Doppler Monitoring Research Articles

Home Monitoring for Fetal Heart Rhythm During Anti-Ro Pregnancies

BackgroundFetal atrioventricular block (AVB) occurs in 2% to 4% of anti-Ro antibody–positive pregnancies and can develop in <24 h. Only rarely has standard fetal heart rate surveillance detected AVB in time for effective treatment. ObjectivesOutcome of anti-Ro pregnancies was surveilled with twice-daily home fetal heart rate and rhythm monitoring (FHRM) and surveillance echocardiography. MethodsAnti-Ro pregnant women were recruited from 16 international centers in a prospective observational study. Between 18 and 26 weeks’ gestation, mothers checked FHRM twice daily with a commercially available Doppler monitor and underwent weekly or biweekly surveillance fetal echocardiograms. If FHRM was abnormal, a diagnostic echocardiogram was performed. Cardiac cycle length and atrioventricular interval were measured, and cardiac function was assessed on all echocardiograms. After 26 weeks, home FHRM and echocardiograms were discontinued, and mothers were monitored during routine obstetrical visits. Postnatal electrocardiograms were performed. ResultsMost mothers (273 of 315, 87%) completed the monitoring protocol, generating 1,752 fetal echocardiograms. Abnormal FHRM was detected in 21 mothers (6.7%) who sought medical attention >12 h (n = 7), 3 to 12 h (n = 9), or <3 h (n = 5) after abnormal FHRM. Eighteen fetuses had benign rhythms, and 3 had second- or third-degree AVB. Treatment of second-degree AVB <12 h after abnormal FHRM restored sinus rhythm. Four fetuses had first-degree AVB diagnosed by echocardiography; none progressed to second-degree AVB. No AVB was missed by home FHRM or developed after FHRM. ConclusionsHome FHRM confirms the rapid progression of normal rhythm to AVB and can define a window of time for successful therapy. (Prospective Maternal Surveillance of SSA [Sjögren Syndrome A] Positive Pregnancies Using a Hand-held Fetal Heart Rate Monitor; NCT02920346)

OC11.02: Outcomes of 271 anti‐Ro antibody‐positive pregnancies surveilled by echocardiography and home Doppler monitoring: an international multicentre prospective study

OC11.02: Outcomes of 271 anti‐Ro antibody‐positive pregnancies surveilled by echocardiography and home Doppler monitoring: an international multicentre prospective study

The predictability of dynamic preload indices depends on the volume of fluid challenge

This study was designed to assess the association between volume of fluid challenge (FC) and predictability of respiratory variation of stroke volume (ΔrespSV) in the operating theater.Patients undergoing intermediate/high-risk surgery and monitored by esophageal Doppler monitoring (EDM) were prospectively included. All patients were under general anesthesia and mechanically ventilated. Exclusion criteria were frequent ectopic beats or preoperative arrhythmia, right ventricular failure, and spontaneous breathing. Hemodynamic parameters and esophageal Doppler indices (SV, cardiac output, ΔrespSV) were collected before, after infusion of 250 mL, and after infusion of 500 mL of crystalloid solution. Responders were defined by a >15% increase of stroke volume after FC at each step.After infusion of a 250 mL FC, 41 patients (32%) were classified as fluid responders (R250). After infusion of a 500 mL FC, 80 patients (63%) were classified as fluid responders (R500). The predictability of ΔrespSV was fair with an area under the curve (AUC) of 0.79 (95% CI 0.71–0.86, P < .001) to predict fluid responsiveness with a 250 mL FC. With an AUC of 0.94 (95% CI 0.88–0.97, P < .0001), ΔrespSV presented an excellent ability to predict fluid responsiveness with a 500-mL FC.Predictability of ΔrespSV changed with the volume of fluid infused to assess fluid responsiveness. The accuracy of ΔrespSV was higher with 500 mL than with 250 mL. Bedside studies evaluating the predictability of dynamic preload indices should define fluid responsiveness as a >15% increase of SV in response to a 500-mL FC.

