Volume therapy with hypertonic saline hydroxyethyl starch solution in cardiac surgery

The ideal solution for volume therapy remains controversial. In cardiac surgery, haemodynamic efficacy as well as the influence of extracorporeal oxygenation are of major interest when administering volume. The present study examines the effects of a new hypertonic saline hydroxyethyl starch solution in comparison to a 6% hydroxyethyl starch solution on haemodynamics and laboratory variables. Patients scheduled for elective aortocoronary bypass grafting received hypertonic saline hydroxyethyl starch (n = 10) or hydroxyethyl starch (n = 10) after induction of anaesthesia in order to double baseline pulmonary capillary wedge pressure. Ten patients without volume therapy served as a control group. Significantly less hypertonic solution than standard solution was effective in doubling pulmonary capillary wedge pressure. Fluid requirements in the patients who received the hypertonic solution were significantly less during, as well as after, cardiopulmonary bypas in comparison to those in the other groups. Cardiac index increased most in the patients who received the hypertonic solution (+34.8%), as did right ventricular end-diastolic volume. Patients in that group showed the highest decrease in total systemic resistance (-29.8%), whereas arterial pressure and right ventricular ejection fraction remained almost unchanged in all groups. No negative alteration in coagulation or organ function was demonstrated within the investigation period. It can be concluded that hypertonic saline hydroxyethyl starch solution seems to be a valuable alternative to conventional volume therapy in cardiac surgery.     

A trial of fresh autologous whole blood to treat dilutional coagulopathy following cardiopulmonary bypass in infants

BACKGROUND: Transfusion of fresh whole blood is superior to blood component therapy in correcting coagulopathies in children following cardiopulmonary bypass (CPB); however, a supply of fresh homologous whole blood is difficult to maintain. We hypothesized that transfusion of fresh autologous whole blood obtained prior to heparinization for CPB and infused following CPB would be associated with improved coagulation function when compared with standard therapy. METHODS: A total of 32 infants 5-12 kg undergoing noncomplex open cardiac surgery were randomly assigned to either the treatment or control group. In the treatment group, 15 ml x kg(-1) of autologous whole blood was collected into a CPDA bag prior to heparinization while 15 ml x kg(-1) of 5% albumin was infused intravenously. After reversal of heparin, coagulation tests were drawn in both groups, and the autologous whole blood was infused over 20 min in the treatment group. RESULTS: The treatment group had greater (P < 0.05) improvement in platelet count, prothrombin time, and fibrinogen than the control group. CONCLUSIONS: We conclude that collection of fresh autologous whole blood prior to heparinization and reinfusion following CPB is associated with greater improvement of coagulation status after CPB in infants.     

Effect of topical glyceryl trinitrate on anodermal blood flow in patients with chronic anal fissures

Introduction : Recent studies have highlighted the role of increased internal anal sphincter pressure and decreased anodermal blood flow in the pathogenesis of chronic anal fissures. The duration of the effect of topical 0.2% glyceryl trinitrate (GTN) ointment on anodermal blood flow in fissure and normal areas was investigated in patients with chronic anal fissures. Methods : Six patients with chronic anal fissures in the posterior midline participated in the study. Blood flow measurements were performed on the anoderm using laser Doppler flowmetry before and immediately after the topical application of 0.2% GTN ointment and subsequent readings were taken at 5, 15, 30, 45 and 60 min in all four quadrants. Results : The mean anodermal blood flow in the fissure region is significantly lower than the mean blood flow of the rest of the anoderm before 0.2% GTN ointment is applied (228.7 ± 61.8 flux units vs 439.3 ± 25.5 flux units, respectively; P < 0.05). Immediately after the application of local 0.2% GTN ointment there is a significant increase in anodermal blood flow over the anal fissure region (457.8 ± 56.5 flux units; P < 0.05) compared to the rest of the anoderm (457.4 ± 30.8 flux units). This increase is most marked at 5 min post‐GTN ointment application in the fissure area (474.6 ± 41.1 flux units) and the blood flow in the fissure region is consistently above the rest of the anoderm for most of the 60 min. Conclusion : There is clearly reduced blood flow to the chronic anal fissure region compared to the rest of the anoderm. Topical application of glyceryl trinitrate ointment seems to significantly improve the blood flow to the fissured area in the first hour. This may therefore help in the healing of chronic anal fissures.     

