Does goal-directed haemodynamic and fluid therapy improve peri-operative outcomes?: A systematic review and meta-analysis

Cardiac index-guided therapy to maintain optimised postinduction cardiac index in high-risk patients having major open abdominal surgery: the multicentre randomised iPEGASUS trial

BACKGROUND

It is unclear whether optimising intraoperative cardiac index can reduce postoperative complications. We tested the hypothesis that maintaining optimised postinduction cardiac index during and for the first 8 h after surgery reduces the incidence of a composite outcome of complications within 28 days after surgery compared with routine care in high-risk patients having elective major open abdominal surgery.

METHODS

In three German and two Spanish centres, high-risk patients having elective major open abdominal surgery were randomised to cardiac index-guided therapy to maintain optimised postinduction cardiac index (cardiac index at which pulse pressure variation was <12%) during and for the first 8 h after surgery using intravenous fluids and dobutamine or to routine care. The primary outcome was the incidence of a composite outcome of moderate or severe complications within 28 days after surgery.

RESULTS

We analysed 318 of 380 enrolled subjects. The composite primary outcome occurred in 84 of 152 subjects (55%) assigned to cardiac index-guided therapy and in 77 of 166 subjects (46%) assigned to routine care (odds ratio: 1.87, 95% confidence interval: 1.03-3.39, P=0.038). Per-protocol analyses confirmed the results of the primary outcome analysis.

CONCLUSIONS

Maintaining optimised postinduction cardiac index during and for the first 8 h after surgery did not reduce, and possibly increased, the incidence of a composite outcome of complications within 28 days after surgery compared with routine care in high-risk patients having elective major open abdominal surgery. Clinicians should not strive to maintain optimised postinduction cardiac index during and after surgery in expectation of reducing complications.

CLINICAL TRIAL REGISTRATION

NCT03021525.

Reliability of Bioreactance and Pulse-Power Analysis in Measuring Cardiac Index During Open Abdominal Aortic Surgery

OBJECTIVE

To investigate the accuracy, precision, and trending ability of noninvasive bioreactance-based Starling SV and the mini invasive pulse-power device LiDCOrapid as compared to thermodilution cardiac output (TDCO) as measured by pulmonary artery catheter when assessing cardiac index (CIx) in the setting of elective open abdominal aortic (AA) surgery.

DESIGN

A prospective method-comparison study.

SETTING

Oulu University Hospital, Finland.

PARTICIPANTS

Forty patients undergoing elective open abdominal aortic surgery.

INTERVENTIONS

Intraoperative CI measurements were obtained simultaneously with TDCO and the study monitors, resulting in 627 measurement pairs with Starling SV and 497 with LiDCOrapid.

MEASUREMENTS AND MAIN RESULTS

The Bland-Altman method was used to investigate the agreement among the devices, and four-quadrant plots with error grids were used to assess trending ability. The agreement between TDCO and Starling SV was associated with a bias of 0.18 L/min/m2 (95% confidence interval [CI] = 0.13 to 0.23), wide limits of agreement (LOA = -1.12 to 1.47 L/min/m2), and a percentage error (PE) of 63.7 (95% CI = 52.4-71.0). The agreement between TDCO and LiDCOrapid was associated with a bias of -0.15 L/min/m2 (95% CI = -0.21 to -0.09), wide LOA (-1.56 to 1.37), and a PE of 68.7 (95% CI = 54.9-79.6). The trending ability of neither device was sufficient.

CONCLUSION

The CI measurements achieved with Starling SV and LiDCOrapid were not interchangeable with TDCO, and the ability to track changes in CI was poor. These results do not support the use of either study device in monitoring CI during open AA surgery.

Haemodynamic monitoring during noncardiac surgery: past, present, and future

During surgery, various haemodynamic variables are monitored and optimised to maintain organ perfusion pressure and oxygen delivery - and to eventually improve outcomes. Important haemodynamic variables that provide an understanding of most pathophysiologic haemodynamic conditions during surgery include heart rate, arterial pressure, central venous pressure, pulse pressure variation/stroke volume variation, stroke volume, and cardiac output. A basic physiologic and pathophysiologic understanding of these haemodynamic variables and the corresponding monitoring methods is essential. We therefore revisit the pathophysiologic rationale for intraoperative monitoring of haemodynamic variables, describe the history, current use, and future technological developments of monitoring methods, and finally briefly summarise the evidence that haemodynamic management can improve patient-centred outcomes.

Intraoperative hypotension and postoperative acute kidney injury: A systematic review

BACKGROUND

There is no consensus regarding safe intraoperative blood pressure thresholds that protect against postoperative acute kidney injury (AKI). This review aims to examine the existing literature to delineate safe intraoperative hypotension (IOH) parameters to prevent postoperative AKI.

METHODS

PubMed, Cochrane Central, and Web of Science were systematically searched for articles published between 2015 and 2022 relating the effects of IOH on postoperative AKI.

RESULTS

Our search yielded 19 articles. IOH risk thresholds ranged from <50 to <75 ​mmHg for mean arterial pressure (MAP) and from <70 to <100 ​mmHg for systolic blood pressure (SBP). MAP below 65 ​mmHg for over 5 ​min was the most cited threshold (N ​= ​13) consistently associated with increased postoperative AKI. Greater magnitude and duration of MAP and SBP below the thresholds were generally associated with a dose-dependent increase in postoperative AKI incidence.

CONCLUSIONS

While a consistent definition for IOH remains elusive, the evidence suggests that MAP below 65 ​mmHg for over 5 ​min is strongly associated with postoperative AKI, with the risk increasing with the magnitude and duration of IOH.

Goal-directed therapy guided by the FloTrac sensor in major surgery: a systematic review and meta-analysis

OBJECTIVE

To provide insights into the potential benefits of goal-directed therapy guided by FloTrac in reducing postoperative complications and improving outcomes.

METHODS

We performed a systematic review and meta-analysis of randomized controlled trials to evaluate goal-directed therapy guided by FloTrac in major surgery, comparing goal-directed therapy with usual care or invasive monitoring in cardiac and noncardiac surgery subgroups. The quality of the articles and evidence were evaluated with a risk of bias tool and GRADE.

RESULTS

We included 29 randomized controlled trials with 3,468 patients. Goal-directed therapy significantly reduced the duration of hospital stay (mean difference -1.43 days; 95%CI 2.07 to -0.79; I2 81%), intensive care unit stay (mean difference -0.77 days; 95%CI -1.18 to -0.36; I2 93%), and mechanical ventilation (mean difference -2.48 hours, 95%CI -4.10 to -0.86, I2 63%). There was no statistically significant difference in mortality, myocardial infarction, acute kidney injury or hypotension, but goal-directed therapy significantly reduced the risk of heart failure or pulmonary edema (RR 0.46; 95%CI 0.23 - 0.92; I2 0%).

CONCLUSION

Goal-directed therapy guided by the FloTrac sensor improved clinical outcomes and shortened the length of stay in the hospital and intensive care unit in patients undergoing major surgery. Further research can validate these results using specific protocols and better understand the potential benefits of FloTrac beyond these outcomes.

Comparison of Dynamic Measures in Intraoperative Goal-Directed Fluid Therapy of Patients with Morbid Obesity Undergoing Laparoscopic Sleeve Gastrectomy

INTRODUCTION

Obesity increases the risk of morbidity and mortality during surgical procedures. Goal-directed fluid therapy (GDFT) is a new concept for perioperative fluid management that has been shown to improve patient prognosis. This study aimed to investigate the role of the Pleth Variability Index (PVI), systolic pressure variation (SPV), and pulse pressure variation (PPV) in maintaining tissue perfusion and renal function during GDFT management in patients undergoing laparoscopic sleeve gastrectomy (LSG).

MATERIALS AND METHODS

Two hundred ten patients were enrolled in our prospective randomized controlled clinical trial. Demographic data, hemodynamic parameters, biochemical parameters, the amount of crystalloid and colloid fluid administered intraoperatively, and the technique of goal-directed fluid management used were recorded. Patients were randomly divided into three groups: PVI (n = 70), PPV (n = 70), and SPV (n = 70), according to the technique of goal-directed fluid management. Postoperative nausea and vomiting, time of return of bowel movement, and hospital stay duration were recorded.

RESULTS

There was no statistically significant difference between the number of crystalloids administered in all three groups. However, the amount of colloid administered was statistically significantly lower in the SPV group than in the PVI group, and there was no significant difference in the other groups. Statistically, there was no significant difference between the groups in plasma lactate, blood urea, and creatinine levels.

CONCLUSION

In LSG, dynamic measurement techniques such as PVI, SPV, and PPV can be used in patients with morbid obesity without causing intraoperative and postoperative complications. PVI may be preferred over other invasive methods because it is noninvasive.

Effect of using hypotension prediction index versus conventional goal-directed haemodynamic management to reduce intraoperative hypotension in non-cardiac surgery: A randomised controlled trial

STUDY OBJECTIVE

It remains unclear whether it is the hypotension prediction index itself or goal-directed haemodynamic therapy that mitigates intraoperative hypotension.

DESIGN

A single centre randomised controlled trial.

SETTING

Sapporo Medical University Hospital.

PATIENTS

A total of 64 adults patients undergoing major non-cardiac surgery under general anaesthesia.

