Interobserver Agreement in Detecting Spectral-Domain Optical Coherence Tomography Features of Diabetic Macular Edema

PurposeTo evaluate interobserver agreement for the detection of spectral-domain optical coherence tomography (SDOCT) features of diabetic macular edema (DME).MethodCross-sectional study in which 2 retinal specialists evaluated SDOCT scans from eyes receiving treatment for DME. Scans from 50 eyes with DME of 39 patients were graded for features of DME including intra-retinal fluid (IRF), diffuse retinal oedema (DRE), hyper-reflective foci (HRF), subretinal fluid (SRF), macular fluid and vitreomacular traction (VMT). Features were graded as present or absent at zones involving the fovea, 1mm from the fovea and the whole scan of 49 line scans. Analysis was performed using cross-tabulations for percentage concordance and kappa values (κ).ResultsIn the 2950 line scans analysed, there was an increase in percentage concordance for DRE and HRF when moving from a foveal line scan, 1mm zone and then to a whole scan analysis (88% vs 94% vs 96%) and (88% vs 94% vs 94%) respectively with κ ranging from substantial to almost perfect. Percentage concordance for SRF was 96% at all 3 regions analysed, whilst IRF was 96% at fovea and 98% at higher number of line-scans analysed. Concordance for MF was 100% at fovea and 98% at 1mm zone and whole scan with almost perfect and substantial κ respectively. κ agreement was substantial for VMT at all regions analysed.ConclusionWe report a high level of interobserver agreement in the detection of SDOCT features of DME. This finding is important as detection of macular fluid is used to guide retreatment with anti-angiogenic agents.     

Simultaneous determination of the accuracy and precision of closed-circuit cardiac output rebreathing techniques.

Foreign and soluble gas rebreathing methods are attractive for determining cardiac output (Q(c)) because they incur less risk than traditional invasive methods such as direct Fick and thermodilution. We compared simultaneously obtained Q(c) measurements during rest and exercise to assess the accuracy and precision of several rebreathing methods. Q(c) measurements were obtained during rest (supine and standing) and stationary cycling (submaximal and maximal) in 13 men and 1 woman (age: 24 +/- 7 yr; height: 178 +/- 5 cm; weight: 78 +/- 13 kg; Vo(2max): 45.1 +/- 9.4 ml.kg(-1).min(-1); mean +/- SD) using one-N(2)O, four-C(2)H(2), one-CO(2) (single-step) rebreathing technique, and two criterion methods (direct Fick and thermodilution). CO(2) rebreathing overestimated Q(c) compared with the criterion methods (supine: 8.1 +/- 2.0 vs. 6.4 +/- 1.6 and 7.2 +/- 1.2 l/min, respectively; maximal exercise: 27.0 +/- 6.0 vs. 24.0 +/- 3.9 and 23.3 +/- 3.8 l/min). C(2)H(2) and N(2)O rebreathing techniques tended to underestimate Q(c) (range: 6.6-7.3 l/min for supine rest; range: 16.0-19.1 l/min for maximal exercise). Bartlett's test indicated variance heterogeneity among the methods (P < 0.05), where CO(2) rebreathing consistently demonstrated larger variance. At rest, most means from the noninvasive techniques were +/-10% of direct Fick and thermodilution. During exercise, all methods fell outside the +/-10% range, except for CO(2) rebreathing. Thus the CO(2) rebreathing method was accurate over a wider range (rest through maximal exercise), but was less precise. We conclude that foreign gas rebreathing can provide reasonable Q(c) estimates with fewer repeat trials during resting conditions. During exercise, these methods remain precise but tend to underestimate Q(c). Single-step CO(2) rebreathing may be successfully employed over a wider range but with more measurements needed to overcome the larger variability.     

Measurement of Cardiac Index by Transpulmonary Thermodilution Using an Implanted Central Venous Access Port: A Prospective Study in Patients Scheduled for Oncologic High-Risk Surgery

Background

Transpulmonary thermodilution allows the measurement of cardiac index for high risk surgical patients. Oncologic patients often have a central venous access (port-a-catheter) for chronic treatment. The validity of the measurement by a port-a-catheter of the absolute cardiac index and the detection of changes in cardiac index induced by fluid challenge are unknown.

