sodium-bicarbonate and Critical-Illness

Sodium bicarbonate is a frequently used electrolyte for the acute treatment of metabolic acidosis in critically ill patients. We performed a systematic review and meta-analysis to determine the effect of sodium bicarbonate on hemodynamics, gas exchange and oximetry in critically children.. A systematic review of published manuscripts was conducted to identify studies of children who received sodium bicarbonate as part of the treatment for metabolic acidosis. A meta-analysis was then conducted to determine the impact of sodium bicarbonate on hemodynamics, gas exchange and oximetry. The following parameters were captured: base deficit, heart rate, mean arterial pressure, blood concentration of carbon dioxide, blood concentration of hydrogen ion, and pulse oximetry.. A total of six studies with 341 patients were included in the analyses. All included studies were completed in critically ill infants with a mean age of 1.1 months. The mean dose of sodium bicarbonate was 1.7 meq/kg with a mean time of 67 min prior to repeat hemodynamics being collected after sodium bicarbonate administration. Base deficit significantly improved with a decrease of 2.80 (. Sodium bicarbonate has a statistically significant but not clinically significant impact on partial pressure of carbon dioxide and base deficit 60 min after sodium bicarbonate administration in critically ill infants. There is no difference noted in pH, partial pressure of oxygen, or saturation by pulse oximetry.

Topics: Acidosis; Carbon Dioxide; Child; Critical Illness; Hemodynamics; Humans; Hydrogen-Ion Concentration; Infant; Oxygen; Sodium Bicarbonate

Topics: Acidosis; Acute Kidney Injury; Buffers; Critical Care; Critical Illness; Humans; Sodium Bicarbonate

We aimed to assess the biochemical and physiological effects, clinical efficacy, and safety, of intravenous NaHCO3 therapy in critically ill patients with acute metabolic acidosis.. We conducted a scoping review concerning the biochemical and physiological effects of NaHCO3 (PART A), and a systematic review regarding clinical efficacy (PART B). We searched MEDLINE in Part A and MEDLINE, EMBASE, Cochrane, the National Institute of Health Clinical Trials Register, and the WHOICTRP for randomised controlled trials in Part B.. Twelve studies in Part A and two trials in Part B fulfilled the eligibility criteria. Intravenous NaHCO3 increased blood pH, base excess, serum bicarbonate, sodium, and PaCO2 during and after administration and decreased anion gap and potassium value. For clinical efficacy, only one study contributed to the effect estimate. The risk ratio (RR) for all-cause mortality was 0.83 (95% confidence interval, 0.68 to 1.02), and the risk of hypocalcaemia was increased in the bicarbonate group (RR 1.65, 95% confidence interval 1.09 to 2.50). There were inadequate data on hemodynamic indices.. Given the lack of data on the effects of intravenous NaHCO3 therapy to support its clinical use and the frequency of bicarbonate therapy, a program of investigation appears justified.

Topics: Acidosis; Beryllium; Critical Illness; Humans; Potassium; Sodium; Sodium Bicarbonate; Treatment Outcome

Acute kidney injury (AKI) is a common sequela of critical illness. Clinical manifestation of AKI varies and can include electrolyte abnormalities, anion gap, or non-anion-gap metabolic acidosis. Treatment strategies require careful identification of the cause of the AKI, relying on both clinical history and laboratory data. Once the cause has been identified, treatment can then target the underlying cause and avoid further insults. Conservative management should first be attempted for patients with AKI. If conservative management fails, renal replacement therapy or hemodialysis can be used.