INTERVENTIONS

Patients were randomly assigned to either group receiving conventional goal-directed therapy (FloTrac group) or combination of the hypotension prediction index and conventional goal-directed therapy (HPI group). To investigate the independent utility of the index, the peak rates of arterial pressure and dynamic arterial elastance were not included in the treatment algorithm for the HPI group.

MEASUREMENTS

The primary outcome was the time-weighted average of the areas under the threshold. Secondary outcomes were area under the threshold, the number of hypotension events, total duration of hypotension events, mean mean arterial pressure during the hypotension period, number of hypotension events with mean arterial pressure < 50 mmHg, amounts of fluids, blood products, blood loss, and urine output, frequency and amount of vasoactive agents, concentration of haemoglobin during the monitoring period, and 30-day mortality.

MAIN RESULTS

The time-weighted average of the area below the threshold was lower in the HPI group than in the control group; 0.19 mmHg (interquartile range, 0.06-0.80 mmHg) vs. 0.66 mmHg (0.28-1.67 mmHg), with a median difference of -0.41 mmHg (95% confidence interval, -0.69 to -0.10 mmHg), p = 0.005. Norepinephrine was administered to 12 (40%) and 5 (17%) patients in the HPI and FloTrac groups, respectively (p = 0.045). No significant differences were observed in the volumes of fluid and blood products between the study groups.

CONCLUSIONS

The current randomised controlled trial results suggest that using the hypotension prediction index independently lowered the cumulative amount of intraoperative hypotension during major non-cardiac surgery.

Association of Sarcopenia, as Defined Based on the Skeletal Muscle Index, With Mortality and Morbidity After Cardiac Surgery: A Retrospective Cohort Study

OBJECTIVE

To investigate whether "sarcopenia," defined based on the preoperative skeletal muscle index (SMI), can predict major postoperative morbidity and all-cause mortality.

DESIGN

A retrospective observational cohort study.

SETTING

At the authors' Department of Critical Care Medicine.

PARTICIPANTS

A total of 986 adult Chinese patients underwent cardiac surgery (coronary artery bypass graft, valve surgery, combined surgery, or aortic surgery) between January 2019 and August 2022.

MEASUREMENTS AND MAIN RESULTS

The skeletal muscle area at the third lumbar level (L3) was measured via preoperative computed tomography (up to 3 months from the date of imaging to the date of surgery) and normalized to patient height (skeletal muscle index). Sarcopenia was determined based on the skeletal muscle index being in the lowest sex-specific quartile. The primary outcome was all-cause mortality. The secondary outcome was major morbidity. A total of 968 patients were followed for a median of 2.00 years, ranging from 1.06 to 2.90 years. After the follow-up, 76 patients died during the follow-up period. Multivariate Cox proportional analysis showed a relationship between sarcopenia (adjusted hazard ratio 1.80, 95% CI 1.04-3.11; p = 0.034) and all-cause mortality. Kaplan-Meier curves revealed a significantly lower survival rate in the sarcopenia group than in the nonsarcopenia group. Overall, 199 (20.6%) patients had major morbidity. Multivariate analysis showed a significant relationship between sarcopenia (adjusted odds ratio = 2.21, 95% CI 1.52∼3.22, p < 0.001) and major morbidity.

CONCLUSIONS

Sarcopenia, defined by the skeletal muscle index, is associated with all-cause mortality and major morbidity after cardiac surgery, thereby suggesting the need for perioperative sarcopenia risk assessment for patients undergoing cardiac surgery to guide the prevention and management of adverse outcomes.

Closed-loop anesthesia: foundations and applications in contemporary perioperative medicine

A closed-loop automatically controls a variable using the principle of feedback. Automation within anesthesia typically aims to improve the stability of a controlled variable and reduce workload associated with simple repetitive tasks. This approach attempts to limit errors due to distractions or fatigue while simultaneously increasing compliance to evidence based perioperative protocols. The ultimate goal is to use these advantages over manual care to improve patient outcome. For more than twenty years, clinical studies in anesthesia have demonstrated the superiority of closed-loop systems compared to manual control for stabilizing a single variable, reducing practitioner workload, and safely administering therapies. This research has focused on various closed-loops that coupled inputs and outputs such as the processed electroencephalogram with propofol, blood pressure with vasopressors, and dynamic predictors of fluid responsiveness with fluid therapy. Recently, multiple simultaneous independent closed-loop systems have been tested in practice and one study has demonstrated a clinical benefit on postoperative cognitive dysfunction. Despite their advantages, these tools still require that a well-trained practitioner maintains situation awareness, understands how closed-loop systems react to each variable, and is ready to retake control if the closed-loop systems fail. In the future, multiple input multiple output closed-loop systems will control anesthetic, fluid and vasopressor titration and may perhaps integrate other key systems, such as the anesthesia machine. Human supervision will nonetheless always be indispensable as situation awareness, communication, and prediction of events remain irreplaceable human factors.

Can perioperative pCO2 gaps predict complications in patients undergoing major elective abdominal surgery randomized to goal-directed therapy or standard care? A secondary analysis

The difference between venous and arterial carbon dioxide pressure (pCO2 gap), has been used as a diagnostic and prognostic tool. We aimed to assess whether perioperative pCO2 gaps can predict postoperative complications. This was a secondary analysis of a multicenter RCT comparing goal-directed therapy (GDT) to standard care in which 464 patients undergoing high-risk elective abdominal surgery were included. Arterial and central venous blood samples were simultaneously obtained at four time points: after induction, at the end of surgery, at PACU/ICU admission, and PACU/ICU discharge. Complications within the first 30 days after surgery were recorded. Similar pCO2 gaps were found in patients with and without complications, except for the pCO2 gap at the end of surgery, which was higher in patients with complications (6.0 mmHg [5.0-8.0] vs. 6.0 mmHg [4.1-7.5], p = 0.005). The area under receiver operating characteristics curves for predicting complications from pCO2 gaps at all time points were between 0.5 and 0.6. A weak correlation between ScvO2 and pCO2 gaps was found for all timepoints (ρ was between - 0.40 and - 0.29 for all timepoints, p < 0.001). The pCO2 gap did not differ between GDT and standard care at any of the selected time points. In our study, pCO2 gap was a poor predictor of major postoperative complications at all selected time points. Our research does not support the use of pCO2 gap as a prognostic tool after high-risk abdominal surgery. pCO2 gaps were comparable between GDT and standard care. Clinical trial registration Netherlands Trial Registry NTR3380.

Effect of different targets of goal-directed fluid therapy on intraoperative hypotension and fluid infusion in robot-assisted laparoscopic gynecological surgery: a randomized non-inferiority trial

Carotid corrected flow time (FTc) and tidal volume challenge pulse pressure variation (VtPPV) are useful clinical parameters for assessing volume status and fluid responsiveness in robot-assisted surgery, but their usefulness as goal-directed fluid therapy (GDFT) targets is unclear. We investigated whether FTc or VtPPV as targets are inferior to PPV in GDFT. This single-center, prospective, randomized, non-inferiority study included 133 women undergoing robot-assisted laparoscopic gynecological surgery in the modified head-down lithotomy position. Patients were equally divided into three groups, and the GDFT protocol was guided by FTc, VtPPV, or PPV during surgery. Primary outcomes were non-inferiority of the time-weighted average of hypotension, intraoperative fluid volume, and urine output. Secondary outcomes were optic nerve sheath diameter (ONSD) pre- and post-operatively and creatinine and blood urea nitrogen preoperatively and on day 1 post-operatively. No significant differences were observed in intraoperative hypotension index, infusion and urine volumes, and ONSD post-operatively between the FTc and VtPPV groups and the PPV group. No differences in serum creatinine and urea nitrogen levels were identified between the FTc and VtPPV groups preoperatively, but on day 1 post-operatively, the urea nitrogen level in the FTc group was higher than that in the PPV group (4.09 ± 1.28 vs. 3.0 ± 1.1 mmol/L, 1.08 [0.59, 1.58], p < 0.0001), and the difference from the preoperative value was smaller than that in the PPV group (- 2 [- 2.97, 1.43] vs. - 1.34 [- 1.9, - 0.67], p = 0.004). FTc- or VtPPV-guided protocols are not inferior to that of PPV in GDFT during robot-assisted laparoscopic surgery in the modified head-down lithotomy position.Trial registration: Chinese Clinical Trial Registry (ChiCTR2200064419).

Improving perioperative care in low-resource settings with goal-directed therapy: a narrative review

Perioperative Goal-Directed Therapy (PGDT) has significantly showed to decrease complications and risk of death in high-risk patients according to numerous meta-analyses. The main goal of PGDT is to individualize the therapy with fluids, inotropes, and vasopressors, during and after surgery, according to patients' needs in order to prevent organic dysfunction development. In this opinion paper we aimed to focus a discussion on possible alternatives to invasive hemodynamic monitoring in low resource settings.

Evolving trends in the surgical, anaesthetic, and intensive care management of acute spinal cord injuries in the UK

PURPOSE

We surveyed the treatment of acute spinal cord injuries in the UK and compared current practices with 10 years ago.