Methods

We conducted a monocentric prospective study. 27 patients were enrolled. 250 ml colloid volume expansions for fluid challenge were performed during ovarian cytoreductive surgery. The volume expansion-induced changes in cardiac index measured by transpulmonary thermodilution by a central venous access (CIcvc) and by a port-a-catheter (CIport) were recorded.

Results

23 patients were analyzed with 123 pairs of measurements. Using a Bland and Altman for repeated measurements, the bias (lower and upper limits of agreement) between CIport and CIcvc was 0.14 (−0.59 to 0.88) L/min/m². The percentage error was 22%. The concordance between the changes in CIport and CIcvc observed during volume expansion was 92% with an r = 0.7 (with exclusion zone). No complications (included sepsis) were observed during the follow up period.

Conclusions

The transpulmonary thermodilution by a port-a-catheter is reliable for absolute values estimation of cardiac index and for measurement of the variation after fluid challenge.

Trial Registration

clinicaltrials.gov NCT02063009     

Concurrent validity of five prediction equations to evaluate fat percentage in a sports group expected to yield high performance from Medellín,Colombia

IntroductionNo equations to predict the body composition of athletes from Medellín expected to have high performance have been constructed and, thus, decisions regarding their training and nutrition plans lack support.ObjectiveTo calculate the concurrent validity of five prediction equations for fat percentage in a group of athletes from Medellín, Colombia, expected to yield high performance.Materials and methodsWe conducted a cross-sectional analysis to validate diagnostic tests using secondary-source data of athletes under the age of 18 who were part of the “Medellín Team”. The gold standard was dual-energy X-ray densitometry (DEXA). We analyzed the Slaughter, Durnin and Rahaman, Lohman, and Johnston prediction equations, as well as the five-component model. We used the intraclass correlation coefficient to assess the consistency of the methods and the Bland-Altman plot to calculate the average bias and agreement limits of each of the equations.ResultsWe included 101 athletes (50,5% of them women). The median age was 14,8 years (IR: 13,0 - 16,0). The concurrent validity was “good/excellent” for the Johnston and the Durnin and Rahaman equations and the five-components model. The Lohman equation overestimated the fat percentage in 12,7 points. All of the equations showed broad agreement limits.ConclusionsThe Durnin and Rahaman and the Johnston equations, as well as the five- component model, can be used to predict the FP in the study population as they showed a “good/excellent” concurrent validity and a low average bias. The equations analyzed have low accuracy, which hinders their use to diagnose the individual fat percentage within this population.     

Transluminal attenuation-gradient coronary CT angiography on a 320-MDCT volume scanner: Effect of scan timing,coronary artery stenosis,and cardiac output using a contrast medium flow phantom

PurposeTransluminal-attenuation-gradient (TAG) may reflect patient characteristics and physiological parameters. Furthermore, TAG may be affected by factors such as the CT scanner speed, scanning method, scan timing after contrast-medium (CM) injection, and the injection methods. The purpose of our study was to investigate quantitative TAG at different scan timing points after CM injection for coronary CT angiography.Materials and methodsUsing a CM flow phantom and two types of connecting tube mimicking 0% and 70% coronary artery stenosis, we performed 320-detector volume scanning. The heart rate was set at 60 bpm and cardiac-output (CO) at 2.0 and 4.0 l/min, respectively. The acquisition time repeated at 0.5-s intervals for 40 and 25 s at a CO of 2.0- and 4.0 l/min. We measured the CT number on the same slice level, calculated the time-density-curve (TDC) and the TAG at each time point.ResultsAt COs of 2.0 and 4.0 l/min at 0% stenosis, TAG exhibited smaller variations (−3.02 to +0.55 HU/cm at 2.0 l/min, −2.63 to +0.43 HU/cm at 4.0 l/min) than at 70% stenosis at each time point along the TDC. Compared with a CO at 2.0 l/min with 70% stenosis, the TAG curve for a CO at 4.0 l/min gradually changed with time (−6.64 to +1.18 HU/cm at 2.0 l/min vs. −3.46 to +2.75 HU/cm at 4.0 l/min).ConclusionThe TAG value was affected by scan timing after CM injection and by CO although the size of the connecting tube with and without stenosis was identical.     