Topics: Acute Kidney Injury; Critical Illness; Diuretics; Emergency Medicine; Emergency Service, Hospital; Fluid Therapy; Humans; Renal Replacement Therapy; Sodium Bicarbonate; Vasoconstrictor Agents; Water-Electrolyte Imbalance

The management of airway secretions in the mechanically ventilated patient is a routine task throughout all intensive care units. The current treatment strategies are primarily based on anecdotal experiences rather than statistical evidence. Areas covered: This review article evaluates the data from published trials surrounding mucoactive agents and their use in the critically ill patient population. We completed an extensive search through PUBMED and CINAHL via EBSCO, along with the Cochran library to find all trials using mucoactive agents in the critically ill patient population. Expert commentary: Overall, the role of mucoactive agents in the intensive care unit is a field within pulmonary critical care that is in need of evidence-based recommendations. We feel that there is great opportunity for investigators to evaluate different mucoactive therapies in this patient population and to determine their effect on clinical outcomes.

Topics: Acetylcysteine; Ambroxol; Critical Care; Critical Illness; Deoxyribonuclease I; Expectorants; Guaifenesin; Humans; Intensive Care Units; Mannitol; Mucociliary Clearance; Potassium Dichromate; Recombinant Proteins; Respiration, Artificial; Saline Solution, Hypertonic; Sodium Bicarbonate

Topics: Acute Kidney Injury; Contrast Media; Critical Illness; Drug-Related Side Effects and Adverse Reactions; Fluid Therapy; Humans; Membranes, Artificial; Osmolar Concentration; Pharmaceutical Preparations; Prognosis; Renal Dialysis; Risk Factors; Sodium Bicarbonate; Sodium Chloride

The recognition and management of acid-base disorders is a commonplace activity for intensivists. Despite the frequency with which non-bicarbonate-losing forms of metabolic acidosis such as lactic acidosis occurs in critically ill patients, treatment is controversial. This article describes the properties of several buffering agents and reviews the evidence for their clinical efficacy. The evidence supporting and refuting attempts to correct arterial pH through the administration of currently available buffers is presented.

Topics: Acid-Base Imbalance; Acidosis; Buffers; Critical Care; Critical Illness; Dichloroacetic Acid; Humans; Sodium Bicarbonate; Treatment Outcome; Tromethamine

Renal and electrolyte problems are common in patients in the ICU. Several advances that occurred in the recent past have been incorporated in the diagnosis and management of these disorders and were reviewed in this article. Unfortunately, many important questions remain unanswered, especially in the area of ARF, where new therapies are anxiously awaited to make the transition from bench to bedside. Better studies are sorely needed to define the best approach to dialysis in patients who have ARF.

Topics: Acid-Base Imbalance; Acute Kidney Injury; Alkalosis; Amphotericin B; Antifungal Agents; Cardiotonic Agents; Critical Care; Critical Illness; Dopamine; Humans; Kidney Diseases; Renal Dialysis; Sodium Bicarbonate

This article reviews the current body of knowledge regarding lactic acidosis in critically ill patients. The classification of disordered lactate metabolism and its pathogenesis are examined. The utility of lactate as a metabolic monitor of shock is examined and current therapeutic strategies in the treatment of patients suffering from lactic acidosis are extensively reviewed. The paper is designed to integrate basic concepts with a current approach to lactate in critical illness that the clinician can use at the bedside.. Comprehensive review of the available, basic science, medical, surgical, and critical care literature.. The severity of lactic acidosis in critically ill patients correlates with overall oxygen debt and survival. Lactate determinations may be useful as an ongoing monitor of perfusion as resuscitation proceeds. Therapy of critically ill patients with lactic acidosis is designed to maximize oxygen delivery in order to reduce tissue hypoxia by increasing cardiac index, while maintaining hemoglobin concentration. Buffering agents have not been shown to materially affect outcome from lactic acidosis caused by shock. The benefits of other specific therapies designed to reduce the severity of lactic acidosis remain unproven.

