Goal-directed therapy: hit early and personalize!

Establishing targets for goal-directed anesthesia in renal transplantation: a cohort analysis of high-saliency surgical time-courses

Delayed graft function (DGF) increases morbidity and mortality in kidney transplant recipients. Operative parameters, including hemodynamic manipulation through vasopressors and fluids can impact perfusion to the newly transplanted kidney and influence DGF incidence. We analyzed intraoperative time-series data in 5-minute intervals from kidney transplant recipient operations (n=545) in conjunction with pre-transplant characteristics and post-surgical outcomes, including DGF incidence, 60-day creatinine, and graft survival. 127 DGF events were captured in our cohort from a single academic transplant center (57/278 DBDs, 65/150 DCDs, 5/117 live donors). In multiple regression, post-anastomosis hypotension defined as MAP < 75 mmHg was a risk factor for DGF independent of conventional predictors of DGF, in DCD and DBD kidneys. DCD recipients with DGF had lower average post-anastomosis MAP (DGF: 80.1±8.1 mmHg vs. no DGF: 76.4±6.7 mmHg, p=0.004). Interaction analysis demonstrated above-average doses of vasopressors and crystalloids were associated with improved outcomes when used at MAPs of 75 mmHg or lower, but associated with increased DGF at MAPs above 75 mmHg, suggesting that that incidence of DGF can be highly influenced by intraoperative hemodynamic controls. This analysis of surgical time-courses has identified potential new strategies for goal-directed anesthesia in renal transplantation. [193/200 words].

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.

Perioperative trajectory of plasma viscosity: a prospective, observational, exploratory study in cardiac surgery

OBJECTIVE

Plasma viscosity is one of the critical factors that regulate microcirculatory flow but has received scant research attention. The main objective of this study was to evaluate plasma viscosity in cardiac surgery with respect to perioperative trajectory, main determinants and impact on outcome.

METHODS

Prospective, single center, observational study, including 50 adult patients undergoing cardiac surgery with cardiopulmonary bypass between 1 February 2020 - 31 May 2021. Clinical perioperative characteristics, short term outcome, standard blood analysis, plasma viscosity, total proteins and fibrinogen concentrations were recorded at ten distinct time points during the first perioperative week.

RESULTS

The longitudinal analysis showed that plasma viscosity is strongly influenced by proteins and measurement time points. Plasma viscosity showed a coefficient of variation of 11.3 +/- 1.08 for EDTA and 12.1 +/-2.1 for citrate, similarly to total proteins and hemoglobin, but significantly lower than fibrinogen (p<0.001). Plasma viscosity had lower percentage changes compared to hemoglobin (RANOVA, p<0.001), fibrinogen (RANOVA, p<0.001), and total proteins (RANOVA, p<0.001). The main determinant of plasma viscosity was protein concentrations. No association with outcome was found, but the study may have been underpowered to detect it.

CONCLUSION

Plasma viscosity had a low coefficient of variation and low perioperative changes, suggesting tight regulation. Studies linking plasma viscosity with outcome would require large patient cohorts.

Individualized Hemodynamic Management in Sepsis

Hemodynamic optimization remains the cornerstone of resuscitation in the treatment of sepsis and septic shock. Delay or inadequate management will inevitably lead to hypoperfusion, tissue hypoxia or edema, and fluid overload, leading eventually to multiple organ failure, seriously affecting outcomes. According to a large international survey (FENICE study), physicians frequently use inadequate indices to guide fluid management in intensive care units. Goal-directed and "restrictive" infusion strategies have been recommended by guidelines over "liberal" approaches for several years. Unfortunately, these "fixed regimen" treatment protocols neglect the patient's individual needs, and what is shown to be beneficial for a given population may not be so for the individual patient. However, applying multimodal, contextualized, and personalized management could potentially overcome this problem. The aim of this review was to give an insight into the pathophysiological rationale and clinical application of this relatively new approach in the hemodynamic management of septic patients.

Initial Fluid Resuscitation Following Adjusted Body Weight Dosing in Sepsis and Septic Shock

INTRODUCTION

Fluid administration is considered a fundamental part of early sepsis treatment. Despite abundant research, fundamental questions about the amount of fluids to be given remain unanswered. Recently, the idea of adjusting the fluid load to the ideal body weight emerged, as obesity rates are increasing, and fluid overload was proven to increase mortality.