METHODS

A questionnaire survey was conducted amongst neurosurgeons, neuroanaesthetists, and neurointensivists that manage patients with acute spinal cord injuries. The survey gave two scenarios (complete and incomplete cervical spinal cord injuries). We obtained opinions on the speed of transfer, timing and aim of surgery, choice of anaesthetic, intraoperative monitoring, targets for physiological parameters, and drug treatments.

RESULTS

We received responses from 78.6% of UK units that manage acute spinal cord injuries (33 neurosurgeons, 56 neuroanaesthetists/neurointensivists). Most neurosurgeons operate within 12 h for incomplete (82%) and complete (64%) injuries. There is a significant shift from 10 years ago, when only 61% (incomplete) and 30% (complete) of neurosurgeons operated within 12 h. The preferred anaesthetic technique in 2022 is total intravenous anaesthesia (TIVA), used by 69% of neuroanaesthetists. Significantly more intraoperative monitoring is now used at least sometimes, including bispectral index (91%), non-invasive cardiac output (62%), and neurophysiology (73-77%). Methylprednisolone is no longer used by surgeons. Achieving at least 80 mmHg mean arterial blood pressure is recommended by 70% neurosurgeons, 62% neuroanaesthetists, and 75% neurointensivists.

CONCLUSIONS

Between 2012 and 2022, there was a paradigm shift in managing acute spinal cord injuries in the UK with earlier surgery and more intraoperative monitoring. Variability in practice persists due to lack of high-quality evidence and consensus guidelines.

Impact of goal-directed hemodynamic therapy on perioperative outcomes in head and neck free flap surgery: A before-and-after pilot study

Background

Free flap reconstruction for head and neck cancer is associated with a high risk of perioperative complications. One of the modifiable risk factors associated with perioperative morbidity is intraoperative hypotension (IOH). The main aim of this pilot study is to determine if the intraoperative use of goal-directed hemodynamic therapy (GDHT) is associated with a reduction in the number of IOH events in this population.

Methods

A before-and-after study design. The patients who had intraoperative GDHT were compared to patients from a previous period before the implementation of GDHT. The primary outcome was the number of IOH episodes defined as five or more successive minutes with a mean arterial pressure <65 mmHg. The secondary outcomes included major postoperative morbidity and 30-day mortality.

Results

A total of 414 patients were included. These were divided into two groups. The control group (n = 346; January 1, 2018, to December 31, 2019), and the monitored group (n = 68; January 1, 2020, to May 1, 2021). The median intraoperative administered fluid volume was similar between the control and monitored groups (2250 interquartile range [IQR] [1607-3050] vs. 2210 IQR [1700-2807] mL). The monitored group was found to have an increased use of norepinephrine and dobutamine (respectively, 1.2% vs. 5.9% and 2.4% vs. 30.9%; p < 0.05). When adjusting for confounders (comorbidities, estimated blood loss, and duration of anesthesia) the incidence rate ratio (95% confidence interval) of number of IOH events was 0.94 (0.86-1.03), p = 0.24. The rate of postoperative flap and medical complications did not differ between the two groups.

Conclusions

Even though the use of vasopressors/inotropes was higher in the monitored group, the number of IOH episodes and postoperative morbidity and mortality were similar between the two groups. Further change in hemodynamic management will require the use of specific blood pressure targets in the GDHT fluid algorithm.

Intraoperative haemodynamic monitoring and management of adults having non-cardiac surgery: Guidelines of the German Society of Anaesthesiology and Intensive Care Medicine in collaboration with the German Association of the Scientific Medical Societies

Haemodynamic monitoring and management are cornerstones of perioperative care. The goal of haemodynamic management is to maintain organ function by ensuring adequate perfusion pressure, blood flow, and oxygen delivery. We here present guidelines on "Intraoperative haemodynamic monitoring and management of adults having non-cardiac surgery" that were prepared by 18 experts on behalf of the German Society of Anaesthesiology and Intensive Care Medicine (Deutsche Gesellschaft für Anästhesiologie und lntensivmedizin; DGAI).

Hemodynamic monitoring in liver transplantation 'the hemodynamic system'

PURPOSE OF REVIEW

The purpose of this article is to provide a comprehensive review of hemodynamic monitoring in liver transplantation.

RECENT FINDINGS

Radial arterial blood pressure monitoring underestimates the aortic root arterial blood pressure and causes excessive vasopressor and worse outcomes. Brachial and femoral artery monitoring is well tolerated and should be considered in critically ill patients expected to be on high dose pressors. The pulmonary artery catheter is the gold standard of hemodynamic monitoring and is still widely used in liver transplantation; however, it is a highly invasive monitor with potential for serious complications and most of its data can be obtained by other less invasive monitors. Rescue transesophageal echocardiography relies on few simple views and should be available as a standby to manage sudden hemodynamic instability. Risk of esophageal bleeding from transesophageal echocardiography in liver transplantation is the same as in other patient populations. The arterial pulse waveform analysis based cardiac output devices are minimally invasive and have the advantage of real-time beat to beat monitoring of cardiac output. No hemodynamic monitor can improve clinical outcomes unless integrated into a goal-directed hemodynamic therapy. The hemodynamic monitoring technique should be tailored to the patient's medical status, surgical technique, and the anesthesiologist's level of expertise.

SUMMARY

The current article provides a review of the current hemodynamic monitoring systems and their integration in goal-directed hemodynamic therapy.

Update on guidelines and recommendations for enhanced recovery after thoracic surgery

PURPOSE OF REVIEW

Enhanced recovery after thoracic surgery (ERATS) has continued its growth in popularity over the past few years, and evidence for its utility is catching up to other specialties. This review will present and examine some of that accumulated evidence since guidelines sponsored by the Enhanced Recovery after Surgery (ERAS) Society and the European Society of Thoracic Surgeons (ESTS) were first published in 2019.

RECENT FINDINGS

The ERAS/ESTS guidelines published in 2019 have not been updated, but new studies have been done and new data has been published regarding some of the individual components of the guidelines as they relate to thoracic and lung resection surgery. While there is still not a consensus on many of these issues, the volume of available evidence is becoming more robust, some of which will be incorporated into this review.

SUMMARY

The continued accumulation of data and evidence for the benefits of enhanced recovery techniques in thoracic and lung resection surgery will provide the thoracic anesthesiologist with guidance on how to best care for these patients before, during, and after surgery. The data from these studies will also help to elucidate which components of ERAS protocols are the most beneficial, and which components perhaps do not provide as much benefit as previously thought.

Prediction of hematocrit decline and the impact of peri-operative fluid use in lumbar spinal fusion surgery

PURPOSE

Peri-operative blood loss unaccounted for and post-operative hematocrit decline could have a significant impact on the outcome of elective spinal surgery patients. The study assesses the accuracy of predictive models of hematocrit decline and blood loss in spinal surgery and determines the impact of peri-operative fluid administration on hematocrit levels of patients undergoing first-time single level lumbar fusion surgery for degenerative spine disease and the trend thereof in the first 24 h post-operatively.

METHODS

Clinical and biochemical parameters were prospectively collected in patients undergoing single level lumbar spinal surgery. Predictive models were applied to assess their accuracy in intra-operative blood loss and post-operative hematocrit decline.

RESULTS

High correlation (0.98 Pearson correlation coefficient) occurred between calculated (predicted) and recorded hematocrit from hours 2 to 6 post-operatively. Predictive accuracy declined thereafter yet remained moderate. Patients received an average intra-operative fluid volume of 545.45 ml per hour (47% of estimated total blood volume). A significant hematocrit decline occurred post-induction (43.47-39.78%, p < 0.001) with total fluid volume received being the significant contributing variable (p < 0.001). Hypertensive patients were the only subgroup to drop below the safe hematocrit threshold of 30%.

CONCLUSION

Iatrogenic hemodilution can accurately be predicted for the first six hours post-operatively, with high risk patients identifiable. Fluid therapy should be goal directed rather than generic, and good communication between the surgeon and anesthesiologist remains the cornerstone to manage physiological changes secondary to blood loss. Although helpful, predictive formulas are not universally applicable to all phenotypes.

Error traps and preventative strategies for adolescent idiopathic scoliosis spinal surgery

Anesthesia for posterior spinal fusion for adolescent idiopathic scoliosis remains one of the most common surgeries performed in adolescents. These procedures have the potential for significant intraprocedural and postoperative complications. The potential for pressure injuries related to prone positioning must be understood and addressed. Additionally, neuromonitoring remains a mainstay for patient care in order to adequately assess patient neurologic integrity and alert the providers to a reversible action. As such, causes of neuromonitoring signal loss must be well understood, and the provider should have a systematic approach to signal loss. Further, anesthetic design must facilitate intraoperative wake-up to allow for a definitive assessment of neurologic function. Perioperative bleeding risk is high in posterior spinal fusion due to the extensive surgical exposure and potentially lengthy operative time, so the provider should undertake strategies to reduce blood loss and avoid coagulopathy. Pain management for adolescents undergoing spinal fusion is also challenging, and inadequate analgesia can delay recovery, impede patient/family satisfaction, increase the risk of chronic postsurgical pain/disability, and lead to prolonged opioid use. Many of the significant complications associated with this procedure, however, can be avoided with intentional and evidence-based approaches covered in this review.

