Ultrasound based estimate of central venous pressure:Are we any closer?

Central venous pressure(CVP)serves as a direct approximation of right atrial pressure and is influenced by factors like total blood volume,venous compliance,cardiac output,and orthostasis.Normal CVP falls within 8-12 mmHg but varies with volume status and venous compliance.Monitoring and managing disturbances in CVP are vital in patients with circulatory shock or fluid disturbances.Elevated CVP can lead to fluid accumulation in the interstitial space,impairing venous return and reducing cardiac preload.While pulmonary artery catheterization and central venous catheter obtained measurements are considered to be more accurate,they carry risk of complications and their usage has not shown clinical improvement.Ultrasound-based assessment of the internal jugular vein(IJV)offers real-time,non-invasive measurement of static and dynamic parameters for estimating CVP.IJV parameters,including diameter and ratio,has demonstrated good correlation with CVP.Despite significant advancements in non-invasive CVP measurement,a reliable tool is yet to be found.Present methods can offer reasonable guidance in assessing CVP,provided their limitations are acknowledged.

Accuracy of Mean Value of Central Venous Pressure from Monitor Digital Display: Influence of Amplitude of Central Venous Pressure during Respiration

Background A simple measurement of central venous pressure(CVP)-mean by the digital monitor display has become increasingly popular.However,the agreement between CVP-mean and CVP-end(a standard method of CVP measurement by analyzing the waveform at end-expiration)is not well determined.This study was designed to identify the relationship between CVP-mean and CVP-end in critically ill patients and to introduce a new parameter of CVP amplitude(ΔCVP=CVPmax-CVPmin)during the respiratory period to identify the agreement/disagreement between CVP-mean and CVP-end.Methods In total,291 patients were included in the study.CVP-mean and CVP-end were obtained simultaneously from each patient.CVP measurement difference(|CVP-mean-CVP-end|)was defined as the difference between CVP-mean and CVP-end.TheΔCVP was calculated as the difference between the peak(CVPmax)and the nadir value(CVPmin)during the respiratory cycle,which was automatically recorded on the monitor screen.Subjects with|CVP-mean-CVP-end|≥2 mm Hg were divided into the inconsistent group,while subjects with|CVP-mean-CVP-end|2 mm Hg were divided into the consistent group.ResultsΔCVP was significantly higher in the inconsistent group[7.17(2.77)vs.5.24(2.18),P0.001]than that in the consistent group.There was a significantly positive relationship betweenΔCVP and|CVP-mean-CVP-end|(r=0.283,P 0.0001).Bland-Altman plot showed the bias was-0.61 mm Hg with a wide 95%limit of agreement(-3.34,2.10)of CVP-end and CVP-mean.The area under the receiver operating characteristic curves(AUC)ofΔCVP for predicting|CVP-mean-CVP-end|≥2 mm Hg was 0.709.With a high diagnostic specificity,usingΔCVP3 to detect|CVP-mean-CVP-end|lower than 2mm Hg(consistent measurement)resulted in a sensitivity of 22.37%and a specificity of 93.06%.UsingΔCVP8 to detect|CVP-mean-CVPend|8 mm Hg(inconsistent measurement)resulted in a sensitivity of 31.94%and a specificity of 91.32%.Conclusions CVP-end and CVP-mean have statistical discrepancies in specific clinical scenarios.ΔCVP during the respiratory period is related to the variation of the two CVP methods.A highΔCVP indicates a poor agreement between these two methods,whereas a lowΔCVP indicates a good agreement between these two methods.

