Comparison of bicarbonate-buffered fluid and isotonic saline solution as Cell Saver washing fluids for packed red blood cells.

OBJECTIVES: Massive transfusion (MT) can cause severe electrolyte and acid-base disturbances in neonates and infants due to the unphysiological composition of packed red blood cells (PRBCs). Washing of the PRBCs using Cell Saver systems prior to MT is recommended for this reason. AIM: The composition of normal saline (NaCl), the standard wash fluid for Cell Saver systems, is considerably different from that of physiological plasma. The aim of the study presented here was to investigate the effect of washing the PRBCs with a bicarbonate-buffered hemofiltration solution (BB-HS) in comparison with washing with NaCl and to evaluate the impact on electrolyte concentrations, acid-base balance and the stability of PRBCs. METHODS: In an experimental in vitro setting, PRBCs were washed with Cell Saver systems prepared with NaCl or BB-HS as washing solutions. Before and after the washing procedure, electrolyte concentrations, acid-base parameters, adenosine triphosphate (ATP) and free hemoglobin (fHb) concentrations were measured. RESULTS: In both groups, the potassium concentrations decreased (baseline: 18.4 ± 5.17 mmol·l(-1), end of study: NaCl 2.71 ± 1,81 mmol·l(-1), BB-HS 2.50 ± 1.54 mmol·l(-1), P < 0.05) while the acid-base balance improved only in the BB-HS-group (baseline: base excess -21.6 ± 3.52 mmol·l(-1), end of study: NaCl -30.2 ± 1.42 mmol·l(-1), BB-HS -7.51 ± 2.49 mmol·l(-1) , P < 0.05). Furthermore, markers of erythrocyte stability such as fHb and ATP concentrations were improved in the BB-HS-group. CONCLUSIONS: Washing of PRBCs with BB-HS rather than NaCl results in a more physiological composition with improvements of electrolyte concentrations, acid-base balance and erythrocyte stability.

Hydroxyethyl starch 130/0.42/6:1 for perioperative plasma volume replacement in 1130 children: results of an European prospective multicenter observational postauthorization safety study (PASS).

INTRODUCTION: Third-generation hydroxyethyl starch (HES) is now approved also for the use in children, but safety studies including large numbers of pediatric patients are still missing. Therefore, we performed an European multicentric prospective observational postauthorization safety study (PASS) to evaluate the use of HES 130/0.42/6:1 in normal saline (ns-HES) or a balanced electrolyte solution (bal-HES) in children undergoing surgery. METHODS: Children aged up to 12 years with ASA risk scores of I-III receiving ns-HES (Venofundin 6%; Braun) or bal-HES (Tetraspan 6%; Braun) were followed perioperatively. Demographic data, surgical procedures performed, anesthesia, hemodynamic and laboratory data, adverse events (AE), and adverse drug reactions (ADR) were documented using a standardized case report form. RESULTS: Of 1130 children studied at 11 European pediatric centers from 2006 to 2009 (ns-HES, 629 children; bal-HES, 475 children; mean age, 3.6 ± 3.8 [range, day of birth-12 years]; and body weight, 15.4 ± 13 [0.9-90 kg]), 1104 were included for analysis. The mean infused HES volume was 10.6 ± 5.8 (0.83-50) ml·kg(-1). In the 399 (36.1%) cases with blood gas analysis before and after HES infusion, hemoglobin and strong ion difference decreased significantly in both groups, whereas bicarbonate and base excess (BE before infusion: ns-HES -1.8 ± 3.1, bal-HES -1.2 ± 3.3 mm; after infusion: ns-HES -2.5 ± 2.8; bal-HES -1.1 ± 3.2 mm, P < 0.05) decreased only with ns-HES but remained stable with bal-HES. Chloride concentrations increased in both groups and were significantly higher with ns-HES (Cl before infusion: ns-HES 105.5 ± 3.6, bal-HES 104.9 ± 2.9 mm; Cl after infusion: ns-HES 107.6 ± 3.4, bal-HES 106.3 ± 2.9 mm, P < 0.05). For the AE/ADR rates, dose-response but no age relationships could be demonstrated. No serious and no severe ADR directly related to HES (i.e. anaphylactoid reaction, clotting disorders, renal failure) were observed. CONCLUSION: Moderate doses of HES 130/0.42/6:1 for perioperative plasma volume replacement seem to be safe even in neonates and small infants. The probability of serious ADR is lower than 0.3%. Changes in acid-base balance may be decreased when HES is used in an acetate-containing balanced electrolyte solution instead of normal saline. Caution should be exercised in patients with renal function disturbances and those with an increased bleeding risk.