Normal Range of Hepatic Fat Fraction on Dual- and Triple-Echo Fat Quantification MR in Children

ObjectivesTo evaluate hepatic fat fraction on dual- and triple-echo gradient-recalled echo MRI sequences in healthy children.ResultsIn 54 children (M:F = 26:28; 5–15 years; mean 9 years), the dual fat fraction (0.1–8.0%; median 1.6%) was not different from the triple fat fraction (0.4–6.5%; median 2.7%) (p = 0.010). The dual- and triple-echo fat fractions showed good agreement using a Bland-Altman plot (-0.6 ± 2.8%). Eight children (14.8%) on dual-echo sequences and six (11.1%) on triple-echo sequences had greater than 5% fat fraction. From these children, six out of eight children on dual-echo sequences and four out of six children on triple-echo sequences had a 5–6% hepatic fat fraction. When using a cut-off value of a 6% fat fraction derived from a reference interval, only 3.7% of children were diagnosed with fatty liver. There was no significant correlation between clinical and laboratory findings with dual and triple-echo fat fractions.ConclusionsDual fat fraction was not different from triple fat fraction. We suggest a cut-off value of a 6% fat fraction is more appropriate for diagnosing fatty liver on both dual- and triple-echo sequences in children.     

Biventricular pacing in the early postoperative period after cardiac surgery

Cardiac resynchronization therapy is not commonly used in the early postoperative period in patients undergoing cardiac surgery who have left ventricular (LV) dysfunction and a history of heart failure. We performed a prospective randomized clinical trial to compare atrial synchronous right ventricular (DDD RV) and biventricular (DDD BIV) pacing within 72 hours after cardiac surgery in patients with an EF ≤35 %, a QRS interval longer than 120 msec and who had LV dyssynchrony detected by real-time three-dimensional echocardiography (RT3DE). Epicardial pacing was provided by a modified Medtronic INSYNC III pacemaker. An LV epicardial pacing lead was implanted on the latest activated segment of the LV based on RT3DE. The study included 18 patients with ischemic heart disease, with or without valvular heart disease (14 men, 4 women, average age 71 years). Patients undergoing DDD BIV pacing had a statistically significant greater CO and CI (CO 6.7±1.8 l/min, CI 3.4±0.7 l/min/m(2)) than patients undergoing DDD RV pacing (CO 5.5±1.4 l/min, CI 2.8±0.7 l/min/m(2)), p<0.001. DDD BIV pacing in the early postoperative period after cardiac surgery corrects LV dyssynchrony and has better hemodynamic results than DDD RV pacing.     

Measuring stroke volume of the ascending aorta with an extravascular Doppler ultrasound probe in comparison with aortic thermodilution]

Currently, no reliable minimally invasive method of measuring cardiac output continuously in neonates and children undergoing cardiac surgery is available. An extravascular Doppler probe was used to measure cardiac output in 15 New Zealand White rabbits (average weight 3.5 kg, range 2.5-4.5 kg). The results obtained were compared with cardiac outputs determined using the aortic thermodilution principle. The mean cardiac outputs measured with the extravascular Doppler probe was 0.37 +/- 0.01 l/min as compared with 0.39 +/- 0.01 l/min with aortic thermodilution. Regression analysis revealed a close correlation (r = 0.973) between the two techniques. The extravascular Doppler techniques is an option for continuous and reliable cardiac output measurement in small animals used in surgical experiments (open chest models) and in neonates or children during surgical repair of complicated congenital heart conditions.     