Application of neuronavigation combined with intraoperative related assistive technology in craniotomy

Objective To explore the role of neuronavigation combined with intraoperative ultrasound Doppler and neurophysiological monitoring in intracranial lesion surgery. Methods A total of 34 patients with intracranial lesions who underwent surgical treatment at Neurosurgery Department of the First Affiliated Hospital of Inner Mongolia Medical University from January 2012 to July 2015 were retrospectively reviewed. All operations were guided by neuronavigation combined with intraoperative ultrasonic Doppler localization. Intraoperative resuscitation and intraoperative electrophysiological monitoring were performed in 10 cases with lesions located at functional areas. Results In 34 cases, brain shift occurred in 24 cases after intraoperative navigation and the distance was 4-13 (6.7±2.4) mm. For ultrasonic assisted navigation, the lesion localizing accuracy rate was 100%. Intraoperative ultrasonography showed that total resection was achieved in 27 cases, subtotal resection in 5 and partial resection in 2. There were 2 cases of transient unilateral motion dysfunction, 1 case of transient language disorder, 1 case of intracranial infection, 1 case of epileptic seizure and no deaths. Postoperative images showed that the brain damage was mild, the cortex was intact and the extent of lesion resection was consistent with intraoperative ultrasound demonstration. None of the 10 patients with functional area lesions showed postoperative functional impairment. Conclusion Neuronavigation combined with intraoperative assistive technology could help precisely localize lesions, protect brain cortex, maximize the removal of lesions and reduce the complications related to the operations. Key words: Brain diseases; Neurosurgical procedures; Neuronavigation; Ultrasonography; Nervous system physiological processes; Intraoperative waken-up

A rare case of acute twin-to-twin transfusion syndrome with late manifestation in monochorionic diamniotic twins

A rare case of acute twin-to-twin transfusion syndrome developed after 32 weeks of gestation is presented. This syndrome caused intrauterine death of one of the twins and newborn’s death of another one. Previous examination was performed 19 days earlier. Ultrasound examination, Doppler and fetal monitoring have shown normal findings. Postnatal colour stain of the placental anastomosis, pathophysiological research of lost life fetus and clinical tests of survived newborn confirmed our suggestions.

Early High Frequency Oscillatory Ventilation in Pediatric Acute Respiratory Failure

AbstractBackground: High frequency oscillatory ventilation (HFOV) has been a staple in the management of children with acute respiratory failure (ARF). HFOV is a mode of mechanical ventilation that recruits diseased lung and improves oxygen-ation through the use of high mean airway pressures with tidal volumes less than anatomic dead space. Although HFOV is commonly used in children, efficacy data are limited and predate the era of low tidal volume (Vt) conventional mechan-ical ventilation (CMV).Aim of the Study: It was to compare the impact of early high frequency oscillatory ventilation (within 24-48 hours of endotracheal intubation) to conventional mechanical ventilation and/or late high frequency oscillatory ventilation in children with acute respiratory failure.Patients and Methods: The study was carried out on thirty patients with acute respiratory failure (ARF) who attended to the pediatric intensive care unit, Pediatric Department, Tanta University Hospital. All studied children were subjected to detailed history taking, complete physical examination, mon-itoring of SV, SVI, CO, CI, SVR, SVRI through trans-esophageal doppler monitoring and oxygenation index.Results: There was significant decrease of O2Sat of Early HFOV group compared with P-CMV and Late HFOV. there was significant increase of O2Sat in Early HFOV in 2nd and 3rd days compared with 1st day There was significant decrease of oxygenation index in late HFOV and P-CMV groups compared with Early HFOV group. It is one of most important prognostic factors for detection timing of HFOV according to ROC curve.Conclusion: As hypoxia worsened, patient percentage with Early HFOV increased Oxygenation index was significant as a predictor and prognostic factor for early HFOV success.