Low central venous pressure reduces blood loss in hepatectomy

AIM： To investigate the effect of low central venous pressure （LCVP） on blood loss during hepatectomy for hepatocellular carcinoma （HCC）. METHODS： By the method of sealed envelope, 50 HCC patients were randomized into LCVP group （n=25） and control group （n=25）. In LCVP group, CVP was maintained at 2-4 mmHg and systolic blood pressure （SBP） above 90 mmHg by manipulation of the patient＇s posture and administration of drugs during hepatectomy, while in control group hepatectomy was performed routinely without lowering CVP. The patients＇ preoperative conditions, volume of blood loss during hepatectomy, volume of blood transfusion, length of hospital stay, changes in hepatic and renal functions were compared between the two groups. RESULTS： There were no significant differences in patients＇ preoperative conditions, maximal tumor dimension, pattern of hepatectomy, duration of vascular occlusion, operation time, weight of resected liver tissues, incidence of post-operative complications, hepatic and renal functions between the two groups. LCVP group had a markedly lower volume of total intraoperative blood loss and blood loss during hepatectomy than the control group, being 903.9 ± 180.8 mL vs 2 329.4 ±2 538.4 （W=495.5, P〈0.01） and 672.4±429.9 mL vs 1 662.6±1 932.1 （W=543.5, P〈0.01）. There were no remarkable differences in the pre-resection and post-resection blood losses between the two groups. The length of hospital stay was significantly shortened in LCVP group as compared with the control group, being 16.3±6.8 d vs 21.5 ± 8.6 d （W= 532.5, P〈0.05）.CONCLUSION： LCVP is easily achievable in technique. Maintenance of CVP ≤4 mmHg can help reduce blood loss during hepatectomy, shorten the length of hospital stay, and has no detrimental effects on hepatic or renal function.

Controlled low central venous pressure reduces blood loss and transfusion requirements in hepatectomy

AIM: To evaluate the effect of low central venous pressure (LCVP) on blood loss and blood transfusion in patients undergoing hepatectomy.

Optimal central venous pressure during partial hepatectomy for hepatocellular carcinoma

BACKGROUND:Low central venous pressure(CVP) affects hemodynamic stability and tissue perfusion.This prospective study aimed to evaluate the optimal CVP during partial hepatectomy for hepatocellular carcinoma(HCC).METHODS:Ninety-seven patients who underwent partial hepatectomy for HCC had their CVP controlled at a level of 0 to 5 mmHg during hepatic parenchymal transection.The systolic blood pressure(SBP) was maintained,if possible,at 90 mmHg or higher.Hepatitis B surface antigen was positive in 90 patients(92.8%) and cirrhosis in 84 patients(86.6%).Pringle maneuver was used routinely in these patients with clamp/unclamp cycles of 15/5 minutes.The average clamp time was 21.4±8.0 minutes.These patients were divided into 5 groups based on the CVP:group A:0-1 mmHg;B:1.1-2 mmHg;C:2.1-3 mmHg;D:3.1-4 mmHg and E:4.1-5 mmHg.The blood loss per transection area during hepatic parenchymal transection and the arterial blood gas before and after liver transection were analyzed.RESULTS:With active fluid load,a constant SBP ≥90 mmHg which was considered as optimal was maintained in 18.6% in group A(95% CI:10.8%-26.3%);39.2% in group B(95% CI:29.5%-48.9%);72.2% in group C(95% CI:63.2%-81.1%);89.7% in group D(95% CI:83.6%-95.7%);and 100% in group E(95% CI:100%-100%).The blood loss per transection area during hepatic parenchymal transection decreased with a decrease in CVP.Compared to groups D and E,blood loss in groups A,B and C was significantly less(analysis of variance test,P【0.05).Compared with the baseline,the blood oxygenation decreased significantly when the CVP was reduced.Base excess and HCO 3-in groups A and B were significantly decreased compared with those in groups C,D and E(P【0.05).CONCLUSION:In consideration of blood loss,SBP,base excess and HCO 3-,a CVP of 2.1-3 mmHg was optimal in patients undergoing partial hepatectomy for HCC.

Hemodynamics and oxygen transport dynamics during hepatic resection at different central venous pressures in a pig model

BACKGROUND: Although low central venous pressure (CVP) has been used to minimize blood loss during hepatectomy the impact of variations of CVP on the rate of blood loss and on the perfusion of end-organs has not been evaluated This animal study aimed to evaluate the hemodynamics and oxygen transport changes during hepatic resection at different CVP levels. METHODS: Forty-eight anesthetized Bama miniature pigs were divided into 8 groups with CVP during hepatic resection controlled at 0 to <1, 1 to <2, 2 to <3, 3 to <4, 4 to <5, 5 to <6, 6 to <7, and 7 to <8 cmH 2 O. Intergroup comparisons were made for hemodynamic parameters, oxygen transport dynamics, and the rate of blood loss. RESULTS: The rate of blood loss and the hepatic venous pressure during hepatic resection were almost linearly related to the CVP. A significant drop in the mean arterial pressure cardiac output, and cardiac index occurred between CVP ≥2 and <2 cmH 2 O. Oxygen delivery (DO 2 ), oxygen consumption (VO 2 ) and oxygen extraction ratio (ERO 2 ) remained relatively constant between CVPs of 2 to <8 cmH 2 O. There was a significant drop in DO 2 when the CVP was <2 cmH 2 O. There was also a significant drop in VO 2 and ExO 2 when the CVP was <1 cmH 2 O.CONCLUSION: The optimal CVP for hepatic resection is 2to 3 cmH2O.