OCOSO2: study protocol for a single-blinded, multicentre, randomised controlled trial assessing a central venous oxygen saturation-based goal-directed therapy to reduce postoperative complications in high-risk patients after elective major surgery

BACKGROUND

Fluid loading-based goal-directed therapy is a cornerstone of anaesthesia management in major surgery. Its widespread application has contributed to a significant improvement in perioperative morbidity and mortality. In theory, only hypovolemic patients should receive fluid therapy. However, to achieve such a diagnosis, a surrogate marker of cardiac output adequacy must be used. Current methods of fluid loading-based goal-directed therapy do not assess cardiac output adequacy. Nowadays, new devices make it possible to continuously monitor central venous oxygen saturation (ScvO2) and therefore, to assess the adequacy of perioperative cardiac output during surgery. In major surgery, ScvO2-based goal-directed therapy can be used to enhance fluid therapy and improve patient outcomes.

METHODS

We designed a prospective, randomised, single-blinded, multicentre controlled superiority study with a 1:1 allocation ratio. Patients to be included will be high-risk major surgery patients (> 50 years old, ASA score > 2, major intra-abdominal or intra-thoracic surgery > 90 min). Patients in the control group will undergo standard fluid loading-based goal-directed therapy, as recommended by the guidelines. Patients in the intervention group will have ScvO2-based goal-directed therapy and receive fluid loading only if fluid responsiveness and cardiac output inadequacy are present. The primary outcome will be the Comprehensive Complication Index on day five postoperatively.

DISCUSSION

This study is the first to address the issue of cardiac output adequacy in goal-directed therapy. Our hypothesis is that cardiac output optimisation during major surgery achieved by continuous monitoring of the ScvO2 to guide fluid therapy will result in a reduction of postoperative complications as compared with current goal-directed fluid therapy practices.

TRIAL REGISTRATION

ClinicalTrials.gov. NCT03828565. Registered on February 4, 2019.

The effect of goal-directed hemodynamic therapy on clinical outcomes in patients undergoing radical cystectomy: a randomized controlled trial

BACKGROUND

This study investigated the effects of intraoperative goal-directed hemodynamic therapy (GDHT) on postoperative outcomes in patients undergoing open radical cystectomy.

METHODS

This prospective, single-center, randomized controlled trial included 82 patients scheduled for open radical cystectomy between September 2018 and November 2021. The GDHT group (n = 39) received the stroke volume index- and cardiac index-based hemodynamic management using advanced hemodynamic monitoring, while the control group (n = 36) received the standard care under the discretion of attending anesthesiologists during surgery. The primary outcome was the incidence of a composite of in-hospital postoperative complications during hospital stays.

RESULTS

A total of 75 patients were included in the final analysis. There was no significant difference in the incidence of in-hospital postoperative complications (28/39 [71.8%] vs. 30/36 [83.3%], risk difference [95% CI], -0.12 [-0.30 to 0.07], P = 0.359) between the groups. The amounts of intraoperative fluid administered were similar between the groups (2700 [2175-3250] vs. 2900 [1950-3700] ml, median difference [95% CI] -200 [-875 to 825], P = 0.714). The secondary outcomes, including the incidence of seven major postoperative complications, duration of hospital stay, duration of intensive care unit stay, and grade of complications, were comparable between the two groups. Trends in postoperative estimated glomerular filtration rate, serum creatinine, and C-reactive protein did not differ significantly between the two groups.

CONCLUSIONS

Intraoperative GDHT did not reduce the incidence of postoperative in-hospital complications during the hospital stay in patients who underwent open radical cystectomy.

TRIAL REGISTRATION

This study was registered at http://www.

CLINICALTRIALS

gov (Registration number: NCT03505112; date of registration: 23/04/2018).

Associations between clinical interventions and transcutaneous blood gas values in postoperative patients

PURPOSE

Postoperative monitoring of circulation and respiration is pivotal to guide intervention strategies and ensure patient outcomes. Transcutaneous blood gas monitoring (TCM) may allow for noninvasive assessment of changes in cardiopulmonary function after surgery, including a more direct assessment of local micro-perfusion and metabolism. To form the basis for studies assessing the clinical impact of TCM complication detection and goal-directed-therapy, we examined the association between clinical interventions in the postoperative period and changes in transcutaneous blood gasses.

METHODS

Two-hundred adult patients who have had major surgery were enrolled prospectively and monitored with transcutaneous blood gas measurements (oxygen (TcPO2) and carbon dioxide (TcPCO2)) for 2 h in the post anaesthesia care unit, with recording of all clinical interventions. The primary outcome was changes in TcPO2, secondarily TcPCO2, from 5 min before a clinical intervention versus 5 min after, analysed with paired t-test.

RESULTS

Data from 190 patients with 686 interventions were analysed. During clinical interventions, a mean change in TcPO2 of 0.99 mmHg (95% CI-1.79-0.2, p = 0.015) and TcPCO2 of-0.67 mmHg (95% CI 0.36-0.98, p < 0.001) was detected.

CONCLUSION

Clinical interventions resulted in significant changes in transcutaneous oxygen and carbon dioxide. These findings suggest future studies to assess the clinical value of changes in transcutaneous PO2 and PCO2 in a postoperative setting.

TRIAL REGISTRY

Clinical trial number: NCT04735380.

CLINICAL TRIAL REGISTRY

https://clinicaltrials.gov/ct2/show/NCT04735380.

Enhanced recovery after surgery, current, and future considerations in head and neck cancer

Objectives

Review of the current and relevant literature to develop a list of evidence-based recommendations that can be implemented in head and neck surgical practices. To provide rationale for the multiple aspects of comprehensive care for head and neck surgical patients. To improve postsurgical outcomes for head and neck surgical patients.

Methods

Extensive review of the medical literature was performed and relevant studies in both the head and neck surgery and other surgical specialties were considered for inclusion.

Results

A total of 18 aspects of perioperative care were included in this review. The literature search included 276 publications considered to be the most relevant and up to date evidence. Each topic is concluded with recommendation grade and quality of evidence for the recommendation.

Conclusion

Since it's conception, enhanced recovery after surgery (ERAS) protocols have continued to push for comprehensive and evidence based postsurgical care to improve patient outcomes. Head and neck oncology is one of the newest fields to develop a protocol. Due to the complexity of this patient population and their postsurgical needs, a multidisciplinary approach is needed to facilitate recovery while minimizing complications. Current and future advances in head and neck cancer research will serve to strengthen and add new principles to a comprehensive ERAS protocol.

Level of Evidence

2a.

Implication of age-related changes on anesthesia management

Elderly patients have a high risk of perioperative morbidity and mortality. Pluri-morbidities, polypharmacy, and functional dependence may have a great impact on intraoperative management and request specific cautions. In addition to surgical stress, several perioperative noxious stimuli such as fasting, blood loss, postoperative pain, nausea and vomiting, drug adverse reactions, and immobility may trigger a derangement leading to perioperative complications. Older patients have a high risk of major hemodynamic derangement due to aging of the cardiovascular system and associated comorbidities. The hemodynamic monitoring as well as fluid therapy should be the most accurate as possible. Aging is accompanied by decreased renal function, which is related to a reduction in renal blood flow, renal mass, and the number and size of functioning nephrons. Drugs eliminated predominantly by the renal route need dosage adjustments based on residual renal function. Liver mass, hepatic blood flow, and intrinsic metabolic activity are decreased in the elderly, and all drugs metabolized by the liver have a variable half-life, thus requiring dose reduction. Decreased neural plasticity contributes to a high risk for postoperative delirium. Monitoring of anesthesia depth should be mandatory to avoid overdosage of hypnotic drugs. Prevention of postoperative pulmonary complications requires both protective ventilation strategies and adequate recovery of neuromuscular function at the end of surgery. Avoidance of hypothermia cannot be missed. The aim of this review is to describe comprehensive strategies for intraoperative management plans tailored to meet the unique needs of elderly surgical patients, thus improving outcomes in this vulnerable population.

Perioperative advanced haemodynamic monitoring of patients undergoing multivisceral debulking surgery: an observational pilot study

BACKGROUND

Patients undergoing high-risk surgery show haemodynamic instability and an increased risk of morbidity. However, most of the available data concentrate on the intraoperative period. This study aims to characterise patients with advanced haemodynamic monitoring throughout the whole perioperative period using electrical cardiometry.

METHODS

In a prospective, observational, monocentric pilot study, electrical cardiometry measurements were obtained using an Osypka ICON™ monitor before surgery, during surgery, and repeatedly throughout the hospital stay for 30 patients with primary ovarian cancer undergoing multivisceral cytoreductive surgery. Severe postoperative complications according to the Clavien-Dindo classification were used as a grouping criterion.

RESULTS

The relative change from the baseline to the first intraoperative timepoint showed a reduced heart rate (HR, median - 19 [25-quartile - 26%; 75-quartile - 10%]%, p < 0.0001), stroke volume index (SVI, - 9.5 [- 15.3; 3.2]%, p = 0.0038), cardiac index (CI, - 24.5 [- 32; - 13]%, p < 0.0001) and index of contractility (- 17.5 [- 35.3; - 0.8]%, p < 0.0001). Throughout the perioperative course, patients had intraoperatively a reduced HR and CI (both p < 0.0001) and postoperatively an increased HR (p < 0.0001) and CI (p = 0.016), whereas SVI was unchanged. Thoracic fluid volume increased continuously versus preoperative values and did not normalise up to the day of discharge. Patients having postoperative complications showed a lower index of contractility (p = 0.0435) and a higher systolic time ratio (p = 0.0008) over the perioperative course in comparison to patients without complications, whereas the CI (p = 0.3337) was comparable between groups. One patient had to be excluded from data analysis for not receiving the planned surgery.

