Arteriovenous Exchange Research Articles

Hydrodynamic and Hemodynamic Interactions in Chronic Hydrocephalus.

During a cardiac cycle, intracranial pressure is related to arterial entry into the cranium and its interaction with intracranial compliance. The arterial inflow is compensated by intracranial compliance and, initially, the flushing of cerebrospinal fluid (CSF) into the cervical subarachnoid spaces. Our objective is to analyze the interactions between intracranial arteriovenous exchange and cerebrospinal fluid oscillations. A total of 23 patients (73 ± 8 years) with suspected chronic hydrocephalus (CH) underwent an infusion test and phase-contrast MRI. Rout is an important factor in the diagnosis of CH. Patients were divided into 2 populations: probableCH (Rout: resistance to CSF outflow) (Rout > 12 mmHg/mL/min, 13 patients) and unlikelyCH (Rout < 12 mmHg/mL/min, 10 patients). We measured the intracranial vascular volume (arteriovenous stroke volume: SVvasc) and CSF (CSF stroke volume at upper cervical level: SVCSF) volume variations during the cardiac cycle. In the whole population, we observed a significant correlation between SVvasc and SVCSF (R2 = 0.43; p = 0.0007). In the population unlikelyCH, this correlation was significant (R2 = 0.76; p = 0.001). In the population probableCH, this correlation was not significant (R2 = 0.17, p = 0.16). These results show that the link between the compliance of the oscillating CSF and the abrupt arterial inflow seems to be altered in CH. CSF oscillations between intracranial and cervical fluid spaces limit the impact of the abrupt arterial inflow.

Application of Targeted Nursing in Implementing Arteriovenous Synchronous Exchange for Hemolytic Disease of Newborn

Application of Targeted Nursing in Implementing Arteriovenous Synchronous Exchange for Hemolytic Disease of Newborn

Fully automated simultaneous peripheral arteriovenous exchange transfusion not seen to aggravate brain function and the disorder of the internal environment in neonates with severe hyperbilirubinemia

The acute changes in brain function in newborn infants undergoing ET remain unclear. This study aimed to determine whether fully automated simultaneous peripheral arteriovenous ET would influence the brain function. A retrospective analysis was conducted on the clinical data of 39 neonates with hyperbilirubinemia who received ET. Seventeen patients were in the encephalopathy group, and the other 22 patients were in the non-encephalopathy group. Changes in amplitude-integrated electroencephalogram (aEEG) during ETs were analyzed, including background activities, sleep-wake cycling (SWC), and seizures. Before and after the ET, routine blood test parameters, electrolytes, blood glucose, and blood gas parameters were measured. After ETs, there were no significant changes in the levels of pH, PaO2, PaCO2, lactate, and red blood cells, while the levels of total bilirubin, indirect bilirubin, blood potassium, blood sodium, serum calcium, while blood cells, and platelets were significantly lower and the level of blood glucose was significantly higher compared to those before therapy. There was no significant difference in the changes of electroencephalographic activities during ETs, including background activities, SWC, and seizures. However, there were significant differences in suppressions on background activities, while there were no significant statistical differences in SWC or seizures between the 2 groups. Fully automated simultaneous peripheral arteriovenous ET is safe and efficient without significant influence on the disorder of the internal environment and electroencephalographic activities after ET in neonates. However, background activities are more significantly depressed in infants of bilirubin encephalopathy than infants of non-encephalopathy during ET.

Therapeutic effect of peripheral arteriovenous exchange combined with intravenous gamma globulin on neonatal hemolysis

