A systematic review and meta-analysis on the use of preemptive hemodynamic intervention to improve postoperative outcomes in moderate and high-risk surgical patients

Ward based goal directed fluid therapy (GDFT) in acute pancreatitis (GAP) trial: A feasibility randomised controlled trial

BACKGROUND

Goal-directed fluid therapy (GDFT) reduces complications in patients undergoing major general surgery. There are no reports of cardiac output evaluation being used to optimise the fluid administration for patients with acute pancreatitis (AP) in a general surgery ward.

METHOD

50 patients with AP were randomised to either ward-based GDFT (n = 25) with intravenous (IV) fluids administered based on stroke volume optimisation protocol or standard care (SC) (n = 25), but with blinded cardiac output evaluation, for 48-h following hospital admission. Primary outcome was feasibility.

RESULTS

50 of 116 eligible patients (43.1%) were recruited over 20 months demonstrating feasibility. 36 (72%) completed the 48-h of GDFT; 10 (20%) discharged within 48-h and 4 withdrawals (3 GDFT, 1 SC). Baseline characteristics were similar with only 3 participants having severe disease (6%, 1 GDFT, 2 SC). Similar volumes of IV fluids were administered in both groups (GDFT 5465 (1839) ml, SC 5211 (1745) ml). GDFT group had a lower heart rate, blood pressure and respiratory rate and improved oxygen saturations. GDFT was not associated with any harms. There was no evidence of difference in complications of AP (GDFT 24%, SC 32%) or in the duration of stay in intensive care (GDFT 0 (0), SC 0.7 [(Van DIjk et al., 2017) 33 days). Length of hospital stay was 5 (2.9) days in GDFT and 6.3 (7.6) in SC groups.

CONCLUSION

Ward-based GDFT is feasible and shows a signal of possible efficacy in AP in this early-stage study. A larger multi-site RCT is required to confirm clinical and cost effectiveness.

Intraoperative Circulatory Support in Lung Transplantation: Current Trend and Its Evidence

Lung transplantation has a high risk of haemodynamic complications in a highly vulnerable patient population. The effects on the cardiovascular system of the various underlying end-stage lung diseases also contribute to this risk. Following a literature review and based on our own experience, this review article summarises the current trends and their evidence for intraoperative circulatory support in lung transplantation. Identifiable and partly modifiable risk factors are mentioned and corresponding strategies for treatment are discussed. The approach of first identifying risk factors and then developing an adjusted strategy is presented as the ERSAS (early risk stratification and strategy) concept. Typical haemodynamic complications discussed here include right ventricular failure, diastolic dysfunction caused by left ventricular deconditioning, and reperfusion injury to the transplanted lung. Pre- and intra-operatively detectable risk factors for the occurrence of haemodynamic complications are rare, and the therapeutic strategies applied differ considerably between centres. However, all the mentioned risk factors and treatment strategies can be integrated into clinical treatment algorithms and can influence patient outcome in terms of both mortality and morbidity.

Enhanced Recovery After Surgery Pathway in Kidney Transplantation: The Road Less Traveled

Enhanced recovery after surgery (ERAS) pathway is a multimodal perioperative care pathway designed to achieve early recovery after surgery. ERAS protocols have not yet been well recognized in kidney transplantation. The aim of this study was to investigate the impact of ERAS pathway on early recovery and short-term clinical outcomes of kidney transplant.

PragmaTic, prospEctive, randomized, controlled, double-blind, mulTi-centre, multinational study on the safety and efficacy of a 6% HydroxYethyl Starch (HES) solution versus an electrolyte solution in trauma patients: study protocol for the TETHYS study

BACKGROUND

Trauma may be associated with significant to life-threatening blood loss, which in turn may increase the risk of complications and death, particularly in the absence of adequate treatment. Hydroxyethyl starch (HES) solutions are used for volume therapy to treat hypovolemia due to acute blood loss to maintain or re-establish hemodynamic stability with the ultimate goal to avoid organ hypoperfusion and cardiovascular collapse. The current study compares a 6% HES 130 solution (Volulyte 6%) versus an electrolyte solution (Ionolyte) for volume replacement therapy in adult patients with traumatic injuries, as requested by the European Medicines Agency to gain more insights into the safety and efficacy of HES in the setting of trauma care.

METHODS

TETHYS is a pragmatic, prospective, randomized, controlled, double-blind, multicenter, multinational trial performed in two parallel groups. Eligible consenting adults ≥ 18 years, with an estimated blood loss of ≥ 500 ml, and in whom initial surgery is deemed necessary within 24 h after blunt or penetrating trauma, will be randomized to receive intravenous treatment at an individualized dose with either a 6% HES 130, or an electrolyte solution, for a maximum of 24 h or until reaching the maximum daily dose of 30 ml/kg body weight, whatever occurs first. Sample size is estimated as 175 patients per group, 350 patients total (α = 0.025 one-tailed, power 1-β = 0.8). Composite primary endpoint evaluated in an exploratory manner will be 90-day mortality and 90-day renal failure, defined as AKIN stage ≥ 2, RIFLE injury/failure stage, or use of renal replacement therapy (RRT) during the first 3 months. Secondary efficacy and safety endpoints are fluid administration and balance, changes in vital signs and hemodynamic status, changes in laboratory parameters including renal function, coagulation, and inflammation biomarkers, incidence of adverse events during treatment period, hospital, and intensive care unit (ICU) length of stay, fitness for ICU or hospital discharge, and duration of mechanical ventilation and/or RRT.

DISCUSSION

This pragmatic study will increase the evidence on safety and efficacy of 6% HES 130 for treatment of hypovolemia secondary to acute blood loss in trauma patients.

TRIAL REGISTRATION

Registered in EudraCT, No.: 2016-002176-27 (21 April 2017) and ClinicalTrials.gov, ID: NCT03338218 (09 November 2017).

Goal-Directed Fluid Therapy Enhances Gastrointestinal Recovery after Laparoscopic Surgery: A Systematic Review and Meta-Analysis

(1) Background: Whether goal-directed fluid therapy (GDFT) provides any outcome benefit as compared to non-goal-directed fluid therapy (N-GDFT) in elective abdominal laparoscopic surgery has not been determined yet. (2) Methods: A systematic literature search was conducted in MEDLINE, Embase, CENTRAL, Web of Science, and Scopus. The main outcomes were length of hospital stay (LOHS), time to first flatus and stool, intraoperative fluid and vasopressor requirements, serum lactate levels, and urinary output. Pooled risks ratios (RRs) with 95% confidence intervals (CI) were calculated for dichotomous outcomes and weighted mean difference (WMD) with 95% CI for continuous outcomes. (3) Results: Eleven studies were included in the quantitative, and fifteen in the qualitative synthesis. LOHS (WMD: -1.18 days, 95% CI: -1.84 to -0.53) and time to first stool (WMD: -9.8 h; CI -12.7 to -7.0) were significantly shorter in the GDFT group. GDFT resulted in significantly less intraoperative fluid administration (WMD: -441 mL, 95% CI: -790 to -92) and lower lactate levels at the end of the operation: WMD: -0.25 mmol L-1; 95% CI: -0.36 to -0.14. (4) Conclusions: GDFT resulted in enhanced recovery of the gastrointestinal function and shorter LOHS as compared to N-GDFT.

Effect of post-operative goal-directed fluid therapy (GDFT) on organ function after orthotopic liver transplantation: Secondary outcome analysis of the COLT randomised control trial

BACKGROUND

Goal-directed fluid therapy (GDFT) has been shown to reduce the complications following a variety of major surgical procedures, possibly mediated by improved organ perfusion and function. We have shown that it is feasible to randomise patients to GDFT or standard fluid management following liver transplant in the cardiac-output optimisation following liver transplantation (COLT) trial. The current study compares end organ function in patients from the COLT trial who received GDFT in comparison to those receiving standard care (SC) following liver transplant.

METHODS

Adult patients with liver cirrhosis undergoing liver transplantation were randomised to GDFT or SC for the first 12 h following surgery as detailed in a published trial protocol. GDFT protocol was based on stroke volume (SV) optimisation using 250 ml crystalloid boluses. Total fluid administration and time to extubation were recorded. Hourly SV and cardiac output (CO) readings were recorded from the non-invasive cardiac output monitoring (NICOM) device in both groups. Pulmonary function was assessed by arterial blood gas (ABG) and ventilatory parameters. Lung injury was assessed using PaO₂:FiO₂ ratios and calculated pulmonary compliance. The KDIGO score was used for determining acute kidney injury. Renal and liver graft function were assessed during the post-operative period and at 3 months and 1-year.