Topics: Acidosis, Lactic; Bicarbonates; Blood Gas Analysis; Carbonates; Citric Acid Cycle; Critical Illness; Drug Combinations; Fluid Therapy; Glycolysis; Hemodynamics; Humans; Lactates; Lactic Acid; Metabolic Clearance Rate; Monitoring, Physiologic; Oxygen Consumption; Predictive Value of Tests; Severity of Illness Index; Shock; Sodium; Sodium Bicarbonate; Survival Rate

Long-term prognosis of ICU survivors is a major issue. Severe acidemia upon ICU admission is associated with very high short-term mortality. Since the long-term prognosis of these patients is unknown, we aimed to determine the long-term health-related quality of life and survival of these patients.. Post hoc analysis of a multicenter, randomized, controlled trial.. Twenty-six French ICUs.. Day 28 critically ill survivors admitted with severe acidemia and enrolled in the BICAR-ICU trial.. Sodium bicarbonate versus no sodium bicarbonate infusion according to the randomization group.. The primary outcome was health-related quality of life (HRQoL) measured with the 36-item Short Form Health Survey and the EuroQol 5-D questionnaires. Secondary outcomes were mortality, end-stage renal disease treated with renal replacement therapy or renal transplantation, place of residence, professional status, and ICU readmission. HRQoL was reduced with no significant difference between the two groups. HRQoL was reduced particularly in the role-physical health domain (64/100 ± 41 in the control group and 49/100 ± 43 in the bicarbonate group, p = 0.28), but it was conserved in the emotional domains (96/100 ± 19 in the control group and 86/100 ± 34 in the bicarbonate group, p = 0.44). Forty percent of the survivors described moderate to severe problems walking, and half of the survivors described moderate to severe problems dealing with usual activities. Moderate to severe anxiety or depression symptoms were present in one third of the survivors. Compared with the French general population, HRQoL was decreased in the survivors mostly in the physical domains. The 5-year overall survival rate was 30% with no significant difference between groups.. Long-term HRQoL was decreased in both the control and the sodium bicarbonate groups of the BICAR-ICU trial and was lower than the general population, especially in the physical domains.

Topics: Acidosis; Bicarbonates; Critical Illness; Humans; Intensive Care Units; Quality of Life; Sodium Bicarbonate; Survivors

When both severe metabolic acidemia (pH equal or less than 7.20; PaCO2 equal or less than 45 mm Hg and bicarbonate concentration equal or less than of 20 mmol/L) and moderate-to-severe acute kidney injury are observed, day 28 mortality is approximately 55%-60%. A multiple centre randomised clinical trial (BICARICU-1) has suggested that sodium bicarbonate infusion titrated to maintain the pH equal or more than 7.30 is associated with a higher survival rate (secondary endpoint) in a prespecified stratum of patients with both severe metabolic acidemia and acute kidney injury patients. Whether sodium bicarbonate infusion may improve survival at day 90 (primary outcome) in these severe acute kidney injury patients is currently unknown.. The sodium bicarbonate for the treatment of severe metabolic acidosis with moderate or severe acute kidney injury in the critically ill: a randomised clinical trial (BICARICU-2) trial is an investigator-initiated, multiple centre, stratified, parallel-group, unblinded trial with a computer-generated allocation sequence and an electronic system-based randomisation. After randomisation, the intervention group will receive 4.2% sodium bicarbonate infusion to target a plasma pH equal or more than 7.30 while the control group will not receive sodium bicarbonate. The primary outcome is the day 90 mortality. Main secondary outcomes are organ support dependences.. The trial has been approved by the appropriate ethics committee (CPP Nord Ouest, Rouen, France, 25 April 2019, number: 19.03.15.72446). Informed consent is required. If sodium bicarbonate improves day 90 mortality, it will become part of the routine care.. NCT04010630.