Effect of controlled low central venous pressure on renal function in major liver resection

Objective： To investigate the effects of low central venous pressure （LVCP） on blood loss and evaluate its influence on renal function in patients undergoing hepatectomy. Methods： Forty-six patients, ASA classification Ⅰ-Ⅲ, undergoing liver resection were randomized into LCVP group （n = 23） and control group （n = 23）. In LCVP group, CVP was maintained at 2-4 mmHg and MBP above 60 mmHg during hepatectomy, while in control group hepatectomy was performed routinely without lowering CVP. Volume of blood loss during hepatectomy, volume of blood transfusion, and changes of renal functions were compared between the two groups. Results： There were no significant differences in demographics, ASA score, type of hepatectomy, duration of inflow occlusion, operation time, weight of resected liver tissues, and renal functions between the two groups. LCVP group had a significantly lower volume of total intraoperative blood loss （P 〈 0.01） and RBC transfusion （P 〈 0.05）. Conclusion： Lowering the CVP to less than 5 mmHg is a simple and effective technique to reduce blood loss and blood infusion during liver resection, and has no detrimental effects on renal functions.

Correlation of Inferior Vena Cava Respiratory Variability Index with Central Venous Pressure and Hemodynamic Parameters in Ventilated Pigs with Septic Shock

Septic shock is a common critical condition, for which effective early fluid resuscitation is the therapeutic focus. According to the 2008 international guidelines for management of severe sepsis and septic shock, resuscitation should achieve a central venous pressure （CVP） of 8-12 mmHg within the first 6 h. However, it is still uncertain about the sensitivity and specificity of CVP in reflecting the cardiac preload. Ultrasonography is a simple, rapid, non-invasive, and repeatable method for the measurement of sensitivity and specificity of CVP and has thus gradually attracted the increasing attention of physicians. It was reported that ultrasonography can show the inferior vena cava diameter, respiratory variability index, and blood volume in patients with sepsis or heart failure.

Nitroglycerin reduces augmentation index and central blood pressure independent of effects on cardiac preload

Objective To determine whether reduction in central pressure augmentation and central systolic blood pressure by nitroglycerine (NTG) results from effects on pre-load or is due to arterial dilation. Methods We compared effects of NTG with those of lower body negative pressure (LBNP). Hemodynamic measurements were made at rest,during LBNP (10,20 and 30 mmHg,each for 15 min) and after NTG (10,30 and 100 μg/min,each dose for 15 min) in ten healthy volunteers. Cardiac pre-load,stroke volume and cardiac output were assessed by echocardiography. Central pressure augmentation and central systolic pressure were obtained by radial tonometry using a transfer function. Results LBNP (20 mmHg) and NTG (30 μg/min) reduced pre-load (as measured by the peak velocity of the S wave in the superior vena cava) to a similar degree [by (26.8±3.8)% and (23.9±3.4)%,respectively]. Compared to LBNP,NTG reduced systemic vascular resistance [by (32.9±7.5)%,P<0.01],decreased peripheral and central pressure augmentation [by (20.8±3.4)% units and (12.9±2.9)% units,respectively,each P<0.01]. Conclusion These results suggest that a reduction in pre-load does not explain reduction in pressure augmentation and central systolic blood pressure by NTG and that these effects are mediated through arterial dilation.