Objective To observe the effect of peripheral arteriovenous exchange combined with intravenous gamma in the treatment of neonatal hemolysis. Methods Seventy children with neonatal hemolysis admitted to the first affiliated Hospital of China Medical University from January 2013 to May 2018 and who met the indications for peripheral arteriovenous exchange were selected as the study subjects.The patients were divided into peripheral arteriovenous exchange group and peripheral arteriovenous exchange+ gamma globulin group by random number table method, with 35 cases in each group.Baseline data of the two groups, changes of serum bilirubin before and after treatment, partial blood biochemical indicators, hospitalization time and jaundice regression time were observed. Results The levels of serum bilirubin ((241.5±48.1), (184.6±26.3), (166.3±18.5), (133.5±20.8) μmol/L) in peripheral arteriovenous exchange + gamma group were significantly lower than those in peripheral arteriovenous exchange group ((299.3±32.5), (225.7±38.9), (195.4±21.1), (173.8±35.4) μmol/L) at 12, 24, 48 and 72 hours after treatment, the difference was significant (P<0.05). RBC in children in two groups after treatment was(4.3±0.8)×1012/L, (4.2±1.0)×1012/L vs.before(5.2±1.1)×1012/L, (6.4±1.3)×1012/L, Hb after treatment in both groups was (125.8±11.2) g/L, (124.9±10.5) g/L vs.before (148.9±26.5) g/L, (159.3±14.6) g/L and reticulocyte count after treatment in both groups were (7.6±2.1)%, (7.3±1.8)% vs.(5.2±1.3)%, (3.1±0.5)% were significantly improved, but the peripheral arteriovenous exchange+ gamma group was significantly better than the peripheral arteriovenous transfusion group, the difference was statistically significant (all P<0.05). The hospitalization time (10.3±1.9) d and jaundice regression time (8.6±0.5) d in the peripheral arteriovenous exchange + gamma group were significantly lower than those in the peripheral arteriovenous exchange group ((15.5±2.6) d, (10.0±1.1) d). The difference was statistically significant(t=9.553, 6.855, P<0.05). The children who had re-hemolytic after treatment in the peripheral arteriovenous exchange + gamma group were significantly lower than the peripheral arteriovenous exchange group (5.7%(2/35) vs.25.7%(9/35)), the difference was statistically significant (χ2=5.285, P=0.022). Conclusion Peripheral arteriovenous exchange combined with intravenous gamma is effective in the treatment of neonatal hemolysis.It can significantly reduce serum bilirubin, improve blood biochemical parameters, shorten hospitalization time and jaundice regression time, and is safe and reliable. Key words: Neonatal hemolysis; Peripheral arteriovenous exchange; Gamma globulin; Therapeutic effect

Analysis of short-term clinical outcomes in 98 newborns with severe hyperbilirubinemia treated by peripheral arteriovenous synchronous exchange transfusion

Objective To study the type of disease, the optimal time and clinical effect of peripheral arteriovenous synchronous exchange transfusion in the treatment of newborns with hyperbilirubinemia. Methods The clinical data of admitted neonates with severe hyperbilirubinemia who received peripheral arteriovenous synchronous exchange transfusion were retrospectively analyzed from January 2015 to December 2016. Results Ninety-eight neonates were enrolled and the mean gestational age was(38.7±1.2)weeks, the mean birth weight was(3 275.1±483.7) grams, 76 cases were term infants, 20 cases were preterm infants and 2 cases were post term infants.The causes of hyperbilirubinemia included 39 cases of ABO incompatibility(39.8%), 16 cases of Rh incompatibility(16.3%), 3 cases of C3d incompatibility(3.1%), 2 cases of infection(2.0%), 2 cases of cranial hematoma(2.0%), 2 cases of adrenal hematoma(2.0%) and 34 cases of unknown hyperbilirubinemia(34.7%). The mean age of exchange transfusion was(5.8±4.4)days.Exchange transfusion removed 45.0% of total body bilirubin.After exchange transfusion, the total serum bilirubin, platelet level decreased as compared with those of pre-exchange levels, the differences were statistically significant(t=15.85, P<0.05; t=13.75, P<0.05). The white blood cell counts and hemoglobin increased, the differences were statistically significant(t=4.06, P<0.05; t=4.41, P<0.05). A total of 44 cases who had bilirubin encephalopathy were compared to other 54 cases who didn′t have bilirubin encephalopathy, there were no significant differences in fetal age, age of onset, bilirubin before and after blood exchange.There were significantly differences at time of exchange transfusion and the grade of hospital which the patient admitted at first time(t=2.46, P<0.05; t=6.15, P<0.05). Conclusion Hemorrhagic disease is the most important cause of neonatal severe hyperbilirubinemia.Clinical effect of peripheral arteriovenous synchronous exchange transfusion in the treatment of newborns with hyperbilirubinemia is obvious.Timely exchange transfusion can reduce the occurrence of bilirubinencephalopathy.For basic-level hospitals, it is still necessary to strengthen the implementation of hour-specific bilirubin to predict the risk of neonatal hyperbilirubinemia. Key words: Peripheral arteriovenous synchronous exchange transfusion; Hyperbilirubinemia; Bilirubin encephalopathy; Newborn

Changes of electroencephalographic activities during fully automated simultaneous peripheral arteriovenous exchange transfusion in neonates with hyperbilirubinemia