Topics: Acute Kidney Injury; Bicarbonates; Critical Illness; Humans; Informed Consent; Randomized Controlled Trials as Topic; Sodium Bicarbonate

To help shape the design of a future double blind placebo-controlled randomised clinical trial of bicarbonate therapy for metabolic acidosis, based on opinions of intensive care clinicians in Australia and New Zealand.. An online survey was designed, piloted and distributed electronically to members of the Australian and New Zealand Intensive Care Society Clinical Trials Group (ANZICS CTG) mailing list. The survey sought to collect information about choice of placebo, method of bicarbonate administration, and acid-base monitoring.. Responses to six questions in the following domains were sought: 1) solution to be used as placebo; 2) method of administration; 3) target of the intervention; 4) timing of arterial blood gases to monitor the intervention; 5) duration of therapy; and 6) rate of bolus therapy (if selected as the best option).. One in every eight ANZICS CTG members completed the survey (118/880, 13.4%). Compound sodium lactate was the preferred solution for placebo (54/118, 45.8%), and continuous infusion of bicarbonate (80/118, 67.8%) was the most frequently selected method of administration. A pH > 7.30 was the preferred target (50/118, 42.4%), while monitoring with arterial blood gas analysis every 2 hours until the target is reached and then every 4 hours was the most favoured option (40/118, 33.9%). The preferred duration of therapy was until the target is achieved (53/118, 44.9%).. This survey offers important insights into the preferences of Australian and New Zealand clinicians in regards to any future randomised controlled trial of bicarbonate therapy for metabolic acidosis in the critically ill.

Topics: Acidosis; Australia; Calcium; Critical Care; Critical Illness; Double-Blind Method; Humans; New Zealand; Sodium Bicarbonate; Surveys and Questionnaires; Treatment Outcome

To test whether hydration with bicarbonate rather than isotonic sodium chloride reduces the risk of contrast-associated acute kidney injury in critically ill patients.. Prospective, double-blind, multicenter, randomized controlled study.. Three French ICUs.. Critically ill patients with stable renal function (n = 307) who received intravascular contrast media.. Hydration with 0.9% sodium chloride or 1.4% sodium bicarbonate administered with the same infusion protocol: 3 mL/kg during 1 hour before and 1 mL/kg/hr during 6 hours after contrast medium exposure.. The primary endpoint was the development of contrast-associated acute kidney injury, as defined by the Acute Kidney Injury Network criteria, 72 hours after contrast exposure. Patients randomized to the bicarbonate group (n = 151) showed a higher urinary pH at the end of the infusion than patients randomized to the saline group (n = 156) (6.7 ± 2.1 vs 6.2 ± 1.8, respectively; p < 0.0001). The frequency of contrast-associated acute kidney injury was similar in both groups: 52 patients (33.3%) in the saline group and 53 patients (35.1%) in the bicarbonate group (absolute risk difference, -1.8%; 95% CI [-12.3% to 8.9%]; p = 0.81). The need for renal replacement therapy (five [3.2%] and six [3.9%] patients; p = 0.77), ICU length of stay (24.7 ± 22.9 and 23 ± 23.8 d; p = 0.52), and mortality (25 [16.0%] and 24 [15.9%] patients; p > 0.99) were also similar between the saline and bicarbonate groups, respectively.. Except for urinary pH, none of the outcomes differed between the two groups. Among ICU patients with stable renal function, the benefit of using sodium bicarbonate rather than isotonic sodium chloride for preventing contrast-associated acute kidney injury is marginal, if any.

Topics: Acute Kidney Injury; Adult; Aged; Contrast Media; Critical Illness; Double-Blind Method; Female; Fluid Therapy; Hospital Mortality; Humans; Hydrogen-Ion Concentration; Intensive Care Units; Length of Stay; Male; Middle Aged; Prospective Studies; Renal Replacement Therapy; Sodium Bicarbonate; Sodium Chloride