Alterations of acid-base balance, electrolyte concentrations, and osmolality caused by nonionic hyperosmolar contrast medium during pediatric cardiac catheterization.

OBJECTIVE: This prospective clinical observational study was conducted to investigate the effects of contrast medium on acid-base balance, electrolyte concentrations, and osmolality in children. BACKGROUND: For pediatric cardiac catheterization, high doses of nonionic hyperosmolar contrast medium are widely used. METHODS: Forty pediatric patients (age 0-16 years) undergoing cardiac angiography with more than 3 ml·kg(-1) of nonionic hyperosmolar contrast medium (Iomeprol) were enrolled, and the total amount of the contrast agent given was documented. Before and after contrast medium administration, a blood sample was collected to analyze electrolytes, acid-base parameters, osmolality, hemoglobin, and hematocrit. RESULTS: After cardiac catheterization, pH, hemoglobin, hematocrit, bicarbonate, base excess, sodium, chloride, calcium, anion gap and strong ion difference decreased, whereas osmolality increased significantly (base excess -1.8 ± 1.8 vs -3.4 ± 2.3, sodium 138 ± 2.9 vs 132 ± 4.1 mm, osmolality 284 ± 5.7 vs 294 ± 7.6 mosmol·kg(-1), P < 0.01). Seventy-eight percent of the children developed hyponatremia (sodium <135 mm). No changes were seen in pCO(2) , lactate, and potassium levels. CONCLUSIONS: Regarding the differential diagnosis of metabolic disturbances after pediatric cardiac catheterization, low-anion gap metabolic acidosis and hyponatremia should be considered as a possible side effect of the administered contrast medium.

A novel isotonic balanced electrolyte solution with 1% glucose for intraoperative fluid therapy in neonates: results of a prospective multicentre observational postauthorisation safety study (PASS).

BACKGROUND: Neonates have a higher metabolic rate and an increased risk of perioperative hypoglycemia and lipolysis, but during anesthesia, both oxygen consumption and metabolic rate are decreased, and this may lead to reduced intraoperative glucose requirements. OBJECTIVE: The objective of this prospective multicentre observational postauthorisation safety study was to evaluate the intraoperative use of a novel isotonic balanced electrolyte solution with a low glucose concentration of 1% (BS-G1) in neonates with a particular focus on changes in acid-base, electrolyte, and glucose concentrations. METHODS: Following the local ethics committee approval, neonates with a postmenstrual age under 45 weeks and an ASA risk score of I-IV undergoing intraoperative administration of BS-G1 were enrolled. Patient demographics, the performed procedure, adverse drug reactions, hemodynamic data, and the results of blood gas analysis before and after infusion were documented with a focus on changes in acid-base, electrolyte, and glucose concentrations. RESULTS: In 66 neonates (ASA I-IV; postmenstrual age 38 ± 4, range 25-45 weeks; body weight 2.9 ± 0.9, range 0.65-4.6 kg), the mean infusion rate was 10.4 ± 3.2 (range 4.5-19.6) ml·kg(-1) ·h(-1) BS-G1. During the infusion, hemoglobin, hematocrit, bicarbonate, base excess, anion gap, strong ion difference, and calcium decreased, and chloride and glucose increased significantly within the physiological range. All other measured parameters including sodium and lactate remained stable. Neither hypoglycemia (glucose < 3 mm) nor hyperglycemia (glucose > 10 mm) was documented after BS-G1 infusion. No adverse drug reactions were reported. CONCLUSION: The study shows that the intraoperative use of an isotonic balanced electrolyte solution with 1% glucose and a mean infusion rate of 10 ml·kg(-1) ·h(-1) helps to avoid acid-base dysbalance, hyponatraemia, hypoglycemia, ketoacidosis, and hyperglycemia in surgical neonates. A careful intraoperative monitoring and adaptation of the infusion rate as needed is crucial because the glucose and fluid requirements may vary widely between subjects.

