Continuous Blood Research Articles

Effect of Blood Volume Shift Simulated via Head-up Tilt on Photoplethysmography Morphology.

PPG can provide information on cardiovascular responses to fluid shifts from upper to lower part of body under the condition of orthostatic stress. The current study investigated ability of PPG derived LVET and other PPG derived features to identify progressive central hypovolemia induced by head up tilt (HUT) and evaluated potential use of LVET as early noninvasive indicator of blood loss. Continuous finger PPG, blood pressure, and electrocardiography were recorded simultaneously during 5-minutes of baseline and HUT of 20°, 40°, and 60° from 15 participants (age: 26.5 ± 3 years; height: 177 ± 8 cm; weight: 72 ± 10 kg, mean ± SD). Beat-by-beat pulse rate (PR), systolic amplitude (SA), systolic time (ST), diastolic time (DT), and PP Interval (PPI) and Ratio of pulse rate over systolic amplitude (PR/SA) were derived for each stage. LVET was derived from each stage. Friedman test followed by post-hoc analysis using Tukey-HSD was conducted to highlight the significance of changes induced by HUT. Application of 60° HUT (i.e. moderate category simulated hypovolemia) resulted in a significant change in PR (80±3 bpm vs 68±3 bpm, p=0.0008), DT (264±7 ms vs 303±4 ms, p=0.0008), ST (110±6 ms vs 117±7 ms, p=0.02), PP interval (764±39 ms vs 869±25 ms, p=0.0045), PR/SA (112±16 vs 82±21, p=0.012) , SA (0.875± 0.2 vs 1.69±0.6, p=0.012) and LVET(292 vs 351ms,p=0.0008) compared to baseline. LVET has a strong association with the change in central blood volume and may be used as a sensitive early marker of progressive hypovolemia. The findings of the study support the hypothesis of differentiating simulated hypovolemia based on PPG alone. Keywords: Hypovolemia, HUT, LVET.

0556 Sex-Specific Relationship Between Anxiety and Autonomic Nervous System Dysfunction in Obstructive Sleep Apnea

Abstract Introduction Cardiovascular co-morbidities in obstructive sleep apnea (OSA) are hard to treat, perhaps due to autonomic nervous system (ANS) dysfunction. In OSA, intermittent hypoxia and poor tissue oxygen perfusion damage endothelial and nervous tissue, potentially underlying the dysfunction. Moreover, OSA is strongly associated with anxiety, which is independently associated with ANS dysfunction. We assessed sex-specific relationships between anxiety and cardiovascular markers of ANS dysfunction in OSA. Methods We studied people diagnosed with OSA and healthy controls. We collected 5 minutes of wakeful resting ECG, continuous non-invasive blood pressure, and respiration data. We calculated heart rate (HR), heart rate variability (HRV; sympathetic-vagal balance related to brainstem ANS output), mean arterial blood pressure (MAP), beat-to-beat MAP variability (BPV; related to peripheral autonomic function) and breathing rate (BR). We analyzed these measures with a multivariate regression model of anxiety symptoms (generalized anxiety disorder; GAD-7 scores), sex, and group (OSA vs. control), age/BMI/AHI covariates, and Bonferroni-corrected post-hoc comparisons (p≤0.05). Results We analyzed 64 subjects (32 OSA: AHI [mean±SEM] 24±4events/hour, 12 female, age 52±21years, BMI 33±2kg/m2; 32 control: 19 female, age 46±2; BMI 26±1). We observed significant main effects of anxiety, BMI, AHI, sex on HRV, but only group on BPV; post-hoc comparisons revealed high BPV only in OSA females. Secondary analyses included classifying by anxiety symptoms (GAD-7≥5), showing only OSA females with anxiety had higher BPV. Males showed higher HRV. AHI and anxiety were positively correlated with HRV in OSA males. AHI was negatively correlated with BR in OSA females. Conclusion We observed higher anxiety associated with higher BPV in OSA, especially in females. Unexpectedly, BR was lower in OSA females; longer breaths may have led to the greater BPV. Higher HRV in males complicated by OSA severity and anxiety could be related to higher sympathetic tone. The slightly older control group may have influenced the findings. Overall, our findings suggest anxiety in OSA is associated with peripheral and centrally-mediated autonomic dysfunction, but in a sex-specific manner. Support National Institutes of Health R56-NR-017435 and RO1-HL-135562.