CONCLUSIONS

Substantial decreases in HR, SVI, CI, and index of contractility occurred from the day before surgery to the first intraoperative timepoint. HR and CI were altered throughout the perioperative course. Patients with postoperative complications differed from patients without complications in the markers of cardiac function, a lower index of contractility and a lower SVI. The analyses of trends over the whole perioperative time course by using non-invasive technologies like EC seem to be useful to identify patients with altered haemodynamic parameters and therefore at an increased risk for postoperative complications after major surgery.

Predicting fluid responsiveness using esophagus Doppler monitoring and pulse oximetry derived pleth variability index; retrospective analysis of a hemodynamic study

BACKGROUND

Fluid therapy during major surgery can be managed by providing repeated bolus infusions until stroke volume no longer increases by ≥ 10%. However, the final bolus in an optimization round increases stroke volume by < 10% and is not necessary. We studied how different cut-off values for the hemodynamic indications given by esophagus Doppler monitoring, as well as augmentation by pulse oximetry, are associated with a higher or smaller chance that stroke volume increases by ≥ 10% (fluid responsiveness) before fluid is infused.

METHODS

An esophagus Doppler and a pulse oximeter that displayed the pleth variability index were used to monitor the effects of a bolus infusion in 108 patients undergoing goal-directed fluid therapy during major open abdominal surgery.

RESULTS

The analyzed data set comprised 266 bolus infusions. The overall incidence of fluid responsiveness was 44%, but this varied greatly depending on pre-infusion hemodynamics. The likelihood of being fluid-responsive was 30%-38% in the presence of stroke volume > 80 mL, corrected flow time > 360 ms, or pleth variability index < 10%. The likelihood was 21% if stroke volume had decreased by <8% since the previous optimization, which decreased to 0% if combined with stroke volume > 100 mL. By contrast, the likelihood of fluid responsiveness increased to 50%-55% when stroke volume ≤ 50 mL, corrected flow time ≤ 360 ms, or pleth variability index ≥ 10. A decrease in stroke volume by > 8% since the previous optimization was followed by a 58% likelihood of fluid responsiveness that, in combination with any of the other hemodynamic variables, increased to 66%-76%.

CONCLUSIONS

Single or combined hemodynamic variables provided by esophagus Doppler monitoring and pulse oximetry derived pleth variability index could help clinicians avoid unnecessary fluid bolus infusions.

Closed-Loop Pharmacologic Control of Blood Pressure: A Review of Existing Systems

Blood pressure management is a critical aspect of patient care, particularly in surgical and critical care settings. Closed-loop systems, which utilize real-time data and feedback to adjust treatment interventions, have gained attention for their potential to enhance blood pressure control. This review explores the application of closed-loop systems in blood pressure management. We discuss various closed-loop approaches, including their mechanisms, benefits, and limitations. By harnessing real-time patient data and feedback, closed-loop systems can tailor interventions dynamically, thus enhancing blood pressure regulation. Additionally, we examine the integration of advanced monitoring technologies and artificial intelligence algorithms in closed-loop systems. The review highlights recent studies and their findings, emphasizing the evolving landscape of closed-loop blood pressure management across different clinical scenarios. From the perioperative period to critical care settings, closed-loop systems hold the potential to optimize patient outcomes by precisely adjusting vasopressor administration in response to continuous blood pressure fluctuations. By providing insights into the current state of closed-loop systems for blood pressure control, this review offers a comprehensive overview of their potential contributions to improved patient outcomes and future directions for research and implementation.

Perioperative Fluid Management

The medical complexity of the geriatric patients has been steadily rising. Still, as outcomes of surgical procedures in the elderly are improving, centers are pushing boundaries. There is also a growing appreciation of the importance of perioperative fluid management on postoperative outcomes, especially in the elderly. Optimal fluid management in this cohort is challenging due to the combination of age-related physiological changes in organ function, increased comorbid burden, and larger fluid shifts during more complex surgical procedures. The current state-of-the-art approach to fluid management in the perioperative period is outlined.

Consensus Guidelines for Perioperative Care for Emergency Laparotomy Enhanced Recovery After Surgery (ERAS®) Society Recommendations Part 2-Emergency Laparotomy: Intra- and Postoperative Care

BACKGROUND

This is Part 2 of the first consensus guidelines for optimal care of patients undergoing emergency laparotomy (EL) using an Enhanced Recovery After Surgery (ERAS) approach. This paper addresses intra- and postoperative aspects of care.

METHODS

Experts in aspects of management of high-risk and emergency general surgical patients were invited to contribute by the International ERAS® Society. PubMed, Cochrane, Embase, and Medline database searches were performed for ERAS elements and relevant specific topics. Studies on each item were selected with particular attention to randomized clinical trials, systematic reviews, meta-analyses, and large cohort studies and reviewed and graded using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system. Recommendations were made on the best level of evidence, or extrapolation from studies on elective patients when appropriate. A modified Delphi method was used to validate final recommendations. Some ERAS® components covered in other guideline papers are outlined only briefly, with the bulk of the text focusing on key areas pertaining specifically to EL.

RESULTS

Twenty-three components of intraoperative and postoperative care were defined. Consensus was reached after three rounds of a modified Delphi Process.

CONCLUSIONS

These guidelines are based on best available evidence for an ERAS® approach to patients undergoing EL. These guidelines are not exhaustive but pull together evidence on important components of care for this high-risk patient population. As much of the evidence is extrapolated from elective surgery or emergency general surgery (not specifically laparotomy), many of the components need further evaluation in future studies.

Guidelines on perioperative optimization protocol for the adult patient 2023

OBJECTIVE

The French Society of Anesthesiology and Intensive Care Medicine [Société Française d'Anesthésie et de Réanimation (SFAR)] aimed at providing guidelines for the implementation of perioperative optimization programs.

DESIGN

A consensus committee of 29 experts from the SFAR was convened. A formal conflict-of-interest policy was developed at the outset of the process and enforced throughout. The entire guidelines process was conducted independently of any industry funding. The authors were advised to follow the principles of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system to guide assessment of quality of evidence.

METHODS

Four fields were defined: 1) Generalities on perioperative optimization programs; 2) Preoperative measures; 3) Intraoperative measures and; 4) Postoperative measures. For each field, the objective of the recommendations was to answer a number of questions formulated according to the PICO model (population, intervention, comparison, and outcomes). Based on these questions, an extensive bibliographic search was carried out using predefined keywords according to PRISMA guidelines and analyzed using the GRADE® methodology. The recommendations were formulated according to the GRADE® methodology and then voted on by all the experts according to the GRADE grid method. As the GRADE® methodology could have been fully applied for the vast majority of questions, the recommendations were formulated using a "formalized expert recommendations" format.

RESULTS

The experts' work on synthesis and application of the GRADE® method resulted in 30 recommendations. Among the formalized recommendations, 19 were found to have a high level of evidence (GRADE 1±) and ten a low level of evidence (GRADE 2±). For one recommendation, the GRADE methodology could not be fully applied, resulting in an expert opinion. Two questions did not find any response in the literature. After two rounds of rating and several amendments, strong agreement was reached for all the recommendations.

CONCLUSIONS

Strong agreement among the experts was obtained to provide 30 recommendations for the elaboration and/or implementation of perioperative optimization programs in the highest number of surgical fields.

Peripheral Intravenous Waveform Analysis Responsiveness to Subclinical Hemorrhage in a Rat Model

BACKGROUND

Early detection and quantification of perioperative hemorrhage remains challenging. Peripheral intravenous waveform analysis (PIVA) is a novel method that uses a standard intravenous catheter to detect interval hemorrhage. We hypothesize that subclinical blood loss of 2% of the estimated blood volume (EBV) in a rat model of hemorrhage is associated with significant changes in PIVA. Secondarily, we will compare PIVA association with volume loss to other static, invasive, and dynamic markers.

METHODS

Eleven male Sprague Dawley rats were anesthetized and mechanically ventilated. A total of 20% of the EBV was removed over ten 5 minute-intervals. The peripheral intravenous pressure waveform was continuously transduced via a 22-G angiocatheter in the saphenous vein and analyzed using MATLAB. Mean arterial pressure (MAP) and central venous pressure (CVP) were continuously monitored. Cardiac output (CO), right ventricular diameter (RVd), and left ventricular end-diastolic area (LVEDA) were evaluated via transthoracic echocardiogram using the short axis left ventricular view. Dynamic markers such as pulse pressure variation (PPV) were calculated from the arterial waveform. The primary outcome was change in the first fundamental frequency (F1) of the venous waveform, which was assessed using analysis of variance (ANOVA). Mean F1 at each blood loss interval was compared to the mean at the subsequent interval. Additionally, the strength of the association between blood loss and F1 and each other marker was quantified using the marginal R2 in a linear mixed-effects model.