Is Neuroergonomic Monitoring Non-Intrusive? An Examination of Transcranial Doppler Sonography

One of the primary aims of neuroergonomic research is to identify neural and psychophysiological measures that can be used to index operator state in real time (e.g., Stephens, Scerbo, &amp; Pope, 2012; Tripp &amp; Warm, 2007). Such measures are desired because they may have capabilities that exceed traditional subjective and performance methods of estimating operator state. Physiological monitoring has been proffered as a remedy for the shortcomings of subjective and performance measures of operator state, because it is arguably less intrusive than subjective measures, allows for continuous measurement, and provides estimates of operator state even when performance efficiency is unobservable (Stephens et al., 2012). One area where physiological monitoring may be particularly beneficial is within tasks that require vigilance. Vigilance tasks are common within many military, industrial, and medical settings and generally require an operator to maintain attentional focus for the detection of critical events that tend to occur rarely and unpredictably. However, the ability to maintain vigilance typically declines over time, which is problematic when detection is critical to system safety. Additionally, the demands of vigilance tasks are associated with high workload and task-induced stress (Warm, Parasuraman, &amp; Matthews, 2008). Research suggests that physiological measures may allow for continuous, real-time tracking of an operator’s level of vigilance, and facilitate adaptive interventions (e.g., rest breaks, adaptive automation) to ensure that a loss of vigilance does not lead to errors or accidents (Warm &amp; Parasuraman, 2007). Transcranial Doppler Sonography (TCD) is a physiological measure that is especially well-suited to real-time assessment of operator vigilance (Warm &amp; Parasuraman, 2007). TCD can be used to monitor hemodynamic activity within the brain, which has been closely linked to level of vigilance performance. In short, TCD may serve to predict and prevent loss of vigilance, non-intrusively in operational settings (Warm &amp; Parasuraman, 2007). Before deploying TCD for vigilance monitoring in operational settings users should consider whether it is truly non-intrusive. If TCD monitoring negatively impacts operator state or performance, practical applications may be limited. The current study was designed to determine whether TCD use has intrusive effects on operator state and performance. To assess operator state, we utilized three measures that have been used previously in vigilance tasks: The Short Stress State Questionnaire (SSSQ; Helton, 2004), the Simulator Sickness Questionnaire (Kennedy, Lane, &amp; Berbaum, 1993), and the NASA-TLX. These questionnaires were used to assess task-induced stress, symptoms of simulator sickness, and workload, respectively. Performance was assessed in terms of percentage correct detections. Forty-two students (34 Women, 8 Men) were assigned at random to either a Doppler Monitoring condition or to a Control (No Physiological Monitoring) condition with the restriction that the group size (n = 21) and the ratio of participant sex be identical in both conditions. All participants completed a 40-minute vigilance task based on the procedure used by Greenlee and colleagues (2015), wherein participants monitored a computerized gauge for cases in which the gauge needle deviated from a vertical position (20% signal probability, 50 events per minute). Participants in the Doppler Monitoring condition wore the TCD during the vigil, those in the Control condition did not. Results from both conditions mirror typical vigilance findings. Percentage correct detections declined over time, distress and symptoms of simulator sickness increased, engagement decreased, and workload was rated as high. However, the performance, task-induced stress, reported levels of simulator sickness, and workload of participants equipped with TCD were indistinguishable from values taken from participants in the control condition. With the caveat that these are statistically null results, this supports the possibility that TCD monitoring may be non-intrusive. This finding, combined with research demonstrating the link between TCD measurements and vigilance (e.g., Warm &amp; Parasuraman, 2007), supports the recommendation that TCD should be used in operational settings where operator vigilance is of paramount importance.

Correlation of Matrix Metalloproteinases-9 with Microemboli Shedding in Carotid Endarterectomy

Objective To investigate the change of serum matrix metalloproteinases-9 (MMP-9) expression before,during,and after carotid endarterectomy (CEA) and to investigate the prognostic role of MMP-9. Methods Forty carotid stenosis patients who underwent CEA in the Department of Vascular Surgery,Peking Union Medical College Hospital from February to September 2012 were enrolled in this study. Based on the findings of transcranial doppler monitoring,patients were divided into embolic-positive group and emboli-negative group. Serum samples were obtained from 40 consecutive patients undergoing CEA before operation (pre-op),before de-clamping,30 minutes after de-clamping,and 12 hours after operation (12-h post-op). MMP-9 expression was quantified using enzyme-linked immunosorbent assay and gelatin zymography. Student's t-test and chi-square test were used to compare the differences between these two groups. Results Of these 40 patients,microemboli were detected in 8 patients. The 12-h post-op MMP-9 level was significantly higher than the pre-op level in the emboli-positive group [(904.27±369.47)ng/ml vs. (333.88±126.32) ng/ml,t=4.132,P=0.001].However,there was no difference between pre-op and 12-h post-op MMP-9 levels in the emboli-negative group [(375.83±194.36) ng/ml vs. (472.74±271.21) ng/ml,t=-1.643,P=0.081]. Gelatin zymography also showed higher MMP-9 activity in the emboli-positive group than in the emboli-negative group. Conclusion Serum MMP-9 concentration remarkably increases 12 hours after CEA in patients with microemboli shedding,suggesting MMP-9 may be a potential biomarker for CEA-related cerebral ischemic injury.