Effect of autologous blood donation on the central venous pressure, blood loss and blood transfusion during living donor left hepatectomy

AIM： Autologous blood donation （ABD） is mainly used to reduce the use of banked blood. In fact, ABD can be regarded as acute blood loss. Would ABD 2-3 d before operation affect the CVP level and subsequently result in less blood loss during liver resection was to be determined.METHODS： Eighty-four patients undergoing living donor left hepatectomy were retrospectively divided as group Ⅰ （GⅠ） and group Ⅱ （GⅡ） according to have donated 250-300 mL blood 2-3 d before living donor hepatectomy or not. The changes of the intraoperative CVP, surgical blood loss,blood products used and the changes of perioperative hemoglobin （Hb） between groups were analyzed and compared by using Mann-Whitney Utest.RESULTS： The results show that the intraoperative CVP changes between GⅠ （n = 35） and GⅡ （n = 49） up to graft procurement were the same, subsequently the blood loss,but ABD resulted in significantly lower perioperative Hb levels in GI.CONCLUSION： Since none of the patients required any blood products perioperatively, all the predonated bloods were discarded after the patients were discharged from the hospital. It indicates that ABD in current series had no any beneficial effects, in term of cost, lowering the CVP, blood loss and reduce the use of banked blood products, but resulted in significant lower Hb in perioperative period.

Influence of tissue pressure on central venous pressure/peripheral venous pressure correlation： An experimental report

BACKGROUND： Peripheral venous pressure （PVP） has been shown to correlate with central venous pressure （CVP） in a number of reports. Few studies, however, have explored the relationship between tissue pressure （TP） and PVP/CVP correlation. METHODS： PVP and CVP were simultaneously recorded in a bench-top model of the venous circulation of the upper limb and in a single human volunteer after undergoing graded manipulation of tissue pressure surrounding the intervening venous conduit. Measures of correlation were determined below and above a point wherein absolute CVP exceeded TP. RESULTS： Greater correlation was observed between PVP and CVP when CVP exceeded TP in both models. Linear regression slope was 0.975 （95% CI： 0.959-0.990）; r2 0.998 above tissue pressure 10 cmH20 vs. 0.393 （95% CI： 0.360-0.426）; and r2 0.972 below 10 cmH2O at a flow rate of 2000 mL/h in the in vitro model. Linear regression slope was 0.839 （95% CI： 0.754-0.925）; r2 0.933 above tissue pressure 10 mmHg vs. slope 0.238 （95% CI： -0.052-0.528）; and r20.276 in the en vivo model. CONCLUSIONS： PVP more accurately reflects CVP when absolute CVP values exceed tissue pressure.

Effect of positive end-expiratory pressure ventilation on central venous pressure and intraoperative blood loss in patients undergoing laparoscopic hepatectomy

Objective:Tto investigate the effects of positive end-expiratory pressure(PEEP)ventilation on central venous pressure(CVP)and intraoperative blood loss in patients undergoing laparoscopic hepatectomy.Methods:46 cases of patients undergoing laparoscopic hepatectomy,25 cases of male,female 21 cases,ASAⅠ~Ⅲlevel,were randomly divided into two groups.In group A tidal volume was set to 6 ml/kg(Predicted Body Weight,PBW)and PEEP was set to 0 cmH2O.The tidal volume of group B was set as group A,PEEP was set to 8 cmH2O.CVP,MAP,and Ppeak were recorded in the supine position after intubation(T0),supine position after pneumoperitoneal(T1),anti-trendelenberg position after pneumoperitoneal(T2),supine position after surgery(T3),and Ddyn was calculated.The amount of nitroglycerin and the amount of blood loss were recorded.Results:Compared with group A,the CVP of group B was significantly increased at T1 and T2(P<0.05).Compared to T2 with T1 in group A and group B,CVP was decreased significantly(P<0.05).At T3,Cdyn in group B was significantly higher than that in group A(P<0.05).The amount of nitroglycerin in group B was significantly higher than that in group A(P<0.05).There was no significant difference in intraoperative fluid rehydration and blood loss between the two groups(P>0.05).Conclusion:PEEP with 8cmH2O can improve Ddyn in patients undergoing laparoscopic hepatectomy,but increased CVP.It requires more use of controlled low central venous pressure techniques to reduce intraoperative blood loss.