RESULTS

60 patients were randomised to GDFT (n = 30) or SC (n = 30). All patients completed the 12 h intervention period. GDFT group received a significantly higher total volume of fluid during the 12 h trial intervention period (GDFT 5317 (2335) vs. SC 3807 (1345) ml, p = 0.003); in particular crystalloids (GDFT 3968 (2073) vs. SC 2510 (1027) ml, p = 0.002). There was no evidence of significant difference between the groups in SV or CO during the assessment periods. Time to extubation, PaO2: FIO₂ ratios, pulmonary compliance, ventilatory or blood gas measurements were similar in both groups. There was a significant rise in serum creatinine from baseline (77 μmol/L) compared to first (87 μmol/L, p = 0.039) and second (107 μmol/L, p = 0.001) post-operative days. There was no difference between GDFT and SC in the highest KDIGO scores for the first 7 days post-LT. At 1-year follow-up, there was no difference in need for renal replacement therapy or graft function.

CONCLUSIONS

In this randomised trial of fluid therapy post liver transplant, GDFT was associated with an increased volume of crystalloids administered but did not alter early post-operative pulmonary or renal function when compared with standard care.

Goal-directed haemodynamic therapy during general anaesthesia for noncardiac surgery: a systematic review and meta-analysis

BACKGROUND

During general anaesthesia for noncardiac surgery, there remain knowledge gaps regarding the effect of goal-directed haemodynamic therapy on patient-centred outcomes.

METHODS

Included clinical trials investigated goal-directed haemodynamic therapy during general anaesthesia in adults undergoing noncardiac surgery and reported at least one patient-centred postoperative outcome. PubMed and Embase were searched for relevant articles on March 8, 2021. Two investigators performed abstract screening, full-text review, data extraction, and bias assessment. The primary outcomes were mortality and hospital length of stay, whereas 15 postoperative complications were included based on availability. From a main pool of comparable trials, meta-analyses were performed on trials with homogenous outcome definitions. Certainty of evidence was evaluated using Grading of Recommendations, Assessment, Development, and Evaluations (GRADE).

RESULTS

The main pool consisted of 76 trials with intermediate risk of bias for most outcomes. Overall, goal-directed haemodynamic therapy might reduce mortality (odds ratio=0.84; 95% confidence interval [CI], 0.64 to 1.09) and shorten length of stay (mean difference=-0.72 days; 95% CI, -1.10 to -0.35) but with low certainty in the evidence. For both outcomes, larger effects favouring goal-directed haemodynamic therapy were seen in abdominal surgery, very high-risk surgery, and using targets based on preload variation by the respiratory cycle. However, formal tests for subgroup differences were not statistically significant. Goal-directed haemodynamic therapy decreased risk of several postoperative outcomes, but only infectious outcomes and anastomotic leakage reached moderate certainty of evidence.

CONCLUSIONS

Goal-directed haemodynamic therapy during general anaesthesia might decrease mortality, hospital length of stay, and several postoperative complications. Only infectious postoperative complications and anastomotic leakage reached moderate certainty in the evidence.

Prospective, randomized, controlled, double-blind, multi-center, multinational study on the safety and efficacy of 6% Hydroxyethyl starch (HES) sOlution versus an Electrolyte solutioN In patients undergoing eleCtive abdominal Surgery: study protocol for the PHOENICS study

BACKGROUND

Hydroxyethyl starch (HES) solutions are used for volume therapy to treat hypovolemia due to acute blood loss and to maintain hemodynamic stability. This study was requested by the European Medicines Agency (EMA) to provide more evidence on the long-term safety and efficacy of HES solutions in the perioperative setting.

METHODS

PHOENICS is a randomized, controlled, double-blind, multi-center, multinational phase IV (IIIb) study with two parallel groups to investigate non-inferiority regarding the safety of a 6% HES 130 solution (Volulyte 6%, Fresenius Kabi, Germany) compared with a crystalloid solution (Ionolyte, Fresenius Kabi, Germany) for infusion in patients with acute blood loss during elective abdominal surgery. A total of 2280 eligible patients (male and female patients willing to participate, with expected blood loss ≥ 500 ml, aged > 40 and ≤ 85 years, and ASA Physical status II-III) are randomly assigned to receive either HES or crystalloid solution for the treatment of hypovolemia due to surgery-induced acute blood loss in hospitals in up to 11 European countries. The dosing of investigational products (IP) is individualized to patients' volume needs and guided by a volume algorithm. Patients are treated with IP for maximally 24 h or until the maximum daily dose of 30 ml/kg body weight is reached. The primary endpoint is the treatment group mean difference in the change from the pre-operative baseline value in cystatin-C-based estimated glomerular filtration rate (eGFR), to the eGFR value calculated from the highest cystatin-C level measured during post-operative days 1-3. Further safety and efficacy parameters include, e.g., combined mortality/major post-operative complications until day 90, renal function, coagulation, inflammation, hemodynamic variables, hospital length of stay, major post-operative complications, and 28-day, 90-day, and 1-year mortality.

DISCUSSION

The study will provide important information on the long-term safety and efficacy of HES 130/0.4 when administered according to the approved European product information. The results will be relevant for volume therapy of surgical patients.

TRIAL REGISTRATION

EudraCT 2016-002162-30 . ClinicalTrials.gov NCT03278548.

Increased risk of hip fracture mortality associated with intraoperative hypotension in elderly hip fracture patients is related to under resuscitation

BACKGROUND

As the US and world population ages, hip fractures are increasingly more common. The mortality associated with these fractures remains high both in the immediate postoperative period and at one year. Perioperative resuscitation in this population is of key interest to prevent organ injury and mortality. Our objectives were to evaluate the effect of fluid resuscitation and hemodynamic status in the form of mean arterial pressure (MAP) on inpatient mortality of hip fracture patients.

METHODS

An institutional database was queried to compare elderly hip fracture patients that sustained in-hospital mortality to a matched control cohort. Pre-, intra-, and post-operative intravenous fluid (IVF) administration and MAP were extracted from the electronic medical record. Time from hospital presentation to the OR was also recorded.

RESULTS

1,114 total hip fractures were identified during the two-year study period, 16 of which suffered inpatient mortalities. The mortality cohort was then matched with a control of 394 hip fracture patients for the same period based on age, sex, and Charlson Comorbidity Index (CCI). Conditional logistical regression analysis found odds ratios (OR) indicating that longer time between presentation and surgery (OR per additional hour: 1.05; 95% CI: 1.01-1.08) and lower intraoperative minimum MAP (OR per 5 mmHg decrease: 0.77; 95% CI: 0.61-0.97) were associated with significantly increased odds of mortality. There was also a marginal relationship between greater intraoperative IVF administration and reduced odds of mortality (OR per 500 cc additional fluid: 0.61; 95% CI: 0.37-1.00).

CONCLUSION

Extended time from presentation to surgery and intraoperative hypotension were associated with increased likelihood of inpatient mortality in an elderly hip fracture cohort, with a possible additional effect of under-resuscitation. Further investigation into a safe intraoperative minimum MAP should be pursued.

LEVEL OF EVIDENCE

Level III.

Incidence and predictive factors associated with hemodynamic instability among adult surgical patients in the post-anesthesia care unit, 2021: A prospective follow up study

Background

Hemodynamic instability, which is an independent predictor of long-term patient morbidity and duration of stay in the hospital, is a risk for patients in the post-anesthesia care unit. Multiple factors contribute to the development of postoperative hemodynamic instability. Prevention and treatment of these factors may reduce patients' hemodynamic instability, and its associated morbidity and mortality.

Objective

The aim of this study was to determine the incidence and factors associated with hemodynamic instability among adult surgical patients in the post-anesthesia care unit.

Method

An institution-based prospective follow up study was conducted from April 20, 2021 to June 28, 2021. Four hundred and seventeen (417) adult surgical patients were involved in this study. Descriptive and analytic statistics were used to describe our results. Both the bivariable and multivariable logistic regression with crude odds ratio and adjusted odds ratio were used with a 95% confidence interval to evaluate the strength of association. In multivariable regression, a p-value < 0.05 was considered as statistically significant.

Result

The overall incidence of hemodynamic instability was 59.47% (CI: 0.55, 0.64). The incidence of tachycardia, bradycardia, hypotension, and hypertension were 27.34%, 21.82%, 13.67%, and 15.35% respectively. Preoperative use of beta-blockers, ASA class III, procedure longer than 4 h, intraoperative hemodynamic instability, and regional anesthesia were significantly associated with hemodynamic instability in the post-anesthesia care unit.