Pancreatic-islet microvascular vasomotion dysfunction in mice with spinal cord injury

Patients with spinal cord injury (SCI) have an increased risk for developing type 2 diabetes. It is unknown whether the pancreatic-islet microvascular vasomotion is involved. We used female C57BL/6 mice and a 100-kilodyne T10 Infinite Horizons contusion SCI (or T10 laminectomy) to detect blood glucose and pancreatic-islet microvascular vasomotion. Blood glucose obtained from tail vein was detected using one Touch UltraEasy glucometer. Glucose tolerance test was performed by d-glucose administration intraperitoneally. Functional status of pancreatic-islet microvascular vasomotion was determined by laser Doppler monitoring. Expressions of insulin and glucagon were determined by immunohistochemistry. Expression of VEGF-A was determined by immunohistochemistry and Western blotting. Our result demonstrated that blood glucose was significantly increased at 4 h postinjury compared to that in sham group, with continuous higher blood glucose until 4 days postinjury (p < 0.05). SCI mice at day 7 and day 14 had significantly impaired glucose tolerance following glucose administration (p < 0.01). Average blood perfusion, amplitude, frequency, and relative velocity of vasomotion were significantly lower at 6 h postinjury than those in the sham group (p < 0.05), which were gradually upregulated over time. The expression of insulin was decreased, while the expression of glucagon was increased at 6 h postinjury. Similarly, the expression of VEGF-A was significantly decreased at 6 h postinjury, compared to that in sham group (p < 0.05), with slight increases by 14 days postinjury. Our study suggests that the functional status of pancreatic-islet microvascular vasomotion is impaired after injury, which may have implications for developing effective therapeutic interventions for SCI.

Statin Pretreatment and Microembolic Signals in Large Artery Atherosclerosis.

Background and Purpose- Scarce data indicate that statin pretreatment (SP) in patients with acute cerebral ischemia because of large artery atherosclerosis may be related to lower risk of recurrent stroke because of a decreased incidence of microembolic signals (MES) during transcranial Doppler monitoring. Methods- We performed a systematic review and meta-analysis of available observational studies reporting MES presence/absence or MES burden, categorized according to SP status, in patients with acute cerebral ischemia because of symptomatic (≥50%) large artery atherosclerosis. In studies with partially-published data, authors were contacted for previously unpublished information. We also performed a sensitivity analysis of studies with data on MES burden categorized according to SP status, and an additional subgroup analysis in patients receiving higher-dose SP (atorvastatin 80 mg or rosuvastatin 40 mg daily). Results- Seven eligible study protocols were identified (610 patients, 54% with SP). SP was associated with a reduced risk of MES detection during transcranial Doppler monitoring (risk ratio=0.67; 95% CI, 0.45-0.98), with substantial heterogeneity between studies ( I2=52%). In studies reporting MES burden (n=4), a significantly lower number of MES were identified in patients with compared with those without SP (mean difference=-0.92; 95% CI, -1.64 to -0.19), with no evidence of heterogeneity between studies ( I2=49%). Subgroup analysis revealed that higher-dose SP reduced the risk of detecting MES (risk ratio=0.23; 95% CI, 0.06-0.88), with no evidence of heterogeneity between studies ( I2=0%). Conclusions- SP seems to be associated with a lower incidence and burden of MES in patients with acute cerebral ischemia because of large artery atherosclerosis.

Wall Shear Stress and T1 Contrast Ratio Are Associated With Embolic Signals During Carotid Exposure in Endarterectomy.