Urine alkalinisation with sodium bicarbonate decreases renal oxidative stress and might attenuate sepsisassociated acute kidney injury (s-AKI). The safety and feasibility of urine alkalinisation in patients at risk of s-AKI has never been tested.. We randomly assigned patients at risk of s-AKI (those with systemic inflammatory response syndrome [SIRS], oliguria and elevated [≥150 µg/L] serum neutrophil gelatinase-associated lipocalin [sNGAL] concentration) to receive sodium bicarbonate (treatment group) or sodium chloride (placebo group) in a 0.5 mmol/kg bolus followed by an infusion of 0.2 mmol/kg/hour.. Among 50 patients with SIRS and oliguria, 25 (50%) had an elevated sNGAL concentration. Of these, 13 were randomised to receive sodium bicarbonate and 12 to receive sodium chloride infusion. Study drugs were infused for a mean period of 25.9 hours (SD, 10 hours). Severe electrolyte abnormalities occurred in seven patients (28%) (four [30.8%] in the treatment group and three [25%] in the placebo group). These abnormalities resulted in early protocol cessation in six patients (24%) and study drug suspension in one patient (4%). This adverse event rate was judged to be unacceptable and the study was terminated early. There was no difference between the two groups in sNGAL or urinary NGAL concentrations over time, occurrence of acute kidney injury, requirement for renal replacement therapy, hospital length-of-stay or mortality.. Administration of sodium bicarbonate and sodium chloride solutions to patients at risk of s-AKI was associated with frequent major electrolyte abnormalities and early protocol cessation. The tested protocol does not appear safe or feasible.

Topics: Acute Kidney Injury; Acute-Phase Proteins; Aged; Bicarbonates; Chlorides; Critical Illness; Double-Blind Method; Drug Carriers; Female; Follow-Up Studies; Humans; Kidney; Lipocalin-2; Lipocalins; Male; Oxidative Stress; Prospective Studies; Proto-Oncogene Proteins; Risk Factors; Safety; Sodium; Sodium Bicarbonate; Treatment Outcome

The effect of sodium bicarbonate haemodialysis or haemofiltration on cardiac function was prospectively studied in 8 patients with acute renal failure. All of the patients exhibited consciousness disturbance and seven patients were on mechanical ventilation. All but one of the patients demonstrated moderate hyperlactataemia and seven patients were receiving vasoactive amine support. Arterial and mixed venous gas analysis and haemodynamic measurements were performed before and after haemodialysis/-filtration treatment. The buffer was changed in a randomised order between bicarbonate and acetate and 11 crossover studies were completed. After treatment with bicarbonate, the cardiac index and stroke index decreased significantly (4.0 +/- 0.3 to 3.4 +/- 0.4 L/ min/m2, p < 0.05 and 39.6 +/- 2.5 to 32.9 +/- 1.8 L/m2, p < 0.05), whereas no significant changes were observed in cardiac index or stroke index after treatment with acetate. Therefore, the post-dialytic percent changes of cardiac index, stroke index and left ventricular stroke work index were significantly decreased after bicarbonate sessions, as compared to after acetate sessions. Haemo-dialysis/-filtration using sodium bicarbonate can depress cardiac function in critically ill patients on mechanical ventilation with disturbed consciousness, and in those who are receiving vasoactive amine support due to uncompromised haemodynamics associated with hyperlactataemia.

Topics: Acetates; Acetic Acid; Acute Kidney Injury; Adult; Aged; Aged, 80 and over; Critical Illness; Depression, Chemical; Dialysis Solutions; Female; Heart; Hemofiltration; Humans; Male; Middle Aged; Prospective Studies; Renal Dialysis; Sodium Bicarbonate; Stroke Volume; Ventricular Function, Left