Objective To analyze the changes of electroencephalographic activities during fully automated simultaneous peripheral arteriovenous exchange transfusion(ET) in neonates with hyperbilirubinemia. Methods A total of 45 neonates who suffered from severe hyperbilirubinemia and underwent fully automated simultaneous peripheral arteriovenous exchange transfusion were studied from March 2009 to March 2016 in Neonatal Intensive Care Unit of Guangzhou Women and Children's Medical Center, and 46 ETs were performed in 45 babies who were divided into 2 groups according to the severity of hyperbilirubinemia: the encephalopathy group and the none-encephalopathy group.Nineteen patients were in the encephalopathy group, in which 11 were male and 8 were female.The other 26 patients were in the none-encephalopathy group, in which 15 were male and 11 were female.Changes in amplitude integrated electroencephalogram(aEEG) during ETs were analyzed, including background activities, sleep-wake cycle (SWC) and seizures. Results Forty-five patients with hyperbilirubinemia underwent 46 fully automated simultaneous perip-heral arteriovenous ETs. As a result, total bilirubin dropped from (524.90±110.96) μmol/L before ETs to (245.62±78.97) μmol/L after ETs, with clearance rate of 53.2%. And indirect bilirubin dropped from(486.16±90.39) μmol/L before ETs to(222.19±79.49) μmol/L after ETs, with clearance rate of 54.3%. On the other hand, there was no significant difference in the changes of electroencephalographic activities during ETs, including background activities(χ2=0.16, P>0.05), SWC(χ2=0.71, P>0.05) and seizures(χ2=0.30, P>0.05). However, there were significant difference in suppressions on background activities between the encephalopathy group and the none-encephalopathy group(Fisher's exact test P=0.042), though there were no significant statistical differences in SWC or seizures between the 2 groups ( χ2=0.65, P>0.05; χ2=2.07, P>0.05, respectively). Conclusions In neonatal hyperbilirubinemia, fully automated simultaneous peripheral arteriovenous ET is safe and efficient without significant influence on electroencephalographic activities as a whole.However, background activities are more significantly depressed in infants of bilirubin encephalopathy than that of non-encephalopathy during ET. Key words: Fully automated simultaneous peripheral arteriovenous exchange transfusion; Amplitude integra-ted electroencephalogram; Hyperbilirubinemia; Infant, newborn

Exchange transfusion therapy of neonatal hyperbilirubinemia in 5 patients

Objective To investigate changes in serum bilirubin and internal environment, etc. of neonatal hyperbilirubinemia that before and after the treatment of peripherally arteriovenous synchronous exchange transfusion. Methods In the strict monitoring of vital signs, hyperbilirubinemia peripheral vessels exchange transfusion was applied in five cases of neonatal, and the serum bilirubin, routine blood test, electrolytes before and after the exchange transfusion were detected. Results By comparing the data before and after the exchange transfusion,the total bilirubin and indirect bilirubin decreased obviously, respectively[(414.02±56.04)μmol/L,(225.72±53.54)μmol/L,t =5.433 P=0.01,(381.82±44.68)μmol/L,(199.22±57.37)μmol/L,t=5.615 P=0.01],the difference was statistically significant, and also the platelet count were decreased obviously,respectively[(199.00±42.01)×109/L,(102.00±17.72)×109/L,t=4.758,P=0.001],the difference was statistically significant.After the exchange transfusion, white blood cells,hemoglobin,potassium,sodium,chloride,calcium,glucose,blood pressure,heart rate and blood PH value had decreased or increased slightly,there was no significant difference P>0.05.Cerebral palsy and other complications did not occur after 12 months of follow-up of the five cases. Conclusion The outer peripheral arteriovenous synchronous exchange transfusion therapy for neonatal severe hyperbilirubinemia can quickly reduce serum bilirubin, and has less impact on the body environment, it is an important and effective salvage treatment of neonatal hyperbilirubinemia, thereby reducing damage to the nervous system of bilirubin. Key words: Hyperbilirubinemia; Baby, newborn; Exchange transfusion therapy

Fully automated simultaneous umbilical arteriovenous exchange transfusion in term and late preterm infants with neonatal hyperbilirubinemia