The application of a neural network to predict hypotension and vasopressor requirements non-invasively in obstetric patients having spinal anesthesia for elective cesarean section (C/S)

BackgroundNeural networks are increasingly used to assess physiological processes or pathologies, as well as to predict the increased likelihood of an impending medical crisis, such as hypotension.MethodWe compared the capabilities of a single hidden layer neural network of 12 nodes to those of a discrete-feature discrimination approach with the goal being to predict the likelihood of a given patient developing significant hypotension under spinal anesthesia when undergoing a Cesarean section (C/S). Physiological input information was derived from a non-invasive blood pressure device (Caretaker [CT]) that utilizes a finger cuff to measure blood pressure and other hemodynamic parameters via pulse contour analysis. Receiver-operator-curve/area-under-curve analyses were used to compare performance.ResultsThe results presented here suggest that a neural network approach (Area Under Curve [AUC] = 0.89 [p < 0.001]), at least at the implementation level of a clinically relevant prediction algorithm, may be superior to a discrete feature quantification approach (AUC = 0.87 [p < 0.001]), providing implicit access to a plurality of features and combinations thereof. In addition, the expansion of the approach to include the submission of other physiological data signals, such as heart rate variability, to the network can be readily envisioned.ConclusionThis pilot study has demonstrated that increased coherence in Arterial Stiffness (AS) variability obtained from the pulse wave analysis of a continuous non-invasive blood pressure device appears to be an effective predictor of hypotension after spinal anesthesia in the obstetrics population undergoing C/S.This allowed us to predict specific dosing thresholds of phenylephrine required to maintain systolic blood pressure above 90 mmHg.

Mitigating Risks of Primary Graft Dysfunction with Antegrade Myocardial Perfusion

Primary Graft Dysfunction (PGD) is the leading cause of early mortality after heart transplantation. Several risk factors of PGD have been identified, including; prolonged warm ischaemic time, advanced donor age, gender mismatch and recipient diabetes mellitus. We adopted a novel method of implantation using "antegrade myocardial perfusion (AMP)" during implantation and compared this to the conventional approach. We obtained the retrospective data retrospectively from the Golden Jubilee National Hospital heart transplant database, ClinicalPortal and CIS databases from January/2012-May/2018. Missing data were obtained from the hard copy case notes. We performed AMP utilising continuous cold blood (4-6°C) antegrade cardioplegia to achieve aortic root pressures of 60-70 mmHg. Leucocyte filer was utilised. The infusion would continue with an LV vent insitu until the left atrial and aortic anastomoses were complete. "Hotshot" warm blood was then infused prior to removal of the cross clamp. Multivariable logistic regression with moderate/severe PGD as the outcome measure. Confounders were adjusted for recipient age, total ischaemic time, bypass time, predicted left ventricular (LV) mass mismatch, recipient diabetes mellitus and donor age. A total of 75 patients were included in this study. 44% (n=33) underwent AMP and 56 % (n=42) had orthotopic heart transplantation with the conventional approach. There was no statistically significant difference in age, gender, incidence of diabetes mellitus, preoperative utilisation of mechanical circulatory support between the AMP and the control group. We found that total ischaemia time was significantly shorter in the AMP cohort (154+/-50.2 vs. 181+/-47.1 min, p=0.018). The rate of postoperative VA ECMO support was significantly lower in the AMP cohort (15% vs. 54%, p<0.001). The rate of moderate-severe PGD was significantly lower in the AMP cohort (21% vs. 69%, p<0.001). The odds ratio of PGD in patients in the historical cohort vs AMP was 4.15 (1.21-14.24). Our implantation technique utilising AMP significantly lowers the rate of moderate and severe PGD when compared to the standard implantation technique employed by the historical cohort.

