Application Of Rapid-Sampling, Online Microdialysis To The Monitoring Of Brain Metabolism During Aneurysm Surgery

2006 ◽  
Vol 58 (suppl_4) ◽  
pp. ONS-313-ONS-321 ◽  
Author(s):  
Robin Bhatia ◽  
Parastoo Hashemi ◽  
Ashfaq Razzaq ◽  
Mark C. Parkin ◽  
Sarah E. Hopwood ◽  
...  
Keyword(s):  
At Risk ◽  
Intracranial Aneurysms ◽  
Brain Metabolism ◽  
Arterial Occlusion ◽  
Aneurysm Surgery ◽  
Microdialysis Catheter ◽  
Dialysate Flow ◽  
Rapid Sampling ◽  
Dialysate Flow Rate ◽  
Mean Time

Abstract Objective: To introduce rapid-sampling microdialysis for the early detection of adverse metabolic changes in tissue at risk during aneurysm surgery. Methods: A microdialysis catheter was inserted under direct vision into at-risk cortex at the start of surgery. This monitoring was sustained throughout the course of the operation, during which intraoperative events, for example, temporary arterial occlusion or lobe retraction, were precisely documented. A continuous online flow of dialysate was fed into a mobile bedside glucose and lactate analyser. This comprises flow-injection dual-assay enzyme-based biosensors capable of determining values of metabolites every 30 seconds. Results: Eight patients underwent clipping or wrapping of intracranial aneurysms and were monitored. Time between events and detection: 9 minutes. Mean change in metabolite value ± standard deviation: temporal lobe retraction lactate, +656 ± 562 µmol/L (n = 7, P< 0.05); glucose, -123 ± 138 µmol/L (n = 6, P = 0.08). Glucose intravenous bolus infusion glucose, +512 ± 244 µmol/L (n = 5, P< 0.01); peak at mean time after bolus, 16 minutes. Temporary proximal clip lactate, +731 ± 346 µmol/L (n = 6, P< 0.01); glucose, -139 ± 96 µmol/L (n = 5, P< 0.05); mean clip time, 8.6 minutes. Conclusion: The technique detects changes 9 minutes after intraoperative events occur (limited only by probe-to-sensor tubing length and dialysate flow rate). This provides reliable information to the surgeon and anesthetist promptly. It is a useful method for monitoring glucose and lactate in dialysate, particularly when rapid, transient changes in brain analyte levels need to be determined and the alternative offline methodology would be inadequate.

Revascularization and Aneurysm Surgery: Current Status

Neurosurgery ◽  
1985 ◽  
Vol 16 (1) ◽  
pp. 111-116 ◽  
Author(s):  
Robert F. Spetzler ◽  
Philip L. Carter
Keyword(s):  
Intracranial Aneurysms ◽  
Current Status ◽  
Aneurysm Surgery ◽  
Parent Vessel ◽  
Vessel Occlusion ◽  
Flow Measurements ◽  
Stump Pressure ◽  
Blood Flow Measurements ◽  
Vessel Ligation

Abstract Unclippable intracranial aneurysms are most effectively treated by hunterian ligation; however, the attendant risk of cerebral ischemia is significant. Many techniques have been used in an attempt to predict the safety of proximal vessel occlusion. Unfortunately, there is none that is risk-free and highly successful. A combination of stump pressure and cerebral blood flow measurements has been shown to be the most accurate in the acute assessment. In addition, recent studies have demonstrated that the long term risk of carotid ligation is significant. Extracranial-intracranial bypass grafting (EC-IC) has been shown to improve the safety of parent vessel ligation and is a low risk procedure. Whenever hunterian ligation is planned for the treatment of an intracranial aneurysm, EC-IC should be strongly considered. (Neurosurgery 16:111–116, 1985)

The “Squeezing Maneuver” in Microsurgical Clipping of Intracranial Aneurysms Assisted by Indocyanine Green Videoangiography

2014 ◽  
Vol 10 (2) ◽  
pp. 208-213 ◽  
Author(s):  
Alessandro Della Puppa ◽  
Oriela Rustemi ◽  
Marta Rossetto ◽  
Giorgio Gioffrè ◽  
Marina Munari ◽  
...  
Keyword(s):  
Indocyanine Green ◽  
Intracranial Aneurysms ◽  
Aneurysm Surgery ◽  
Radiological Findings ◽  
Indocyanine Green Videoangiography ◽  
Microsurgical Clipping ◽  
Intraoperative Detection ◽  
Small Series ◽  
Vessel Patency ◽  
Derived Data