The effect of anchoring suture on the anastomotic blood flow in a rat model of human esophagojejunostomy

PURPOSE: An impairment of anastomotic blood flow (ABF) and the resulting hypoxia readily lead to the complications such as leakage and stricture. We performed an animal study to evaluate the effect of anchoring suture for minimizing the impairment of ABF caused by tensile loading. MATERIALS AND METHODS: An end-to-side jejunojejunostomy was done in 20 rats, and this followed the modeling of a human end-to-side esophagojejunostomy. Laser Doppler flowmetry was checked in three different tensile conditions to evaluate the influence of anchoring suture on the ABF. RESULTS: Before anchoring suture, the mean ABF was 129.06 perfusion unit (PU), 96.99 PU, and 69.04 PU, in the order of tensile stress. After anchoring suture, the mean ABF was 121.68, 103.30, and 87.06 PU (P < 0.01). CONCLUSION: Anchoring suture is a novel method to reduce the impairment of the anastomotic blood flow that is caused by tension.     

6%羟乙基淀粉130/0.4对心脏瓣膜置换术患者黏附分子表达的影响

目的观察体外循环（CPB）中使用6％羟乙基淀粉130／0．4（6％HES130／0．4）对心脏瓣膜置换术患者细胞间黏附分子-1（ICAM-1）、血管细胞黏附分子-1（VCAM-1）及血小板内皮细胞黏附分子-1（PECAM-1）表达的影响。方法选择心脏二尖瓣瓣膜置换术患者60例,ASAⅡ或Ⅲ级,随机分为2组,每组30例。6％HES130／0．4组（Ⅴ组）：人工心肺机中预充6％HES130／0．415ml／kg和琥珀酰明胶（Succinyhted Gelatin）对照组（C组）：人工心肺机中预充Succinyhted Gelatin 15ml／kg,两组分别于气管插管后至CPB开始前静脉输注6％HES130／0．4和Succinyhted Gehtin 10ml／kg。麻醉诱导后即刻（T0）、CPB主动脉阻断开放时（T1）、CPB结束时（T2）和手术结束时（T3）分别抽取外周动脉血,分离血清。检测血清中游离黏附分子（sAM）：sICAM-1、sVCAM-1及sPECAM-1）的含量。结果与C组比较,Ⅴ组T0、T1时血清sICAM-1、sVCAM-1及sPECAM-1的含量差异无统计学意义（P〉0．05）;T2、T3时血清sICAM-1、sVCAM-1、sPECAM-1的含量明显减少（P〈0．05）。结论CPB中应用6％HES130／0．4可明显抑制外周血AM的表达,从而减轻CPB触发的炎性反应。     

Effects of intravascular volume therapy using hydroxyethyl starch (130/0.4) on post-operative bleeding and transfusion requirements in children undergoing cardiac surgery: a randomized clinical trial

BACKGROUND: Hydroxyethyl starch (HES) used for intravascular volume expansion may cause coagulation abnormalities, especially in cardiac patients. Although low molecular weight HES (130/0.4) has been developed to minimize its influence on coagulation, experience with HES (130/0.4) in children is limited. Therefore, we evaluated the effects of a HES (130/0.4) infusion on post-operative blood loss in children undergoing cardiac surgery. METHODS: Forty-two children undergoing cardiac surgery were assigned at random to receive either 10 ml/kg fresh frozen plasma (FFP group; n=21) or HES (130/0.4) (HES group; n=21) shortly after cardiopulmonary bypass termination. Activated partial thromboplastin time (aPTT) and international normalization ratio (INR) were measured. In addition, post-operative transfusion requirements and blood loss until the end of the first post-operative day were compared. RESULTS: INR was significantly prolonged after HES infusion in comparison to the FFP group (P<0.05). During the first 24 h after surgery, post-operative blood loss, the use of allogenic blood/blood products and aPTT were similar in all children. CONCLUSIONS: Our study shows that the administration of a moderate dose of HES (130/0.4) in children undergoing cardiac surgery does not cause more bleeding or a higher transfusion requirement than a FFP infusion, and suggests that the administration of 10 ml/kg HES (130/0.4) is a safe alternative to plasma for intravascular volume replacement in this patient population.     