Highly Sensitive Closed Loop Enclosed Split Ring Biosensor With High Field Confinement for Aqueous and Blood-Glucose Measurements

This paper presents a highly sensitive closed loop enclosed split ring biosensor operating in microwave frequencies for measuring blood glucose levels in the human body. The proposed microwave glucose biosensor, working on the principle of high field confinement and concentrated energy, has been tested using both in-vitro and in-vivo methods. This principle allows the sensor to concentrate energy at the surface which results in improved accuracy of measurements. For in-vitro measurements, the biosensor has been tested using de-ionized water glucose solutions of different concentrations. The miniaturized micrometer scale biosensor is fabricated over a thin Si-substrate using photolithographic technique. The biosensor has been designed in a way to operate at desired microwave frequencies. Highly confined fields and concentrated energy inside the closed loop line containing the split ring resonators are responsible for the sensitivity enhancement. This new biosensor has obtained a high sensitivity of 82 MHz/mgmL−1 within the clinical diabetic range during in-vivo testing over the human body. In addition, the subjects (undergoing experiments) steady state has been continuously monitored throughout the experiment which helps in improving the accuracy of the results. The proposed biosensor has further obtained a low detection limit of <0.05 wt.% and can be useful for continuous non-invasive blood glucose monitoring.

Follow-up results of aortic arch cervical debranching performed with the help of a temporary crossover external carotid artery bypass for cerebral protection followed by endovascular thoracic aortic aneurysm repair.

Treating aortic arch aneurysms with conventional open surgical and endovascular stent graft procedures is challenging due to the complex anatomy of the arch and the arteries arising from it that nourish the brain. Cerebral protection is of the utmost importance during the treatment of thoracic aneurysms involving the aortic arch. Between May 2014 and November 2018, 7 patients with thoracic aortic aneurysms involving the aortic arch who underwent aortic arch cervical debranching with our technique were reviewed retrospectively. Because all the patients being considered for conventional surgical aortic arch replacement had serious comorbidities, they were selected to receive hybrid therapy. The mean age of the patients was 71.2 ± 9.4 years. One patient was a woman and 6 patients were men. One patient was given general anaesthesia; the remaining 6 patients had a regional block. A crossover temporary bypass was performed between the external carotid arteries with a 6-mm polytetrafluoroethylene graft for cerebral protection in all patients. Thoracic endovascular aortic repair (TEVAR) was successfully performed in all patients except 1 following debranching. Neurological complications did not occur during the procedures. Patients were followed for a mean of 18.3 ± 4.9 months. One female patient died of exacerbating chronic obstructive pulmonary disease within the first follow-up year. Three other patients died: 1 died of natural causes; 1 died of pneumonia followed by multiorgan failure; and 1 died of myocardial infarction during the mid-term follow-up period. The remaining patients are still being followed and are event free. Endovascular treatment of thoracic aortic diseases involving the aortic arch is facilitated when the aortic arch is debranched. Our cerebral protection method with a temporary crossover bypass between the external carotid arteries provides continuous pulsatile blood flow to the brain; hence, neurologically, it is a reliable procedure. The follow-up results of the patients who underwent aortic arch cervical debranching followed by TEVAR depended on their comorbidities.

