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

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

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

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

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

BACKGROUND

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

OBJECTIVE

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

METHODS AND RESULTS

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

CONCLUSION

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

Impact of perioperative hemodynamic optimization therapies in surgical patients: economic study and meta-analysis

Background

Several studies suggest that hemodynamic optimization therapies can reduce complications, the length of hospital stay and costs. However, Brazilian data are scarce. Therefore, the objective of this analysis was to evaluate whether the improvement demonstrated by hemodynamic optimization therapy in surgical patients could result in lower costs from the perspective of the Brazilian public unified health system.

Methods

A meta-analysis was performed comparing surgical patients who underwent hemodynamic optimization therapy (intervention) with patients who underwent standard therapy (control) in terms of complications and hospital costs. The cost-effectiveness analysis evaluated the clinical and financial benefits of hemodynamic optimization protocols for surgical patients. The analysis considered the clinical outcomes of randomized studies published in the last 20 years that involved surgeries and hemodynamic optimization therapy. Indirect costs (equipment depreciation, estate and management activities) were not included in the analysis.

Results

A total of 21 clinical trials with a total of 4872 surgical patients were selected. Comparison of the intervention and control groups showed lower rates of infectious (RR = 0.66; 95% CI = 0.58–0.74), renal (RR = 0.68; 95% CI = 0.54–0.87), and cardiovascular (RR = 0.87; 95% CI = 0.76–0.99) complications and a nonstatistically significant lower rate of respiratory complications (RR = 0.82; 95% CI = 0.67–1.02). There was no difference in mortality (RR = 1.02; 95% CI = 0.80–1.3) between groups. In the analysis of total costs, the intervention group showed a cost reduction of R$396,024.83-BRL ($90,161.38-USD) for every 1000 patients treated compared to the control group. The patients in the intervention group showed greater effectiveness, with 1.0 fewer days in the intensive care unit and hospital. In addition, there were 333 fewer patients with complications, with a consequent reduction of R$1,630,341.47-BRL ($371,173.27-USD) for every 1000 patients treated.

Conclusions

Hemodynamic optimization therapy is cost-effective and would increase the efficiency of and decrease the burden of the Brazilian public health system.

Individualized, perioperative, hemodynamic goal-directed therapy in major abdominal surgery (iPEGASUS trial): study protocol for a randomized controlled trial

Background

Postoperative morbidity and mortality in patients undergoing surgery is high, especially in patients who are at risk of complications and undergoing major surgery. We hypothesize that perioperative, algorithm-driven, hemodynamic therapy based on individualized fluid status and cardiac output optimization is able to reduce mortality and postoperative moderate and severe complications as a major determinant of the patients’ postoperative quality of life, as well as health care costs.

Methods/design

This is a multi-center, international, prospective, randomized trial in 380 patients undergoing major abdominal surgery including visceral, urological, and gynecological operations. Eligible patients will be randomly allocated to two treatment arms within the participating centers. Patients of the intervention group will be treated perioperatively following a specific hemodynamic therapy algorithm based on pulse-pressure variation (PPV) and individualized optimization of cardiac output assessed by pulse-contour analysis (ProAQT© device; Pulsion Medical Systems, Feldkirchen, Germany). Patients in the control group will be treated according to standard local care based on established basic hemodynamic treatment. The primary endpoint is a composite comprising the occurrence of moderate or severe postoperative complications or death within 28 days post surgery. Secondary endpoints are: (1) the number of moderate and severe postoperative complications in total, per patient and for each individual complication; (2) the occurrence of at least one of these complications on days 1, 3, 5, 7, and 28 in total and for every complication; (3) the days alive and free of mechanical ventilation, vasopressor therapy and renal replacement therapy, length of intensive care unit, and hospital stay at day 7 and day 28; and (4) mortality and quality of life, assessed by the EQ-5D-5L™ questionnaire, after 6 months.