Abstract BACKGROUND: Indocyanine green videoangiography (ICGV) is becoming routine in intracranial aneurysm surgery to assess intraoperatively both sac obliteration and vessel patency after clipping. However, ICGV-derived data have been reported to be misleading at times. We recently noted that a simple intraoperative maneuver, the “squeezing maneuver,” allows the detection of deceptive ICGV data on aneurysm exclusion and allows potential clip repositioning. The squeezing maneuver is based on a gentle pinch of the dome of a clipped aneurysm when ICGV documents its apparent exclusion. OBJECTIVE: To present the surgical findings and the clinical outcome of this squeezing maneuver. METHODS: Data from 23 consecutive patients affected by intracranial aneurysms who underwent the squeezing maneuver were analyzed retrospectively. The clip was repositioned in all cases when the dyeing of the sac was visualized after the maneuver. RESULTS: In 22% of patients, after an initial ICGV showing the aneurysm exclusion after clipping, the squeezing maneuver caused the prompt dyeing of the sac; in all cases, the clip was consequently repositioned. A calcification/atheroma of the wall/neck was predictive of a positive maneuver (P = .001). The aneurysm exclusion rate at postoperative radiological findings was 100%. CONCLUSION: With the limits of our small series, the squeezing maneuver appears helpful in the intraoperative detection of misleading ICGV data, mostly when dealing with aneurysms with atheromatic and calcified walls.

Does the Blood Pump Flow Rate have an Impact on the Dialysis Dose During Low Dialysate Flow Rate Hemodialysis?

2018 ◽  
Vol 46 (4) ◽  
pp. 279-285 ◽  
Author(s):  
Maxime Leclerc ◽  
Clémence Bechade ◽  
Patrick Henri ◽  
Elie Zagdoun ◽  
Erick Cardineau ◽  
...  
Keyword(s):  
Flow Rate ◽  
Blood Pump ◽  
Bivariate Analysis ◽  
Dialysis Dose ◽  
Dialysate Flow ◽  
Pump Flow ◽  
Dialysate Flow Rate ◽  
Pump Flow Rate ◽  
A Prospective Study ◽  
The Impact

We conducted a prospective study to assess the impact of the blood pump flow rate (BFR) on the dialysis dose with a low dialysate flow rate. Seventeen patients were observed for 3 short hemodialysis sessions in which only the BFR was altered (300,350 and 450 mL/min). Kt/V urea increased from 0.54 ± 0.10 to 0.58 ± 0.08 and 0.61 ± 0.09 for BFR of 300, 400 and 450 mL/min. For the same BFR variations, the reduction ratio (RR) of β2microglobulin increased from 0.40 ± 0.07 to 0.45 ± 0.06 and 0.48 ± 0.06 and the RR phosphorus increased from 0.46 ± 0.1 to 0.48 ± 0.08 and 0.49 ± 0.07. In bivariate analysis accounting for repeated observations, an increasing BFR resulted in an increase in spKt/V (0.048 per 100 mL/min increment in BPR [p < 0.05, 95% CI (0.03–0.06)]) and an increase in the RR β2m (5% per 100 mL/min increment in BPR [p < 0.05, 95% CI (0.03–0.07)]). An increasing BFR with low dialysate improves the removal of urea and β2m but with a potentially limited clinical impact.

Myoglobin Clearance during Continuous Veno-Venous Hemofiltration with or without Dialysis

1998 ◽  
Vol 21 (4) ◽  
pp. 205-209 ◽  
Author(s):  
D. Nicolau ◽  
Y.S. Feng ◽  
A.H.B. Wu ◽  
S.P. Bernstein ◽  
C.H. Nightingale
Keyword(s):  
Renal Failure ◽  
Animal Model ◽  
Flow Rate ◽  
Major Complication ◽  
Viable Option ◽  
Effective Technique ◽  
Dialysate Flow ◽  
Continuous Arteriovenous Hemofiltration ◽  
Pump Rate ◽  
Dialysate Flow Rate

The management of acute myoglobinuric renal failure, the major complication of rhab-domyolysis, continues to be a treatment dilemma for the clinician as limited therapeutic options are available. Previously, we have demonstrated that continuous arteriovenous hemofiltration (CAVH) is an effective technique for removing myoglobin in an animal model. In the present study, swine were administered four grams of equine myoglobin intravenously and underwent the continuous veno-venous hemofiltration (CVVH) procedure for six hours each. Animals were studied in each of the following groups: CVVH at a pump rate 100 ml/minute, CVVH at a pump rate 200 ml/minute and CVVH at a pump rate 100 ml/minute plus dialysis at a dialysate flow rate of one Liter/h. Once the filtering process was initiated there was a rapid and sustained production of ultrafiltrate in all groups. The amount of myoglobin excreted in the ultrafiltrate over the six-hour filtering period was 688, 948 and 570 mg which corresponded to 17, 24 and 14 percent of the administered dose, respectively, for the three treatments. In comparison to previous CAVH experiments, CVVH removed more circulating myoglobin and the addition of the dialysis component did not appear to improve removal. Based on these findings, it appears that the CVVH hemofiltration system is a viable option for the removal of systemic myoglobin.

scholarly journals The surgical approach for clipping anterior communicating artery Aneurysm