Background and Purpose- The frictional force because of blood flow may dislodge masses present on the surface of a plaque. Such frictional force is calculated as wall shear stress (WSS) using computational fluid dynamics. The aims of the present study were to determine whether, in addition to carotid plaque intensity on T1-weighted magnetic resonance (MR) imaging, WSS calculated using computational fluid dynamics analysis for carotid arteries is associated with development of an embolism during exposure of carotid arteries during carotid endarterectomy. Methods- One hundred patients with internal carotid artery stenosis (≥70%) underwent carotid plaque imaging with MR, and 54 patients with a vulnerable plaque (intraplaque hemorrhage or lipid/necrotic core) displayed as a high-intensity lesion underwent additional cervical 3-dimensional MR angiography. The maximum value of WSS within the most severe stenotic segment of the internal carotid artery was calculated using MR angiography. Transcranial Doppler monitoring of microembolic signals (MES) in the ipsilateral middle cerebral artery was performed during carotid endarterectomy. Results- Although none of the 46 patients with a nonvulnerable carotid plaque had MES during exposure of carotid arteries, 24 of the 54 patients with a vulnerable carotid plaque (44%) had MES. Logistic regression analysis showed that higher plaque intensity ( P=0.0107) and higher WSS ( P=0.0029) were significantly associated with the development of MES. When both cutoff points of plaque intensity and WSS in the receiver operating characteristic curves for predicting development of MES were combined, specificity (from 63% to 93%) and positive predictive value (from 66% to 90%) became greater than those for plaque intensity alone. Conclusions- In addition to carotid plaque intensity on T1-weighted MR imaging, WSS calculated using computational fluid dynamics analysis for carotid arteries is associated with development of an embolism during exposure of carotid arteries during carotid endarterectomy.

Pulse pressure variation and pleth variability index as predictors of fluid responsiveness in patients undergoing spinal surgery in the prone position.

BackgroundThis study investigated the ability of pulse pressure variation (PPV) and pleth variability index (PVI) to predict fluid responsiveness of patients undergoing spinal surgery in the prone position.Patients and methodsA total of 53 patients undergoing posterior lumbar spinal fusion in the prone position on a Jackson table were studied. PPV, PVI, and hemodynamic and respiratory variables were measured both before and after the administration of 6 mL/kg colloid in both the supine and prone positions. Fluid responsiveness was defined as a 15% or greater increase in stroke volume index, as assessed by esophageal Doppler monitor after fluid loading.ResultsIn the supine position, 40 patients were responders. The areas under the receiver operating characteristic (ROC) curves for PPV and PVI were 0.783 [95% CI 0.648–0.884, P<0.001] and 0.814 (95% CI 0.684–0.908, P<0.001), respectively. The optimal cut-off values of PPV and PVI were 10% (sensitivity 75%, specificity 62%) and 8% (sensitivity 78%, specificity 77%), respectively. In the prone position, 27 patients were responders. The areas under the ROC curves for PPV and PVI were 0.781 (95% CI 0.646–0.883, P<0.001) and 0.756 (95% CI 0.618–0.863, P<0.001), respectively. The optimal cut-off values of PPV and PVI were 7% (sensitivity 82%, specificity 62%) and 8% (sensitivity 67%, specificity 69%), respectively.ConclusionBoth PPV and PVI were able to predict fluid responsiveness; their predictive abilities were maintained in the prone position.

Impact of external carotid artery occlusion at declamping of the external and common carotid arteries during carotid endarterectomy on development of new postoperative ischemic cerebral lesions