A novel isotonic-balanced electrolyte solution with 1% glucose for intraoperative fluid therapy in children: results of a prospective multicentre observational post-authorization safety study (PASS).

BACKGROUND: The recommendations for intraoperative fluid therapy in children have been adapted from hypotonic to isotonic electrolyte solutions with lower glucose concentrations (1-2.5% instead of 5%) to avoid hyponatremia and hyperglycemia. OBJECTIVE: The objective of this prospective multicentre observational post-authorization safety study was to evaluate the intraoperative use of a novel isotonic-balanced electrolyte solution with 1% glucose (BS-G1) with a particular focus on changes in acid-base status, electrolyte and glucose concentrations. METHODS: Following local ethics committee approval, pediatric patients aged up to 4 years with an ASA risk score of I-III undergoing intraoperative administration of BS-G1 were enrolled. Patient demographics, the performed procedure, adverse drug reactions, hemodynamic data, and the results of blood gas analysis before and after infusion were documented with a focus on changes in acid-base status, electrolyte and glucose concentrations. RESULTS: In 107 patients (ASA I-III; age 16.2 ± 15.4, range day of birth to 47.7 months; body weight 8.8 ± 4.8, range 1.6-18.8 kg), the mean volume infused was 20 ± 12.6 (range 3.6-83.3) ml·kg(-1) BS-G1. During the infusion, hemoglobin, hematocrit, anion gap, strong ion difference, and calcium decreased and chloride and glucose increased significantly within the physiologic range. All other measured parameters including sodium, bicarbonate, base excess, and lactate remained stable. Neither hypoglycemia (glucose <2.5 mmol·l(-1) ) nor hyperglycemia (glucose >10 mmol·l(-1) ) was documented after BS-G1 infusion. No adverse drug reactions were reported. CONCLUSION: The studied isotonic-balanced electrolyte solution with 1% glucose helps to avoid perioperative acid-base imbalance, hyponatremia, hyperglycemia, and ketoacidosis in infants and toddlers and may therefore enhance patient safety.

A novel isotonic-balanced electrolyte solution with 1% glucose for perioperative fluid management in children- an animal experimental preauthorization study.

BACKGROUND: The recommendations for perioperative maintenance fluid in children have been adapted from hypotonic to isotonic electrolyte solutions with lower glucose concentrations (1-2.5% instead of 5%) to avoid hyponatremia or hyperglycemia. OBJECTIVE: The objective of this prospective animal study was to determine the margin of safety of a novel isotonic-balanced electrolyte solution with 1% glucose (BS-G1) in comparison with normal saline with 1% glucose (NS-G1) in the case of accidental hyperhydration with a focus on acid-base electrolyte balance, glucose concentration, osmolality and intracranial pressure in piglets. METHODS: Ten piglets (bodyweight 11.8 +/- 1.8 kg) were randomly assigned to receive either 100 ml.kg(-1) of BS-G1 or NS-G1 within one hour. Before, during and after fluid administration, electrolytes, lactate, hemoglobin, hematocrit, glucose, osmolality and acid-base parameters were measured. RESULTS: Unlike BS-G1, administration of NS-G1 produced mild hyperchloremic acidosis (base excess BS-G1 vs NS-G1, baseline 1.9 +/- 1.7 vs 2.9 +/- 0.9 mmol.l(-1), study end 0.2 +/- 1.7 vs -2.7 +/- 0.5 mmol.l(-1), P < 0.05, chloride BS-G1 vs NS-G1 baseline 102.4 +/- 3.4 vs 102.0 +/- 0.7 mmol.l(-1), study end 103.4 +/- 1.8 vs 109.0 +/- 1.4 mmol.l(-1)P < 0.05). The addition of 1% glucose led to moderate hyperglycemia (P < 0.05) with a concomitant increase in serum osmolality in both groups (P < 0.05). CONCLUSION: Both solutions showed a wide margin of safety in the case of accidental hyperhydration with less acid-base electrolyte changes when using BS-G1. This novel solution could therefore enhance patient's safety within the scope of perioperative volume management.