RESULTS

PIVA derived mean F1 decreased significantly after hemorrhage of only 2% of the EBV, from 0.17 to 0.11 mm Hg, P = .001, 95% confidence interval (CI) of difference in means 0.02 to 0.10, and decreased significantly from the prior hemorrhage interval at 4%, 6%, 8%, 10%, and 12%. Log F1 demonstrated a marginal R2 value of 0.57 (95% CI 0.40-0.73), followed by PPV 0.41 (0.28-0.56) and CO 0.39 (0.26-0.58). MAP, LVEDA, and systolic pressure variation displayed R2 values of 0.31, and the remaining predictors had R2 values ≤0.2. The difference in log F1 R2 was not significant when compared to PPV 0.16 (95% CI -0.07 to 0.38), CO 0.18 (-0.06 to 0.04), or MAP 0.25 (-0.01 to 0.49) but was significant for the remaining markers.

CONCLUSIONS

The mean F1 amplitude of PIVA was significantly associated with subclinical blood loss and most strongly associated with blood volume among the markers considered. This study demonstrates feasibility of a minimally invasive, low-cost method for monitoring perioperative blood loss.

Perioperative fluid management for lung transplantation is challenging

Lung transplantation is the definitive end-stage treatment for many lung diseases, and postoperative pulmonary oedema severely affects survival after lung transplantation. Optimizing perioperative fluid management can reduce the incidence of postoperative pulmonary oedema and improve the prognosis of lung transplant patients by removing the influence of patient, donor's lung and ECMO factors. Therefore, this article reviews seven aspects of lung transplant patients' pathophysiological characteristics, physiological characteristics of fluids, the influence of the donor lung on pulmonary oedema as well as current fluid rehydration concepts, advantages or disadvantages of intraoperative monitoring tools or types of fluids on postoperative pulmonary oedema, while showing the existing challenges in section 7. The aim is to show the specificity of perioperative fluid management in lung transplant patients and to provide new ideas for individualised fluid management in lung transplantation.

Goal-directed haemodynamic therapy: an imprecise umbrella term to avoid

'Goal-directed haemodynamic therapy' describes various haemodynamic treatment strategies that have in common that interventions are titrated to achieve predefined haemodynamic targets. However, the treatment strategies differ substantially regarding the underlying haemodynamic target variables and target values, and thus presumably have different effects on outcome. It is an over-simplifying approach to lump complex and substantially differing haemodynamic treatment strategies together under the term 'goal-directed haemodynamic therapy', an imprecise umbrella term that we should thus stop using.

Perioperative Fluid Management and Volume Assessment

Fluid therapy is an integral component of perioperative care and helps maintain or restore effective circulating blood volume. The principal goal of fluid management is to optimize cardiac preload, maximize stroke volume, and maintain adequate organ perfusion. Accurate assessment of volume status and volume responsiveness is necessary for appropriate and judicious utilization of fluid therapy. To accomplish this, static and dynamic indicators of fluid responsiveness have been widely studied. This review discusses the overarching goals of perioperative fluid management, reviews the physiology and parameters used to assess fluid responsiveness, and provides evidence-based recommendations on intraoperative fluid management.

Effect of goal-directed fluid therapy based on plasma colloid osmotic pressure on the postoperative pulmonary complications of older patients undergoing major abdominal surgery

BACKGROUND

As an important component of accelerated rehabilitation surgery, goal-directed fluid therapy (GDT) is one of the optimized fluid therapy strategies and is closely related to perioperative complications and mortality. This article aimed to study the effect of combining plasma colloid osmotic pressure (COP) with stroke volume variation (SVV) as a target for intraoperative GDT for postoperative pulmonary complications in older patients undergoing major abdominal surgery.

METHODS

In this study, older patients (n = 100) undergoing radical resection of gastroenteric tumors were randomized to three groups: Group C (n1 = 31) received a conventional infusion regimen, Group S1 (n2 = 34) received GDT based on SVV, and Group S2 (n3 = 35) received GDT based on SVV and COP. The results were recorded, including the lung injury score (LIS); PaO₂/FiO₂ ratio; lactic acid value at the times of beginning (T0) and 1 h (T1), 2 h (T2), and 3 h (T3) after liquid infusion in the operation room; the total liquid infusion volume; infusion volumes of crystalline and colloidal liquids; urine production rate; pulmonary complications 7 days after surgery; and the severity grading of postoperative pulmonary complications.

RESULTS

The patients in the S2 group had fewer postoperative pulmonary complications than those in the C group (P < 0.05) and the proportion of pulmonary complications of grade 1 and higher than grade 2 in S2 group was significantly lower than that in C group (P <0.05); the patients in the S2 group had a higher PaO₂/FiO₂ ratio than those in the C group (P < 0.05), lower LIS than those in the S1 and C groups (P < 0.05), less total liquid infusion than those in the C group (P < 0.05), and more colloidal fluid infusion than those in the S1 and C groups (P < 0.05).

CONCLUSION

The findings of our study show that intraoperative GDT based on COP and SVV can reduce the incidence of pulmonary complications and conducive to shortening the hospital stay in older patients after gastrointestinal surgery.

TRIAL REGISTRATION

Chinese Clinical Trial. no. ChiCTR2100045671. Registry at www.chictr.org.cn on April 20, 2021.

Non-invasive assessment of Pulse Wave Transit Time (PWTT) is a poor predictor for intraoperative fluid responsiveness: a prospective observational trial (best-PWTT study)

BACKGROUND

Aim of this study is to test the predictive value of Pulse Wave Transit Time (PWTT) for fluid responsiveness in comparison to the established fluid responsiveness parameters pulse pressure (ΔPP) and corrected flow time (FTc) during major abdominal surgery.

METHODS

Forty patients undergoing major abdominal surgery were enrolled with continuous monitoring of PWTT (LifeScope® Modell J BSM-9101 Nihon Kohden Europe GmbH, Rosbach, Germany) and stroke volume (Esophageal Doppler Monitoring CardioQ-ODM®, Deltex Medical Ltd, Chichester, UK). In case of hypovolemia (difference in pulse pressure [∆PP] ≥ 9%, corrected flow time [FTc] ≤ 350 ms) a fluid bolus of 7 ml/kg ideal body weight was administered. Receiver operating characteristics (ROC) curves and corresponding areas under the curve (AUCs) were used to compare different methods of determining PWTT. A Wilcoxon test was used to discriminate fluid responders (increase in stroke volume of ≥ 10%) from non-responders. The predictive value of PWTT for fluid responsiveness was compared by testing for differences between ROC curves of PWTT, ΔPP and FTc using the methods by DeLong.

RESULTS

AUCs (area under the ROC-curve) to predict fluid responsiveness for PWTT-parameters were 0.61 (raw c finger Q), 0.61 (raw c finger R), 0.57 (raw c ear Q), 0.53 (raw c ear R), 0.54 (raw non-c finger Q), 0.52 (raw non-c finger R), 0.50 (raw non-c ear Q), 0.55 (raw non-c ear R), 0.63 (∆ c finger Q), 0.61 (∆ c finger R), 0.64 (∆ c ear Q), 0.66 (∆ c ear R), 0.59 (∆ non-c finger Q), 0.57 (∆ non-c finger R), 0.57 (∆ non-c ear Q), 0.61 (∆ non-c ear R) [raw measurements vs. ∆ = respiratory variation; c = corrected measurements according to Bazett's formula vs. non-c = uncorrected measurements; Q vs. R = start of PWTT-measurements with Q- or R-wave in ECG; finger vs. ear = pulse oximetry probe location]. Hence, the highest AUC to predict fluid responsiveness by PWTT was achieved by calculating its respiratory variation (∆PWTT), with a pulse oximeter attached to the earlobe, using the R-wave in ECG, and correction by Bazett's formula (AUC best-PWTT 0.66, 95% CI 0.54-0.79). ∆PWTT was sufficient to discriminate fluid responders from non-responders (p = 0.029). No difference in predicting fluid responsiveness was found between best-PWTT and ∆PP (AUC 0.65, 95% CI 0.51-0.79; p = 0.88), or best-PWTT and FTc (AUC 0.62, 95% CI 0.49-0.75; p = 0.68).

CONCLUSION

ΔPWTT shows poor ability to predict fluid responsiveness intraoperatively. Moreover, established alternatives ΔPP and FTc did not perform better.

TRIAL REGISTRATION

Prior to enrolement on clinicaltrials.gov (NC T03280953; date of registration 13/09/2017).

Effect of inferior vena cava respiratory variability-guided fluid therapy after laparoscopic hepatectomy: a randomized controlled clinical trial

BACKGROUND

After major liver resection, the volume status of patients is still undetermined. However, few concerns have been raised about postoperative fluid management. We aimed to compare gut function recovery and short-term prognosis of the patients after laparoscopic liver resection (LLR) with or without inferior vena cava (IVC) respiratory variability-directed fluid therapy in the anesthesia intensive care unit (AICU).

