulation of potassium in the intensive care unit (ICU) requires potassium administration with frequent blood potassium measurements and subsequent adjustments of the amount of potassium administrated. The use of a potassium replacement protocol can improve potassium regulation. For safety and efficiency, computerized protocols appear to be superior over paper protocols. The aim of this study was to evaluate if a computerized potassium regulation protocol in the ICU improved potassium regulation. METHODS: In our surgical ICU (12 beds) and cardiothoracic ICU (14 beds) at a tertiary academic center, we implemented a nurse-centered computerized potassium protocol integrated with the pre-existent glucose control program called GRIP (Glucose Regulation in Intensive Care patients). Before implementation of the computerized protocol, potassium replacement was physician-driven. Potassium was delivered continuously either by central venous catheter or by gastric, duodenal or jejunal tube. After every potassium measurement, nurses received a recommendation for the potassium administration rate and the time to the next measurement. In this before-after study we evaluated potassium regulation with GRIP. The attitude of the nursing staff towards potassium regulation with computer support was measured with questionnaires. RESULTS: The patient cohort consisted of 775 patients before and 1435 after the implementation of computerized potassium control. The number of patients with hypokalemia (<3.5 mmol/L) and hyperkalemia (>5.0 mmol/L) were recorded, as well as the time course of potassium levels after ICU admission. The incidence of hypokalemia and hyperkalemia was calculated. Median potassium-levels were similar in both study periods, but the level of potassium control improved: the incidence of hypokalemia decreased from 2.4% to 1.7% (P < 0.001) and hyperkalemia from 7.4% to 4.8% (P < 0.001). Nurses indicated that they considered computerized potassium control an improvement over previous practice. CONCLUSIONS: Computerized potassium control, integrated with the nurse-centered GRIP program for glucose regulation, is effective and reduces the prevalence of hypo- and hyperkalemia in the ICU compared with physician-driven potassium regulation.

Anesthesia for combined liver-thoracic transplantation.

The combined transplantation of a thoracic organ and the liver is performed in patients with dual-organ failure in whom survival is not expected with single-organ transplantation alone. Although uncommonly performed, the number of combined liver-lung and liver-heart transplants is increasing. Anesthetic management of this complex procedure is challenging. Major blood loss, prolonged operation time, difficult weaning of cardiopulmonary bypass and coagulation disturbances are common. Despite the complexity of surgery, the outcome is comparable to single-organ transplant.

Health technology assessment review: Computerized glucose regulation in the intensive care unit--how to create artificial control.

Current care guidelines recommend glucose control (GC) in critically ill patients. To achieve GC, many ICUs have implemented a (nurse-based) protocol on paper. However, such protocols are often complex, time-consuming, and can cause iatrogenic hypoglycemia. Computerized glucose regulation protocols may improve patient safety, efficiency, and nurse compliance. Such computerized clinical decision support systems (Cuss) use more complex logic to provide an insulin infusion rate based on previous blood glucose levels and other parameters. A computerized CDSS for glucose control has the potential to reduce overall workload, reduce the chance of human cognitive failure, and improve glucose control. Several computer-assisted glucose regulation programs have been published recently. In order of increasing complexity, the three main types of algorithms used are computerized flowcharts, Proportional-Integral-Derivative (PID), and Model Predictive Control (MPC). PID is essentially a closed-loop feedback system, whereas MPC models the behavior of glucose and insulin in ICU patients. Although the best approach has not yet been determined, it should be noted that PID controllers are generally thought to be more robust than MPC systems. The computerized Cuss that are most likely to emerge are those that are fully a part of the routine workflow, use patient-specific characteristics and apply variable sampling intervals.

Estimation of sodium and chloride storage in critically ill patients: a balance study.

BACKGROUND: Nonosmotic sodium storage has been reported in animals, healthy individuals and patients with hypertension, hyperaldosteronism and end-stage kidney disease. Sodium storage has not been studied in ICU patients, who frequently receive large amounts of sodium chloride-containing fluids. The objective of our study was to estimate sodium that cannot be accounted for by balance studies in critically ill patients. Chloride was also studied. We used multiple scenarios and assumptions for estimating sodium and chloride balances. METHODS: We retrospectively analyzed patients admitted to the ICU after cardiothoracic surgery with complete fluid, sodium and chloride balance data for the first 4 days of ICU treatment. Balances were obtained from meticulously recorded data on intake and output. Missing extracellular osmotically active sodium (MES) was calculated by subtracting the expected change in plasma sodium from the observed change in plasma sodium derived from balance data. The same method was used to calculate missing chloride (MEC). To address considerable uncertainties on the estimated extracellular volume (ECV) and perspiration rate, various scenarios were used in which the size of the ECV and perspiration were varied. RESULTS: A total of 38 patients with 152 consecutive ICU days were analyzed. In our default scenario, we could not account for 296 ± 35 mmol of MES in the first four ICU days. The range of observed MES in the five scenarios varied from 111 ± 27 to 566 ± 41 mmol (P < 0.001). A cumulative value of 243 ± 46 mmol was calculated for MEC in the default scenario. The range of cumulative MEC was between 62 ± 27 and 471 ± 56 mmol (P = 0.001 and P = 0.003). MES minus MEC varied from 1 ± 51 to 123 ± 33 mmol in the five scenarios. CONCLUSIONS: Our study suggests considerable disappearance of osmotically active sodium in critically ill patients and is the first to also suggest rather similar disappearance of chloride from the extracellular space. Various scenarios for insensible water loss and estimated size for the ECV resulted in considerable MES and MEC, although these estimates showed a large variation. The mechanisms and the tissue compartments responsible for this phenomenon require further investigation.

