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.

Hepatic venous pressure gradient: Inaccurately estimates portal venous pressure gradient in alcoholic cirrhosis and portal hypertension

BACKGROUND Portal hypertension(PHT)in patients with alcoholic cirrhosis causes a range of clinical symptoms,including gastroesophageal varices and ascites.The hepatic venous pressure gradient(HVPG),which is easier to measure,has replaced the portal venous pressure gradient(PPG)as the gold standard for diagnosing PHT in clinical practice.Therefore,attention should be paid to the correlation between HVPG and PPG.METHODS Between January 2017 and June 2020,134 patients with alcoholic cirrhosis and PHT who met the inclusion criteria underwent various pressure measurements during transjugular intrahepatic portosystemic shunt procedures.Correlations were assessed using Pearson’s correlation coefficient to estimate the correlation coefficient(r)and determination coefficient(R^(2)).Bland-Altman plots were constructed to further analyze the agreement between the measurements.Disagreements were analyzed using paired t tests,and P values<0.05 were considered statistically significant.RESULTS In this study,the correlation coefficient(r)and determination coefficient(R2)between HVPG and PPG were 0.201 and 0.040,respectively(P=0.020).In the 108 patients with no collateral branch,the average wedged hepatic venous pressure was lower than the average portal venous pressure(30.65±8.17 vs.33.25±6.60 mmHg,P=0.002).Hepatic collaterals were identified in 26 cases with balloon occlusion hepatic venography(19.4%),while the average PPG was significantly higher than the average HVPG(25.94±7.42 mmHg vs 9.86±7.44 mmHg;P<0.001).The differences between HVPG and PPG<5 mmHg in the collateral vs no collateral branch groups were three cases(11.54%)and 44 cases(40.74%),respectively.CONCLUSION In most patients,HVPG cannot accurately represent PPG.The formation of hepatic collaterals is a vital reason for the strong underestimation of HVPG.

Pre-transjugular-intrahepatic-portosystemic-shunt measurement of hepatic venous pressure gradient and its clinical application: A comparison study

BACKGROUND It is controversial whether transjugular intrahepatic portosystemic shunt(TIPS)placement can improve long-term survival.AIM To assess whether TIPS placement improves survival in patients with hepaticvenous-pressure-gradient(HVPG)≥16 mmHg,based on HVPG-related risk stratification.METHODS Consecutive variceal bleeding patients treated with endoscopic therapy+nonselectiveβ-blockers(NSBBs)or covered TIPS placement were retrospectively enrolled between January 2013 and December 2019.HVPG measurements were performed before therapy.The primary outcome was transplant-free survival;secondary endpoints were rebleeding and overt hepatic ence-phalopathy(OHE).RESULTS A total of 184 patients were analyzed(mean age,55.27 years±13.86,107 males;102 in the EVL+NSBB group,82 in the covered TIPS group).Based on the HVPG guided risk stratification,70 patients had HVPG<16 mmHg,and 114 patients had HVPG≥16 mmHg.The median follow-up time of the cohort was 49.5 mo.There was no significant difference in transplant-free survival between the two treatment groups overall(hazard ratio[HR],0.61;95%confidence interval[CI]:0.35-1.05;P=0.07).In the high-HVPG tier,transplant-free survival was higher in the TIPS group(HR,0.44;95%CI:0.23-0.85;P=0.004).In the low-HVPG tier,transplantfree survival after the two treatments was similar(HR,0.86;95%CI:0.33-0.23;P=0.74).Covered TIPS placement decreased the rate of rebleeding independent of the HVPG tier(P<0.001).The difference in OHE between the two groups was not statistically significant(P=0.09;P=0.48).CONCLUSION TIPS placement can effectively improve transplant-free survival when the HVPG is greater than 16 mmHg.

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.

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.

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.

Comparison of hepatic venous pressure gradient and endoscopic grading of esophageal varices

AIM: To determine the correlation between the hepatic venous pressure gradient and the endoscopic grade of esophageal varices.METHODS: From September 2009 to March 2013, a total of 176 measurements of hepatic venous pressure gradient (HVPG) were done in 146 patients. Each transjugular HVPG was measured twice, first using an end whole catheter (EH-HVPG), and then using a balloon catheter (B-HVPG). The HVPG was compared with the endoscopic grade of esophageal varices (according to the general rules for recording endoscopic findings of esophagogastric varices), which was recorded within a month of the measurement of HVPG.RESULTS: The study included 110 men and 36 women, with a mean age of 56.1 years (range, 43-76 years). The technical success rate of the pressure measurements was 100% and there were no complication related to the procedures. Mean HVPG was 15.3 mmHg as measured using the end hole catheter method and 16.5 mmHg as measured using the balloon catheter method. Mean HVPG (both EH-HVPG and B-HVPG) was not significantly different among patients with different characteristics, including sex and comorbid factors, except for cases with hepatocellular carcinoma (B-HVPG, P = 0.01; EH-HVPG, P = 0.02). Portal hypertension (&#x0003e; 12 mmHg HVPG) occurred in 66% of patients according to EH-HVPG and 83% of patients according to B-HVGP, and significantly correlated with Child&#x02019;s status (B-HVPG, P &#x0003c; 0.000; EH-HVGP, P &#x0003c; 0.000) and esophageal varies observed upon endoscopy (EH-HVGP, P = 0.003; B-HVGP, P = 0.006). One hundred and thirty-five endoscopies were performed, of which 15 showed normal findings, 27 showed grade 1 endoscopic esophageal varices, 49 showed grade 2 varices, and 44 showed grade 3 varices. When comparing endoscopic esophageal variceal grades and HVPG using univariate analysis, the P value was 0.004 for EH-HVPG and 0.002 for B-HVPG.CONCLUSION: Both EH-HVPG and B-HVPG showed a positive correlation with the endoscopic grade of esophageal varices, with B-HVPG showing a stronger correlation than EH-HVPG.