Effects of acute isovolemic hemodilution and anesthesia on regional function in left ventricular myocardium with compromised coronary blood flow

The effects of progressive, isovolemic hemodilution using Dextran 70 and the effect of halothane (0.7, 0.9, 1.1, and 1.3% end-tidal, administered randomly at each level of hemodilution) on global cardiovascular and regional LV contractile functions were investigated in 24 dogs with induced critical constriction of the left anterior descending coronary artery (LAD). Two additional groups of six dogs each (with and without LAD stenosis) not undergoing hemodilution served as time controls. Regional LV contractile function was assessed by sonomicrometry in the flow-compromised apical LAD territory, as well as in three non-compromised LV areas supplied by the left circumflex coronary artery. Regional myocardial function was found to be stable throughout the study period of 4-5 h in both time control groups. Mean arterial and coronary perfusion pressures as well as LV dP/dtmin decreased (P < 0.01) during hemodilution. LV dP/dtmax remained unchanged, and heart rate and LVEDP increased slightly (P < 0.05). Systolic shortening (SS) in the LAD territory was unchanged at a hematocrit (HCT) of 33.5 +/- 0.3% (mean +/- s.e. mean), and decreased marginally at an HCT of 24.2 +/- 0.1% (SS of 17.4 +/- 1.0% as compared to 20.2 +/- 1.6% at critical constriction (CC), P < 0.05). No increase in post-systolic shortening (PSS) occurred in the compromised area. Severe LAD dysfunction was observed in the LAD territory at an HCT of 14.9 +/- 0.1%, as systolic shortening decreased (11.8 +/- 1.1%, P < 0.01 vs CC) and PSS increased (31.2 +/- 3.4%, P < 0.01 vs CC). The effects of hemodilution on global cardiovascular and regional myocardial functions were unaffected by halothane.(ABSTRACT TRUNCATED AT 250 WORDS)     

Retraction statement: ‘Influence of volume replacement with different HES–solutions on microcirculatory blood flow in cardiac surgery’ by J. Boldt,B. Zickmann,J. Rapin,H. Hammermann,F. Dapper and G. Hempelmann

The above article, published online on 30 December 2008 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the journal Editor‐in‐Chief, Prof. Lars S. Rasmussen, and John Wiley & Sons Ltd. The retraction has been agreed following an investigation carried out by the Justus Liebig University, which has concluded that there is evidence that the original research data on which the article builds has been manipulated. Reference Boldt J, Zickmann B, Rapin J, Hammermann H, Dapper F, Hempelmann G. Influence of volume replacement with different HES–solutions on microcirculatory blood flow in cardiac surgery. Acta Anaesthesiol Scand 1994; 38: 432–438. doi: 10.1111/j.1399‐6576.1994.tb03924.x .     

Effect of intradermal injection of saline or a local anaesthetic agent on skin blood flow – a methodological study in man

The influence of intradermal needle insertion and fluid injection on skin blood flow was investigated using laser Doppler flowmetry. Seventeen healthy, young male volunteers participated. Four test sites on each forearm (volar surface) were used in a randomized, double-blind study. Recordings were made at 20, 40, 60 and in Group III also at 90 min after needle insertion or intradermal injection. In Group I (n = 6) different volumes of saline (0.05, 0.1, 0.2, 0.3 and 0.5 ml) were injected, producing an increase in flow, there being no differences between the various volumes. In Group II (n = 4) needle insertions were made using different needle sizes (20 G, 23 G and 30 G), the larger ones being impractical to use. Increases in flow were seen, and were somewhat higher for the larger needles. Group III (n = 12) was studied regarding the effects of three local anaesthetic agents on skin blood flow (0.1 ml, 30 G needle). Injection of bupivacaine 0.75% produced a marked increase in flow, similar to lidocaine 1% but apparently longer lasting. Bupivacaine 0.25% caused less increase in flow, similar to the flow seen with saline. Injections of ropivacaine 0.75% and 0.25%, i.e. in clinical concentrations, caused a decrease in blood flow, this being most marked after 0.25%, indicating a unique flow-decreasing effect of this new local anaesthetic drug.     