Changes in acid-base, electrolyte and hemoglobin concentrations during infusion of hydroxyethyl starch 130/0.42/6 : 1 in normal saline or in balanced electrolyte solution in children.

INTRODUCTION: A balanced volume replacement strategy is a well established concept for correcting hypovolemia using plasma adapted isotonic crystalloid solutions with a physiological electrolyte pattern and acetate as bicarbonate precursor. Recently, third-generation hydroxyethyl starch (HES) has also become available in a balanced electrolyte solution instead of normal saline. Therefore, in this prospective non-interventional clinical study, the perioperative administration of HES 130/0.42/6 : 1 in normal saline (ns-HES) and in balanced electrolyte solution (bal-HES) was evaluated in children with a focus on acid-base, electrolyte and hemoglobin changes. METHODS: Following local ethics committee approval, pediatric patients aged up to 12 years with an ASA risk score of I-III undergoing perioperative administration of HES (ns-HES from May 2006 to December 2007, bal-HES from January 2008 to January 2009) were included. Patient demographics, the performed procedure, adverse drug reactions, hemodynamic data and the results of blood gas analysis were documented with a focus on changes in acid-base, electrolyte and hemoglobin concentrations. RESULTS: Of 396 enrolled patients (ASA I-III; age 2.3 +/- 3, range day of birth - 12 years; body weight 10.8 +/- 9, range 0.9-52 kg), 249 received ns-HES and 147 bal-HES (mean volume infused 9.9 +/- 4 and 9.4 +/- 6.9 ml x kg(-1), respectively). After HES infusion, hemoglobin decreased in both groups, whereas bicarbonate and base excess (BE) decreased only with ns-HES and remained stable with bal-HES (BE before infusion: ns-HES -1.8 +/- 2.8, bal-HES -1.7 +/- 2.7 mmol x l(-1); after infusion: ns-HES -2.6 +/- 2.4; bal-HES -1.6 +/- 2.6 mmol x l(-1), P < 0.05). Chloride (Cl) concentrations increased in both groups and were significantly higher with ns-HES (Cl before infusion: ns-HES 105.6 +/- 3.7, bal-HES 105.1 +/- 2.8 mmol x l(-1); after infusion: ns-HES 107.7 +/- 3.2, bal-HES 106.3 +/- 2.9 mmol x l(-1), P < 0.01). No serious adverse drug reactions were observed. CONCLUSION: Infusion related iatrogenic acid-base and electrolyte alterations can be minimized by using hydroxyethyl starch in a balanced electrolyte solution instead of normal saline.

Perioperative analgesia strategies in fast-track pediatric surgery of the kidney and renal pelvis: lessons learned.

PURPOSE: Effective analgesia is essential for the success of fast-track (FT) pediatric surgery. Aim of the study was to achieve an optimal analgesia protocol for a comfortable postoperative course and early mobilization in children undergoing urological procedures. METHODS: A prospective study of two analgesia concepts in a series of children undergoing laparoscopic pyeloplasty (LP) and nephrectomy (LN) was performed. Thirty-six consecutive patients received analgesia according to the protocol "Fast Track I" (FT I), 23 patients according to the modified analgesia protocol "Fast Track II" (FT II). Differences between the protocols were frequency of pain measurement, more frequent use of local anesthesia and higher dosage of Acetaminophen. End points were pain intensity, use of opioids and side effects. Data derived from the German reimbursement system (G-DRG) regarding lengths of hospital stay were compared. RESULTS: On the day of operation (6:00 p.m.), pain scores of patients using FT II were significantly lower than those using the FT I protocol (1.51 + or - 0.4 FT II versus 3.8 + or - 0.4 FT I, p = 0.001). Pain scores still tended to be lower in the FT II group on the first postoperative day (8:00 a.m.), but from that point on, the difference was not significant (1.52 + or - 0.5 FT II versus 2.3 + or - 0.4 FT I, p = 0.186). Hospital stay was short, compared to the German average, in both groups. CONCLUSION: The modified analgesia protocol FT II leads to earlier and more effective pain reduction, lower use of opioids and fewer side effects than the previously used protocol FT I. Hence, modification of analgesia in pediatric urology is essential.