Real Time Non-Invasive Hemodynamic Assessment of Ventricular Tachycardia

Hemodynamically unstable ventricular tachycardia (VT) is a critical cardiac arrhythmia associated with hemodynamic compromise that requires immediate cardioversion to prevent sudden cardiac death. Since unnecessary cardioverter defibrillators shocks damage the heart and increase the risk of mortality, the discrimination between unstable (i.e. requiring cardioversion) and stable (i.e. not requiring cardioversion) VT is of paramount importance. The aim of this study was to propose and assess non-invasive identification of hemodynamically unstable VT using photoplethysmography (PPG). Seventy-five (n = 75) episodes of VT were recorded in 14 patients undergoing invasive electrophysiological studies for VT catheter ablation. Invasive continuous arterial blood pressure (ABP), PPG and electrocardiogram (ECG) were simultaneously recorded. VTs were classified as unstable if during the first 10 seconds from onset, the mean ABP ( $\overline {P_{VT}}\mathrm { ) was $\overline {P_{VT}}\mathrm { mmHg or if $\text{P}_{\mathrm {VT}}$ dropped more than 30% with respect to a 10 seconds baseline (i.e. ratio $\text{R}_{\mathrm {ABP}} ). Five PPG morphological features were derived and compared to the heart rate from the ECG. PPG markers detected hemodynamically unstable VT with accuracy as high as 86% and were more accurate than the heart rate. The mean absolute slope was the best PPG parameter for classification of $\overline {P_{VT}}\mathrm { mmHg (AUC = 0.85, Sensitivity = 72%, Specificity = 86%) and $\text{R}_{\mathrm {ABP}} (AUC = 0.90, Sensitivity = 83%, Specificity = 89%) and it was automatically selected in the best two-variables logistic regression, for which AUC = 0.94. In conclusion, PPG analysis can accurately identify haemodynamically unstable VTs and has potential to enable optimization of VT therapy and reduce unnecessary and harmful cardioversion shocks.

Normothermic blood cardioplegia. Alternative or adjunct?

Normothermic blood cardioplegia was developed originally to be used during cardioplegic induction and reperfusion as an adjunct for enhancing metabolic reversal of biochemical alterations occurring before, during, and after total myocardial ischemia. This adjunct was introduced clinically after extensive experimental testing. By contrast, continuous normothermic blood cardioplegia without hypothermia was introduced clinically without a scientific infrastructure and has generated great interest because of its simplicity and encouraging early results, but has caused substantial confusion. This report is written to (1) clarify the role of normothermic blood cardioplegia as an adjunct to available hypothermic and antegrade and retrograde methods of myocardial protection, rather than as an alternative to them, (2) call attention to the misconception that continuous coronary perfusion avoids ischemia inasmuch as "unintentional ischemia" may occur despite continuous coronary perfusion, (3) identify theoretic and practical limitations of warm continuous retrograde blood cardioplegia exposed by testing after its clinical introduction, (4) enumerate the unanswered questions posed after clinical use of this method, and (5) focus on the self-imposed inflexibility created by adoption of adversarial positions in regard to cardioprotective strategies that impedes our ability to combine, rationally, the spectrum of approaches to myocardial protection that have evolved from the recognized limitations of individual methods.

A Generalized Transfer Function Method for Reconstruction of Continuous Brachial Artery Pressure Based on Digital Measurement

Objective: To reconstruct brachial artery pressure (BAP) distally from digital artery pressure (DAP). Methods: We hypothesize that continuous BAP can simply be approximated by sum of two halves of the continuous DAP shifted by the delay time. In order to test it, we enrolled 30 healthy volunteers for two experiments. We firstly showed that the pressure wave in the digital artery can be considered twice as much as the forward/backward wave in the finger. A simplified individualized transfer function was then derived so as to estimate BAP from DAP with the parameter of delay time estimated by tenfold cross validation. Finally, by comparing with a reference BAP, we found that the proposed method can correct the DAP. Result: The errors of the proposed method in estimating systolic and diastolic pressures are 0.4 ± 6.2 and 0.7 ± 3.7 mmHg, respectively. These results agree with the standard of Association for the Advancement of Medical Instrumentation (AAMI). Discussion: In our method, large arteries are modeled with a uniform, frictionless tube, while small arteries are represented as a terminal load. The unknown parameter of the delay time are estimated by tenfold cross validation. Conclusion: Our method is therefore promising in estimating continuous proximal blood pressure from peripheral blood pressure in practice.