Conclusion and recommendation

The incidence of hemodynamic instability in the post anesthesia care unit was high. Preoperative use of beta-blockers, intraoperative hemodynamic instability, and prolonged duration of procedures were predictors of hemodynamic instability after operation. Early detection and management of these perioperative risk factors is necessary to reduce hemodynamic instability in the post-anesthesia care unit.

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HDI is a common complication after surgery and anaesthesia

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It results in severe morbidity and mortality

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HDI is associated with multiple predictive factors

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Early detection and intervention of HDI improves outcome after surgery

Early Goal-directed Therapy During Endovascular Coiling Procedures Following Aneurysmal Subarachnoid Hemorrhage: A Pilot Prospective Randomized Controlled Study

BACKGROUND

Maintenance of euvolemia and cerebral perfusion are recommended for the prevention of cerebral vasospasm after aneurysmal subarachnoid hemorrhage (aSAH). We conducted a pilot randomized controlled study to assess the feasibility and efficacy of goal-directed therapy (GDT) to correct fluid and hemodynamic derangements during endovascular coiling in patients with aSAH.

METHODS

This study was conducted between November 2015 and February 2019 at a single tertiary center in Canada. Adult patients with aSAH within 5 days of aneurysm rupture were randomly assigned to receive either GDT or standard therapy during endovascular coiling. The incidence of dehydration at presentation and the efficacy of GDT were evaluated.

RESULTS

Forty patients were allocated to receive GDT (n=21) or standard therapy (n=19). Sixty percent of all patients were found to have dehydration before the coiling procedure commenced. Compared with standard therapy, GDT reduced the duration of intraoperative hypovolemia (mean difference 37.6 [95% confidence interval, 6.2-37.4] min, P=0.006) and low cardiac index (mean difference 30.7 [95% confidence interval, 9.5-56.9] min, P=0.035). There were no differences between the 2 treatment groups with respect to the incidence of vasospasm, stroke, death, and other complications up to postoperative day 90.

CONCLUSIONS

A high proportion of aSAH patients presented at the coiling procedure with dehydration and a low cardiac output state; these derangements were more likely to be corrected if the GDT algorithm was used. Compared with standard therapy, use of the GDT algorithm resulted in earlier recognition and more consistent treatment of dehydration and hemodynamic derangement during endovascular coiling.

Comparison between capnodynamic and thermodilution method for cardiac output monitoring during major abdominal surgery: An observational study

BACKGROUND

Cardiac output (CO) monitoring is the basis of goal-directed treatment for major abdominal surgery. A capnodynamic method estimating cardiac output (COEPBF) by continuously calculating nonshunted pulmonary blood flow has previously shown good agreement and trending ability when evaluated in mechanically ventilated pigs.

OBJECTIVES

To compare the performance of the capnodynamic method of CO monitoring with transpulmonary thermodilution (COTPTD) in patients undergoing major abdominal surgery.

DESIGN

Prospective, observational, method comparison study. Simultaneous measurements of COEPBF and COTPTD were performed before incision at baseline and before and after increased (+10 cmH2O) positive end-expiratory pressure (PEEP), activation of epidural anaesthesia and intra-operative events of hypovolemia and low CO. The first 25 patients were ventilated with PEEP 5 cmH2O (PEEP5), while in the last 10 patients, lung recruitment followed by individual PEEP adjustment (PEEPadj) was performed before protocol start.

SETTING

Karolinska University Hospital, Stockholm, Sweden.

PATIENTS

In total, 35 patients (>18 years) scheduled for major abdominal surgery with advanced hemodynamic monitoring were included in the study.

MAIN OUTCOME MEASURES AND ANALYSIS

Agreement and trending ability between COEPBF and COTPTD at different clinical moments were analysed with Bland--Altman and four quadrant plots.

RESULTS

In total, 322 paired values, 227 in PEEP5 and 95 in PEEPadj were analysed. Respectively, the mean COEPBF and COTPTD were 4.5 ± 1.0 and 4.8 ± 1.1 in the PEEP5 group and 4.9 ± 1.2 and 5.0 ± 1.0 l min-1 in the PEEPadj group. Mean bias (levels of agreement) and percentage error (PE) were -0.2 (-2.2 to 1.7) l min-1 and 41% for the PEEP5 group and -0.1 (-1.7 to 1.5) l min-1 and 31% in the PEEPadj group. Concordance rates during changes in COEPBF and COTPTD were 92% in the PEEP5 group and 90% in the PEEPadj group.

CONCLUSION

COEPBF provides continuous noninvasive CO estimation with acceptable performance, which improved after lung recruitment and PEEP adjustment, although not interchangeable with COTPTD. This method may become a tool for continuous intra-operative CO monitoring during general anaesthesia in the future.

TRIAL REGISTRATION

Clinicaltrials.gov identifier: NCT03444545.

Comparison of Bioimpedance Versus Pulse Contour Analysis for Intraoperative Cardiac Index Monitoring in Patients Undergoing Kidney Transplantation

Background

Cardiac index (CI; cardiac output indexed to body surface area) is routinely measured during kidney transplant surgery. Bioimpedance cardiometry is a transthoracic impedance as the non-invasive alternative for hemodynamic monitoring, using semi-invasive uncalibrated pulse wave or contour (UPC) analysis.

Objectives

We performed a cross-sectional observational study on 50 kidney transplant patients to compare the CI measurement agreement, concordance rate, and trending ability between bioimpedance and UPC analysis.

Methods

For each patient, CI was measured by bioimpedance analysis (ICON^TM) and UPC analysis (EV1000^TM) devices at three time points: after induction, during incision, and at reperfusion. The device measurement accuracy was assessed by the bias value, limit of agreement (LoA), and percentage error (PE) using Bland-Altman analyses. Trending ability was assessed by angular bias and polar concordance through four-quadrant and polar plot analyses.

Results

From each time point and pooled measurement, the correlation coefficients were 0.267, 0.327, 0.321, and 0.348. Bland-Altman analyses showed mean bias values of 1.18, 1.06, 1.48, and 1.30, LoA of -1.35 to 3.72, -1.39 to 3.51, -1.07 to 4.04, and -1.17 to 3.78, and PE of 82.21, 78.50, 68.74, and 74.58%, respectively. Polar plot analyses revealed angular bias values of -10.37º, -15.01º, -18.68º, and -12.62º, with radial LoA of 89.79º, 85.86º, 83.38º, and 87.82º, respectively. The four-quadrant plot concordance rates were 70.77, 67.35, 65.90, and 69.79%. These analyses showed poor agreement, weak concordance, and low trending ability of bioimpedance cardiometry to UPC analysis.

Conclusions

Bioimpedance and UPC analysis for CI measurements were not interchangeable in patients undergoing kidney transplant surgery. Cardiac index monitoring using bioimpedance cardiometry during kidney transplantation should be interpreted cautiously because it showed poor reliability due to low accuracy, precision, and trending ability for CI measurement.

THE USE OF EPHEDRINE TO TREAT ANESTHESIA-ASSOCIATED HYPOTENSION IN PINNIPEDS

Hypotension is a common adverse effect of general anesthesia that has historically been difficult to measure in pinniped species due to technical challenges. A retrospective case review found seven pinniped cases that demonstrated anesthesia-associated hypotension diagnosed by direct blood pressure measurements during general anesthesia at The Marine Mammal Center (Sausalito, CA) between 2017 and 2019. Cases included five California sea lions (CSL: Zalophus californianus), one Hawaiian monk seal (HMS: Neomonachus schauinslandi), and one northern elephant seal (NES: Mirounga angustirostris). Patients were induced using injectable opioids, benzodiazepines, and anesthetics including propofol and alfaxalone. Excluding the HMS, all patients required supplemental isoflurane with a mask to achieve an anesthetic plane allowing for intubation. Each patient was maintained with inhalant isoflurane in oxygen for the duration of the anesthetic event. Each patient was concurrently administered continuous IV fluids and four patients received fluid boluses prior to administration of ephedrine. All hypotensive anesthetized patients were treated with IV ephedrine (0.05-0.2 mg/kg). The average initial systolic (SAP) and mean (MAP) arterial blood pressures for the CSL prior to ephedrine administration were 71 ± 14 mmHg and 48 ± 12 mmHg respectively. The average SAP and MAP for the CSL increased to 119 ± 32 mmHg and 90 ± 34 mmHg respectively within 5 m of ephedrine administration. The NES initial blood pressure measurement was 59/43 (50) (SAP/diastolic [MAP]) mmHg and increased to 80/51 (62) mmHg within 5 m. The initial HMS blood pressure was 79/68 (73) mmHg and increased to 99/78 (85) mmHg within 5 m following ephedrine administration. All patients recovered from anesthesia. These results support the efficacy of IV ephedrine for the treatment of anesthesia-associated hypotension in pinnipeds.