AIM OF THE STUDY

The study aimed to determine whether advanced haemodynamic monitoring supports the adjustment of the initial fluid load to the ideal body weight (IBW).

METHODS

Seventy-one patients with sepsis and septic shock were enrolled in the study. The initial fluid resuscitation was performed using local protocols. The haemodynamic status was assessed after the initial fluid load by transpulmonary thermos-dilution technique and the renal outcome recorded at twenty-four hours.

RESULTS

68.6% of the patients included in the study had weight disorders ranging from BMI+20% to morbid obesity. Before IBW adjustment, only 49.3% received the 30 ml/kg fluid load recommended by Surviving Sepsis Campaign Guidelines (2016) (SSC). After IBW adjustment, 70.4% received the recommended fluid dose. The difference in fluid load/kg before and after the bodyweight adjustment was statistically significant (p<0.01). After the initial fluid load, the majority of the macro haemodynamic parameters were in the targeted range. There was no statistically significant difference between the urinary output outcome at 24 hours or the 28 days mortality rates between the patients resuscitated by the SSC and those who received less fluid.

CONCLUSIONS

Advanced haemodynamic monitoring was in favour of adjusting the initial fluid load to the IBW. There were no statistically significant differences either in the urinary output outcome at twenty-four hours, or in the twenty-eight-day mortality rates between the patients who received the 30 ml/kg IBW and those who received less than 30 ml/kg IBW.

Perioperative goal-directed therapy - What is the evidence?

Perioperative goal-directed therapy aims at optimizing global hemodynamics during the perioperative period by titrating fluids, vasopressors, and/or inotropes to predefined hemodynamic goals. There is evidence on the benefit of perioperative goal-directed therapy, but its adoption into clinical practice is slow and incomprehensive. Current evidence indicates that treating patients according to perioperative goal-directed therapy protocols reduces morbidity and mortality, particularly in patients having high-risk surgery. Perioperative goal-directed therapy protocols need to be started early, should include vasoactive agents in addition to fluids, and should target blood flow related variables. Future promising developments in the field of perioperative goal-directed therapy include personalized hemodynamic management and closed-loop system management.

Hemodynamic early goal-directed therapy: Explaining the fine print

The management of patients after cardiothoracic surgery can be very complex. Variabilities exist in hemodynamic status after cardiac surgery and the use of cardiopulmonary bypass – all of which can have a significant impact on myocardial Frank–Starling curves. Typically, invasive monitoring with pulmonary artery catheters is used to assess the complex physiology that these patients experience in the perioperative setting. However, the use of invasive monitoring is not without risk, and the broader benefits are poorly defined. Furthermore, there is growing evidence to support the use of hemodynamic early goal-directed therapy to optimize outcomes in critically ill patients. The purpose of this editorial statement is the review of some of the current literature with regards to the utility of goal-directed therapy as applied to the postoperative cardiac surgical patient.

Perioperative goal-directed therapy: A systematic review without meta-analysis

BACKGROUND

Perioperative goal-directed therapy aims to optimise haemodynamics by titrating fluids, vasopressors and/or inotropes to predefined haemodynamic targets. Perioperative goal-directed therapy is a complex intervention composed of several independent component interventions. Trials on perioperative goal-directed therapy show conflicting results. We aimed to conduct a systematic review and meta-analysis to investigate the benefits and harms of perioperative goal-directed therapy.

METHODS

PubMED, EMBASE, Web of Science and Cochrane Library were searched. Trials were included if they had a perioperative goal-directed therapy protocol. The primary outcome was all-cause mortality. The first secondary outcome was serious adverse events excluding mortality. Risk of bias was assessed, and GRADE was used to evaluate quality of evidence.

RESULTS

One hundred and twelve randomised trials were included of which one trial (1%) had low risk of bias. Included trials varied in patients: types of surgery which was expected due to inclusion criteria; in intervention and comparison: timing of intervention, monitoring devices, haemodynamic variables, target values, use of fluids, vasopressors and/or inotropes as well as combinations of these within protocols; and in outcome: mortality was reported in 87 trials (78%). Due to substantial clinical heterogeneity also within the various types of surgery a meta-analysis of data, including subgroup analyses, as defined in our protocol was considered inappropriate.

CONCLUSION

Clinical heterogeneity in patients, interventions and outcomes in perioperative goal-directed therapy trials is too large to perform meta-analysis on all trials. Future trials and meta-analyses highly depend on universally agreed definitions on aspects beyond type of surgery of the complex intervention and its evaluation.