ObjectiveThe external carotid artery (ECA) is inadvertently occluded during carotid endarterectomy (CEA). The importance of ECA occlusion has been emphasized as a loss of extracranial to intracranial collaterals, a source of chronic embolization, or a site for extended thrombosis during wound closure. This study aimed to determine whether ECA occlusion that inadvertently developed during endarterectomy and that was eventually detected using blood flow measurement of the ECA after declamping of all carotid arteries is a risk factor for development of new postoperative ischemic lesions at declamping of the ECA and common carotid artery (CCA) while clamping the internal carotid artery (ICA). This study also aimed to determine whether intraoperative transcranial Doppler (TCD) monitoring predicts the risk for development of such lesions. MethodsThis was a prospective observational study that included patients undergoing CEA for severe stenosis (≥70%) of the cervical ICA. When blood flow through the ECA measured using an electromagnetic flow meter decreased rapidly on clamping of only the ECA before carotid clamping for endarterectomy and was not changed by clamping of only the ECA after carotid declamping following endarterectomy, the patient was determined to have developed ECA occlusion. These patients underwent additional endarterectomy for the ECA. TCD monitoring in the ipsilateral middle cerebral artery was also performed throughout surgery to identify microembolic signals (MESs). Brain magnetic resonance diffusion-weighted imaging (DWI) was performed before and after surgery. ResultsThere were 104 patients enrolled in the study. Eight patients developed ECA occlusion during surgery. The incidence of intraoperative ECA occlusion was significantly higher in patients without MESs at the phase of ECA and CCA declamping (8/12 [67%]) than in those with MESs (0/92 [0%]; P < .0001). Six patients exhibited new postoperative ischemic lesions on DWI. The incidence of intraoperative ECA occlusion (P < .0001) and the absence of MESs at declamping of the ECA and CCA while clamping the ICA (P <. 0001) were significantly higher in patients with development of new postoperative ischemic lesions on DWI than in those without. Sensitivity and specificity for the absence of MESs at declamping of the ECA and CCA while clamping the ICA for predicting development of new postoperative ischemic lesions on DWI were 100% (6/6) and 94% (92/98), respectively. ConclusionsECA occlusion at declamping of the ECA and CCA while clamping the ICA during CEA is a risk factor for development of new postoperative ischemic lesions. Intraoperative TCD monitoring accurately predicts the risk for development of such lesions.

Noninvasive haemodynamic monitoring and hypotension management with transesophageal duplex among mechanically-ventilated patients: An analytical study

Introduction: Central venous (CV) line is one of the most common methods of central venous pressure (CVP) measurement and hemodynamic monitoring among patients admitted to the intensive care unit (ICU). However, its complications are not rare and are life-threatening in some cases. Recently, transesophageal duplex is frequently used to monitor the cardiac output (CO) and intravascular fluid volume of patients admitted to ICU. The present study was conducted aiming to assess noninvasive hemodynamic monitoring and hypotension management with transesophageal doppler among mechanically-ventilated patients. Methods: In this descriptive cross-sectional study, 25 patients admitted to the ICU of Imam Reza Hospital, Tabriz, Iran, were studied. CV line had been inserted into the body of the patients prior to the study for various reasons. CO was measured using esophageal duplex and also transthoracic echocardiography (TTE), and CVP was determined via esophageal duplex and CV line findings. Results: Mean CO of the patients was 4.88 ± 0.61 and 4.86 ± 0.59 l/minute measured by esophageal duplex and TTE, respectively. Hence, the difference was not statistically significant between the two methods. The mean CVPs of the patients measured by esophageal duplex and CV line were 4.94 ± 1.15 and 4.54 ± 1.04 mmHg, respectively. In addition, the left ventricular (LV) filling pressure measured by Oesophageal Doppler Monitoring (ODM) and by TTE was 9.28 ± 2.66 and 9.28 ± 2.66 mmHg, respectively. The difference for both of the mentioned variables was statistically significant but clinically negligible. Conclusion: Based on the results of this study, esophageal duplex as a less invasive, safe and precise method can replace the use of CV line among patients undergoing mechanical ventilation. This will help clinicians to obtain accurate haemodynamic data from critically ill patients and avoid unexpected complications imposed by CV line insertion.

Evaluation of hemodynamic goal-directed therapy to reduce the incidence of bone cement implantation syndrome in patients undergoing cemented hip arthroplasty \u2013 a randomized parallel-arm trial