Noninvasive cardiac output measurement is inaccurate in patients with severe aortic valve stenosis undergoing transcatheter aortic valve implantation

Background

Noninvasive cardiac output (CO) measured using ClearSight™ eliminates the need for intra-arterial catheter insertion. The purpose of this study was to examine the accuracy of non-invasive CO measurement in patients with severe aortic stenosis (AS).

Methods

Twenty-eight patients undergoing elective transcatheter aortic valve implantation were prospectively enrolled in this study. The CO was simultaneously measured twice before and twice after valve deployment (total of four times) per patient, and the CO was compared between the ClearSight (CO_ClearSight) system and the pulmonary artery catheter (PAC) thermodilution (CO_TD) method as a reference. The Bland-Altman analysis was used to compare the percentage errors between the methods.

Results

A total of 112 paired data points were obtained. The percentage error between the CO_ClearSight and CO_TD was 43.1%. The paired datasets were divided into the following groups according to the systemic vascular resistance index (SVRI): low (< 1,200 dyne s/cm⁵/m²) and normal (1,200–2,500 dyne s/cm⁵/m²). The percentage errors were 44.9% and 49.4%, respectively. The discrepancy of CO between CO_ClearSight and CO_TD was not significantly correlated with SVRI (r = −0.06, P < 0.001). The polar plot analysis showed the trending ability of the CO_ClearSight after artificial valve deployment was 51.1% which below the acceptable cut-off (92%).

Conclusions

The accuracy and the trending ability of the ClearSight CO measurements were not acceptable in patients with severe AS. Therefore, the ClearSight system is not interchangeable with the PAC thermodilution for determining CO in this population.

Lung Ultrasound Assisted Comparison of Volume Effects of Fluid Replacement Regimens in Pediatric Patients Undergoing Penile Hypospadias Repair: A Randomized Controlled Trial

Background

Effective perioperative fluid therapy is a great consideration.

Objectives

Using lung ultrasound (LUS), this study evaluated the preference of the conventional and restrictive fluid replacement regimens for their volume impact in pediatric patients undergoing a relatively long procedure with limited volume loss (hypospadias repair).

Methods

Eighty pediatric patients scheduled for hypospadias repair surgery were enrolled for conventional (CG) or restrictive fluid management groups (RG). The CG obtained Ringer's lactate at the conventional calculated doses, while the RG obtained infusion of Ringer's lactate at a rate of 3 mL/kg/h. B-line numbers in the LUS, recovery score, urine output, blood pressure (BP), heart rate HR, and oxygen saturation (SpO₂) were recorded.

Results

As evidenced by the LUS, RG showed a higher incidence of normal lung morphology with a mean and SD of 1.3 ± 2.2 for B-line numbers, whereas, in CG, they were 3.1 ± 2.2 with a P-value < 0.001. Urine output was 3.2 ± 0.8 and 2.9 ± 0.7 for CG and RG, respectively, with a P-value equal to 0.07. HR, BP, and SpO₂ differences between groups were statistically insignificant. The recovery score was higher in RG (5.8 ± 0.4) than in CG (5.1 ± 0.8) at the first postoperative 20 minutes, with a P-value < 0.001.

Conclusions

In lengthy procedures with limited volume loss, using a moderately restrictive regimen is preferred over the conventional intraoperative fluid regimen considering both respiratory dysfunctions and recovery score.

Perioperative goal-directed therapy in high-risk abdominal surgery. A multicenter randomized controlled superiority trial

STUDY OBJECTIVE

The potential of perioperative goal-directed therapy (PGDT) to improve outcome after high-risk abdominal surgery remains subject of debate. In particular, there is a need for large, multicenter trials focusing on relevant patient outcomes to confirm the evidence found in small, single center studies including minor complications in their composite endpoints. The present study therefore aims to investigate the effect of an arterial waveform analysis based PGDT algorithm on the incidence of major complications including mortality after high-risk abdominal surgery.

DESIGN

Prospective randomized controlled multicenter trial.

SETTING

Operating theatres and Post-Anesthesia/Intensive Care units (PACU/ICU) of four tertiary hospitals in The Netherlands.

PATIENTS

A total number of 482 patients undergoing elective, abdominal surgery that is considered high-risk due to the extent of the procedure and/or patient comorbidities.

INTERVENTIONS

Hemodynamic therapy using an age-specific PGDT algorithm including cardiac index (CI) and stroke volume variation (SVV) measurements during a 24-h perioperative period starting at induction of anesthesia.

MEASUREMENTS

The average number of major complications (including mortality) within 30 days after surgery, the number of minor complications, hospital and PACU/ICU length of stay (LOS), amounts of fluids and vasoactive medications used. Complications were graded using the Accordion severity grading system.

RESULTS

The average number of major complications per patient was 0.79 (PGDT group) versus 0.69 (control group) (p = 0.195). There were no statistically significant differences in the number of minor complications, hospital LOS, PACU/ICU LOS, or grading of complications. Patients in the PGDT group received more fluids intraoperatively, more dobutamine intra- and postoperatively, while patients in the control group received more phenylephrine during the operation.

CONCLUSIONS

PGDT based on a CI and SVV driven algorithm did not result in improved outcomes after high-risk abdominal surgery.

CLINICAL TRIAL REGISTRATION

Netherlands Trial Registry: NTR3380.

Pharmacodynamic analysis of a fluid challenge with 4 ml kg-1 over 10 or 20 min: a multicenter cross-over randomized clinical trial

Purpose

A number of studies performed in the operating room evaluated the hemodynamic effects of the fluid challenge (FC), solely considering the effect before and after the infusion. Few studies have investigated the pharmacodynamic effect of the FC on hemodynamic flow and pressure variables. We designed this trial aiming at describing the pharmacodynamic profile of two different FC infusion times, of a fixed dose of 4 ml kg⁻¹.

Methods

Forty-nine elective neurosurgical patients received two consecutive FCs of 4 ml kg⁻¹ of crystalloids in 10 (FC₁₀) or 20 (FC₂₀) minutes, in a random order. Fluid responsiveness was defined as stroke volume index increase ≥ 10%. We assessed the net area under the curve (AUC), the maximal percentage difference from baseline (d_max), time when the d_max was observed (t_max), change from baseline at 1-min (d₁) and 5-min (d₅) after FC end.

Results

After FC₁₀ and FC_20, 25 (51%) and 14 (29%) of 49 patients were classified as fluid responders (p = 0.001). With the exception of the AUCs of SAP and MAP, the AUCs of all the considered hemodynamic variables were comparable. The d_max and the t_max were overall comparable. In both groups, the hemodynamic effects on flow variables were dissipated within 5 min after FC end.

Conclusions

The infusion time of FC administration affects fluid responsiveness, being higher for FC₁₀ as compared to FC₂₀. The effect on flow variables of either FCs fades 5 min after the end of infusion.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10877-021-00756-3.

Machine Learning, Deep Learning, and Closed Loop Devices-Anesthesia Delivery

With the tremendous volume of data captured during surgeries and procedures, critical care, and pain management, the field of anesthesiology is uniquely suited for the application of machine learning, neural networks, and closed loop technologies. In the past several years, this area has expanded immensely in both interest and clinical applications. This article provides an overview of the basic tenets of machine learning, neural networks, and closed loop devices, with emphasis on the clinical applications of these technologies.

A performance comparison of the most commonly used minimally invasive monitors of cardiac output

BACKGROUND

Shock is common in critically ill and injured patients. Survival during shock is highly dependent on rapid restoration of tissue oxygenation with therapeutic goals based on cardiac output (CO) optimization. Despite the clinical availability of numerous minimally invasive monitors of CO, limited supporting performance data are available.

METHODS

Following approval of the University of Saskatchewan Animal Research Ethics Board, we assessed the performance and trending ability of PiCCOplus™, FloTrac™, and CardioQ-ODM™ across a range of CO states in pigs. In addition, we assessed the ability of invasive mean arterial blood pressure (iMAP) to follow changes in CO using a periaortic transit-time flow probe as the reference method. Statistical analysis was performed with function-fail, bias and precision, percent error, and linear regression at all flow, low-flow (> 1 standard deviation [SD] below the mean), and high-flow (> 1 SD above the mean) CO conditions.