Changes in Brachial and Central Blood Pressure after Short Term Continuous Positive Airway Pressure Treatment of Patients with Moderate-to-Severe Obstructive Sleep Apnoea and Impaired Renal Function

Background: Previous studies of continuous positive airway pressure (CPAP) treatment for obstructive sleep apnoea (OSA) have shown conflicting results on the effect on blood pressure (BP), and patients with chronic kidney disease (CKD) have not been included in these studies. As OSA is a frequent comorbidity in patients with CKD, it is of relevance to evaluate the effect of CPAP treatment on BP in this population. Aim: In this prospective follow-up study, we measured the effect of short term CPAP treatment of moderate-to-severe OSA on brachial and central BP, plasma level of syndecan-1 and vasoactive hormones, renal handling of sodium, subjective sleepiness, and quality of life in patients with impaired renal function. Methods: From December 2015 until March 2017, 25 patients were invited to participate in the study at the University Clinic in Nephrology and Hypertension, Aarhus University and Holstebro Hospital. At baseline and at follow-up after three to four months of CPAP treatment, we performed 24 h brachial and central ambulatory BP measurement, blood sampling measurements of plasma concentrations of syndecan-1, renin, angiotensin II, aldosterone, vasopressin, creatinine, haemoglobin A1c, and cholesterol, cardio respiratory monitoring, 24 h urine collection for measurement of urinary excretion of albumin, aquaporin-2, and epithelial sodium channel, Epworth Sleepiness Scale (ESS), and SF-36 (quality of life). Results: At follow-up, the 17 included patients with mean baseline estimated glomerular filtration rate 66 mL/min/1.73 m2 had a significant decrease in systolic office-, 24 h- and daytime-BP (13, 7, and 8 mmHg, respectively, p Conclusion: Short-term CPAP treatment of patients with moderate-to-severe OSA and reduced renal function decreased 24 h- and daytime-BP significantly and reduced urinary albumin excretion. Our results underline the importance of treatment of OSA in hypertensive patients with impaired renal function.

Seeing beneath the surface:Harnessing point-of-care ultrasound for internal jugular vein evaluation

Point-of-care ultrasound(POCUS)of the internal jugular vein(IJV)offers a noninvasive means of estimating right atrial pressure(RAP),especially in cases where the inferior vena cava is inaccessible or unreliable due to conditions such as liver disease or abdominal surgery.While many clinicians are familiar with visually assessing jugular venous pressure through the internal jugular vein,this method lacks sensitivity.The utilization of POCUS significantly enhances the visualization of the vein,leading to a more accurate identification.It has been demonstrated that combining IJV POCUS with physical examination enhances the specificity of RAP estimation.This review aims to provide a comprehensive summary of the various sonographic techniques available for estimating RAP from the internal jugular vein,drawing upon existing data.

Portal vein pulsatility:An important sonographic tool assessment of systemic congestion for critical ill patients

In this editorial we comment on the article by Kuwahara et al,published in the recent issue of the World Journal of Cardiology.In this interesting paper,the authors showed a correlation between portal vein pulsatility ratio,examined by bedside ultrasonography,and prognosis of hospitalized patients with acute heart failure.Systemic congestion is being notoriously underdetected in the acutely ill population with conventional methods like clinical examination,biomarkers,central venous pressure estimation and X-rays.However,congestion should be a key therapeutic target due to its deleterious effects to end organ function and subsequently patient prognosis.Doppler flow assessment of the abdominal veins is gaining popularity worldwide,as a valuable tool in estimating comprehensively congestion and giving a further insight into hemodynamics and patient management.

The effect of acute aerobic exercise on central arterial stiffness,wave reflections,and hemodynamics in adults with diabetes:A randomized cross-over design

Background:Individuals with diabetes have greater central arterial stiffness,wave reflections,and hemodynamics,all of which promote the accelerated cardiovascular pathology seen in this population.Acute aerobic exercise has been shown to be an effective strategy for reducing central arterial stiffness,wave reflections,and hemodynamics in healthy individuals;however,the effects of acute aerobic exercise in reducing these outcomes is not well established in people with diabetes.Recently,implementation of high-intensity interval exercise(HIIE)has shown superior improvements in cardiovascular health outcomes when compared to traditional aerobic exercise.Yet,the effect of HIIE on the aforementioned outcomes in people with diabetes is not known.The purpose of this study was to(i)describe the central arterial stiffness,wave reflections,and hemodynamic responses to a bout of HIIE and moderate-intensity continuous exercise(MICE)in adults with diabetes;and(ii)compare the effects of HIIE and MICE on the aforementioned outcomes.Methods:A total of 24 adult men and women(aged 29-59 years old)with type 1(n=12)and type 2(n=12)diabetes participated in a randomized cross-over study.All participants completed the following protocols:(i)HIIE:cycling for 4×4 min at 85%-95%of heart rate peak(HR_(peak)),interspersed with 3 min of active recovery at 60%-70%HR_(peak);(ii)MICE:33 min of continuous cycling at 60%-70%HR_(peak);and(iii)control(CON):lying quietly in a supine position for 30 min.Results:A significant group￡time effect was found for changes in central systolic blood pressure(F=3.20,p=0.01)with a transient reduction for the HIIE group but not for the MICE or CON groups.There was a significant group￡time effect for changes in augmentation index at a heart rate of 75 beats/min(F=2.32,p=0.04)with a decrease following for HIIE and MICE but not for CON.For all other measures of central arterial stiffness and hemodynamics,no significant changes were observed(p>0.05).Conclusion:A bout of HIIE appears to lead to a greater transient reduction in central systolic blood pressure than the reduction observed following MICE;however,both HIIE and MICE improved augmentation index at a heart rate of 75 beats/min in people with diabetes.There was no significant difference in response to HIIE and MICE in all outcomes.This provides preliminary evidence on the role of HIIE on such outcomes in people with diabetes.

