Ziemowit Rzecki

Volatile Anesthetics Reduce Biochemical Markers of Brain Injury and Brain Magnesium Disorders in Patients Undergoing Coronary Artery Bypass Graft Surgery

OBJECTIVES Neuropsychological disorders are some of the most common complications of coronary artery bypass graft (CABG) surgery. The early diagnosis of postoperative brain damage is difficult and mainly based on the observation of specific brain injury markers. The aim of this study was to analyze the effects of volatile anesthesia (VA) on plasma total and ionized arteriovenous magnesium concentrations in the brain circulation (a-vtMg and a-viMg), plasma matrix metalloproteinase-9 (MMP-9), and glial fibrillary acidic protein (GFAP) in adult patients undergoing CABG surgery. DESIGN An observational study. SETTING The Department of Cardiac Surgery in a Medical University Hospital. PATIENTS AND METHODS Studied parameters were measured during surgery and in the early postoperative period. Patients were assigned to 3 groups: group O, patients who did not receive VA; group ISO, patients who received isoflurane; and group SEV, patients who received sevoflurane. RESULTS Ninety-two patients were examined. CABG surgery increased MMP-9 and GFAP. The highest MMP-9, GFAP, and the most dramatic disorders in a-vtMg and a-viMg were noted in group O. CONCLUSIONS Cardiac surgery increased plasma MMP-9 and GFAP concentrations. Changes in MMP-9, GFAP, and arteriovenous tMg and iMg were significantly higher in group O. Volatile anesthetics, such as ISO or SEV, reduced plasma MMP-9, GFAP concentrations, and disturbances in a-vtMg and a-viMg.

Continuous veno-venous hemofiltration to adjust fluid volume excess in septic shock patients reduces intra-abdominal pressure.

OBJECTIVE To analyze the effect and the time course of continuous veno-venous hemofiltration (CVVH) with net ultrafiltration (UF) on intra-abdominal pressure (IAP) body fluid volumes in septic shock patients with acute kidney injury (AKI). METHODS Patients were studied at baseline and after 6, 12, 24, 48, 72, and 96 hours of CVVH treatment. IAP was measured via the bladder, and abdominal perfusion pressure (APP) was calculated as mean arterial pressure minus IAP. Fluid volume excess (VE), total body water (TBW), extracellular body water (ECW), and intracellular body water (ICW) were derived from wholebody bioimpedance analysis (BIA). RESULTS 30 patients entered final analysis, of which 6 died during CVVH (non-survivors). Fluid VE, TBW, ECW, ICW, and IAP significantly decreased in 24 survivors, whereas these variables remained essentially unchangedin non-survivors. APP slowly increased in survivors, while it did not change in nonsurvivors. IAP strongly correlated with VEin survivors: The lower the IAP, the lower the fluid volume excess. CONCLUSION CVVH with net UF successfully reduced IAP, TBW, ECW, and ICW in critically ill patients who survived 96 h of CVVH. Failure to increase APP was associated with fatal outcome, and, finally, IAP correlated with fluid volume excess. BIA could be helpful to monitor fluid status in patients with AKI.

Disturbance in Venous Outflow From the Cerebral Circulation Intensifies the Release of Blood-Brain Barrier Injury Biomarkers in Patients Undergoing Cardiac Surgery

OBJECTIVE Disturbances in venous outflow from the cerebral circulation may result in brain injury. Severe increases in brain venous pressure lead to brain ischemia and, subsequently, brain edema and intracranial hemorrhages. The purpose of this study was to determine the effect of changes in jugular venous bulb pressure (JVBP) on plasma blood brain-barrier biomarkers concentration and disturbances in arteriovenous total and ionized magnesium (a-vtMg and a-viMg) in brain circulation in patients undergoing coronary artery bypass grafting surgery (CABG) with cardiopulmonary bypass (CPB). DESIGN Prospective observational study. SETTING Department of Cardiac Surgery at a Medical University Hospital. PARTICIPANTS Ninety-two adult patients undergoing elective CABG with CPB under general anaesthesia were studied. METHODS Central venous pressure (CVP) was measured using a pulmonary artery catheter. The right jugular vein was cannulized retrogradely for jugular venous bulb pressure (JVBP) measurement. Concentrations of plasma S100β protein, matrix metalloproteinase 9 (MMP-9), creatine kinase isoenzyme BB (CK-BB) a-vtMg and a-viMg were measured as the markers of blood-brain barrier dysfunction. All of them were analyzed in comparison with JVBP during surgery and the early postoperative period. RESULTS Elevated JVBP was noted after CPB and after surgery. Its increase above 12 mmHg intensified release of S100β, MMP-9 and CK-BB as well as disorders in a-vtMg and a-viMg. CVP correlated with JVBP, S100β, and MMP-9. Moreover, JVBP correlated with S100β and MMP-9. CONCLUSIONS Cardiac surgery increased JVBP, and JVBP elevated above 12 mmHg intensified an increase in biomarkers of plasma blood-brain barrier disruption.