RESULTS

We made a total of 116,957 paired CO measurements. The non-invasive CO monitors often failed to provide a CO value (CardioQ-ODM: 40.6% failed measurements; 99% confidence interval [CI], 38.5 to 42.6; FloTrac: 9.6% failed measurements; 99% CI, 8.7 to 10.5; PiCCOplus: 4.7% failed measurements; 99% CI, 4.5 to 4.9; all comparisons, P < 0.001). The invasive mean arterial pressure provided zero failures, failing less often than any of the tested CO monitors (all comparisons, P < 0.001). The PiCCOplus was most interchangeable with the flow probe at all flow states: PiCCOplus (20% error; 99% CI, 19 to 22), CardioQ-ODM (25% error; 99% CI, 23 to 27), FloTrac (34% error; 99% CI, 32 to 38) (all comparisons, P < 0.001). At low-flow states, CardioQ-ODM (43% error; 99% CI, 32 to 63) and Flotrac (45% error; 99% CI, 33 to 70) had similar interchangeability (P = 0.07), both superior to PiCCOplus (48% error; 99% CI, 42 to 60) (P < 0.001). Regarding CO trending, the CardioQ-ODM (correlation coefficient, 0.82; 99% CI, 0.81 to 0.83) was statistically superior to other monitors including iMAP, but at low flows iMAP (correlation coefficient, 0.58; 99% CI, 0.58 to 0.60) was superior to all minimally invasive CO monitors (all comparisons P < 0.001).

CONCLUSIONS

None of the minimally invasive monitors of CO performed well at all tested flows. Invasive mean arterial blood pressure most closely tracked CO change at critical flow states.

Perioperative liberal versus restrictive fluid strategies and postoperative outcomes: a systematic review and metanalysis on randomised-controlled trials in major abdominal elective surgery

Background

Postoperative complications impact on early and long-term patients’ outcome. Appropriate perioperative fluid management is pivotal in this context; however, the most effective perioperative fluid management is still unclear. The enhanced recovery after surgery pathways recommend a perioperative zero-balance, whereas recent findings suggest a more liberal approach could be beneficial. We conducted this trial to address the impact of restrictive vs. liberal fluid approaches on overall postoperative complications and mortality.

Methods

Systematic review and meta-analysis, including randomised controlled trials (RCTs). We performed a systematic literature search using MEDLINE (via Ovid), EMBASE (via Ovid) and the Cochrane Controlled Clinical trials register databases, published from 1 January 2000 to 31 December 2019. We included RCTs enrolling adult patients undergoing elective abdominal surgery and comparing the use of restrictive/liberal approaches enrolling at least 15 patients in each subgroup. Studies involving cardiac, non-elective surgery, paediatric or obstetric surgeries were excluded.

Results

After full-text examination, the metanalysis finally included 18 studies and 5567 patients randomised to restrictive (2786 patients; 50.0%) or liberal approaches (2780 patients; 50.0%). We found no difference in the occurrence of severe postoperative complications between restrictive and liberal subgroups [risk difference (95% CI) = 0.009 (− 0.02; 0.04); p value = 0.62; I₂ (95% CI) = 38.6% (0–66.9%)]. This result was confirmed also in the subgroup of five studies having a low overall risk of bias. The liberal approach was associated with lower overall renal major events, as compared to the restrictive [risk difference (95% CI) = 0.06 (0.02–0.09); p value  = 0.001]. We found no difference in either early (p value  = 0.33) or late (p value  = 0.22) postoperative mortality between restrictive and liberal subgroups

Conclusions

In major abdominal elective surgery perioperative, the choice between liberal or restrictive approach did not affect overall major postoperative complications or mortality. In a subgroup analysis, a liberal as compared to a restrictive perioperative fluid policy was associated with lower overall complication renal major events, as compared to the restrictive.

Trial Registration

CRD42020218059; Registration: February 2020, https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=218059.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-021-03629-y.

Preoperative carbohydrate loading and intraoperative goal-directed fluid therapy for elderly patients undergoing open gastrointestinal surgery: a prospective randomized controlled trial

Background

The effect of a combination of a goal-directed fluid protocol and preoperative carbohydrate loading on postoperative complications in elderly patients still remains unknown. Therefore, we designed this trial to evaluate the relative impact of preoperative carbohydrate loading and intraoperative goal-directed fluid therapy versus conventional fluid therapy (CFT) on clinical outcomes in elderly patients following gastrointestinal surgery.

Methods

This prospective randomized controlled trial with 120 patients over 65years undergoing gastrointestinal surgery were randomized into a CFT group (n=60) with traditional methods of fasting and water-deprivation, and a GDFT group (n=60) with carbohydrate (200ml) loading 2h before surgery. The CFT group underwent routine monitoring during surgery, however, the GDFT group was conducted by a Vigileo/FloTrac monitor with cardiac index (CI), stroke volume variation (SVV), and mean arterial pressure (MAP). For all patients, demographic data, intraoperative parameters and postoperative outcomes were recorded.

Results

Patients in the GDFT group received significantly less crystalloids fluid (1111442.9ml vs 1411412.6ml; p<0.001) and produced significantly less urine output (200ml [150300] vs 400ml [290500]; p<0.001) as compared to the CFT group. Moreover, GDFT was associated with a shorter average time to first flatus (5614.1h vs 6422.3h; p=0.002) and oral intake (7216.9h vs 8526.8h; p=0.011), as well as a reduction in the rate of postoperative complications (15 (25.0%) vs 29 (48.3%) patients; p=0.013). However, postoperative hospitalization or hospitalization expenses were similar between groups (p>0.05).

Conclusions

Focused on elderly patients undergoing open gastrointestinal surgery, we found perioperative fluid optimisation may be associated with improvement of bowel function and a lower incidence of postoperative complications.

Trial registration

ChiCTR, ChiCTR1800018227. Registered 6 September 2018 - Retrospectively registered.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-021-01377-8.

The Effect of Intraoperative Fluid Management According to Stroke Volume Variation on Postoperative Bowel Function Recovery in Colorectal Cancer Surgery

Stroke volume variation (SVV) has been used to predict fluid responsiveness; however, it remains unclear whether goal-directed fluid therapy using SVV contributes to bowel function recovery in abdominal surgery. This prospective randomized controlled trial aimed to compare bowel movement recovery in patients undergoing colon resection surgery between groups using traditional or SVV-based methods for intravenous fluid management. We collected data between March 2015 and July 2017. Bowel function recovery was analyzed based on the gas-passing time, sips of water time, and soft diet (SD) time. Finally, we analyzed data from 60 patients. There was no significant between-group difference in the patients’ characteristics. Compared with the control group (n = 30), the SVV group (n = 30) had a significantly higher colloid volume and lower crystalloid volume. Moreover, the gas-passing time (77.8 vs. 85.3 h, p = 0.034) and SD time (67.6 vs. 85.1 h, p < 0.001) were significantly faster in the SVV group than in the control group. Compared with the control group, the SVV group showed significantly lower scores of pain on a numeric rating scale and morphine equivalent doses during post-anesthetic care, at 24 postoperative hours, and at 48 postoperative hours. Our findings suggested that, compared with the control group, the SVV group showed a faster postoperative SD time, reduced acute postoperative pain intensity, and lower rescue analgesics. Therefore, SVV-based optimal fluid management is expected to potentially contribute to postoperative bowel function recovery in patients undergoing colon resection surgery.

Association between serosal intestinal microcirculation and blood pressure during major abdominal surgery

Background

In clinical practice, blood pressure is used as a resuscitation goal on a daily basis, with the aim of maintaining adequate perfusion and oxygen delivery to target organs. Compromised perfusion is often indicated as a key factor in the pathophysiology of anastomotic leakage. This study was aimed at assessing the extent to which the microcirculation of the bowel coheres with blood pressure during abdominal surgery.

Methods

We performed a prospective and observational cohort study. In patients undergoing abdominal surgery, the serosal microcirculation of either the small intestine or the colon was visualized using handheld vital microscopy (HVM). From the acquired HVM image sequences, red blood cell velocity (RBCv) and total vessel density (TVD) were calculated using MicroTools and AVA software, respectively. The association between microcirculatory parameters and blood pressure was assessed using Pearson's correlation analysis. We considered a two-sided P-value of <0.050 to be significant.

Results

In 28 patients undergoing abdominal surgery, a total of 76 HVM images were analyzed. The RBCv was 335 ± 96 µm/s and the TVD was 13.7 ± 3.4 mm/mm². Mean arterial pressure (MAP) was 71 ± 12 mm Hg during microcirculatory imaging. MAP was not correlated with RBCv (Pearson's r = -0.049, P = 0.800) or TVD (Pearson's r = 0.310, P = 0.110).