Closed-loop Vasopressor Infusion Using Continuous Noninvasive Blood Pressure Monitoring

Closed-loop Vasopressor Infusion Using Continuous Noninvasive Blood Pressure Monitoring

Abstract 041: Hypoxic Peripheral Chemoreceptor Activation Engages Sympathetic Brainstem and Hypothalamic Nuclei in Human Subjects

Peripheral carotid chemoreceptors, which raise sympathetic activation at the brainstem level, may serve as targets for antihypertensive therapy. However, human peripheral chemoreflex regulation in the brainstem is poorly understood due to lack of suitable methodologies. Therefore, we combined measurements of beat-by-beat blood pressure and SpO 2 , and high-resolution functional magnetic resonance imaging (fMRI) to elucidate human brainstem circuits engaged through hypoxic peripheral chemoreceptor activation. We submitted 12 healthy men (29.7 ±6.6 years; 24.0 ±1.86 kg/m 2 ) to five hypoxic episodes by breathing 10% oxygen for 180 seconds followed by 90 seconds normoxia during multiband fMRI brain acquisitions. We monitored continuous finger arterial blood pressure using customized hardware, ECG, and SpO 2 . Brainstem and hypothalamus fMRI images were analyzed to identify nuclei involved in peripheral chemoreflex processing. Systolic blood pressure (SBP) and SpO 2 time courses were correlated with the blood-oxygen-level dependent signals with a general linear model. With hypoxia, SpO 2 decreased by 12.32 ±3.68% (p &lt; 0.01), heart rate increased 13.86 ±3.47 bpm (p &lt; 0.01), and SBP decreased with hypoxia 5.45 ±5.5 mmHg (p &lt; 0.01). In the brainstem, the nucleus tractus solitarii (t-values: SpO 2 : 5.9; SBP: 4.79), the caudal ventrolateral medulla (SpO 2 : 5.61; SBP: 5.59), intermediate reticular nucleus (SpO 2 : 4.7, SBP: 5.98), nucleus ambiguus (SpO 2 : 5.03, SBP: 5.59), dorsal motor nucleus of the vagal nerve (SBP: 4.79), and inferior olive (SpO 2 : 4.7, SBP: 6.16) were identified with high sensitivity and corrected for multiple comparisons (p &lt; 0.01). Furthermore, we observed activation of the following hypothalamic nuclei: paraventricular nucleus (SpO 2 : 7.67), anterior and lateral hypothalamic area (SpO 2 : 7.67, SBP: 4.79), supraoptic nucleus, and tuberomammillary nucleus (SpO 2 : 7.07). High-resolution brainstem fMRI during repeated hypoxia traces brainstem circuits engaged by peripheral chemoreceptors. The methodology can be applied to study peripheral chemoreceptor contributions to human cardiovascular disease and may have utility in identifying patients likely to respond to peripheral chemoreceptor modulation.

Observational, Data Collection Study for Subjects With Diabetes Using Daily Insulin Injections and Monitoring Glucose by Continuous Glucose Monitoring or Self-Monitoring Blood Glucose

Observational, Data Collection Study for Subjects With Diabetes Using Daily Insulin Injections and Monitoring Glucose by Continuous Glucose Monitoring or Self-Monitoring Blood Glucose

Effects of different fluid therapy strategies on fetuses during caesarean section under combined spinal-epidural anesthesia