To analyze the cardiovascular effects of sodium bicarbonate in neonates with metabolic acidosis.. Prospective, open, non-randomized, before-after intervention study with hemodynamic measurements performed before and 1, 5, 10, 20, and 30 min after bicarbonate administration.. Neonatal intensive care unit, tertiary care center.. Sequential sample of 16 paralysed and mechanically ventilated newborn infants with a metabolic acidosis (pH < 7.25 in premature and < 7.30 in term infants, base deficit > -8).. An 8.4% sodium bicarbonate solution diluted 1:1 with water (final osmolality of 1000 mOsm/l) was administered in two equal portions at a rate of 0.5 mmol/min. The dose in mmol was calculated using the formula "base deficit x body weight (kg) x 1/3 x 1/2".. Sodium bicarbonate induced a significant but transient rise in pulsed Doppler cardiac output (CO) (+27.7%), aortic blood flow velocity (+15.3%), systolic blood pressure (BP) (+9.3%), (+14.6%), transcutaneous carbon dioxide pressure (PtcCO2) (+11.8%), and transcutaneous oxygen pressure (PtcO2) (+8%). In spite of the PaCO2 elevation, pH significantly improved (from a mean of 7.24 to 7.30), and the base deficit decreased (-39.3%). Calculated systemic vascular resistance (SVR) (-10.7%) and diastolic BP (-11.7%) decreased significantly, while PaO2 and heart rate (HR) did not change. Central venous pressure (CVP) (+6.5%) increased only slightly. By 30 min after bicarbonate administration all hemodynamic parameters, with the exception of the diastolic BP, had returned to baseline.. Sodium bicarbonate in neonates with metabolic acidosis induces an increase in contractility and a reduction in afterload.

Topics: Acidosis, Lactic; Bicarbonates; Birth Weight; Blood Gas Analysis; Blood Gas Monitoring, Transcutaneous; Critical Illness; Echocardiography, Doppler; Gestational Age; Hemodynamics; Humans; Infant, Newborn; Infant, Premature; Infusions, Intravenous; Intensive Care Units, Neonatal; Myocardial Contraction; Prospective Studies; Respiration, Artificial; Sodium; Sodium Bicarbonate

Topics: Acute Kidney Injury; Contrast Media; Critical Illness; Humans; Sodium Bicarbonate; Sodium Chloride

The recommended method for elucidating the effects of strong ions other than lactate on acid-base balance is to calculate the non-lactate strong ion difference (SIDnl). A relationship between HCO3 (-) and SIDnl in hyperchloremic patients has already been demonstrated; in the present study, the relationships between SIDnl, the apparent strong ion difference (SIDa), and mortality at intensive care unit (ICU) admission were investigated.. In our two-center study, 2691 patients admitted to the ICU were retrospectively evaluated, including 1069 critically ill patients. These patients were divided into three subgroups according to their SIDnl levels at admission to the ICU: low (<38 mmol L(-1)), normal (38-40 mmol L(-1)), and high (>40 mmol L(-1)). Patient age, gender, diagnosis, blood gas values, length of ICU stay, and mortality were recorded.. The low-SIDnl group included 768 patients (71.8 %), the normal-SIDnl group consisted of 127 patients (11.9 %), and the high-SIDnl group contained 174 patients (16.3 %). There was no significant difference in lactate levels among the SIDnl groups (p = 0.635). In a multivariate logistic regression model, likelihood of mortality was increased 1.24-fold (1.20-1.28), 2.56-fold (1.61-4.08) and 2.55-fold (1.003-6.47) by APACHE II, lactate level ≥2mmol L(-) and low SIDnl (p < 0.001, p < 0.001, and p = 0.049, respectively).. SIDnl can be used to determine the effects of strong ions other than lactate on SIDa values and acid-base balance. Furthermore, a low SIDnl at ICU admission can be a prognostic indicator of mortality.

Topics: Acid-Base Imbalance; Adult; Aged; Aged, 80 and over; APACHE; Chlorides; Critical Care; Critical Illness; Female; Hospital Mortality; Humans; Ions; Lactic Acid; Male; Middle Aged; Prognosis; Retrospective Studies; Sodium Bicarbonate