Conclusion

In 28 patients undergoing abdominal surgery, we found no association between serosal intestinal microcirculatory parameters and blood pressure.

Anesthetic Consideration for Geriatric Patients

The geriatric population experiences significant alterations of numerous organ systems as a result of the aging process. They also have several co-morbidities including hypertension, cardiac disease, diabetes, cerebrovascular disease and renal dysfunction. Geriatric patients are considerably vulnerable and especially sensitive to the stress of trauma, surgery and anesthesia. A high incidence of postoperative complications in this population is observed. Appropriate perioperative care was required for geriatric patients. To date, development in anesthesia and surgical techniques has substantially reduced morbidity and mortality in the geriatric patients. Several anesthetic techniques have been utilized for these patients. However, anesthesia-related mortality in geriatric patients is quiet high. All geriatric patients undergoing surgical procedures require a preprocedural evaluation and preparation, monitoring patients during intraprocedural and postprocedural periods as well as postprocedural management. This chapter highlights the physiological changes, preprocedure assessment and preparation, anesthetic techniques, intraprocedural and postprocedural management in geriatric population.

Perioperative hemodynamic optimization: from guidelines to implementation-an experts' opinion paper

Despite a large body of evidence, the implementation of guidelines on hemodynamic optimization and goal-directed therapy remains limited in daily routine practice. To facilitate/accelerate this implementation, a panel of experts in the field proposes an approach based on six relevant questions/answers that are frequently mentioned by clinicians, using a critical appraisal of the literature and a modified Delphi process. The mean arterial pressure is a major determinant of organ perfusion, so that the authors unanimously recommend not to tolerate absolute values below 65 mmHg during surgery to reduce the risk of postoperative organ dysfunction. Despite well-identified limitations, the authors unanimously propose the use of dynamic indices to rationalize fluid therapy in a large number of patients undergoing non-cardiac surgery, pending the implementation of a "validity criteria checklist" before applying volume expansion. The authors recommend with a good agreement mini- or non-invasive stroke volume/cardiac output monitoring in moderate to high-risk surgical patients to optimize fluid therapy on an individual basis and avoid volume overload. The authors propose to use fluids and vasoconstrictors in combination to achieve optimal blood flow and maintain perfusion pressure above the thresholds considered at risk. Although purchase of disposable sensors and stand-alone monitors will result in additional costs, the authors unanimously acknowledge that there are data strongly suggesting this may be counterbalanced by a sustained reduction in postoperative morbidity and hospital lengths of stay. Beside existing guidelines, knowledge and explicit clinical reasoning tools followed by decision algorithms are mandatory to implement individualized hemodynamic optimization strategies and reduce postoperative morbidity and duration of hospital stay in high-risk surgical patients.

Enhanced Recovery after Surgery: History, Key Advancements and Developments in Transplant Surgery

Enhanced recovery after surgery (ERAS) aims to improve patient outcomes by controlling specific aspects of perioperative care. The concept was introduced in 1997 by Henrik Kehlet, who suggested that while minor changes in perioperative practise have no significant impact alone, incorporating multiple changes could drastically improve outcomes. Since 1997, significant advancements have been made through the foundation of the ERAS Society, responsible for creating consensus guidelines on the implementation of enhanced recovery pathways. ERAS reduces length of stay by an average of 2.35 days and healthcare costs by $639.06 per patient, as identified in a 2020 meta-analysis of ERAS across multiple surgical subspecialties. Carbohydrate loading, bowel preparation and patient education in the pre-operative phase, goal-directed fluid therapy in the intra-operative phase, and early mobilisation and enteral nutrition in the post-operative phase are some of the interventions that are commonly implemented in ERAS protocols. While many specialties have been quick to incorporate ERAS, uptake has been slow in the transplantation field, leading to a scarcity of literature. Recent studies reported a 47% reduction in length of hospital stay (LOS) in liver transplantation patients treated with ERAS, while progress in kidney transplantation focuses on pain management and its incorporation into enhanced recovery protocols.

Perioperative echocardiography-guided hemodynamic therapy in high-risk patients: a practical expert approach of hemodynamically focused echocardiography

The number of high-risk patients undergoing surgery is growing. To maintain adequate hemodynamic functioning as well as oxygen delivery to the vital organs (DO2) amongst this patient population, a rapid assessment of cardiac functioning is essential for the anesthesiologist. Pinpointing any underlying cardiovascular pathophysiology can be decisive to guide interventions in the intraoperative setting. Various techniques are available to monitor the hemodynamic status of the patient, however due to intrinsic limitations, many of these methods may not be able to directly identify the underlying cause of cardiovascular impairment. Hemodynamic focused echocardiography, as a rapid diagnostic method, offers an excellent opportunity to examine signs of filling impairment, cardiac preload, myocardial contractility and the function of the heart valves. We thus propose a 6-step-echocardiographic approach to assess high-risk patients in order to improve and maintain perioperative DO2. The summary of all echocardiographic based findings allows a differentiated assessment of the patient's cardiovascular function and can thus help guide a (patho)physiological-orientated and individualized hemodynamic therapy.

Velocity-pressure loops can estimate intrinsic and pharmacologically induced changes in cardiac afterload during non-cardiac surgery. An observational study

PURPOSE

Continuous measurement of aortic pressure and aortic flow velocity signals in the operating theatre allows us to draw velocity-pressure (Vel-Pre) loops. The global afterload angle (GALA), derived from the Vel-Pre loops, has been linked to cardiac afterload indicators. As age is the major determinant of constitutive arterial stiffness, we aimed to describe (1) the evolution of the GALA according to age in a large cohort of anesthetized patients and (2) GALA variations induced by haemodynamic interventions.

METHODS

We included patients for whom continuous monitoring of arterial pressure and cardiac output were indicated. Fluid challenges or vasopressors were administered to treat intra-operative hypotension. The primary endpoint was the comparison of the GALA values between young and old patients. The secondary endpoint was the difference in the GALA values before and after haemodynamic interventions.

RESULTS

We included 133 anaesthetized patients: 66 old and 67 young patients. At baseline, the GALA was higher in the old patients than in young patients (38 ± 6 vs. 25 ± 4 degrees; p < 0.001). The GALA was positively associated with age (p < 0.001), but the mean arterial pressure (MAP) and cardiac output were not. The GALA did not change after volume expansion, regardless of the fluid response, but it did increase after vasopressor administration. Furthermore, while a vasopressor bolus led to a similar increase in MAP, phenylephrine induced a more substantial increase in the GALA than noradrenaline (+ 12 ± 5° vs. + 8 ± 5°; p = 0.01).

CONCLUSION

In non-cardiac surgery, the GALA seems to be associated with both intrinsic rigidity (reflected by age) and pharmacologically induced vasoconstriction changes (by vasopressors). In addition, the GALA can discriminate the differential effects of phenylephrine and noradrenaline. These results should be confirmed in a prospective, ideally randomized, trial.

Role of central venous - Arterial pCO2 difference in determining microcirculatory hypoperfusion in off-pump coronary artery bypass grafting surgery

Background:

Cardiac surgery is frequently associated with macro and microcirculatory hypoperfusion. Patients with normal central venous oxygen saturation (Scvo2) also suffer from hypoperfusion. We hypothesized that monitoring central venous-arterial pco2 difference (dCO₂) could also serve as additional marker in detecting hypoperfusion in cardiac surgery patient.

Methods:

This is a prospective observational study. Patients undergoing off-pump coronary artery bypass grafting included in this study. The dCO2 was measured postoperatively. The patients with a ScvO2 ≥70% were divided in to 2 groups, the high-dCO2 group (≥8 mmHg) and the low-dCO2 group (<8 mmHg).

Results:

The 65 patient had scvO₂ ≥70%. Out of these, 20 patients were assigned to the high dCO₂ group and 45 patients to the low dCO₂ group. Patients with high dco2 had higher lactate levels after ICU admission. They also had significantly prolonged need for mechanical ventilation (14.90 ± 10.33 vs 10 ± 9.65, P = 0.0402), ICU stay (5.05 ± 2.52 d vs 3.75 ± 2.36 d, P = 0.049) and hospital stay (12.25 ± 5.90 d vs 8.57 ± 5.55 d P = 0.018). The overall rate of post-operative complications was similar in both the group.

Conclusion:

The present study demonstrates dCO₂ as an easy to assess and routinely available tool to detect global and microcirculatory hypoperfusion in off-pump CABG patients, with assumed adequate fluid status and ScvO₂ as a hemodynamic goal. We observed that high dCO₂ (>8 mmHg) was associated with decreased DO₂I, increased oxygen extraction ratio, the longer need for mechanical ventilation and longer ICU stay.