Objective To investigate the effects of different fluid therapy strategies on fetuses during caesarean section under combined spinal-epidural anesthesia. Methods A total of 100 pregnant women [American Society of Anesthesiologists (ASA)grade Ⅱ] who were scheduled to undergo caesarean were enrolled and randomly divided into to a control group (group C) and a goal directed fluid therapy (GDFT) group (group G). Both groups were given 10 ml/kg Lactated Ringer′s at a bolus and maintained at the rate of 2 ml·kg-1·h-1. Group C were treated with vasopressors when the blood pressure was 80% lower than the baseline or the systolic blood pressure (SBP) was lower than 90 mmHg (1 mmHg=0.133 kPa). Meanwhile, group G was treated with GDFT guided by LiDCOrapid-CNAP (continuous noninvasive arterial blood pressure measurement). After delivery, neonate Apgar scores and blood gas analysis results of the umbilical artery and vein were recorded. Results The Apgar scores of the neonates in group C were 10, expect 1 case of 9 score and 1 case of 8 score. All the neonates in group G had 10 Apgar scores. Compared with group C, group G presented remarkable increases in umbilical vein pH value and pulse oxygen saturation (SpO2) and umbilical arterial oxygen saturation (SO2) as well as marked decreases in lactate (Lac) levels and partial pressure of carbon dioxide(PCO2)(P<0.05). Conclusions GDFT guided by LiDCOrapid-CNAP can improve oxygen and metabolism to fetuses during caesarean section. Key words: Goal-directed fluid therapy; Caesarean section; Combined spinal-epidural anesthesia

Effects of strength training with continuous or intermittent blood flow restriction on the hypertrophy, muscular strength and endurance of men

The aim of the present study was to compare the effects of strength training (ST) with continuous or intermittent blood flow restriction (BFR) on the muscle hypertrophy (MH), dynamic muscle strength (DMS), isometric muscle strength (IMS) and localized muscular endurance (LME) of healthy men. Twenty-five men with experience in ST were randomly divided into 3 experimental groups: a) 4 low-load exercises at 20% of the one-repetition maximum (1RM) combined with continuous BFR (LL+CBFR), b) 4 low-load exercises at 20% of 1RM combined with intermittent BFR (LL+IBFR); and c) 4 low-load exercises at 20% of 1RM without BFR (LL). Twelve sessions of ST were performed (twice a week for 6 weeks). There were no differences between groups for all variables (p > 0.05). However, there were significant differences in time for the LME in the triceps pulley only in the LL+CBFR group (p < 0.001) and in the biceps pulley in the groups LL+CBFR, LL+IBFR and LL (p < 0.001, p = 0.002, p = 0.032), respectively, with large magnitudes only for the two forms of the BFR. It can be concluded that continuous or intermittent BFR seems to be a good alternative for the increase of the LME of the upper limbs in single-joint exercises.

Effectiveness and accuracy of a domestic continuous non-invasive blood pressure device in monitoring intraoperative blood pressure

Objective To evaluate the effectiveness and accuracy of a domestic continuous non-invasive blood pressure (NIBP) device in monitoring intraoperative blood pressure. Methods Sixty patients of both sexes, aged 18-64 yr, with body mass index of 18-30 kg/m2, of American Society of Anesthesiologists physical status Ⅰ or Ⅱ, undergoing elective surgery under general anesthesia, were included in the study.The invasive blood pressure (IBP) and NIBP were simultaneously measured in the radial artery.Systolic and diastolic blood pressure (SBP, DBP) was continuously recorded, and the paired data and data of waveform were collected.For paired data, the agreement was evaluated using Bland-Altman analyses between the two monitoring methods.For waveform data, Pearson linear correlate analysis was performed between the two monitoring methods. Results For paired data, the bias of NIBP value from IBP value were (-2.1±5.4)mmHg(95% CI -3.5-0.7 mmHg) and (2.6±6.4)mmHg (95% CI 1.0-4.3 mmHg) for SBP and DBP, respectively.The 95% limit of agreement of bias between the two methods was -12.6-8.5 mmHg for SBP and -10.0-15.3 mmHg for DBP.For waveform data, the bias of NIBP value from IBP value were (-2.1±6.5) mmHg(95% CI -3.7-0.4 mmHg) and (3.1±6.8) mmHg (95% CI 1.3-4.8 mmHg) for SBP and DBP, respectively.The correlation coefficient between the two methods was 0.82 for SBP and 0.88 for DBP, P<0.01. Conclusion The effectiveness and accuracy of this domestic continuous NIBP monitoring device in monitoring intraoperative blood pressure is clinically acceptable. Key words: Blood pressure determination; Monitoring, intraoperative