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.

Hepatic venous pressure gradient measurement before TIPS for acute variceal bleeding

Hepatic venous pressure gradient(HVPG)is an independent predictor of variceal rebleeding in patients with cirrhosis.After pharmacological and/or endoscopic therapy,the use of a transjugular intrahepatic portosystemic shunt(TIPS)may be necessary in HVPG non-responders,but not in responders.Thus,HVPG measurement may be incorporated into the treatment algorithm for acute variceal bleeding,which further identifies the candidates that should undergo early insertion of TIPS or maintain the traditional pharmacological and/or endoscopic therapy.The potential benefits are to reduce the cost and prevent TIPS-related complications.

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.

Computed tomography perfusion in liver and spleen for hepatitis B virus-related portal hypertension:A correlation study with hepatic venous pressure gradient

BACKGROUND Hepatic venous pressure gradient(HVPG)is the gold standard for diagnosis of portal hypertension(PH).However,its use can be limited because it is an invasive procedure.Therefore,it is necessary to explore a non-invasive method to assess PH.AIM To investigate the correlation of computed tomography(CT)perfusion of the liver with HVPG and Child-Pugh score in hepatitis B virus(HBV)-related PH.METHODS Twenty-eight patients(4 female,24 male)with gastroesophageal variceal bleeding induced by HBV-related PH were recruited in our study.All patients received CT perfusion of the liver before transjugular intrahepatic portosystemic stent-shunt(TIPS)therapy.Quantitative parameters of CT perfusion of the liver,including liver blood flow(LBF),liver blood volume(LBV),hepatic artery fraction,splenic blood flow and splenic blood volume were measured.HVPG was recorded during TIPS therapy.Correlation of liver perfusion with Child-Pugh score and HVPG were analyzed,and the receiver operating characteristic curve was analyzed.Based on HVPG(>12 mmHg vs≤12 mmHg),patients were divided into moderate and severe groups,and all parameters were compared.RESULTS Based on HVPG,18 patients were classified into the moderate group and 10 patients were classified into the severe group.The Child-Pugh score,HVPG,LBF and LBV were significantly higher in the moderate group compared to the severe group(all P<0.05).LBF and LBV were negatively associated with HVPG(r=-0.473,P<0.05 and r=-0.503,P<0.01,respectively),whereas splenic blood flow was positively associated with hepatic artery fraction(r=0.434,P<0.05).LBV was negatively correlated with Child-Pugh score.Child-Pugh score was not related to HVPG.Using a cutoff value of 17.85 mL/min/100 g for LBV,the sensitivity and specificity of HVPG≥12 mmHg for diagnosis were 80%and 89%,respectively.CONCLUSION LBV and LBF were negatively correlated with HVPG and Child-Pugh scores.CT perfusion imaging is a potential non-invasive quantitative predictor for PH in HBV-related liver cirrhosis.

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.

Sildenafil does not influence hepatic venous pressure gradient in patients with cirrhosis

AIM： To investigate if sildenafil increases splanchnic blood flow and changes the hepatic venous pressure gradient （HVPG） in patients with cirrhosis. Phosphodiesterase type-5 inhibitors are valuable in the treatment of erectile dysfunction and pulmonary hypertension in patients with end-stage liver disease. However, the effect of phosphodiesterase type-5 inhibitors on splanchnic blood flow and portal hypertension remains essentially unknown. METHODS： Ten patients with biopsy proven cirrhosis （five females/five males, mean age 54：1：8 years） and an HVPG above 12 mmHg were studied after informed consent. Measurement of splanchnic blood flow and the HVPG during liver vein catheterization were done before and 80 min after oral administration of 50 mg sildenafil. Blood flow was estimated by use of indocyanine green clearance technique and Fick＇s principle, with correction for non-steady state. RESULTS： The plasma concentration of sildenafil was 222 ± 136 ng/mL 80 min after administration. Mean arterial blood pressure decreased from 77 ±7 mmHg to 66 ± 12 mmHg, P = 0.003, while the splanchnicblood flow and oxygen consumption remained unchanged at 1.14 ± 0.71 L/min and 2.3 ± 0.6 mmol/ min, respectively. Also the HVPG remained unchanged （18 ± 2 mmHg vs 16 ± 2 mmHg） with individual changes ranging from -8 mmHg to ±2 mmHg. In seven patients, HVPG decreased and in three it increased. CONCLUSION： In spite of arterial blood pressure decreases 80 min after administration of the phosphodiesterase type-5 inhibitor sildenafil, the present study could not demonstrate any clinical relevant influence on splanichnic blood flow, oxygen consumption or the HVPG.

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.

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.

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.

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.