Association of different central venous pressure levels with outcome of living-donor liver transplantation in children under 12 years

Background Pediatric liver transplantation is an important modality for treating biliary atresia.The overall survival(OS)rate of pediatric liver transplantation has significantly improved compared with that of 20 years ago,but it is still unsatisfactory.The anesthesia strategy of maintaining low central venous pressure(CVP)has shown a positive effect on prognosis in adult liver transplantation.However,this relationship remains unclear in pediatric liver transplantation.Thus,this study was conducted to review the data of pediatric living-donor liver transplantation to analyze the associations of different CVP levels with the prognosis of recipients.Methods This was a retrospective study and the patients were divided into two groups according to CVP levels after abdominal closure:low CVP(LCVP)(≤10 cmH2O,n=470)and high CVP(HCVP)(>10 cmH2O,n=242).The primary outcome measured in the study was the overall survival rate.The secondary outcomes included the duration of mechanical ventilation in the intensive care unit(ICU),length of stay in the ICU,and postoperative stay in the hospital.Patient demographic and perioperative data were collected and compared between the two groups.Kaplan-Meier curves were constructed to determine the associations of different CVP levels with the survival rate.Results In the study,712 patients,including 470 in the LCVP group and 242 in the HCVP group,were enrolled.After propensity score matching,212 pairs remained in the group.The LCVP group showed a higher overall survival rate than the HCVP group in the Kaplan-Meier curves and multivariate Cox regression analyses(P=0.018),and the HCVP group had a hazard ratio of 2.445(95%confidence interval,1.163–5.140).Conclusion This study confirmed that a low-CVP level at the end of surgery is associated with improved overall survival and a shorter length of hospital stay.

Correlation between Glasgow Coma Scale with central venous pressure and near-infrared spectroscopy in patients with acquired brain injury in the intensive care unit of Adam Malik Hospital Medan

Background:Acquired brain injury(ABI)is caused by trauma or nontrauma to the brain after birth.Increased intracranial pressure in patients with traumatic or nontraumatic brain injury affects the cerebral perfusion pressure.After traumatic brain injury,there is an increase in air content in the brain and an increase in volume of blood flow to the brain,which can cause increased intracranial pressure,herniation of brain tissue,impaired cerebral perfusion,and brain damage.Most patients with traumatic brain injury die from uncontrolled increases in intracranial pressure.Near-infrared spectroscopy(NIRS)and central venous pressure(CVP)monitoring are also associated with cerebral perfusion.This study aimed to determine the relationship between the Glasgow Coma Scale(GCS)scores and CVP and NIRS values in patients with ABI.Methods:This prospective analytical study used a cross-sectional design to compareGCS scores with CVP and NIRS values in patients with traumatic and nontraumatic brain injury in the intensive care unit(ICU)of Haji Adam Malik Hospital Medan.GCS,CVP,and NIRS descriptive data in patients with brain injury were presented in terms of mean and standard deviation if the data were normally distributed,or median(interquartile range)values if the data were not normally distributed.The relationship between GCS scores and CVP and NIRS values was assessed using the Pearson correlation test if the data were normally distributed,or the Spearman test if the data were not normally distributed.Results:In this study,the mean GCS score and CVP values were 7.04±2.69 and 5.63±25.82 mmHg,respectively.The right tissue oxygen saturation(StO2)was 55.61%±18.72%,and the left StO2 was 57.57%±17.48%with normally distributed data.There was no correlation between GCS scores and CVP values(P=0.829),and no correlation between moderate GCS scores and right and left StO2(P=0.343;P=0.121);however,there was a significantly strong positive correlation between severe GCS scores and right and left StO2(P=0.028,r=0.656;P=0.005,r=0.777).Conclusion:There was no significant correlation between GCS scores and CVP values,and no correlation between moderate GCS scores and NIRS values;however,there was a significantly strong positive correlation between severe GCS scores and NIRS values in patients with ABI at the ICU of Haji Adam Malik Hospital Medan.