BackgroundThe bone cement implantation syndrome (BCIS) is a frequent and potentially disastrous intraoperative complication in patients undergoing cemented hip arthroplasty. Several risk factors have been identified, however randomized controlled trials to reduce the incidence of BCIS are still pending. We hypothesized that goal-directed hemodynamic therapy guided by esophageal Doppler monitoring (EDM) may reduce the incidence of BCIS in a randomized, controlled parallel-arm trial.MethodsAfter approval of the local ethics committee, 90 patients scheduled for cemented hip arthroplasty at the Medical Center – University of Freiburg were randomly assigned to either standard hemodynamic management or goal-directed therapy (GDT) guided by an esophageal Doppler monitoring-based algorithm. The primary endpoint was the incidence of overall BCIS including grade 1–3 after cementation of the femoral stem. Secondary endpoints included cardiac function, length of hospital stay and postoperative complications.ResultsNinety patients were finally analyzed. With regards to the primary endpoint, the overall incidence of BCIS showed no difference between the GDT and control group. Compared to the control group, patients of the GDT group showed a higher cardiac index before and after bone cement implantation (2.7 vs. 2.2 [l●min− 1●m− 2]; 2.8 vs. 2.4 [l●min− 1●m− 2]; P = 0.003, P = 0.042), whereas intraoperative amount of fluids and mean arterial pressure did not differ.ConclusionsThe implementation of a specific hemodynamic goal-directed therapy did not reduce the overall incidence of BCIS in patients undergoing cemented hip arthroplasty.Trial registrationThis randomized clinical two-arm parallel study was approved by the local Ethics Committee, Freiburg, Germany [EK 160/15, PI: U. Goebel] and registered in the German Clinical Trials Register (DRKS No. 00008778, 16th of June, 2015).

Using Laser Doppler Imaging and Monitoring to Analyze Spinal Cord Microcirculation in Rat.

Laser Doppler flowmetry (LDF) is a noninvasive method for blood flow (BF) measurement, which makes it preferable for measuring microcirculatory alterations of the spinal cord. In this article, our goal was to use both Laser Doppler imaging and monitoring to analyze the change of BF after spinal cord injury. Both the laser Doppler image scanner and the probe/monitor were being employed to obtain each readout. The data of LDPI provided a local distribution of BF, which gave an overview of perfusion around the injury site and made it accessible for comparative analysis of BF among different locations. By intensely measuring the probing area over a period of time, a combined probe was used to simultaneously measure the BF and oxygen saturation of the spinal cord, showing overall spinal cord perfusion and oxygen supply. LDF itself has a few limitations, such as relative flux, sensitivity to movement, and biological zero signal. However, the technology has been applied in clinical and experimental study due to its simple setup and rapid measurement of BF.

Using Laser Doppler Imaging and Monitoring to Analyze Spinal Cord Microcirculation in Rat

Using Laser Doppler Imaging and Monitoring to Analyze Spinal Cord Microcirculation in Rat

Cardiac output-based fluid optimization for kidney transplant recipients: a proof-of-concept trial.

Intravenous fluid management for deceased donor kidney transplantation is an important, modifiable risk factor for delayed graft function (DGF). The primary objective of this study was to determine if goal-directed fluid therapy using esophageal Doppler monitoring (EDM) to optimize stroke volume (SV) would alter the amount of fluid given. This randomized, proof-of-concept trial enrolled 50 deceased donor renal transplant recipients. Data collected included patient characteristics, fluid administration, hemodynamics, and complications. The EDM was used to optimize SV in the EDM group. In the control group, fluid management followed the current standard of practice. The groups were compared for the primary outcome of total intraoperative fluid administered. There was no difference in the mean (standard deviation) volume of intraoperative fluid administered to the 24 control and 26 EDM patients [2,307 (750) mL vs 2,675 (842) mL, respectively; mean difference, 368 mL; 95% confidence interval (CI), -87 to +823; P=0.11]. The incidence of complications in the control and EDM groups was similar (15/24 vs 17/26, respectively; P=0.99), as was the incidence of delayed graft failure (8/24 vs 11/26, respectively; P=0.36). Goal-directed fluid therapy did not alter the volume of fluid administered or the incidence of complications. This proof-of-concept trial provides needed data for conducting a larger trial to determine the influence of fluid therapy on the incidence in DGF in deceased donor kidney transplantation. www.clinicaltrials.gov (NCT02512731). Registered 31 July 2015.