To determine nutrient requirements by the carbon oxidation techniques, it is necessary to know the fraction of carbon dioxide produced during the oxidative process but not excreted. This fraction has not been described in critically ill children. By measuring the dilution of (13)C infused by metabolically produced carbon dioxide, the rates of carbon dioxide appearance can be estimated. Energy expenditure can be determined by bicarbonate dilution kinetics if the energy equivalents of carbon dioxide (food quotient) from the diet ingested are known.. We conducted a 6-h, primed, continuous tracer infusion of NaH(13)CO(3) in critically ill children fed parenterally or enterally or receiving only glucose and electrolytes, to determine bicarbonate fractional recovery, bicarbonate rates of appearance, and energy expenditure.. Thirty-one critically ill children aged 1 mo-20 y who were admitted to a pediatric intensive care unit at a tertiary-care center were studied. Patients were stratified by age, BMI, and severity score (PRISM III).. Fractional bicarbonate recovery was 0.69, 0.70, and 0.63, respectively, for the parenterally fed, enterally fed, and glucose-electrolytes groups, and it correlated with the severity of disease in the parenteral (P < 0.01) and glucose-electrolytes (P < 0.05) groups. Rates of appearance varied between 0.17 and 0.19 micromol . kg(-1) . h(-1) With these data and estimates of the energy equivalents of carbon dioxide (a surrogate for respiratory quotient), energy expenditure was determined.. The 2001 World Health Organization and Schofield predictive equations overestimated and underestimated, respectively, energy requirements compared with those obtained by bicarbonate dilution kinetics. Bicarbonate kinetics allows accurate determination of energy needs in critically ill children.

Topics: Adolescent; Adult; Age Factors; Body Mass Index; Carbon Dioxide; Carbon Isotopes; Child; Child, Preschool; Critical Illness; Energy Metabolism; Enteral Nutrition; Female; Humans; Infant; Intensive Care Units, Pediatric; Male; Nutrition Assessment; Nutritional Requirements; Oxygen Consumption; Parenteral Nutrition, Total; Predictive Value of Tests; Reproducibility of Results; Sensitivity and Specificity; Severity of Illness Index; Sodium Bicarbonate

The continuous intravenous administration of isotopic bicarbonate (NaH13CO2) has been used for the determination of the retention of the 13CO2 fraction or the 13CO2 recovered in expired air. This determination is important for the calculation of substrate oxidation. The aim of the present study was to evaluate, in critically ill patients with sepsis under mechanical ventilation, the 13CO2 recovery fraction in expired air after continuous intravenous infusion of NaH13CO2 (3.8 micromol/kg diluted in 0.9% saline in ddH2O). A prospective study was conducted on 10 patients with septic shock between the second and fifth day of sepsis evolution (APACHE II, 25.9 +/- 7.4). Initially, baseline CO2 was collected and indirect calorimetry was also performed. A primer of 5 mL NaH13CO2 was administered followed by continuous infusion of 5 mL/h for 6 h. Six CO2 production (VCO2) measurements (30 min each) were made with a portable metabolic cart connected to a respirator and hourly samples of expired air were obtained using a 750-mL gas collecting bag attached to the outlet of the respirator. 13CO2 enrichment in expired air was determined with a mass spectrometer. The patients presented a mean value of VCO2 of 182 +/- 52 mL/min during the steady-state phase. The mean recovery fraction was 0.68 +/- 0.06%, which is less than that reported in the literature (0.82 +/- 0.03%). This suggests that the 13CO2 recovery fraction in septic patients following enteral feeding is incomplete, indicating retention of 13CO2 in the organism. The severity of septic shock in terms of the prognostic index APACHE II and the sepsis score was not associated with the 13CO2 recovery fraction in expired air.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; APACHE; Carbon Dioxide; Carbon Isotopes; Critical Illness; Energy Metabolism; Female; Humans; Infusions, Intravenous; Male; Middle Aged; Oxygen Consumption; Prognosis; Prospective Studies; Pulmonary Gas Exchange; Reference Values; Respiration, Artificial; Sepsis; Sodium Bicarbonate; Young Adult