Discussion

This is a large, international randomized controlled study evaluating the effect of perioperative, individualized, algorithm-driven ,hemodynamic optimization on postoperative morbidity and mortality.

Trial registration

Trial registration: NCT03021525. Registered on 12 January 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2620-9) contains supplementary material, which is available to authorized users.

Hemodynamic comparison of different multisites and multipoint pacing strategies in cardiac resynchronization therapies

PURPOSE

In order to increase the responder rate to CRT, stimulation of the left ventricular (LV) from multiple sites has been suggested as a promising alternative to standard biventricular pacing (BIV). The aim of the study was to compare, in a group of candidates for CRT, the effects of different pacing configurations-BIV, triple ventricular (TRIV) by means of two LV leads, multipoint (MPP), and multipoint plus a second LV lead (MPP + TRIV) pacing-on both hemodynamics and QRS duration.

METHODS

Fifteen patients (13 male) with permanent AF (mean age 76 ± 7 years; left ventricular ejection fraction 33 ± 7%; 7 with ischemic cardiomyopathy; mean QRS duration 178 ± 25 ms) were selected as candidates for CRT. Two LV leads were positioned in two different branches of the coronary sinus. Acute hemodynamic response was evaluated by means of a RADI pressure wire as the variation in LVdp/dtmax.

RESULTS

Per patient, 2.7 ± 0.7 veins and 5.2 ± 1.9 pacing sites were evaluated. From baseline values of 998 ± 186 mmHg/s, BIV, TRIV, MPP, and MPP-TRIV pacing increased LVdp/dtmax to 1200 ± 281 mmHg/s, 1226 ± 284 mmHg/s, 1274 ± 303 mmHg, and 1289 ± 298 mmHg, respectively (p < 0.001). Bonferroni post-hoc analysis showed significantly higher values during all pacing configurations in comparison with the baseline; moreover, higher values were recorded during MPP and MPP + TRIV than at the baseline or during BIV and also during MPP + TRIV than during TRIV. Mean QRS width decreased from 178 ± 25 ms at the baseline to 171 ± 21, 167 ± 20, 168 ± 20, and 164 ± 15 ms, during BIV, TRIV, MPP, and MPP-TRIV, respectively (p < 0.001).

CONCLUSIONS

In patients with AF, the acute response to CRT improves as the size of the early activated LV region increases.

Cost analysis of the stroke volume variation guided perioperative hemodynamic optimization - an economic evaluation of the SVVOPT trial results

Background

Perioperative goal directed therapy (GDT) can substantially improve the outcomes of high risk surgical patients as shown by many clinical studies. However, the approach needs initial investment and can increase the already very high staff workload. These economic imperatives may be at least partly responsible for weak adherence to the GDT concept. A few models are available for the evaluation of GDT cost-effectiveness, but studies of real economic data based on a recent clinical trial are lacking. In order to address this we have performed a retrospective analysis of the data from the “Intraoperative fluid optimization using stroke volume variation in high risk surgical patients” trial (ISRCTN95085011).

Methods

The health-care payers perspective was used in order to evaluate the perioperative hemodynamic optimization costs. Hospital invoices from all patients included in the trial were extracted. A direct comparison between the study (GDT, N = 60) and control (N = 60) groups was performed. A cost tree was constructed and major cost drivers evaluated.

Results

The trial showed a significant improvement in clinical outcomes for GDT treated patients. The mean cost per patient were lower in the GDT group 2877 ± 2336€ vs. 3371 ± 3238€ in controls, but without reaching a statistical significance (p = 0.596). The mean cost of all items except for intraoperative monitoring and infusions were lower for GDT than control but due to the high variability they all failed to reach statistical significance. Those costs associated with clinical care (68 ± 177€ vs. 212 ± 593€; p = 0.023) and ward stay costs (213 ± 108€ vs. 349 ± 467€; p = 0.082) were the most important differences in favour of the GDT group.