Influence of intraoperative fluid volume on cardiopulmonary bypass hematocrit and blood transfusions in coronary artery bypass surgery

A hematocrit (Hct) of less than 25% during cardiopulmonary bypass (CPB) and transfusion of homologous packed red blood cells (PRBC) are each associated with an increased probability of adverse events in cardiac surgery. Although the CPB circuit is a major contributor to hemodilution intravenous (IV) fluid volume may also significantly influence the level of hemodilution. The objective of this study was to explore the influence of asanguinous IV fluid volume on CPB Hct and intraoperative PRBC transfusion. After Institutional Review Board approval, a retrospective chart review of 90 adult patients that had undergone an elective, isolated CABG with CPB was conducted. Regression analysis was used to determine if pre-CPB fluid volume was associated with the lowest CPB Hct and the incidence of an intraoperative PRBC transfusion. In separate multivariate analyses, higher pre-CPB fluid volume was associated with lower minimum CPB Hct (p < .0001), and higher minimum CPB Hct was associated with a decreased probability of PRBC transfusion (p < .0001). Compared to patients that received <1600 mL (n = 55) of pre-CPB fluid, those that received >1600 mL (n = 35) had a decreased mean low CPB Hct (22.4% vs 25.6%, p < .0001), an increased incidence of a CPB Hct <25% (74% vs. 38%, p = .0008) and PRBC transfusion (60% vs. 16%, p < .0001), and increased median PRBC units transfused (2.0 vs 1.0, p = .1446) despite no significant difference in gender, age, patient size, baseline Hct, or CPB prime volume. Patients that received a PRBC transfusion (n = 30) received a significantly higher volume of pre-CPB fluid than nontransfused patients (1800 vs. 1350 mL, p = .0039). These findings suggest that pre-CPB fluid volume can significantly contribute to hemodilutional anemia in cardiac surgery. Optimizing pre-CPB volume may preserve baseline Hct and help limit intraoperative hemodilution.     

高渗氯化钠羟乙基淀粉溶液对脑动脉瘤出血介入术后脑血管痉挛的影响及机制

目的 探讨术中及术后输注高渗氯化钠羟乙基淀粉溶液(hypertonic sodium chloride hydroxyethyl starch solution,HSH)对脑动脉瘤破裂出血介入术后脑血管痉挛(cerebral vasospasm,CVS)的影响及其机制. 方法 发病后3d内拟行颅内动脉瘤介入栓塞术的动脉瘤破裂蛛网膜下腔出血(aneurysm subarachnoid hemorrhage,aSAH)患者30例.ASA分级Ⅱ、Ⅲ级,Hunt和Hess(原发性蛛网膜下腔出血的临床状态)分级Ⅱ、Ⅲ级,改良Fisher分级1、2级,格拉斯哥昏迷评分(Glasgow ComaScale,GCS) 13～15分,年龄18～80岁.按随机数字表法分为两组(每组15例):实验组(H组),输注4.2％ HSH 4 ml/kg;对照组(N组),输注等量生理盐水.两组均于术前(T0),输注HSH或生理盐水结束时(T1),手术结束时(T9及术后第1天(T3)、第2天(T4)、第3天(T5)、第4天(T6)、第5天(T7)的上午8点,分别记录MAP、CVP、血浆渗透压(plasma osmotic pressure,POP)、HR、Na+、K+、C1-等数值;采用经颅多普勒超声(transcranial doppler,TCD)监测T0及T3～T7时右侧大脑中动脉血流速度,ELISA检测上述时间点血浆中IL-6、TNF-α、内皮素-1(endothelin-1,ET-1)及一氧化氮(nitric oxide,NO)等因子浓度,同时记录患者GCS得分、神经功能缺损评分(china stroke scale,CSS)及24 h出入量. 结果 H组CVP在T1～T7时分别高于N组(P＜0.05);POP在T2～T7时高于N组(P＜0.05).两组患者大脑中动脉血流速度术后呈上升趋势,H组患者在T5～T7时低于N组(P＜0.05);H组患者在T7时血浆IL-6、TNF-α浓度低于N组(P＜0.05);T5～T7时,H组ET-1浓度低于N组(P＜0.05);T4～T7时,H组NO浓度高于N组(P＜0.05);上述指标其他时间点及两组间GCS得分、CSS评分、24h出入量比较,差异无统计学意义(P＞0.05). 结论 脑动脉瘤破裂出血患者围手术期小量输注HSH能有效减轻脑血管介入手术后CVS发生程度,其机制可能与抑制炎症介质及血管舒缩因子平衡紊乱有关.     