Modelflow underestimates cardiac output in heat-stressed individuals

An estimation of cardiac output can be obtained from arterial pressure waveforms using the Modelflow method. However, whether the assumptions associated with Modelflow calculations are accurate during whole body heating is unknown. This project tested the hypothesis that cardiac output obtained via Modelflow accurately tracks thermodilution-derived cardiac outputs during whole body heat stress. Acute changes of cardiac output were accomplished via lower-body negative pressure (LBNP) during normothermic and heat-stressed conditions. In nine healthy normotensive subjects, arterial pressure was measured via brachial artery cannulation and the volume-clamp method of the Finometer. Cardiac output was estimated from both pressure waveforms using the Modeflow method. In normothermic conditions, cardiac outputs estimated via Modelflow (arterial cannulation: 6.1 ± 1.0 l/min; Finometer 6.3 ± 1.3 l/min) were similar with cardiac outputs measured by thermodilution (6.4 ± 0.8 l/min). The subsequent reduction in cardiac output during LBNP was also similar among these methods. Whole body heat stress elevated internal temperature from 36.6 ± 0.3 to 37.8 ± 0.4°C and increased cardiac output from 6.4 ± 0.8 to 10.9 ± 2.0 l/min when evaluated with thermodilution (P < 0.001). However, the increase in cardiac output estimated from the Modelflow method for both arterial cannulation (2.3 ± 1.1 l/min) and Finometer (1.5 ± 1.2 l/min) was attenuated compared with thermodilution (4.5 ± 1.4 l/min, both P < 0.01). Finally, the reduction in cardiac output during LBNP while heat stressed was significantly attenuated for both Modelflow methods (cannulation: -1.8 ± 1.2 l/min, Finometer: -1.5 ± 0.9 l/min) compared with thermodilution (-3.8 ± 1.19 l/min). These results demonstrate that the Modelflow method, regardless of Finometer or direct arterial waveforms, underestimates cardiac output during heat stress and during subsequent reductions in cardiac output via LBNP.     

Perioperative Non-Invasive Indocyanine Green-Clearance Testing to Predict Postoperative Outcome after Liver Resection

BackgroundPostoperative liver dysfunction may lead to morbidity and mortality after liver resection. Preoperative liver function assessment is critical to identify preexisting liver dysfunction in patients prior to resection. The aim of this study was to evaluate the predictive potential of perioperative indocyanine green (ICG)-clearance testing to prevent postoperative liver dysfunction and morbidity using standardized outcome parameters in a routine Western-clinical-setting.ResultsPreoperative reduced ICG—plasma disappearance rate (PDR) as well as increased ICG—retention rate at 15 min (R15) were able to significantly predict postoperative liver dysfunction (Area under the curve = PDR: 0.716, P = 0.018; R15: 0.719, P = 0.016). Furthermore, PDR <17%/min. or R15 >8%, were able to accurately predict postoperative complications prior to surgery. In addition to this, ICG-clearance on postoperative day 1 comparably predicted postoperative liver dysfunction (Area under the curve = PDR: 0.895; R15: 0.893; both P <0.001), specifically, PDR <10%/min or R15 >20% on postoperative day 1 predicted poor postoperative outcome.ConclusionPDR and R15 may represent useful parameters to distinguish preoperative high and low risk patients in a Western collective as well as on postoperative day 1, to identify patients who require closer monitoring for potential complications.     

Differences of cardiac output measurements by open-circuit acetylene uptake in pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension: a cohort study

Background

As differences in gas exchange between pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) have been demonstrated, we asked if cardiac output measurements determined by acetylene (C₂H₂) uptake significantly differed in these diseases when compared to the thermodilution technique.

Method

Single-breath open-circuit C₂H₂ uptake, thermodilution, and cardiopulmonary exercise testing were performed in 72 PAH and 32 CTEPH patients.

Results

In PAH patients the results for cardiac output obtained by the two methods showed an acceptable agreement with a mean difference of -0.16 L/min (95% CI -2.64 to 2.32 L/min). In contrast, the agreement was poorer in the CTEPH group with the difference being -0.56 L/min (95% CI -4.96 to 3.84 L/min). Functional dead space ventilation (44.5 ± 1.6 vs. 32.2 ± 1.4%, p < 0.001) and the mean arterial to end-tidal CO₂ gradient (9.9 ± 0.8 vs. 4.1 ± 0.5 mmHg, p < 0.001) were significantly elevated among CTEPH patients.

Conclusion

Cardiac output evaluation by the C₂H₂ technique should be interpreted with caution in CTEPH, as ventilation to perfusion mismatching might be more relevant than in PAH.     