METHODS

This randomized controlled clinical trial enrolled 70 patients undergoing LLR. The IVC respiratory variability was used to optimize fluid management of the intervention group in AICU, while the standard practice of fluid management was used for the control group. The primary outcome was the time to flatus after surgery. The secondary outcomes included other indicators of gut function recovery after surgery, postoperative length of hospital stay (LOS), liver and kidney function, the severity of oxidative stress, and the incidence of severe complications associated with hepatectomy.

RESULTS

Compared with patients receiving standard fluid management, patients in the intervention group had a shorter time to anal exhaust after surgery (1.5 ± 0.6 days vs. 2.0 ± 0.8 days) and lower C-reactive protein activity (21.4 [95% confidence interval (CI): 11.9-36.7] mg/L vs. 44.8 [95%CI: 26.9-63.1] mg/L) 24 h after surgery. There were no significant differences in the time to defecation, serum concentrations of D-lactic acid, malondialdehyde, renal function, and frequency of severe postoperative complications as well as the LOS between the groups.

CONCLUSION

Postoperative IVC respiratory variability-directed fluid therapy in AICU was facilitated in bowel movement but elicited a negligible beneficial effect on the short-term prognosis of patients undergoing LLR.

TRIAL REGISTRATION

ChiCTR-INR-17013093.

Comparison of two techniques of goal directed fluid therapy in elective neurosurgical patients - a randomized controlled study

BACKGROUND

Goal directed fluid therapy (GDFT) may be a rational approach to adopt in neurosurgical patients, in whom intravascular volume optimization is of utmost importance. Most of the parameters used to guide GDFT are derived invasively. We postulated that the total volume of intraoperative intravenous fluid administered during elective craniotomy for supratentorial brain tumours would be comparable between two groups receiving GDFT guided either by the non-invasively derived plethysmography variability index (PVI) or by stroke volume variation (SVV).

METHODS

60 ASA category 1, 2 and 3 patients between 18 and 70 years of age were randomized to receive intraoperative fluid guided either by SVV (SVV group; n = 31) or PVI (PVI group; n = 29). The total volume of fluid administered intraoperatively was recorded. Serum creatinine was measured before the surgery, at the end of the surgery, 24 h after surgery and on the fifth post-operative day. Arterial cannulation was performed before induction in all patients. Serum lactate was measured before induction, once in 2 h intraoperatively, at the end of the surgery and 24 h after the surgery. Brain relaxation score was assessed by the surgeon during dural opening and dural closure. Patients were followed up till discharge or death. The duration of mechanical ventilation and the duration of hospital stay was noted for all patients.

RESULTS

The volume of fluid given intraoperatively was significantly higher in the SVV group (p = 0.005). The two groups were comparable with respect to serum lactate and serum creatinine measured at pre-determined time intervals. Brain relaxation score was also comparable between the groups. SVV and PVI displayed moderate to strong correlation intraoperatively. The duration of mechanical ventilation and the length of the hospital stay were comparable between the two groups.

CONCLUSIONS

PVI and SVV are equally effective in guiding GDFT in adults undergoing elective craniotomy for supratentorial brain tumours.

Effects of Goal-Directed Hemodynamic Therapy Using a Noninvasive Finger-Cuff Monitoring Device on Intraoperative Cerebral Oxygenation and Early Delayed Neurocognitive Recovery in Patients Undergoing Beach Chair Position Shoulder Surgery: A Randomized Controlled Trial

BACKGROUND

Perioperative cerebral desaturation events (CDEs) and delayed neurocognitive recovery are common among patients undergoing beach chair position (BCP) shoulder surgery and may be caused by cerebral hypoperfusion. This study tested the hypothesis that the application of goal-directed hemodynamic therapy (GDHT) would attenuate these conditions.

METHODS

We randomly assigned 70 adult patients undergoing BCP shoulder surgery to GDHT group or control at a 1:1 ratio. Cerebral oxygenation was monitored using near-infrared spectroscopy, and GDHT was administered using the ClearSight pulse wave analysis system. The primary outcome was CDE duration, whereas the secondary outcomes were CDE occurrence, delayed neurocognitive recovery occurrence, and Taiwanese version of the Quick Mild Cognitive Impairment (Qmci-TW) test score on the first postoperative day (T 2 ) adjusted for the baseline score (on the day before surgery; T 1 ).

RESULTS

CDE duration was significantly shorter in the GDHT group (0 [0-0] vs 15 [0-75] min; median difference [95% confidence interval], -8 [-15 to 0] min; P = .007). Compared with the control group, fewer patients in the GDHT group experienced CDEs (23% vs 51%; relative risk [95% confidence interval], 0.44 [0.22-0.89]; P = .025) and mild delayed neurocognitive recovery (17% vs 40%; relative risk [95% confidence interval], 0.60 [0.39-0.93]; P = .034). The Qmci-TW scores at T 2 adjusted for the baseline scores at T 1 were significantly higher in the GDHT group (difference in means: 4 [0-8]; P = .033).

CONCLUSIONS

Implementing GDHT using a noninvasive finger-cuff monitoring device stabilizes intraoperative cerebral oxygenation and is associated with improved early postoperative cognitive scores in patients undergoing BCP shoulder surgery.

Prediction of fluid responsiveness by dynamic preload parameters in children undergoing thoracoscopic surgery with one-lung ventilation - A prospective observational study

Optimal perioperative fluid management is essential for reducing complications in children undergoing thoracoscopic surgery. The study aimed to assess the performance of 2 dynamic preload parameters - pulse pressure variation (PPV) and stroke volume variation (SVV)- either used alone or combined into a multivariable regression model for predicting fluid responsiveness in children undergoing video-assisted thoracoscopic surgery with one-lung ventilation. Children aged 1 to 6 years old undergoing video-assisted pulmonary segmentectomy or lobectomy were enrolled. Volume loading with 5 mL/kg of hydroxyethyl starch was administered over 15 minutes after establishment of artificial pneumothorax. PPV, SVV, cardiac index, cardiac cycle efficiency, and the difference between systolic blood pressure and dicrotic pressure were recorded using the pressure recording analytical method before and after volume loading. Patients with an elevation in cardiac index greater than 10% were defined as responders, and the remaining patients were nonresponders. Of 40 children, 36 were included in the final analysis, containing 13 responders and 23 nonresponders. SVV had an accuracy of 74% (95% confidence interval, 55-93%) for predicting fluid responsiveness, and a best cutoff of 22% showed a sensitivity of 62% and a specificity of 96%. PPV was incapable of discriminating responders from nonresponders. The multivariate regression model did not perform better than SVV alone. We found PPV failed to predict fluid responsiveness, while SVV predicted fluid responsiveness reasonably in the present context. There was no enhancement in predictivity accuracy with multivariable regression models. The accuracy of these approaches was limited, and more discriminative methods need to be found.

The Impact of Individualized Hemodynamic Management on Intraoperative Fluid Balance and Hemodynamic Interventions during Spine Surgery in the Prone Position: A Prospective Randomized Trial

Background and Objectives: The effect of individualized hemodynamic management on the intraoperative use of fluids and other hemodynamic interventions in patients undergoing spinal surgery in the prone position is controversial. This study aimed to evaluate how the use of individualized hemodynamic management based on extended continuous non-invasive hemodynamic monitoring modifies intraoperative hemodynamic interventions compared to conventional hemodynamic monitoring with intermittent non-invasive blood pressure measurements. Methods: Fifty adult patients (American Society of Anesthesiologists physical status I−III) who underwent spinal procedures in the prone position and were then managed with a restrictive fluid strategy were prospectively randomized into intervention and control groups. In the intervention group, individualized hemodynamic management followed a goal-directed protocol based on continuously non-invasively measured blood pressure, heart rate, cardiac output, systemic vascular resistance, and stroke volume variation. In the control group, patients were monitored using intermittent non-invasive blood pressure monitoring, and the choice of hemodynamic intervention was left to the discretion of the attending anesthesiologist. Results: In the intervention group, more hypotensive episodes (3 (2−4) vs. 1 (0−2), p = 0.0001), higher intraoperative dose of ephedrine (0 (0−10) vs. 0 (0−0) mg, p = 0.0008), and more positive fluid balance (680 (510−937) vs. 270 (196−377) ml, p < 0.0001) were recorded. Intraoperative norepinephrine dose and postoperative outcomes did not differ between the groups. Conclusions: Individualized hemodynamic management based on data from extended non-invasive hemodynamic monitoring significantly modified intraoperative hemodynamic management and was associated with a higher number of hemodynamic interventions and a more positive fluid balance.

Comparison of Stroke Volume Variation-based goal-directed Therapy Versus Standard Fluid Therapy in Patients Undergoing Head and Neck Surgery: A Randomized Controlled Study

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The Impact of Goal-Directed Fluid Therapy on Postoperative Nausea and Vomiting in High-Risk Patients Undergoing Laparoscopic Sleeve Gastrectomy

PURPOSE

Patients with laparoscopic sleeve gastrectomy (LSG) are at high risk of postoperative nausea and vomiting (PONV). Goal-directed fluid therapy (GDFT) has been proven effective in improving postoperative gastrointestinal function in patients with obesity, but its effect on prevention of PONV remains controversial. This study aimed to investigate the impact of GDFT on PONV in high-risk patients with LSG.