0069 Spectral Analyses of Slow Wave Sleep and Rapid Eye Movement Sleep are Associated with Changes in Continuous Nocturnal Blood Pressure

0069 Spectral Analyses of Slow Wave Sleep and Rapid Eye Movement Sleep are Associated with Changes in Continuous Nocturnal Blood Pressure

Efficacy of a continuous non-invasive arterial blood pressure monitor system for bronchoscope diagnosis and treatment under general anesthesia

Objective To compare continuous non-invasive arterial blood pressure (CNAP) monitoring with non-invasive blood pressure (NIBP) monitoring in anesthesia monitoring application value of bronchoscope diagnosis and treatment, and to find whether the CNAP can improve the detection rate of hypotension and detect low blood pressure earlier so that improve the safety of patients. Methods Twenty patients undergoing bronchoscope diagnosis and treatment under general anesthesia from outpatient were included in this study. The NIBP monitoring was put on one side of the upper limb and the CNAP monitoring was connected to the other side upper limb before inducement of general anesthesia. Both connections were kept until the end of operation. The systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP) of the CNAP were recorded one time per minute whereas the SBP, DBP and MAP of NIBP were recorded one time every 3 min. The low blood pressure (SBP<80 mmHg, 1 mmHg=0.133 kPa) frequency of CNAP and NIBP were respectively counted. The low blood pressure detection rate and the hypotension checkout time of NIBP and CNAP were calculated respectively. The consistency and correlation between the two blood pressure measurements were compared. At the same time, the complications of the two methods of monitoring were recorded and compared. Results The low blood pressure detection rate of CNAP and NIBP was 17.2% and 14.7% (P<0.05). The hypotension checkout time of CNAP and NIBP were (1.2±0.4) min and (3.0±0.0) min respectively (P<0.05). The SBP, DBP and MAP bias of CNAP and NIBP measurement were (1.5±8.8), (1.1±8.2) mmHg and (1.3±7.1) mmHg respectively. Consistency limits were -18.70-15.70 mmHg, -17.20-14.90 mmHg and -15.30-12.70 mmHg respectively. The proportion within the scope of the consistency of its corresponding boundary were 96.70%, 97.10% and 97.10% respectively. The correlation coefficients of SBP, DBP and MAP measured by CNAP and NIBP were 0.910, 0.861 and 0.941 respectively (P<0.05). None of the patients had complications. Conclusions CNAP is more sensitive and timely in detecting hypotension. It has higher consistency and more correlation than NIBP. Thus, CNAP can improve the safety of anesthesia monitoring for bronchoscope diagnosis and treatment. Key words: Continuous non-invasive arterial blood pressure monitoring; Bronchoscope diagnosis and treatment; Anesthesia, general