羟乙基淀粉容量替代治疗对手术患者血流动力学和凝血功能的影响

目的评价不同取代级羟乙基淀粉术中容量替代治疗对普通外科手术患者凝血功能和血流动力学的影响。方法顺序选取67例ASAⅠ~Ⅱ级择期普通外科手术患者,随机分为3组,6%羟乙基淀粉130/0.4组（R1组,23例）和6%羟乙基淀粉200/0.5组（R2组,24例）,林格溶液对照组（C组,20例）,患者术前无肝肾功能异常,血常规、凝血功能各项检查正常,手术前2周未接受抗凝治疗,预计失血量超过400ml,观察其手术前后血流动力学指标及凝血功能指标的变化。结果手术期间各组血流动力学指标稳定、血红蛋白（Hb）、血小板计数（Plt）、血浆凝血酶原时间（PT）、活化部分凝血活酶时间（APTT）差异无统计学意义;与C组比较,R1和R2组患者容量治疗中液体总输入量明显减少,差异有统计学意义（P〈0.05）。结论 6%羟乙基淀粉130/0.4和6%羟乙基淀粉200/0.5是容量替代治疗中有效的扩容剂,在维持血流动力学稳定的同时,可最低限度减少对凝血功能的影响。     

Influence of dopexamine hydrochloride on haemodynamics and regulators of circulation in patients undergoing major abdominal surgery

Background: Catecholaminergic support is often used to improve haemodynamics in patients undergoing major abdominal surgery. Dopexamine is a synthetic vasoactive catecholamine with beneficial microcirculatory properties. Methods: The influence of perioperative administration of dopexamine on cardiorespiratory data and important regulators of macro- and microcirculation were studied in 30 patients undergoing Whipple pancreaticduodenectomy. The patients received randomized and blinded either 2 μg · kg^?1 · min^?1 of dopexamine (n=15) or placebo (n=15, control group). The infusion was started after induction of anaesthesia and continued until the morning of the first postoperative day. Endothelin-1 (ET-1), vasopressin, atrial natriuretic peptide (ANP), and catecholamine plasma levels were measured from arterial blood samples. Measurements were carried out after induction of anaesthesia, 2 h after onset of surgery, at the end of surgery, 2 h after surgery, and on the morning of the first postoperative day. Results: Cardiac index (CI) increased significantly in the dopexamine group (from 2.61±0.41 to 4.57±0.78 1 · min^?1 · m^?2) and remained elevated until the morning of the first postoperative day. Oxygen delivery index (DO₂I) and oxygen consumption index (VO₂I) were also significantly increased in the dopexamine group (DO₂I: from 416±91 to 717±110 ml/m² · m²; VO₂I: from 98±25 to 157±22 ml/m² · m²), being significantly higher than in the control group. pHi remained stable only in the dopexamine patients, indicating adequate splanchnic perfusion. Vasopressive regulators of circulation increased significantly only in the untreated control patients (vasopressin: from 4.37±1.1 to 35.9±12.1 pg/ml; ET-1: from 2.88±0.91 to 6.91±1.20 pg/ml). Conclusion: Patients undergoing major abdominal surgery may profit from prophylactic perioperative administration of dopexamine hydrochloride in the form of improved haemodynamics and oxygenation as well as beneficial influence on important regulators of organ blood flow.     

The effects of in vitro hemodilution with 6% hydroxyethyl starch (HES) (130/0.4) solution on thrombelastograph analysis in patients undergoing liver transplantation

Bang SR, Kim YH, Kim GS. The effects of in vitro hemodilution with 6% hydroxyethyl starch (HES) (130/0.4) solution on thrombelastograph analysis in patients undergoing liver transplantation.
Clin Transplant 2011: 25: 450–456. © 2010 John Wiley & Sons A/S. Abstract: Introduction: The aim of this study was to determine the effects of in vitro hemodilution with 6% HES (130/0.4) solution on thrombelastograph^® (TEG) parameters in whole blood samples from patients with end‐stage liver disease (ESLD). Methods: Enrollment consisted of 95 patients with ESLD undergoing liver transplantation. Blood was diluted by 11%, 22%, and 33% with 6% HES (130/0.4) solution. Normal saline was used as a control diluent. Results: When blood was diluted by 33% with normal saline, only the reaction time (r) was increased (p < 0.0001) compared to the baseline value. When blood was diluted with 6% HES (130/0.4), 11% dilution decreased maximum amplitude (MA) (p = 0.003) compared to baseline. At 33% dilution, the r (p < 0.0001, vs. baseline) and K (p < 0.0001, vs. baseline; p < 0.0001, vs. normal saline) increased, and the MA, alpha angle, and coagulation index (p < 0.0001, vs. baseline; p < 0.0001, vs. normal saline) decreased. Conclusion: Hemodilution with 6% HES (130/0.4) solution results in TEG abnormalities even with 11% hemodilution, in whole blood samples of patients with ESLD undergoing liver transplantation.     