Dependence of platelet function on underlying liver disease in orthotopic liver transplantation.

OBJECTIVE: The purpose of the present study was to explore the platelet function during the perioperative period of orthotopic liver transplantation (OLT) due to the underlying liver disease. METHODS: The blood coagulation parameters, platelet surface markers and the determination of platelet aggregation were analyzed in 34 patients who underwent OLT. Blood samples were drawn preoperatively, anhepatic, 10 min and 1 hour after reperfusion, 1 day, 3 and 7 days postoperatively. Conventional coagulation screens, thrombopoietin (TPO) serum levels, P-selectin, GPIIb/IIIa and GPIb binding sites on the surface of platelets as evaluated by flow cytometry and platelet aggregation response were measured. RESULTS: Coagulation factors, maximum aggregation and rate of aggregation were significantly different before transplantation due to the underlying liver disease. Further we found a markedly depressed GPIIb/IIIa and P-selectin expression and a reduced rate of aggregation in all patients throughout the study. In contrast maximum aggregation of platelets was restored on the third day after reperfusion without intergroup differences and almost comparable to healthy controls. An inverse correlation was found between peripheral platelet count pre-transplantation and peak TPO concentrations one weak post-transplantation. CONCLUSIONS: In the entire process of OLT, coagulation factors, maximum aggregation and rate of platelet aggregation depend on the surgical phases during transplantation and on the underlying liver disease. The data obtained in this study might contribute to a better understanding of the pathophysiology and assessment of bleeding risk in OLT.

Unsaturated long-chain fatty acids induce the respiratory burst of human neutrophils and monocytes in whole blood.

BACKGROUND: It is increasingly recognized that infectious complications in patients treated with total parenteral nutrition (TPN) may be caused by altered immune responses. Neutrophils and monocytes are the first line of defence against bacterial and fungal infection through superoxide anion production during the respiratory burst. To characterize the impact of three different types of lipid solutions that are applied as part of TPN formulations, we investigated the unstimulated respiratory burst activation of neutrophils and monocytes in whole blood. METHODS: Whole blood samples were incubated with LCT (Intralipid(R)), LCT/MCT (Lipofundin(R)) and LCT-MUFA (ClinOleic(R)) in three concentrations (0.06, 0.3 and 0.6 mg ml-1) for time periods up to one hour. Hydrogen peroxide production during the respiratory burst of neutrophils and monocytes was measured by flow cytometry. RESULTS: LCT and LCT-MUFA induced a hydrogen peroxide production in neutrophils and monocytes without presence of a physiological stimulus in contrast to LCT/MCT. CONCLUSION: We concluded that parenteral nutrition containing unsaturated oleic (C18:1) and linoleic (C18:2) acid can induce respiratory burst of neutrophils and monocytes, resulting in an elevated risk of tissue damage by the uncontrolled production of reactive oxygen species. Contradictory observations reported in previous studies may in part be the result of different methods used to determine hydrogen peroxide production.

Continuous monitoring of central venous oxygen saturation in neonates and small infants: in vitro evaluation of two different oximetry catheters.

BACKGROUND: Accurate assessment and monitoring of the cardiocirculatory function are essential during major pediatric and pediatric cardiac surgery. Monitoring of the central venous oxygen saturation (ScvO(2)) may be a better indicator of tissue oxygenation and derangement of cellular oxygen utilization than the more commonly used vital parameters. Therefore, we compared oxygen saturation measurements with thin fiberoptic oximetry catheters and standard blood gas oximetry in an in vitro setting. METHODS: Two different size continuous fiberoptic oximetry catheters (2-4-F) were inserted in an extracorporeal circuit filled with human red blood cells in normal saline (haematocrit 30%, flow 600 ml.min(-1)). The results of fiberoptic oximetry were then compared with standard blood gas oximetry for a wide range of different oxygen saturations using linear regression. RESULTS: The oxygen saturations found ranged from 9% to 100%. The results of the two different fiberoptic oximetry catheters correlated significantly (r = 0.99, P < 0.0001) with standard blood gas oximetry. CONCLUSION: The results of fiberoptic oximetry are nearly identical with standard blood gas oximetry for a wide range of different oxygen saturations. Thin oximetry catheters can be inserted percutaneously even in neonates and small infants. The continuous monitoring of ScvO(2) may be beneficial, especially in patients who are in danger of developing low cardiac output or sudden cardiovascular collapse.