The impact of a reduced dose of dexamethasone on glucose control after coronary artery bypass surgery.

BACKGROUND: Intensive insulin therapy to maintain normoglycemia after cardiac surgery reduces morbidity and mortality. We investigated the magnitude and duration of hyperglycemia caused by dexamethasone administered after cardiopulmonary bypass. METHODS: A single-center before-after cohort study was performed. All consecutive patients undergoing coronary artery bypass grafting with cardiopulmonary bypass during a 6-month period were included. Insulin administration was guided by a sliding scale protocol. Halfway the observation period, the dexamethasone protocol was changed. The single dose (1D) group received a pre-operative dose of dexamethasone of 1 mg/kg. The double dose group (2D) received an additional dose of 0.5 mg/kg of dexamethasone post-operatively at ICU admission. RESULTS: We included 116 patients in the 1D group and 158 patients in the 2D group. There were no significant baseline differences between the groups. Median Euroscore was 5. In univariable analysis, the glucose level was different between groups 1D and 2D at 4, 6, 9, 12 and 24 hours after ICU admission (all p < 0.001). Insulin infusion was higher in the 1D group. Corrected for insulin dose in multivariable linear analysis, the difference in glucose between the 1D and 2D groups was 1.5 mmol/L (95% confidence interval 1.0-2.0, p < 0.001) 12 hours after ICU admission. CONCLUSION: Dexamethasone exerts a hyperglycemic effect in cardiac surgery patients. Patients receiving high-dose corticosteroid therapy should be monitored and treated more intensively for hyperglycemic episodes.

Postoperative fluid retention after heart surgery is accompanied by a strongly positive sodium balance and a negative potassium balance.

The conventional model on the distribution of electrolyte infusions states that water will distribute proportionally over both the intracellular (ICV) and extracellular (ECV) volumes, while potassium homes to the ICV and sodium to the ECV Therefore, total body potassium is the most accurate measure of ICV and thus potassium balances can be used to quantify changes in ICV In cardiothoracic patients admitted to the ICU we performed complementary balance studies to measure changes in ICV and ECV In 39 patients, fluid, sodium, potassium, and electrolyte-free water (EFW) balances were determined to detect changes in ICV and ECV Cumulatively over 4 days, these patients received a mean ± SE infusion of 14.0 ± 0.6 L containing 1465 ± 79 mmol sodium, 196 ± 11 mmol potassium and 2.1 ± 0.1 L EFW This resulted in strongly positive fluid (4.0 ± 0.6 L) and sodium (814 ± 75 mmol) balances but in negative potassium (-101 ± 14 mmol) and EFW (-1.1 ± 0.2 L) balances. We subsequently compared potassium balances (528 patients) and fluid balances (117 patients) between patients who were assigned to either a 4.0 or 4.5 mmol/L blood potassium target. Although fluid balances were similar in both groups, the additionally administered potassium (76 ± 23 mmol) in the higher target group was fully excreted by the kidneys (70 ± 23 mmol). These findings indicate that even in the context of rapid and profound volume expansion neither water nor potassium moves into the ICV.

Computer-assisted glucose regulation during rapid step-wise increases of parenteral nutrition in critically ill patients: a proof of concept study.

BACKGROUND: Early delivery of calories is important in critically ill patients, and the administration of parenteral nutrition (PN) is sometimes required to achieve this goal. However, PN can induce acute hyperglycemia, which is associated with adverse outcome. We hypothesized that initiation of PN using a rapid "step-up" approach, coupled with a computerized insulin-dosing protocol, would result in a desirable caloric intake within 24 hours without causing hyperglycemia. METHODS: In our surgical intensive care unit (ICU), glucose is regulated by a nurse-centered computerized glucose regulation program. When adequate enteral feeding was not possible, PN was initiated according to a simple step-up rule at an infusion rate of 10 mL/h (approximately 10 kcal/h) and subsequently increased by steps of 10 mL/h every 4 hours, provided glucose was <10 mmol/L, until the target caloric intake (1 kcal/kg/h) was reached. All glucose levels and insulin doses were collected during the step-up period and for 24 hours after achieving target feeding. RESULTS: In all 23 consecutive patients requiring PN, mean intake was 1 kcal/kg/h within 24 hours. Of the 280 glucose samples during the 48-hour study period, mean ± standard deviation glucose level was 7.4 ± 1.4 mmol/L. Only 4.5% of glucose measurements during the step-up period were transiently ≥10 mmol/L. After initiating PN, the insulin requirement rose from 1.1 ± 1.5 units/h to 2.9 ± 2.5 units/h (P < .001). CONCLUSIONS: This proof of concept study shows that rapid initiation of PN using a step-up approach coupled with computerized glucose control resulted in adequate caloric intake within 24 hours while maintaining adequate glycemic control.