The therapeutic effect of hypertonic solutions on the changes in the effective circulating plasma volume in acute necrotizing pancreatitis in rats

125 I]bovine serum albumin. Samples of blood and of ascitic fluid were obtained 3, 6, and 12 h after the onset of pancreatitis. Lactated Ringer's solution (LR) and HS were administered consecutively for 3 h beginning 3 h after the induction of pancreatitis. ECPV was measured 6 h after the onset of pancreatitis. The survival rates were investigated for up to 10 days. The mean ECPV decreased significantly from 24.9 ± 1.1 ml/kg before disease onset to 11.5 ± 1.3 ml/kg 6 h postoperatively. LR failed to achieve a normal value for ECPV even following a 150 ml/kg infusion. HS200 and HS300 restored the ECPV to the normal level, and with smaller volumes infused. All rats in the untreated group died within 3 days. LR and HS improved the survival rates, with the infusion of HS200, 100 ml/kg, thus attaining a 45% survival at 10 days. (Received for publication on May 20, 1997; accepted on Mar. 10, 1998)     

The effect of three different doses of tranexamic acid on blood loss after cardiac surgery with mild systemic hypothermia (32°C)

Prophylactic administration of tranexamic acid (TA), an antifibrinolytic agent, decreases bleeding after cardiac surgery with systemic hypothermia (25°C to 29°C). Warmer systemic temperatures during cardiopulmonary bypass (CPB) may reduce bleeding and thus alter the requirement for TA. The effect of three different doses of TA on bleeding after cardiac surgery with mild systemic hypothermia (32°C) is evaluated. Double-blind, prospective, randomized study. University hospital. One hundred fifty adult patients undergoing aortocoronary bypass or valvular cardiac surgery. Patients received TA, 50 (n = 50), 100 (n = 50), or 150 (n = 50) mg/kg intravenously before CPB with mild systemic hypothermia. Blood loss through chest drains over 6, 12, and 24 hours after surgery and total hemoglobin loss were measured. Autotransfused blood, transfused banked blood and blood products, and coagulation profiles were measured. Analysis of variance on log-transformed data for blood loss and confidence intervals (Cis) of 0.95 were calculated and transformed to milliliters of blood. No patient was re-explored for bleeding. Blood loss at 6 hours was statistically greater in the 50-mg/kg group compared with the other two groups (p = 0.03; p = 0.02). Total hemoglobin loss was statistically greater in the 50-mg/kg group compared with the 150-mg/kg group (p = 0.04). There was no statistical difference in blood transfusion rate or coagulation profiles among the three groups. However, preoperative hemoglobin level was statistically lower in the 150-mg/kg group compared with the other two groups (p = 0.01). Of the three doses of TA studied, the most efficacious and cost-effective dose to reduce bleeding after cardiac surgery with mild hypothermic systemic perfusion is 100 mg/kg.     

The effect of prone positioning with surgical bolsters on liver blood flow in healthy volunteers

This study sought to identify changes in hepatic flood flow and cardiac output during prone positioning on surgical bolsters in awake volunteers, and was prompted by a local incident of significant hepatic dysfunction following surgery in the prone position. Cardiac output was determined using the non‐invasive Peñáz technique, and plasma disappearance rate of indocyanine green (ICG‐PDR) was measured as a surrogate maker for hepatic blood flow along with serum hepatic enzyme assays. Measurements were made after one hour in supine, prone and returned supine positions. Ten volunteers completed the study. There were significant changes in the disappearance rate of indocyanine green, which decreased this from mean (SD) 31.1 (9.70) supine to 19.6 (4.37)%.min prone, respectively (p = 0.02), increasing on return to the supine position to 24.6 (5.54)%.min (p = 0.019). Cardiac output was also significantly reduced when changing from the supine to the prone position, from mean (SD) 4.7 (1.0 to 3.5 (1.1) (l.min^?1), respectively (p = 0.002). We demonstrated an acute and reversible change in both hepatocellular function and cardiac output associated with the prone position.