Hemodynamic changes during acute elevation of intra-abdominal pressure in rabbits.

BACKGROUND: The intra-abdominal pressure (IAP) may be increased during pneumoperitoneum for minimally invasive surgery, after high tension repairs of congenital abdominal wall defects, major abdominal surgery, liver transplantation, abdominal trauma, peritonitis or ileus. The aim of this study was to investigate hemodynamic changes during elevation of IAP using an experimental setting, which mirrors anatomical and physiological conditions of neonates and small infants as closely as possible. METHODS: In five fasted, anesthetized, mechanically ventilated and multicatheterized New Zealand rabbits, the IAP was gradually increased by intra-abdominal infusion of normal saline (total volume 1000 ml). At baseline and after each infusion of 100 ml normal saline cardiac output (CO, transcardiopulmonary thermodilution), pressure in the superior (SVCP) and inferior vena cava (IVCP), mean arterial pressure (MAP), peak airway pressure (PAP) and IAP was recorded. RESULTS: During the study, IAP, SVCP and IVCP increased significantly. IVCP was significantly higher than SVCP from timepoint 200 ml to study end. After abdominal decompression IAP, SVCP and IVCP decreased to baseline levels. Changes in MAP were not significant. CO increased significantly from baseline to timepoint 200 ml (peak value), remained nearly constant until timepoint 800 ml and decreased thereafter until the abdominal infusion ceased. After abdominal decompression CO returned to baseline level. SVCP, IVCP and PAP correlated significantly with IAP (SVCP, r = 0.73; IVCP, r = 0.97; PAP, r = 0.94; P < 0.0001). CONCLUSIONS: The hemodynamic changes caused by increased IAP cannot be recognized by routine monitoring of arterial blood pressure and transcutaneous oxygen saturation. The increase in central venous pressure may be misinterpreted as an elevation of cardiac preload. One major effect of a prolonged increase in IAP is a decreased CO.

Correlation of oxygen delivery with central venous oxygen saturation, mean arterial pressure and heart rate in piglets.

BACKGROUND: Accurate assessment and monitoring of the cardiocirculatory function is essential during major pediatric and pediatric cardiac surgery. Invasive monitoring of cardiac output and oxygen delivery (DO(2)) is expensive and sometimes associated with adverse events. Measurement of central venous oxygen saturation (ScvO(2)) is less invasive and may reflect the DO(2). Therefore, we investigated the correlation of ScvO(2) with cardiac index (CI) and DO(2) and in comparison the more common monitored parameters heart rate (HR) and mean arterial pressure (MAP) with DO(2) in an animal experimental setting. METHODS: In five fasted, anesthetized and mechanically ventilated piglets CI (transpulmonary thermodilution), venous and arterial blood gases, HR and MAP was measured during normal conditions, volume loading, inotropic support, and exsanguination. RESULTS: In the five piglets 168 measurements could be performed. In a wide hemodynamic range (CI 22-335 ml x kg(-1) min(-1)) we found significant correlations of ScvO(2) with DO(2)) (r(2) = 0.91, P < 0.0001) and CI (r(2) = 0.88, P < 0.0001) and also between DO(2) and MAP (r = 0.86, P < 0.0001) and HR (r = 0.19, P < 0.05). CONCLUSIONS: ScvO(2) is a better parameter for indirect estimation of DO(2) than MAP and heart rate. Measurement of ScvO(2) is simple and does not necessitate additional invasive techniques. In the clinical setting ScvO(2) should be used in combination with other standard vital parameters, i.e. MAP, central venous pressure, lactate, base excess, and urine output.