Efficacy of corrected left ventricular ejection time and stroke volume in guiding volume therapy during single lung transplantation: transesophageal Doppler monitoring

Objective To evaluate the efficacy of corrected left ventricular ejection time (LVETc) and stroke volume (SV) monitored by transesophageal Doppler in guiding volume therapy during single lung transplantation. Methods Twenty-six American Society of Anesthesiologists physical status Ⅲ or Ⅳ patients, aged 32-55 yr, with body mass index of 18.0-24.6 kg/m2, scheduled for elective single lung transplantation, were divided into 2 groups (n=13 each) using a random number table: control group (group C) and LVETc plus SV group (group LS). After implanting double lumen endobronchial tube, a transesophageal probe was inserted to monitor LVETc and SV in group LS, and Swan-Ganz catheter was inserted via the right internal jugular vein puncture to monitor CVP in group C. Fluid infusion was given according to CVP, and CVP was maintained at 6-12 cmH2O in group C. In group LS, fluid infusion was given according to LVETc and SV, LVETc was maintained at 0.35-0.40 s, and the fluctuation of SV was less than 10% of the baseline before fluid replacement.At 5 min before one-lung ventilation, 30 min of one-lung ventilation, 30 min of pulmonary artery occlusion and 30 min of pulmonary artery unclamping and at the end of operation, blood samples were collected from the radial artery for blood gas analysis, blood lactate levels were recorded, and oxygenation index was calculated.The liquid intake and output volume was recorded before pulmonary artery occlusion (from the end of one-lung ventilation until the time point before pulmonary artery occlusion), during pulmonary artery occlusion and during pulmonary artery unclamping (from removal of atrial clamp until the end of operation). The consumption of intraoperative furosemide and metaraminol was recorded.The development of pharyngeal mucosal membrane injury, esophageal perforation, hemorrhage or local hematoma was recorded after operation. Results Compared with group C, the oxygenation index was significantly increased and blood lactate concentrations were decreased at 30 min of pulmonary artery occlusion, 30 min of pulmonary artery unclamping and at the end of operation, the amount of crystalloid and colloid solution infused was increased before and during pulmonary artery occlusion and reduced during pulmonary artery unclamping, the urine output was increased in each period, and the consumption of intraoperative metaraminol was reduced in group LS (P<0.05). No postoperative esophageal perforation, bleeding or local hematoma was found in two groups, and only one patient had pharyngeal mucous membrane injury after operation in group LS. Conclusion LVETc and SV monitored by transesophageal Doppler can not only keep circulation capacity and tissue perfusion effective, but also maintain hemodynamics relatively stable during operation for patients undergoing single lung transplantation. Key words: Lung transplantation; Ventricular function, left; Stroke volume; Fluid therapy; Transesophageal, Doppler

Surgical left subclavian artery revascularization for thoracic aortic stent grafting: a single-centre experience in 101 patients.

To evaluate the indications, perioperative strategy and postoperative outcome of surgical left subclavian artery (LSA) revascularization combined with thoracic endovascular aortic repair (TEVAR) covering the LSA. Between 2000 and 2017, a total of 101 consecutive patients underwent surgical revascularization of the LSA prior to, concomitant or following TEVAR. Revascularization was performed through a small supraclavicular incision and consisted of a transposition or bypass graft, using intraoperative transcranial Doppler monitoring. Data regarding indication, procedural details and postoperative results were retrospectively analysed. In total, 63 subclavian-carotid bypass grafts and 38 subclavian-carotid transpositions were performed in the context of TEVAR. The majority was performed prior to stent grafting to reduce the risk of stroke (n = 50), spinal cord ischaemia (n = 20), left arm malperfusion (n = 10) or to preserve a patent left internal mammary artery coronary bypass graft (n = 2). Secondary revascularization was performed in 14 patients, 2 times immediately due to acute left arm malperfusion and 12 times to treat invalidating left arm claudication. No in-hospital mortality and permanent spinal cord ischaemia occurred. Two (2%) ischaemic strokes were observed in patients with concomitant procedures, and none when separate, staged procedures were performed. Additional complications observed were permanent peripheral nerve palsies (9%), chyle leakage requiring diet (6%) and 1 bypass occlusion requiring a redo procedure. In patients predominantly selected upon the anticipated risk of (posterior) stroke, spinal cord ischaemia and left arm malperfusion, surgical revascularization of the LSA proved to be a safe treatment option to preserve antegrade LSA flow in the context of TEVAR.