Decrease in cardiac output and muscle sympathetic activity during vasovagal syncope

The importance of cardiac output (CO) to blood pressure level during vasovagal syncope is unknown. We measured thermodilution CO, mean blood pressure (MBP), and leg muscle mean sympathetic nerve activity (MSNA) each minute during 60 degrees head-up tilt in 26 patients with recurrent syncope. Eight patients tolerated tilt (TT) for 45 min (mean age 60 +/- 5 yr) and 15 patients developed syncope during tilt (TS) (mean age 58 +/- 4 yr, mean tilt time 15.4 +/- 2 min). In TT patients, CO decreased during the first minute of tilt (from 3.2 +/- 0.2 to 2.5 +/- 0.3 l x min(-1) x m(-2), P = 0.001) and thereafter remained stable between 2.5 +/- 0.3 (P = 0.001) and 2.4 +/- 0.2 l x min(-1) x m(-2) (P = 0.004) at 5 and 45 min, respectively. In TS patients, CO decreased during the first minute (from 3.3 +/- 0.2 to 2.7 +/- 0.1 l x min(-1) x m(-2), P = 0.02) and was stable until 7 min before syncope, falling to 2.0 +/- 0.2 at syncope (P = 0.001). Regression slopes for CO versus time during tilt were -0.01 min(-1) in TT versus -0.1 l x min(-1) x m(-2) x min(-1) in TS (P = 0.001). However, MBP was more closely correlated to total peripheral resistance (R = 0.56, P = 0.001) and MSNA (R = 0.58, P = 0.001) than CO (R = 0.32, P = 0.001). In vasovagal reactions, a progressive decline in CO may contribute to hypotension some minutes before syncope occurs.     

Can we reduce oxidative stress with liver transplantation?

BackgroundThe aim of this study was to determine the levels of lipid peroxidation (MDA) and antioxidants such as reduced glutathione (GSH), catalase (CAT) and superoxide dismutase (SOD) in the blood serum of patients with cirrhosis and liver transplantation.MethodsIn this study, serum malondialdehyde acid (MDA) levels, superoxide dismutase (SOD), reduced glutathione (GSH), and catalase (CAT) activities were measured spectrophotometrically and compared to the results of the healthy control group.ResultsSOD, CAT and GSH activities were significantly decreased in the patient groups compared to the healthy control group (p<0.05). MDA levels were significantly higher in the patient group compared to the healthy control group (p <0.05).ConclusionsIn conclusion, this study demonstrated that oxidative stress may play an important role in the development of liver cirrhosis and in liver transplantation. This study is the first one to show how MDA, SOD, CAT and GSH levels change in liver cirrhosis and liver transplantation, while further studies are essential to investigate antioxidant enzymes and oxidative stress status in patients with cirrhosis and liver transplantation.     

Alginate Microencapsulated Hepatocytes Optimised for Transplantation in Acute Liver Failure

MethodsHuman hepatocyte microbeads (HMBs) were prepared using sterile GMP grade materials. We determined physical stability, cell viability, and hepatocyte metabolic function of HMBs using different polymerisation times and cell densities. The immune activation of peripheral blood mononuclear cells (PBMCs) after co-culture with HMBs was studied. Rats with ALF induced by galactosamine were transplanted intraperitoneally with rat hepatocyte microbeads (RMBs) produced using a similar optimised protocol. Survival rate and biochemical profiles were determined. Retrieved microbeads were evaluated for morphology and functionality.ResultsThe optimised HMBs were of uniform size (583.5±3.3 µm) and mechanically stable using 15 min polymerisation time compared to 10 min and 20 min (p<0.001). 3D confocal microscopy images demonstrated that hepatocytes with similar cell viability were evenly distributed within HMBs. Cell density of 3.5×10⁶ cells/ml provided the highest viability. HMBs incubated in human ascitic fluid showed better cell viability and function than controls. There was no significant activation of PBMCs co-cultured with empty or hepatocyte microbeads, compared to PBMCs alone. Intraperitoneal transplantation of RMBs was safe and significantly improved the severity of liver damage compared to control groups (empty microbeads and medium alone; p<0.01). Retrieved RMBs were intact and free of immune cell adherence and contained viable hepatocytes with preserved function.ConclusionAn optimised protocol to produce GMP grade alginate-encapsulated human hepatocytes has been established. Transplantation of microbeads provided effective metabolic function in ALF. These high quality HMBs should be suitable for use in clinical transplantation.     