2019 ◽  
Vol 16 (1) ◽  
pp. 10-20
Author(s):  
Robin Bhattarai ◽  
Chuan Chen ◽  
Chao Feng Liang ◽  
Teng Chao Huang ◽  
Hui Wang ◽  
...  
Keyword(s):  
Minimally Invasive Surgery ◽  
Intracranial Aneurysms ◽  
Artery Aneurysm ◽  
Anterior Communicating Artery ◽  
Aneurysm Surgery ◽  
Pterional Approach ◽  
Supraorbital Approach ◽  
Lateral Supraorbital Approach ◽  
Eyebrow Incision ◽  
Frontal Branch

Anterior communicating artery (ACoA) aneurysm, accounts for 30%-35% of all the aneurysm making it one of the most common intracranial aneurysms. Although the Pterional approach is considered as the safe and appropriate method in ACoA aneurysm surgery, temporalis atrophy and injury to a frontal branch of the facial nerve are few inexorable complications. With the advancement of minimally invasive surgery several modified approaches, such as the supraorbital eyebrow incision approach, the minipterional approach, the mini-supraorbital approach, and the lateral supraorbital approach has been recently introduced and has been used as an alternative.

Clearance of Levofloxacin by an in Vitro Model of Continuous Venovenous Hemodialysis (CVVHD)

2007 ◽  
Vol 30 (10) ◽  
pp. 889-895 ◽  
Author(s):  
S. Siewert ◽  
B. Drewelow ◽  
S.C. Mueller
Keyword(s):  
In Vitro Model ◽  
Urea Clearance ◽  
Flow Rates ◽  
Dialysate Flow ◽  
Dialysate Flow Rate ◽  
Continuous Venovenous Hemodialysis ◽  
Vitro Model ◽  
Positive Correlations

Information about the elimination and the adequate dosing of levofloxacin during renal replacement therapy is scarce. The aim of this study was to characterize in vitro the elimination of levofloxacin during continuous venovenous hemodialysis (CVVHD) and to investigate whether the CVVHD clearances of creatinine and urea are correlated with the levofloxacin clearance in order to facilitate dosage adjustments. An in vitro model of CVVHD was established using five dialyzer membranes at varying dialysate flow rates applied in the clinical setting (8, 16, 25, 33 and 41 ml/min). Plasma and dialysate samples were drawn for determination of levofloxacin, creatinine and urea concentrations to evaluate clearances by CVVHD. During CVVHD, the clearance of levofloxacin varied between 9.02 and 33.30 ml/min, depending on the chosen setup. Positive correlations (p<0.001) were received for: dialysate flow rate (QD) and creatinine/urea clearances (R>0.93); QD and levofloxacin clearance (R 0.59–0.71); levofloxacin and creatinine clearance (R 0.69–0.75); and levofloxacin and urea clearance (R 0.56–0.75) as well. When dosing critically ill patients, therefore, extracorporeal as well as total clearance of levofloxacin should be considered.

scholarly journals P1117EXPLORATORY COMPARISON OF DIALYSIS EFFICIENCY AT DIFFERENT DIALYSATE FLOW (QD) IN EXPANDED HEMODIALYSIS IN TWO CENTERS IN COLOMBIA

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Alejandra Molano Trivino ◽  
Eduardo Zúñiga ◽  
Mauricio Sanabria ◽  
Jasmin Vesga ◽  
Carolina Ramos ◽  
...  
Keyword(s):  
Recent Literature ◽  
Demographic Data ◽  
Reduction Rate ◽  
Interleukin 10 ◽  
Wilcoxon Test ◽  
Flow Rates ◽  
Dialysate Flow ◽  
Dialysate Flow Rate ◽  
Middle Molecules

Abstract Background and Aims Dialysate flow rate (Qd) has minimal effect in removal of molecules in hemodialysis, allowing to use lower amounts of dialysate with no effect in clearance of molecules. According to recent literature, Expanded hemodialysis (HDx) improves the clearance of middle size molecules, diminishing the effect of Qd in adequacy. We found no data about clearance at different dialysate flow rates in HDx. Our aim is to evaluate the clearance of middle molecules (beta 2 microglobuline [Mβ2], interleukin-6 [IL-6], interleukin-10 [IL-10 light chains (CLL-κ -λ) with HDx at different Qd using membranes TheranovaMR in patients with body weight less than 70 Kg. Method We performed an observational retrospective analysis of clearance of Mβ2, IL-6, IL-10, CLL-κ; CLL-λ in HDx using TheranovaMR filters with Qd 400 mL/min and 500 mL/min. We performed variance analysis, T student test and Wilcoxon test. Data were extracted from an HDx multicentric trial performed in Bogotá, Colombia in 2018. Results 11 (47%) patients received Qd 400 mL/min and 12 (52.1%) patients with Qd 500ml/min. Demographic data are included in table 1. We found no differences in reduction rate of mid-molecules. (Table 2) We found that lower water consume in the Qd 400 mL/min group, with water savings of 24 Liters/patient (13824 L in 12 weeks of follow up). (Table 3) Conclusion Expanded hemodialysis seems to allow diminishing Qd rate without changes in mid-size molecules clearance.

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