Objectives: The purpose of this study was to compare the efficacy and safety of two different catheterization techniques of exchange transfusion (ET) used in the therapy of newborn jaundice: fully automated two-way ET technique and the classical one-way ET.Patients and methods: The study included babies at gestational age of >34 weeks. In total, 107 ETs were performed on 86 babies. Totally, the umbilical vein (UV) group included 54 babies having undergone 69 ETs and the UV/UA group included 32 babies having undergone 38 ETs.Results: The declines in bilirubin levels right after ET (p = 0.018) and 8 h after ET (p = 0.014) were higher in the fully automated UV/UA technique than in the classical UV technique. Furthermore, the duration of intensive phototherapy following ET was shorter in the UV/UA method than in the UV method (p = 0.003). There was no difference between the two methods in terms of ET-associated complications (p = 0.927).Conclusions: In neonatal hyperbilirubinemia, ET with fully automated UV/UA technique is more efficient than the classical ET technique, causing no additional side-effects. It is also more physiological than the classical technique, since it minimizes the fluctuations in the blood volume and intravascular pressure during ET.

Study on the treatment of severe neonatal hyperbilirubinemia by peripheral arteriovenous synchronous exchange transfusion

Objective To evaluate the efficacy, safety, and then understand the indication, clini-cal application of the peripheral arteriovenous synchronous exchange transfusion therapy on the infants with severe neonatal hyperbilirubinemia. Methods peripheral arteriovenous synchronous exchange transfusion was performed on 96 newly-born infants with hyperbilirnbinaemia. The changes of their blood routine, serum bilirubin, electrolyte, coagulation functions and blood glucose before and after the exchange transfusion were analyzed and the neurological symptoms, blood routine and serum bilirubin were continuously observed after treatment. Results The average decrease in serum total bilirubin concentration was 48.6%, mainly in indirect bilirubin, after exchange transfusion. Levels of leukocyte, template and serum potassium all had showed distinctive downtrend with P 0.05 through the treatment. The analysis of coagulation functions showed that both fibrinogen and active partial thromboplastin time decreased signifi-cantly with P 0.05 compared with itself before the exchange transfusion. Respiration/circulation suppression or necrotizing enterocolitis only oc-curred in individual cases. Conclusions Peripheral arteriovenous synchronous exchange transfusion has the advantages of good efficacy, safety find simple operation, but it is necessary to pay close attention on patients' life sign during and after the treatment. Key words: Exchange transfusion; Neonatal hyperbilirubinemia; Treatment

Influence of age and resistance exercise on human skeletal muscle proteolysis: a microdialysis approach.

We combined the interstitial sampling method of microdialysis with the natural tracer qualities (i.e. non-recyclability) of the amino acid 3-methylhistidine (3MH) to uniquely study in vivo degradation of the two most abundant skeletal muscle proteins, myosin and actin. Interstitial 3MH concentration was measured before and for 24 h following a single bout of resistance exercise in eight young (27 +/- 2 years) and eight old (75 +/- 4 years) men. The exercise bout consisted of four exercises (3 sets of 8 repetitions at 80% one-repetition maximum (1RM) per exercise) emphasizing the quadriceps. Interstitial 3MH concentration was calculated using the internal reference method from microdialysate samples that were obtained from two microdialysis probes placed in the vastus lateralis. Resting interstitial 3MH concentration was 44% higher (P < 0.05) in the old (6.16 +/- 0.56 nmol ml(-1)) as compared with the young (4.28 +/- 0.27 nmol ml(-1)). Interstitial 3MH was not different (P > 0.05) from preexercise at any time point within the 24 h following exercise in both the young and the old. Leg arteriovenous exchange measurements in a separate group of young subjects also showed no increase in 3MH release during the 4 h following a resistance exercise bout compared with a non-exercised control leg (control leg: -28 +/- 6, exercise leg: -28 +/- 11 nmol min(-1)). These results suggest that myosin and actin proteolysis are not increased in the first 24 h following a standard bout of resistance exercise, and this response is not altered with ageing. The higher interstitial 3MH concentration in the old suggests an increased proteolysis of the two main contractile proteins in the rested and fasted state, which is consistent with a decrease in muscle mass with ageing. Microdialysis is an appropriate methodology for use in ageing individuals and is compatible with high-intensity resistance exercise.