Optimization of central venous pressure during the perioperative period is associated with improved prognosis of high-risk operation patients

Background:While central venous pressure(CVP)measurement is used to guide fluid management for high-risk surgical patients during the perioperative period,its relationship to patient prognosis is unknown.Methods:This single-center,retrospective observational study enrolled patients undergoing high-risk surgery from February 1,2014 to November 31,2020,who were admitted to the surgical intensive care unit(ICU)directly after surgery.Patients were divided into the following three groups according to the first CVP measurement(CVP1)after admission to the ICU:low,CVP1<8 mmHg;moderate,8 mmHg≤CVP1≤12 mmHg;and high,CVP1>12 mmHg.Perioperative fluid balance,28-day mortality,length of stay in the ICU,and hospitalization and surgical complications were compared across groups.Results:Of the 775 high-risk surgical patients enrolled in the study,228 were included in the analysis.Median(interquartile range)positive fluid balance during surgery was lowest in the low CVP1 group and highest in the high CVP1 group(low CVP1:770[410,1205]mL;moderate CVP1:1070[685,1500]mL;high CVP1:1570[1008,2000]mL;all P<0.001).The volume of positive fluid balance during the perioperative period was correlated with CVP1(r=0.336,P<0.001).The partial arterial pressure of oxygen(PaO 2)/fraction of inspired oxygen(FiO 2)ratio was significantly lower in the high CVP1 group than in the low and moderate CVP1 groups(low CVP1:400.0[299.5,443.3]mmHg;moderate CVP1:362.5[330.0,434.9]mmHg;high CVP1:335.3[254.0,363.5]mmHg;all P<0.001).The incidence of postoperative acute kidney injury(AKI)was lowest in the moderate CVP1 group(low CVP1:9.2%;moderate CVP1:2.7%;high CVP1:16.0%;P=0.007).The proportion of patients receiving renal replacement therapy was highest in the high CVP1 group(low CVP1:1.5%;moderate CVP1:0.9%;high CVP1:10.0%;P=0.014).Logistic regression analysis showed that intraoperative hypotension and CVP1>12 mmHg were risk factors for AKI within 72 h after surgery(adjusted odds ratio[aOR]=3.875,95%confidence interval[CI]:1.378–10.900,P=0.010 and aOR=1.147,95%CI:1.006–1.309,P=0.041).Conclusions:CVP that is either too high or too low increases the incidence of postoperative AKI.Sequential fluid therapy based on CVP after patients are transferred to the ICU post-surgery does not reduce the risk of organ dysfunction caused by an excessive amount of intraoperative fluid.However,CVP can be used as a safety limit indicator for perioperative fluid management in high-risk surgical patients.

Numerical simulation of typhoon-induced storm surge along Jiangsu coast,PartⅠ:Analysis of tropical cyclone

The Tropical Cyclone Best Track Dataset issued by the Shanghai Typhoon Institute of the China Meteorological Administration, for the period from 1949 to 2013, was analyzed, and the typhoons threatening the Jiangsu coast were categorized into three different classes in terms of track, including typhoons making straight landfall, typhoons active in offshore areas, and typhoons moving northward after landfall. On the basis of the 65-year dataset, the typhoon parameters of these three categories, including the central pressure and the maximum wind speed, were investigated. Statistical analysis suggested that the minimum central pressure increased northward and shoreward gradually. The relationship between the maximum wind speed and the minimum central pressure was established through second-order polynomial fitting. Considering typhoons No. 1210, No. 0012, and No. 9711 as the basic typhoons, ten hypothetical cyclones with typical tracks and minimum central pressure occurring during the period from 1949 to 2013 were designed, providing the driving conditions for numerical simulation of typhoon-induced storm surges along the Jiangsu coast.