METHODS

In a randomized, single-blinded, two-arm trial, patients with an Apfel score ≥ 3 and scheduled for LSG were included. Patients in the GDFT group received stroke volume-guided fluid therapy. Patients in the control group received conventional fluid therapy. The primary outcome was the incidence of PONV within 48 h after LSG. The second outcome included intensity of PONV, use of rescue therapy, recovery of gastrointestinal function, and postoperative length of stay (LOS).

RESULTS

A total of 137 patients were analyzed. The incidence of PONV in the GDFT group was lower than that in the control group (47.1% vs. 71.6%; odds ratio [95%CI], 0.35 [0.17-0.72]; P = 0.004). Fewer patients in the GDFT group received rescue therapy (30% vs. 58.2%; P = 0.001). Patients following GDFT protocol had a faster return of flatus (27.5 (19, 31) vs. 31 (20, 48) hours, P = 0.037) and shorter postoperative LOS (6.1 ± 1.0 vs. 6.6 ± 1.1 days; P = 0.007).

CONCLUSION

GDFT is conducive to deceasing PONV occurrence, restoring intestinal function, and shortening postoperative LOS in high-risk patients undergoing LSG.

Efficacy of early goal-directed therapy using FloTrac/EV1000 to improve postoperative outcomes in patients undergoing off-pump coronary artery bypass surgery: a randomized controlled trial

Background

Early goal-directed therapy (EGDT) using FloTrac reduced length of stay (LOS) in intensive care (ICU) and hospital among patients undergoing coronary artery bypass graft (CABG) with a cardiopulmonary bypass. However, this platform in off-pump CABG (OPCAB) has received scant attention, so we evaluated the efficacy of EGDT using FloTrac/EV1000 as a modality for improving postoperative outcomes in patients undergoing OPCAB.

Methods

Forty patients undergoing OPCAB were randomized to the EV1000 or Control group. The Control group received fluid, inotropic, or vasoactive drugs (at the discretion of the attending anesthesiologist) to maintain a mean arterial pressure 65–90 mmHg; central venous pressure 8–12 mmHg; urine output ≥ 0.5 mL kg⁻¹ h⁻¹; SpO₂ > 95%; and hematocrit ≥ 30%. The EV1000 group achieved identical targets using information from the FloTrac/EV1000. The goals included stroke volume variation < 13%; cardiac index (CI) of 2.2–4.0 L min⁻¹ m⁻²; and systemic vascular resistance index of 1500–2500 dynes s⁻¹ cm⁻⁵ m⁻².

Results

The EV1000 group had a shorter LOS in ICU (mean difference − 1.3 d, 95% CI − 1.8 to − 0.8; P < 0.001). The ventilator time for both groups was comparable (P = 0.316), but the hospital stay for the EV1000 group was shorter (mean difference − 1.4 d, 95% CI − 2.1 to − 0.6; P < 0.001).

Conclusions

EGDT using FloTrac/EV1000 compared to conventional protocol reduces LOS in ICU and hospital among patients undergoing OPCAB.

Trial registration This study was retrospectively registered at www.ClinicalTrials.gov (NCT04292951) on 3 March 2020.

Microcirculatory tissue perfusion during general anaesthesia and noncardiac surgery: An observational study using incident dark field imaging with automated video analysis

BACKGROUND

Handheld vital microscopy allows direct observation of red blood cells within the sublingual microcirculation. Automated analysis allows quantifying microcirculatory tissue perfusion variables - including tissue red blood cell perfusion (tRBCp), a functional variable integrating microcirculatory convection and diffusion capacities.

OBJECTIVE

We aimed to describe baseline microcirculatory tissue perfusion in patients presenting for elective noncardiac surgery and test that microcirculatory tissue perfusion is preserved during elective general anaesthesia for noncardiac surgery.

DESIGN

Prospective observational study.

SETTING

University Medical Center Hamburg-Eppendorf, Hamburg, Germany.

PATIENTS

120 elective noncardiac surgery patients (major abdominal, orthopaedic or trauma and minor urologic surgery) and 40 young healthy volunteers.

MAIN OUTCOME MEASURES

We measured sublingual microcirculation using incident dark field imaging with automated analysis at baseline before induction of general anaesthesia, under general anaesthesia before surgical incision and every 30 min during surgery. We used incident the dark field imaging technology with a validated automated analysis software.

RESULTS

A total of 3687 microcirculation video sequences were analysed. Microcirculatory tissue perfusion variables varied substantially between individuals - but ranges were similar between patients and volunteers. Under general anaesthesia before surgical incision, there were no important changes in tRBCp, functional capillary density and capillary haematocrit compared with preinduction baseline. However, total vessel density was higher and red blood cell velocity and the proportion of perfused vessels were lower under general anaesthesia. There were no important changes in any microcirculatory tissue perfusion variables during surgery.

CONCLUSION

In patients presenting for elective noncardiac surgery, baseline microcirculatory tissue perfusion variables vary substantially between individuals - but ranges are similar to those in young healthy volunteers. Microcirculatory tissue perfusion is preserved during general anaesthesia and noncardiac surgery - when macrocirculatory haemodynamics are maintained.

Prediction of Fluid Responsiveness by the Effect of the Lung Recruitment Maneuver on the Perfusion Index in Mechanically Ventilated Patients During Surgery

Introduction

Excessive or inadequate fluid administration during perioperative period affects outcomes. Adjustment of volume expansion (VE) by performing fluid responsiveness (FR) test plays an important role in optimizing fluid infusion. Since changes in stroke volume (SV) during lung recruitment maneuver (LRM) can predict FR, and peripheral perfusion index (PI) is related to SV; therefore, we hypothesized that the changes in PI during LRM (ΔPILRM) could predict FR during perioperative period.

Methods

Patients who were scheduled for elective non-laparoscopic surgery under general anesthesia with a mechanical ventilator and who required VE (250 mL of crystalloid solution infusion over 10 min) were included. Before VE, LRM was performed by a continuous positive airway pressure of 30 cm H2O for 30 sec; hemodynamic variables with their changes (PI, obtained by pulse oximetry; and ΔPILRM, calculated by using [(PI before LRM—PI after LRM)/PI before LRM]*100) were obtained before and after LRM. After SV (measured by esophageal doppler) and PI had returned to the baseline values, VE was infused, and the values of these variables were recorded again, before and after VE. Fluid responders (Fluid-Res) were defined by an increase in SV ≥10% after VE. Receiver operating characteristic curves of the baseline values and ΔPILRM were constructed and reported as areas under the curve (AUC) with 95% confidence intervals, to predict FR.

Results

Of 32 mechanically ventilated adult patients included, 13 (41%) were in the Fluid-Res group. Before VE and LRM, there were no differences in the mean arterial pressure (MAP), heart rate, SV, and PI between patients in the Fluid-Res and fluid non-responders (Fluid-NonRes) groups. After LRM, SV, MAP, and, PI decreased in both groups, ΔPILRM was greater in the Fluid-Res group than in Fluid-NonRes group (55.2 ± 17.8% vs. 35.3 ± 17.3%, p &lt; 0.001, respectively). After VE, only SV and cardiac index increased in the Fluid-Res group. ΔPILRM had the highest AUC [0.81 (0.66–0.97)] to predict FR with a cut-off value of 40% (sensitivity 92.3%, specificity 73.7%).

Conclusions

ΔPILRM can be applied to predict FR in mechanical ventilated patients during the perioperative period.

A comparison of ClearSight noninvasive cardiac output and pulmonary artery bolus thermodilution cardiac output in cardiac surgery patients

BACKGROUND

The ClearSight system measures blood pressure non-invasively and determines cardiac output by analyzing the continuous pressure waveform. We performed a multi-center clinical study in China to test the equivalence of cardiac output measured with the ClearSight system (CSCO) and cardiac output measured with the pulmonary artery catheter bolus thermodilution (TDCO) method.

METHODS

We included adult patients undergoing cardiac surgery in three Chinese hospitals and measured TDCO and CSCO simultaneously after induction of anesthesia. Hemodynamic stability was required during measurement of TDCO and CSCO. At least four TDCO determinations were performed. The corresponding CSCO was determined as the average over a 30-s period following the injection of each bolus. A data pair for the comparison included the average of three or four accepted TDCO values and the average of the matching CSCO values. Main outcomes included Bland-Altman analysis of bias and standard deviation (SD) and the percentage error (PE).

RESULTS

One hundred twenty-five subjects were enrolled, and 122 TDCO and CSCO data pairs were available for analysis. Ninety-five (75.4%) data pairs were collected in hemodynamically stable conditions, mean (SD) CSCO was 4.21 (0.78) l/min, and mean TDCO was 3.90 (0.67) l/min. Bias was 0.32 (0.51) l/min, and PE was 25.2%. Analyzing all 122 data pairs resulted in a mean CSCO of 4.19 (0.82) l/min and a mean TDCO of 3.83 (0.71) l/min. Resulting bias was 0.36 (0.53) l/min, and PE was 26.4%.

CONCLUSIONS

CSCO and TDCO agreed with a low systematic bias. Besides, mean PE was well below the pre-defined 30%. Hemodynamic stability only had a small impact on the analysis. We conclude that CSCO is equivalent to TDCO in cardiac surgery patients. The trial was retrospectively registered in ClinicalTrials.gov, identifier NCT03807622 ; January 17, 2019.