Plasma matrix metalloproteinase 9 correlates with disorders of brain magnesium homeostasis in patients undergoing coronary artery bypass surgery

BACKGROUND Changes in plasma matrix metalloproteinase 9 (MMP-9) concentrations and parallel changes in brain magnesium homeostasis have not been examined in cardiac surgery patients. The purpose of the present study was to analyse these relationships in patients undergoing coronary artery bypass surgery (CABG) with extracorporeal circulation (ECC). Additionally, the effect of volatile anaesthetics was considered. PATIENTS AND METHODS Adult patients undergoing CABG with ECC under general anaesthesia were studied. Plasma MMP-9 and total (tMg) and ionized (iMg) magnesium concentrations were measured during surgery and during the early postoperative period. The plasma arteriovenous (a-v) tMg and iMg differences in the brain circulation were considered to be markers for brain magnesium homeostasis. The Mini-Mental State Examination test and computer tomography were used to diagnose postoperative neuropsychological disorders (PNPDs). RESULTS In total, 92 patients were examined. PNPDs were noted in 17 cases. Cardiac surgery resulted in increased plasma levels of MMP-9. The highest MMP-9 concentrations were observed in patients with PNPDs. MMP-9 concentrations strongly correlated with a-v tMg and a-v iMg differences. Compared with arterial measurements, venous tMg and iMg concentrations were higher during and immediately after surgery and lower during the early postoperative period. The most severe differences in a-v tMg and iMg were noted in patients with PNPDs. CONCLUSION 1. Cardiac surgery resulted in an increase in plasma MMP-9 concentrations. 2. This increase in MMP-9 was significantly greater in patients with PNPDs. 3. The plasma MMP-9 concentration was correlated with disorders of brain Mg homeostasis.

Intra-Abdominal Pressure Correlates with Extracellular Water Content

Background Secondary increase in intra-abdominal pressure (IAP) may result from extra-abdominal pathology, such as massive fluid resuscitation, capillary leak or sepsis. All these conditions increase the extravascular water content. The aim of this study was to analyze the relationship between IAP and body water volume. Material and Methods Adult patients treated for sepsis or septic shock with acute kidney injury (AKI) and patients undergoing elective pharyngolaryngeal or orthopedic surgery were enrolled. IAP was measured in the urinary bladder. Total body water (TBW), extracellular water content (ECW) and volume excess (VE) were measured by whole body bioimpedance. Among critically ill patients, all parameters were analyzed over three consecutive days, and parameters were evaluated perioperatively in surgical patients. Results One hundred twenty patients were studied. Taken together, the correlations between IAP and VE, TBW, and ECW were measured at 408 time points. In all participants, IAP strongly correlated with ECW and VE. In critically ill patients, IAP correlated with ECW and VE. In surgical patients, IAP correlated with ECW and TBW. IAP strongly correlated with ECW and VE in the mixed population. IAP also correlated with VE in critically ill patients. ROC curve analysis showed that ECW and VE might be discriminative parameters of risk for increased IAP. Conclusion IAP strongly correlates with ECW.

Increase in intra-abdominal pressure raises brain venous pressure, leads to brain ischaemia and decreases brain magnesium content.

BACKGROUND Intra-abdominal hypertension (IAH) may increase brain venous pressure, which may lead to brain injury. The aim of the present study was to analyse the effect of IAH on brain venous pressure and brain total and ionised magnesium (tMg and iMg), calcium (Ca) and zinc (Zn) contents in rats. MATERIAL AND METHODS Forty four adult Wistar rats were examined. Animals were divided into two groups: control, and IAH: rats with intra-abdominal pressure (IAP) elevated to 25 mmHg. IAP was measured directly in the abdominal cavity. After retrograde cannulation of the jugular vein, the jugular venous pressure (JVP) was measured as the brain venous pressure. JVP and IAP were noted after induction of anaesthesia, immediately following induction of IAH and 90 min after induction of IAH. In all rats, brains were removed for biochemical and histological analysis. RESULTS Biochemical analysis was performed in 30 rats, histological visualisation in 14. IAP elevated to 25 mmHg increased JVP in the IAH group. After 90 min, JVP decreased; however, its value was still higher compared with pre-IAH. In the IAH group, tMg and iMg were significantly lower than in the control group. Moreover, Ca and Zn levels were higher in the IAH group compared with the control group. The histological examination showed changes indicative of ischaemic neuronal cell stress. CONCLUSIONS Firstly, increase in IAP elevates JVP. Secondly, raised JVP decreases tMg and iMg. Thirdly, raised JVP increases the Ca and Zn content in the rat brain. Fourthly, IAH leads to changed characteristics of brain ischaemia.