Evaluation of a noninvasive continuous cardiac output monitoring system based on thoracic bioreactance

Noninvasive cardiac output (CO) measurement can be useful in many clinical settings where invasive monitoring is not desired. Bioimpedance (intrabeat measurement of changes in transthoracic voltage amplitude in response to an injected high-frequency current) has been explored for this purpose but is limited in some clinical settings because of inherently low signal-to-noise ratio. Since changes in fluid content also induce changes in thoracic capacitive and inductive properties, we tested whether a noninvasive CO measurement could be obtained through measurement of the relative phase shift of an injected current (i.e., bioreactance). We constructed a prototype device that applies a 75-kHz current and determines the relative phase shift (dPhi/dt) of the recorded transthoracic voltage. CO was related to the product of peak dPhi/dt, heart rate, and ventricular ejection time. The preclinical study was done in nine open-chest pigs put on right heart bypass so that CO could be varied at known values. This was followed by a feasibility study in 27 postoperative patients who had a Swan-Ganz catheter (SGC). The measurements of noninvasive CO measurement and cardiopulmonary bypass pump correlated to each other (r = 0.84) despite the large variation in CO and temperatures. Similarly, in patients, mean CO values were 5.18 and 5.17 l/min as measured by SGC and the noninvasive CO measurement system, respectively, and were highly correlated over the range of values studied (r = 0.90). Preclinical and clinical data demonstrate the feasibility of using blood flow-related phase shifts of transthoracic electric signals to perform noninvasive continuous CO monitoring.     

Nuclear Expression of the Deubiquitinase CYLD Is Associated with Improved Survival in Human Hepatocellular Carcinoma

Background & Aims

The deubiquitinase CYLD removes (K-63)-linked polyubiquitin chains from proteins involved in NF-κB, Wnt/ß-catenin and Bcl-3 signaling. Reduced CYLD expression has been reported in different tumor entities, including hepatocellular carcinoma (HCC). Furthermore, loss of CYLD has been shown to contribute to HCC development in knockout animal models. This study aimed to assess subcellular CYLD expression in tumor tissues and its prognostic significance in HCC patients undergoing liver resection or liver transplantation.

Methods

Subcellular localization of CYLD was assessed by immunohistochemistry in tumor tissues of 95 HCC patients undergoing liver resection or transplantation. Positive nuclear CYLD staining was defined as an immunhistochemical (IHC) score ≥3. Positive cytoplasmic CYLD staining was defined as an IHC score ≥6. The relationship with clinicopathological parameters was investigated. Cell culture experiments were performed to analyze subcellular CYLD expression in vitro.

Results

Cytoplasmic CYLD expression was observed in 57 out of 95 (60%) HCC specimens (^cyt°CYLD⁺). Nuclear CYLD staining was positive in 52 out of 95 specimens (55%, ^nucCYLD⁺). 13 out of 52 ^nucCYLD⁺ patients (25%) showed a lack of cytoplasmic CYLD expression. ^nucCYLD⁺ was associated with prolonged overall survival in patients after resection or liver transplantation (P = 0.007). 5-year overall survival rates were 63% in ^nucCYLD⁺ vs. 26% in ^nucCYLD^- patients. Nuclear CYLD staining strongly correlated with tumor grading (P<0.001) and Ki67 positivity (P = 0.005). ^nucCYLD⁺ did not prove to be an independent prognostic parameter. In vitro, Huh7, Hep3B and HepG2 showed reduced CYLD levels compared to the non-malignant liver cell line THLE-2. Induction of CYLD expression by doxorubicin treatment led to increased cytoplasmic and nuclear expression of CYLD.

Conclusions

Expression of nuclear CYLD is a novel prognostic factor for improved survival in patients with HCC undergoing liver resection or transplantation.     