Our objective was to study the risk factors and mechanisms of hypernatraemia in critically ill patients, a common and potentially serious problem.. In 2005, all patients admitted to the medical, surgical or neurological intensive care unit (ICU) of a university hospital were reviewed. A 1:2 matched case-control study was performed, defining cases as patients who developed a serum sodium >/=150 mmol/l in the ICU.. One hundred and thirty cases with ICU-acquired hypernatraemia (141 +/- 3 to 156 +/- 6 mmol/l) were compared to 260 controls. Sepsis (9% versus 2%), hypokalaemia (53% versus 34%), renal dysfunction (53% versus 13%), hypoalbuminaemia (91% versus 55%), the use of mannitol (10% versus 1%) and use of sodium bicarbonate (23% versus 0.4%) were more common in cases (P < 0.05 for all) and were independently associated with hypernatraemia. During the development of hypernatraemia, fluid balance was negative in 80 cases (-31 +/- 2 ml/kg/day), but positive in 50 cases (72 +/- 3 ml/kg/day). Cases with a positive fluid balance received more sodium plus potassium (148 +/- 2 versus 133 +/- 3 mmol/l, P < 0.001). On average, cases were polyuric (40 +/- 5 ml/kg). Mortality was higher in cases (48% versus 10%, P < 0.001), for which hypernatraemia was an independent predictor (odds ratio 4.3, 95% confidence interval 2.5 to 7.2).. Hypernatraemia seems to develop in the ICU because various factors promote renal water loss, which is then corrected with too little water or overcorrected with relatively hypertonic fluids. Therapy should therefore rely on adding electrolyte-free water and/or creating a negative sodium balance. Adjustments in intravenous fluid regimens may prevent hypernatraemia.

Topics: Adult; Aged; Case-Control Studies; Critical Illness; Female; Fluid Therapy; Humans; Hypernatremia; Hypoalbuminemia; Hypokalemia; Intensive Care Units; Kidney Diseases; Male; Mannitol; Middle Aged; Risk Factors; Sepsis; Sodium Bicarbonate; Water-Electrolyte Balance

The outcome and metabolic control was studied in 60 critically ill patients with acute renal failure (ARF) treated by continuous arteriovenous hemodiafiltration (CAVHD) in a single surgical intensive care unit. Mean age (+/- SEM) was 60 +/- 2 years with a male predominance (80%). The majority of patients required mechanical ventilation (83%) and/or vasopressor support (70%) and suffered from multiorgan failure [mean number of organ system failures 3.3 +/- 0.3 (range 1-6)]. CAVHD resulted in a rapid decline of serum urea and creatinine levels during the first 72 h (urea 47.4 +/- 2.3 to 30.3 +/- 1.4 mmol/l, p < 0.05, and creatinine 572 +/- 27 to 361 +/- 23 mumol/l, p < 0.05); thereafter, controlled steady-state levels were achieved with serum urea levels kept below 30 mmol/l with full protein alimentation and often despite hypotension, surgery and septicemia. Significant electrolyte derangements could be easily corrected and maintained within normal limits. Bicarbonate homeostasis could be restored within 48 h in patients with severe metabolic acidosis (HCO3- < 20 mmol/l) with use of bicarbonate as a buffering anion (17 +/- 0.5 to 23.2 +/- 0.6, p < 0.05). CAVHD allowed rapid removal of excess body and lung water (up to 5 liters/day) without hemodynamic instability. Despite a mean pretreatment APACHE II score of 26.5, 26 patients (43%) survived until discharge from the intensive care unit, of whom 23 (38%) survived to leave hospital. Requirement of mechanical ventilation or vasopressor support, higher APACHE II scores and septicemia were all associated with a poor prognosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Acidosis; Acute Kidney Injury; Adolescent; Adult; Aged; Aged, 80 and over; APACHE; Creatinine; Critical Illness; Female; Hemodiafiltration; Hemodynamics; Humans; Male; Middle Aged; Phosphates; Potassium; Sodium; Sodium Bicarbonate; Time Factors; Treatment Outcome; Urea