The effect of arterialization of blood by hand warming on the interpretation of forearm metabolic studies

Although sampling of arterialized blood is widely used as an alternative to arterial sampling in metabolic studies, the arterialization procedures have been criticized because they may produce metabolic and haemodynamic effects that confound interpretation of results, especially in studies involving arteriovenous exchange of metabolites across the contralateral forearm. This study aimed to assess the effect of warming the hand for 10 or 20 min (a procedure which may be used to arterialize superficial venous blood) on the blood flow to the skin and muscle of the whole of the contralateral forearm. Hand warming, produced by placing the hand in a box kept at 67+or-3 degrees C for 10 min (standard errors of mean, SEM), produced no significant change in the blood flow of the whole forearm (4.14+or-0.28 versus 4.34+or-0.26 ml per 100 ml forearm min-1, measured with the hand circulation occluded), muscle (1.9+or-0.12 versus 1.82+or-0.15 ml per 100 ml forearm min-1, measured by 133Xe) or skin (5.2+or-4.0 versus 4.6+or-2.9 arbitrary units, measured by photoplethysmography). After 20 min of hand warming, there was no significant change in the concentration of a variety of metabolites in the deep venous blood draining the contralateral forearm. It is concluded that, unlike other 'arterialization' procedures, that used in this study had no important effect on the blood flow to the contralateral forearm or its distribution between muscular and nonmuscular tissues. Therefore, this procedure of arterialization can be employed in arteriovenous studies that aim to assess the exchange of metabolites between blood and forearm tissues.

Glycerol exchange across the human forearm assessed by a combination of tracer and arteriovenous exchange techniques.

1. Whole-body kinetics and regional exchange of glycerol across forearm muscle were assessed in eight lean subjects by a combination of a tracer method (infusion of [2H5]glycerol) and arteriovenous catheterization. 2. During an apparent steady state, the enrichment of glycerol in deep venous blood from the muscle bed of the forearm was about half (4.40 +/- 1.72 atom per cent excess) that observed in arterialized blood (8.41 +/- 4.30 atom per cent excess). Under the same conditions, the circulating concentrations of glycerol in arterialized (91 +/- 24 mumol/l) and venous (87 +/- 32 mumol/l) blood were similar. 3. In a further group of 37 subjects it was found that about half had a positive arteriovenous concentration difference and the other had half a negative arteriovenous concentration difference (mean -1.6 +/- 11.9 mumol/l; range -25 to +22 mumol/l). 4. These results suggest: (a) that human muscle does not always release glycerol and may take it up; (b) that there is substantial isotopic exchange of glycerol across forearm muscle tissue, which is not reflected by the net exchange of glycerol; this could be due to slow equilibrium of enriched glycerol from the circulation, with unenriched free glycerol in the muscle pool, or due to the simultaneous metabolic utilization of enriched glycerol and metabolic production of unenriched glycerol; (c) that the estimation of glycerol flux rates is strongly dependent on whether the blood is arterialized or deep venous.

Arteriovenous exchange of AA across the muscle and gastrointestinal tract during intravenous administration of the dipeptide Ala-Gln in catabolic dog : [formula omitted], J.Karner, Judith Hanusch, F.Mühlbacher, J.Funovics, I.Amberger, P.Fürst Institute of Nutrition and Biological Chemistry, University Hohenheim, FRG, 1st Surgical Department, Metabolic Research Laboratory, University Vienna, Austria

Arteriovenous exchange of AA across the muscle and gastrointestinal tract during intravenous administration of the dipeptide Ala-Gln in catabolic dog : [formula omitted], J.Karner, Judith Hanusch, F.Mühlbacher, J.Funovics, I.Amberger, P.Fürst Institute of Nutrition and Biological Chemistry, University Hohenheim, FRG, 1st Surgical Department, Metabolic Research Laboratory, University Vienna, Austria

Brain temperatures in running quail.

Hypothalamic (Tb) and colonic (Tc) temperatures of adult bobwhite (colinus virginianus) were measured simultaneously while the birds were resting and running on a motor-driven treadmill at fixed belt speeds ranging from 0.42 to 0.75 m.s-1 at two air temperatures, room and 30 degrees C. For comparison, Tb and Tc were also recorded simultaneously in resting bobwhite exposed to air temperatures of 30 to 45 degrees C. Hypothalamic temperatures of both environmentally heat-stressed and running bobwhite were consistently below colonic temperatures. The mean magnitude of this body-to-brain temperature difference in birds running at the highest speeds (i.e., with the greatest exercise heat loads) and at a high air temperature (30 degrees C) was similar to that of extremely heat-stressed resting birds [ambient temperature (Ta) = 45 degrees C]. Furthermore, the body-to-brain temperature difference in quail running at 30 degrees C increases with running speed. That these birds running at maximum speeds can maintain their Tb nearly constant while Tc increases suggests enhanced heat transfer in the rete mirabile ophthalmicum, an extracranial site of arteriovenous heat exchange.