Cleavage and Re-Supply of von Willebrand Factor in Continuous Flow Blood Pump

Purpose Mechanical circulatory support devices are needed to enable recovery or provide a bridge to decision for patients with heart failure. The effectiveness of extending treatment duration in this therapy was previously reported to increase adverse events, such as acquired von Willebrand disease and gastrointestinal bleeding. Blood-related damage caused by medical devices is one of the most critical parameters needed to determine the performance of medical devices. For the treatment of these complications, we considered that it is very important to analyze the relationship between the cleavage of von Willebrand factor (VWF) due to shear stress and re-supply of VWF from activated platelets during blood pump circulation. We aimed to examine the alterations in the dynamics of VWF multimers in the circulating blood during VAD therapy. Methods In this study, two types (axial and centrifugal) of implantable blood pumps and a disposable blood pump (centrifugal type) for temporary use were used. A simple mock circulation test (5L/min, 100 mmHg) was performed to investigate with both whole-blood samples and platelet-poor plasma (PPP) using fresh bovine blood. Results In an analysis based on SDS-agarose gel electrophoresis and serum VWF values (antigen and activity), high-molecular-weight multimers (HMWMs) in VWF are reduced immediately after the initiation of blood circulation using the axial flow pump, and it had plateaued 60 minutes later. On the other hand, in the study using a centrifugal pump, cleavage of the HMWMs compared to that in the case of using a centrifugal pump was very slight. Moreover, in the whole-blood sample study, HMWMs reduced once, and it had been observed to recover after 60 minutes. However, HMWMs in the PPP sample was observed to reduce continuously during a circulation test. Conclusion In this result, the dynamics of VWF within the blood pump was shown to depend on the type of the blood pump, and this study demonstrated that re-supply of VWF due to platelet activation and cleavage of VWF due to shear stress in the pump occurred at the same time by circulating within the blood pump.

Innovative, yet simple method to tackle Vascular complications after Radial Artery Cannulation

Arterial cannulations are used routinely for continuous hemodynamic monitoring and blood sampling during major surgery and in critically ill patients but are not without complications. We devised simple cost-effective innovative technique in comparison to manual compression to prevent the vascular complications like hematoma formation and blood ooze from skin arteriotomy site. JMS 2018;21(1):49-50

Cardiac autotransplantation and ex vivo surgical repair of giant left atrium: a case presentation

BackgroundChronic Mitral Valve disease is strongly associated with Left atrial enlargement; the condition has a high mortality risk. Clinical manifestations include atrial fibrillation, pulmonary hypertension, thromboembolic events, and in cases of Giant Left Atrium (GLA) and a distorted cardiac silhouette. Full sternotomy, conventional open-heart surgery, reductive atrioplasty and atrioventricular valve repair are required to resolve symptoms. However, these procedures can be complicated due to the posterior location of the GLA and concomitant right lateral protrusion.Cardiac autotransplantation is superior under these conditions; it provides improved visual access to the posterior atrial wall and mitral valve, hence, facilitates corrective surgical procedures.We aimed to assess the clinical outcome of patients undergoing cardiac autotransplantation as the primary treatment modality to resolve GLA. Moreover, we evaluated the procedural safety profile and technical feasibility.Case presentationFour patients, mean EuroSCORE II of 23.7% ± 7.7%, presented with heart failure, atrial fibrillation, left atrial diameter > 6.5 cm and a severe distorted cardiac silhouette; X-ray showed prominent right lateral protrusion.We performed cardiac autotransplantation using continuous retrograde perfusion with warm blood supplemented with glucose followed by atrioplasty, atrial plication, valve annuloplasty and valve repair on the explanted beating heart. The surgical approach reduced the left atrial area, mean reduction was − 90.71 cm2 [CI95% -153.3 cm2 to − 28.8 cm2, p = 0.02], and normalized pulmonary arterial pressure, mean decrease − 11.25 mmHg [CI95% -15.23 mmHg to − 7.272 mmHg, p = 0.003]. 3 out of 4 patients experienced an uneventful postoperative course; 2 out of 4 patients experienced a transient return to sinus rhythm following surgery. One was operated on in 2017 and is still in good condition; two other patients survived for more than 10 years; Kaplan-Meier determined median survival is 10.5 years.ConclusionsCardiac autotransplantation is an elegant surgical procedure that facilitates the surgical remodelling of Giant Left Atrium. Surgical repair on the ex vivo beating heart, under continuous warm blood perfusion, is a safe procedure applicable also to high-risk patients.