A simple mortality risk prediction score for viper envenoming in India (VENOMS): A model development and validation study

BackgroundSnakebite is a neglected problem with a high mortality in India. There are no simple clinical prognostic tools which can predict mortality in viper envenomings. We aimed to develop and validate a mortality-risk prediction score for patients of viper envenoming from Southern India.MethodsWe used clinical predictors from a prospective cohort of 248 patients with syndromic diagnosis of viper envenoming and had a positive 20-minute whole blood clotting test (WBCT 20) from a tertiary-care hospital in Puducherry, India. We applied multivariable logistic regression with backward elimination approach. External validation of this score was done among 140 patients from the same centre and its performance was assessed with concordance statistic and calibration plots.FindingsThe final model termed VENOMS from the term “Viper ENvenOming Mortality Score included 7 admission clinical parameters (recorded in the first 48 hours after bite): presence of overt bleeding manifestations, presence of capillary leak syndrome, haemoglobin <10 g/dL, bite to antivenom administration time > 6.5 h, systolic blood pressure < 100 mm Hg, urine output <20 mL/h in 24 h and female gender. The lowest possible VENOMS score of 0 predicted an in-hospital mortality risk of 0.06% while highest score of 12 predicted a mortality of 99.1%. The model had a concordance statistic of 0·86 (95% CI 0·79–0·94) in the validation cohort. Calibration plots indicated good agreement of predicted and observed outcomes.ConclusionsThe VENOMS score is a good predictor of the mortality in viper envenoming in southern India where Russell’s viper envenoming burden is high. The score may have potential applications in triaging patients and guiding management after further validation.     

Unreliable Tracking Ability of the Third-Generation FloTrac/Vigileo? System for Changes in Stroke Volume after Fluid Administration in Patients with High Systemic Vascular Resistance during Laparoscopic Surgery

Background

The FloTrac/Vigileo^™ system does not thoroughly reflect variable arterial tones, due to a lack of external calibration. The ability of this system to measure stroke volume and track its changes after fluid administration has not been fully evaluated in patients with the high systemic vascular resistance that can develop during laparoscopic surgery.

Methods

In 42 patients undergoing laparoscopic prostatectomy, the stroke volume derived by the third-generation FloTrac/Vigileo^™ system (SV-Vigileo), the stroke volume measured using transesophageal echocardiography (SV-TEE) as a reference method, and total systemic vascular resistance were evaluated before and after 500 ml fluid administration during pneumoperitoneum combined with the Trendelenburg position.

Results

Total systemic vascular resistance was 2159.4 ± 523.5 dyn·s/cm⁵ before fluid administration. The SV-Vigileo was significantly higher than the SV-TEE both before (68.8 ± 15.9 vs. 57.0 ± 11.0 ml, P < 0.001) and after (73.0 ± 14.8 vs. 64.9 ± 12.2 ml, P = 0.003) fluid administration. During pneumoperitoneum combined with the Trendelenburg position, Bland-Altman analysis for repeated measures showed a 53.8% of percentage error between the SV-Vigileo and the SV-TEE. Four-quadrant plot (69.2% of a concordance rate) and polar plot analysis (20.6° of a mean polar angle, 16.4° of the SD of a polar angle, and ±51.5° of a radial sector containing 95% of the data points) did not indicate a good trending ability of the FloTrac/Vigileo^™ system.

Conclusions

The third-generation FloTrac/Vigileo^™ system may not be useful in patients undergoing laparoscopic surgery, based on unreliable performance in measuring the stroke volume and in tracking changes in the stroke volume after fluid administration during pneumoperitoneum combined with the Trendelenburg position.     

Echocardiographic measurement of cardiac output in rats

The systematic evaluation of different transthoracic echocardiographic (TTE) methods to determine cardiac output (CO) and the effect of changes in intravascular volume on echocardiographically determined indexes of cardiovascular structure in the rat has not been documented. With the use of 11 Wistar rats, simultaneous echocardiographic and thermodilution measurements of CO were compared at baseline and after blood withdrawal or transfusion at 43 different levels of intravascular volume and using 10 different echocardiographic approaches. The best correlation (r = 0.93; P < 0.0001), least bias (-3 ml/min), and best precision (16 ml/min) between thermodilution and echocardiographic methods were obtained at the level of aortic annulus using pulsed Doppler. In conclusion, CO could be accurately assessed in rats using TTE and pulsed Doppler at the level of the aortic annulus. This annulus was demonstrated to remain stable, but pulmonary annulus, thoracic aorta, mitral valve, and left ventricular diameters were found to be more modifiable during volumic changes.