Blood metabolomic profiling predicts postoperative gastrointestinal function of colorectal surgical patients under the guidance of goal-directed fluid therapy

Postoperative gastrointestinal function influences postoperative recovery and length of hospital stay for patients undergoing colorectal surgery. Goal-directed fluid therapy (GDFT) restricts fluid administration to an amount required to prevent dehydration. Although the fluid management of GDFT could decrease the incidence of postoperative complications in patients who undergo high-risk surgery, certain patients may not respond to GDFT. Thus, to achieve optimal treatment, identification of patients suitable for GDFT is necessary. Metabolomic profiling of 48 patients undergoing surgery for colorectal cancer was performed. Patients were divided into delayed- and enhanced-recovered groups based on gastrointestinal function within 72 hours, and the results of omics analysis showed differential serum metabolites between the two groups of patients in the post anesthesia care unit 24 hours after surgery. A support vector machine model was applied to evaluate the curative effects of GDFT in different patients. Four metabolites, oleamide, ubiquinone-1, acetylcholine, and oleic acid, were found to be highly associated with postoperative gastrointestinal function and could be used as potential biomarkers. Moreover, four pathways were found to be highly related to postoperative gastrointestinal recovery. Among them, the vitamin B6 metabolism pathway may be a common pathway for improving postoperative recovery in various diseases. Our findings proposed a novel method to predict postoperative recovery of gastrointestinal function based on metabolomic profiling and suggested the potential mechanisms contributing to gastrointestinal function after surgical resection of colorectal cancer under the fluid management of GDFT.

New Advances in Monitoring Cardiac Output in Circulatory Mechanical Assistance Devices. A Validation Study in a Porcine Model

Cardiac output (CO) measurement by continuous pulmonary artery thermodilution (CO_CTD) has been studied in patients with pulsatile-flow LVADs (left ventricular assist devices), confirming the clinical utility. However, it has not been validated in patients with continuous-flow LVADs. Therefore, the aim of this study was to assess the validity of CO_CTD in continuous-flow LVADs. Continuous-flow LVADs were implanted in six miniature pigs for partial assistance of the left ventricle. Both methods of measuring CO—measurement by CO_CTD and intermittent pulmonary artery thermodilution, standard technique (CO_ITD)—were used in four consecutive moments of the study: before starting the LVAD (basal moment), and with the LVAD started in normovolemia, hypervolemia (fluid overloading), and hypovolemia (shock hemorrhage). At the basal moment, CO_CTD and CO_ITD were closely correlated (r² = 0.97), with a mean bias of −0.13 ± 0.16 L/min and percentage error of 11%. After 15 min of partial support LVAD, CO_CTD and CO_ITD were closely correlated (r² = 0.91), with a mean bias of 0.31 ± 0.35 L/min and percentage error of 20%. After inducing hypervolemia, CO_CTD and CO_ITD were closely correlated (r² = 0.99), with a mean bias of 0.04 ± 0.07 L/min and percentage error of 5%. After inducing hypovolemia, CO_CTD and CO_ITD were closely correlated (r² = 0.74), with a mean bias of 0.08 ± 0.22 L/min and percentage error of 19%. This study shows that continuous pulmonary thermodilution could be an alternative method of monitoring CO in a porcine model with a continuous-flow LVAD.

[Perioperative optimization using hemodynamically focused echocardiography in high-risk patients-A practice guide]

BACKGROUND

The number of high-risk patients undergoing surgery is steadily increasing. In order to maintain and, if necessary, optimize perioperative hemodynamics as well as the oxygen supply to the organs (DO₂) in this patient population, a timely assessment of cardiac function and the underlying pathophysiological causes of hemodynamic instability is essential for the anesthesiologist. A variety of hemodynamic monitoring procedures are available for this purpose; however, due to method-immanent limitations they are often not able to directly identify the underlying cause of cardiovascular impairment.

OBJECTIVE

To present a stepwise algorithm for a perioperative echocardiography-based hemodynamic optimization in noncardiac surgery high-risk patients. In this context, echocardiography on demand according to international guidelines can be performed under certain conditions (hemodynamic instability, nonresponse to hemodynamic treatment) as well as in the context of a planned intraoperative procedure, mostly as a transesophageal echocardiography.

METHODS AND RESULTS

Hemodynamically focused echocardiography as a rapidly available bedside method, enables the timely diagnosis and assessment of cardiac filling obstructions, volume status and volume response, right and left heart function, and the function of the heart valves.

CONCLUSION

Integrating all echocardiographic findings in a differentiated assessment of the patient's cardiovascular function enables a (patho)physiologically oriented and individualized hemodynamic treatment.

Bioelectrical Impedance Analysis in Patients Undergoing Major Head and Neck Surgery: A Prospective Observational Pilot Study

Background: Head and neck patients are prone to malnutrition. Perioperative fluids administration in this patient group may influence nutritional status. We aimed to investigate perioperative changes in patients undergoing major head and neck surgery and to examine the impact of perioperative fluid administration on body composition and metabolic changes using bioelectrical impedance. Furthermore, we sought to correlate these metabolic changes with postoperative complication rate. In this prospective observational pilot study, bioelectrical impedance analysis (BIA) was performed preoperatively and on postoperative days (POD) 2 and 10 on patients who underwent major head and neck surgeries. BIA was completed in 34/37 patients; mean total intraoperative and post-anesthesia fluid administration was 3682 ± 1910 mL and 1802 ± 1466 mL, respectively. Total perioperative fluid administration was associated with postoperative high extra-cellular water percentages (p = 0.038) and a low phase-angle score (p < 0.005), which indicates low nutritional status. Patients with phase angle below the 5th percentile at POD 2 had higher local complication rates (p = 0.035) and longer hospital length of stay (LOS) (p = 0.029). Multivariate analysis failed to demonstrate that high-volume fluid administration and phase angle are independent factors for postoperative complications. High-volume perioperative fluids administration impacts postoperative nutritional status with fluid shift toward the extra-cellular space and is associated with factors that increase the risk of postoperative complications and longer LOS. An adjusted, low-volume perioperative fluid regimen should be considered in patients with comorbidities in order to minimize postoperative morbidity.

Association between perioperative fluid administration and postoperative outcomes: a 20-year systematic review and a meta-analysis of randomized goal-directed trials in major visceral/noncardiac surgery

Background

Appropriate perioperative fluid management is of pivotal importance to reduce postoperative complications, which impact on early and long-term patient outcome. The so-called perioperative goal-directed therapy (GDT) approach aims at customizing perioperative fluid management on the individual patients’ hemodynamic response. Whether or not the overall amount of perioperative volume infused in the context of GDT could influence postoperative surgical outcomes is unclear.

Methods

We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) comparing the efficacy of GDT approach between study population and control group in reducing postoperative complications and perioperative mortality, using MEDLINE, EMBASE and the Cochrane Controlled Clinical trials register. The enrolled studies were grouped considering the amount infused intraoperatively and during the first 24 h after the admission in the critical care unit (perioperative fluid).

Results

The metanalysis included 21 RCTs enrolling 2729 patients with a median amount of perioperative fluid infusion of 4500 ml. In the studies reporting an overall amount below or above this threshold, the differences in postoperative complications were not statically significant between controls and GDT subgroup [43.4% vs. 34.2%, p value = 0.23 and 54.8% vs. 39.8%; p value = 0.09, respectively].

Overall, GDT reduced the overall rate of postoperative complications, as compared to controls [pooled risk difference (95% CI) = − 0.10 (− 0.14, − 0.07); Chi₂ = 30.97; p value < 0.0001], but not to a reduction of perioperative mortality [pooled risk difference (95%CI) = − 0.016 (− 0.0334; 0.0014); p value = 0.07]. Considering the rate of organ-related postoperative events, GDT did not reduce neither renal (p value = 0.52) nor cardiovascular (p value = 0.86) or pulmonary (p value = 0.14) or neurological (p value = 0.44) or infective (p value = 0.12) complications.

Conclusions

Irrespectively to the amount of perioperative fluid administered, GDT strategy reduces postoperative complications, but not perioperative mortality.

Trial Registration

CRD42020168866; Registration: February 2020

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=168866

Non-invasive electrical cardiometry cardiac output monitoring during prehospital helicopter emergency medical care: a feasibility study

Purpose

Introducing advanced hemodynamic monitoring might be beneficial during Helicopter Emergency Medical Service (HEMS) care. However, it should not increase the on-scene-time, it should be easy to use and should be non-invasive. The goal of this study was to investigate the feasibility of non-invasive cardiac output measurements by electrical cardiometry (EC) and the quality of the EC signal during pre-hospital care provided by our HEMS.