Raised Jugular Venous Pressure Intensifies Release of Brain Injury Biomarkers in Patients Undergoing Cardiac Surgery

OBJECTIVES Neurologic damage after cardiac surgery with extracorporeal circulation is multifactorial. Despite several studies, its pathophysiology is poorly understood. The purpose of this study was to determine the changes in jugular venous pressure and to analyze their effect on perioperative brain injury measured by biomarkers in patients undergoing coronary artery bypass grafting. DESIGN Observational study. SETTING Department of cardiac surgery in a medical university hospital. PARTICIPANTS Adult patients undergoing elective coronary artery bypass grafting with extracorporeal circulation under general anesthesia. INTERVENTIONS The right jugular vein was cannulated in retrograde fashion. Jugular venous pressure was measured in the jugular vein bulb (JVBP). Concentrations of plasma glial fibrillary acidic protein, tau protein, arteriovenous lactate, and jugular vein saturation were measured as the markers of brain injury during the surgery and early postoperative period. All were analyzed in relation to JVBP. MEASUREMENTS AND MAIN RESULTS Increased JVBP was noted after extracorporeal circulation and after surgery. A significant increase >12 mmHg for JVBP, increased plasma glial fibrillary acidic protein, tau protein, arteriovenous lactate concentrations, and decreased jugular vein saturation were observed. CONCLUSIONS Cardiac surgery increased JVBP and an increased JVBP > 12 mmHg intensified an increase in brain injury biomarker concentrations.

Brain damage in cardiac surgery patients

Neuropsychological disorders and brain injury are still a serious problem in cardiac surgery patients. Owing to multifactorial mechanism of brain injury during extracorporeal circulation, the effective and safe protection is extremely difficult. Despite several studies, the ideal neuroprotective treatment has not been found. Based on literature we analysed the main mechanisms of brain injury and new methods of brain protection.

Plasma magnesium concentration in patients undergoing coronary artery bypass grafting

[b]Introduction[/b]. Magnesium (Mg) plays a crucial role in cell physiology and its deficiency may cause many disorders which often require intensive treatment. The aim of this study was to analyse some factors affecting preoperative plasma Mg concentration in patients undergoing coronary artery bypass grafting (CABG). [b]Materials and method[/b]. Adult patients scheduled for elective CABG with cardio-pulmonary bypass (CPB) under general anaesthesia were studied. Plasma Mg concentration was analysed before surgery in accordance with age, domicile, profession, tobacco smoking and preoperative Mg supplementation. Blood samples were obtained from the radial artery just before the administration of anaesthesia. [b]Results. [/b]150 patients were studied. Mean preoperative plasma Mg concentration was 0.93 ± 0.17 mmol/L; mean concentration in patients - 1.02 ± 0.16; preoperative Mg supplementation was significantly higher than in patients without such supplementation. Moreover, intellectual workers supplemented Mg more frequently and had higher plasma Mg concentration than physical workers. Plasma Mg concentration decreases in elderly patients. Patients living in cities, on average, had the highest plasma Mg concentration. Smokers had significantly lower plasma Mg concentration than non-smokers. [b]Conclusions. [/b]1. Preoperative magnesium supplementation increases its plasma concentration. 2. Intellectual workers frequently supplement magnesium. 3. Smoking cigarettes decreases plasma magnesium concentration.

Intra-abdominal hypertension increases spatial QRS-T angle and elevates ST-segment J-point in healthy women undergoing laparoscopic surgery

BACKGROUND Intra-abdominal hypertension (IAH) impairs cardiovascular function, however an effect of IAH on cardiac electrophysiology has been poorly documented. The aim of this study was to evaluate the effect of IAH following pneumoperitoneum on vectorcardiographic variables reflecting cardiac repolarisation and depolarisation. METHODS Otherwise healthy women undergoing elective gynaecological laparoscopy were studied. Intra-abdominal pressure (IAP), spatial QRS-T angle and ST-segment J-point (STJ) were observed during surgery and the early postoperative period. RESULTS Forty women, ages 22 to 43 were examined. Induction of IAH to 15mmHg significantly widened the spatial QRS-T angle, whereas the Trendelenburg position subsequently reduced this widening. IAH also increased STJ voltage in leads III, aVF, V2 and V3 during surgery, with increased STJ voltage persisting in several leads through the morning of postoperative day 1. CONCLUSION Induction of IAH impacts the relationship between cardiac depolarisation and repolarisation and increases spatial QRS-T angle and STJ voltage.