Methods

A convenience sample of fifty patients who required HEMS assistance were included in this study. Problems with respect to connecting the patient, entering patient characteristics and measuring were inventoried. Quality of EC signal of the measurements was assessed during prehospital helicopter care. We recorded the number of measurements with a signal quality indicator (SQI) ≥ 80 and the number of patients having at least 1 measurement with a SQI ≥ 80. Furthermore, the SQI value distribution of the measurements within each patient was analysed.

Results

In the experience of the attending HEMS caregivers application of the device was easy and did not result in increased duration of on-scene time. Patch adhesion was reported as a concern due to clammy skin in 22% of all cases. 684 measurements were recorded during HEMS care. In 47 (94%) patients at least 1 measurement with an SQI ≥ 80 was registered. Of all recorded measurements 5.8% had an SQI < 40, 11.4% had an SQI 40–59, 14.9% had a SQI between 60 and 79 and 67.8% had SQI ≥ 80.

Conclusion

Cardiac output measurements are feasible during prehospital HEMS care with good quality of the EC signal. Monitoring was easy to use and quick to install. In our view it is an promising candidate for the prehospital setting. Further research is needed to determine its clinical value during clinical decision making.

[Summary of the S3 guideline on abdominal aortic aneurysm from an anesthesiological perspective]

The current article is a summary of the 2018 revised S3 guideline on screening, diagnosis, therapy, and follow-up of the abdominal aortic aneurysm (AAA) from an anesthesiological point of view. It is the only interdisciplinary guideline that describes in particular the perioperative anesthesiological and intensive care management.

Perioperative management and anaesthetic considerations in pelvic exenterations using Delphi methodology: results from the PelvEx Collaborative

BACKGROUND

The multidisciplinary perioperative and anaesthetic management of patients undergoing pelvic exenteration is essential for good surgical outcomes. No clear guidelines have been established, and there is wide variation in clinical practice internationally. This consensus statement consolidates clinical experience and best practice collectively, and systematically addresses key domains in the perioperative and anaesthetic management.

METHODS

The modified Delphi methodology was used to achieve consensus from the PelvEx Collaborative. The process included one round of online questionnaire involving controlled feedback and structured participant response, two rounds of editing, and one round of web-based voting. It was held from December 2019 to February 2020. Consensus was defined as more than 80 per cent agreement, whereas less than 80 per cent agreement indicated low consensus.

RESULTS

The final consensus document contained 47 voted statements, across six key domains of perioperative and anaesthetic management in pelvic exenteration, comprising preoperative assessment and preparation, anaesthetic considerations, perioperative management, anticipating possible massive haemorrhage, stress response and postoperative critical care, and pain management. Consensus recommendations were developed, based on consensus agreement achieved on 34 statements.

CONCLUSION

The perioperative and anaesthetic management of patients undergoing pelvic exenteration is best accomplished by a dedicated multidisciplinary team with relevant domain expertise in the setting of a specialized tertiary unit. This consensus statement has addressed key domains within the framework of current perioperative and anaesthetic management among patients undergoing pelvic exenteration, with an international perspective, to guide clinical practice, and has outlined areas for future clinical research.

CON: Pulmonary artery catheter use should be forgone in modern clinical practice

The pulmonary artery catheter (PAC) and its role in the practice of modern medicine remains to be questioned and has experienced a substantial decline in its use in the most recent decades. The complications associated to its use, the lack of consistency of the interpretation provided by the PAC among clinicians, the development of new hemodynamic methods, and the deleterious cost profile associated to the PAC are some of the reasons behind the decrease in its use. Since its introduction into clinical practice, the PAC and the data obtained from its use became paramount in the management of critically ill patients as well as for the high-risk/invasive procedures. Initially, many clinicians were under the impression that regardless the clinical setting, acquiring the information provided by the PAC justified its use, until a growing body of evidence demonstrated its lack of mortality and morbidity improvement, as well as several reports of the presence of difficulties—some of them fatal—during its insertion. The authors present an updated review discussing the futility of the PAC in current clinical practice, the complications associated to its insertion, the lack of mortality benefit in critically ill patients and cardiac surgery, as well as present alternative hemodynamic methods to the PAC.

PRO: The pulmonary artery catheter has a paramount role in current clinical practice

Ever since its clinical introduction, the utilization of the pulmonary artery catheter (PAC) has been surrounded by multiple controversies, mostly related to imprecise clinical indications and the complications derived from its placement. Currently, one of the most important criticisms of the PAC is the ambiguity in the interpretation of its hemodynamic measurements and therefore, in the translation of this data into specific therapeutic interventions. The popularity of the PAC stems from the fact that it provides hemodynamic data that cannot be obtained from clinical examination. The assumption is that this information would allow better understanding of the individual's hemodynamic profile which would trigger therapeutic interventions that improve patient outcomes. Nevertheless, even with the current diversity of hemodynamic devices available, the PAC remains a valuable tool in a wide variety of clinical settings. The authors present a review exposing the benefits of the PAC, current clinical recommendations for its use, mortality and survival profile, its role in goal-directed therapy, and other applications of the PAC beyond cardiac surgery and the intensive care unit.

Postoperative renal morbidity and mortality after volume replacement with hydroxyethyl starch 130/0.4 or albumin during surgery: a propensity score-matched study

PURPOSE

We aimed to compare retrospectively the rates of renal morbidity and mortality in surgical patients receiving 6% HES 130/0.4 to those receiving albumin.

METHODS

From a Japanese nationwide medical database between 2014 and 2016, we identified adults who received HES 130/0.4 (HES group) or albumin (albumin group) as a single colloid solution on the day of surgery. After propensity score matching, the two groups were analyzed with χ2 or Mann Whitney U test. The primary outcome was the incidence of acute kidney injury (AKI). Secondary outcomes included the incidence of renal-replacement therapy, hospital length of stay, in-hospital 30-day mortality, the use of vasoactive agents, and the fluid requirement on the day of surgery.

RESULTS

Of 76,048 patients in the database, propensity score matching identified 289 matched pairs. There was no statistically significant difference in the incidence of AKI between the HES and the albumin group (15.2% vs. 20.8%, respectively: P = 0.08). The secondary outcomes did not differ between groups except the following. Median hospital stay was 5 days shorter in the HES group (18 vs. 23 days; P < 0.001), and the median net fluid requirement on the day of surgery was 15 mL/kg lower in the HES group (140 vs. 155 mL/kg, respectively; P = 0.01).

CONCLUSIONS

Postoperative renal morbidity and mortality did not differ between patients receiving HES 130/0.4 and those receiving albumin. HES 130/0.4 was associated with shorter hospital stay and less fluid requirement compared to albumin. These findings support the use of 6% HES 130/0.4 for perioperative volume replacement as an alternative to albumin.

TRIAL REGISTRATION

UMIN000027896 and the date of registration was June 30, 2017 at https://www.umin.ac.jp/ctr/index-j.html .

Classification and differential effectiveness of goal-directed hemodynamic therapies in surgical patients: A network meta-analysis of randomized controlled trials

PURPOSE

To investigate the most effective goal-directed hemodynamic therapy (GDHT) in surgical patients.

METHODS

GDHTs were classified as methods for intravascular volume, preload, stroke volume, cardiac output, oxygen delivery, systemic oxygenation, or tissue oxygenation optimization, alone or in combination. Their relative effectiveness and ranking were assessed using network meta-analysis and the surface under the cumulative ranking curve (SUCRA), respectively.

RESULTS

101 randomized controlled trials investigating GDHT effectiveness in surgical patients were eligible. The most commonly reported outcomes were 30-day mortality, acute kidney injury (AKI), and arrhythmia. Mortality was significantly reduced by GDHTs aimed at intravascular volume and cardiac output optimization (OR 0.40; 95% CrI 0.14-0.997; low quality). AKI was significantly reduced by GDHT aimed at intravascular volume optimization (OR 0.26; 95% CrI 0.08-0.71; moderate quality). No GDHT significantly reduced arrhythmia. GDHT aimed at intravascular volume and stroke volume optimization was likely most effective for mortality reduction (SUCRA = 78.8%) while that aimed at intravascular volume, stroke volume, and cardiac output optimization was likely most effective for AKI reduction (SUCRA = 85.4%).

CONCLUSIONS

Different GDHTs likely have different and outcome-dependent effectiveness in surgical patients. GDHTs aimed at intravascular volume, stroke volume, and cardiac output optimization are likely most effective as per the overall evidence.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number: CRD42020159978.