Conclusions

Intraoperative fluid optimization with the use of stroke volume variation and Vigileo/FloTrac system showed not only a substantial improvement of morbidity, but was associated with an economic benefit. The cost-savings observed in the overall costs of postoperative care trend to offset the investment needed to run the GDT strategy and intraoperative monitoring.

Trial registration

ISRCTN95085011

[Perioperative acute kidney injury and failure]

Perioperative period is very likely to lead to acute renal failure because of anesthesia (general or perimedullary) and/or surgery which can cause acute kidney injury. Characterization of acute renal failure is based on serum creatinine level which is imprecise during and following surgery. Studies are based on various definitions of acute renal failure with different thresholds which skewed their comparisons. The RIFLE classification (risk, injury, failure, loss, end stage kidney disease) allows clinicians to distinguish in a similar manner between different stages of acute kidney injury rather than using a unique definition of acute renal failure. Acute renal failure during the perioperative period can mainly be explained by iatrogenic, hemodynamic or surgical causes and can result in an increased morbi-mortality. Prevention of this complication requires hemodynamic optimization (venous return, cardiac output, vascular resistance), discontinuation of nephrotoxic drugs but also knowledge of the different steps of the surgery to avoid further degradation of renal perfusion. Diuretics do not prevent acute renal failure and may even push it forward especially during the perioperative period when venous retourn is already reduced. Edema or weight gain following surgery are not correlated with the vascular compartment volume, much less with renal perfusion. Treatment of perioperative acute renal failure is similar to other acute renal failure. Renal replacement therapy must be mastered to prevent any additional risk of hemodynamic instability or hydro-electrolytic imbalance.

Comparison of different invasive hemodynamic methods for AV delay optimization in patients with cardiac resynchronization therapy: implications for clinical trial design and clinical practice

Background

Reproducibility and hemodynamic efficacy of optimization of AV delay (AVD) of cardiac resynchronization therapy (CRT) using invasive LV dp/dt_max are unknown.

Method and results

25 patients underwent AV delay (AVD) optimisation twice, using continuous left ventricular (LV) dp/dt_max, systolic blood pressure (SBP) and pulse pressure (PP). We compared 4 protocols for comparing dp/dt_max between AV delays:

Immediate absolute: mean of 10 s recording of dp/dt_max acquired immediately after programming the tested AVD,

Delayed absolute: mean of 10 s recording acquired 30 s after programming AVD,

Single relative: relative difference between reference AVD and the tested AVD,

Multiple relative: averaged difference, from multiple alternations between reference and tested AVD.

We assessed for dp/dt_max, LVSBP and LVPP, test–retest reproducibility of the optimum.

Optimization using immediate absolute dp/dt_max had poor reproducibility (SDD of replicate optima = 41 ms; R² = 0.45) as did delayed absolute (SDD 39 ms; R² = 0.50). Multiple relative had better reproducibility: SDD 23 ms, R² = 0.76, and (p < 0.01 by F test).

Compared with AAI pacing, the hemodynamic increment from CRT, with the nominal AV delay was LVSBP 2% and LVdp/dt_max 5%, while CRT with pre-determined optimal AVD gave 6% and 9% respectively.

Conclusions

Because of inevitable background fluctuations, optimization by absolute dp/dt_max has poor same-day reproducibility, unsuitable for clinical or research purposes. Reproducibility is improved by comparing to a reference AVD and making multiple consecutive measurements. More than 6 measurements would be required for even more precise optimization — and might be advisable for future study designs. With optimal AVD, instead of nominal, the hemodynamic increment of CRT is approximately doubled.

Preoperative levosimendan decreases mortality and the development of low cardiac output in high-risk patients with severe left ventricular dysfunction undergoing coronary artery bypass grafting with cardiopulmonary bypass

BACKGROUND

The calcium sensitizer levosimendan has been used in cardiac surgery for the treatment of postoperative low cardiac output syndrome (LCOS) and difficult weaning from cardiopulmonary bypass (CPB).

OBJECTIVES

To evaluate the effects of preoperative treatment with levosimendan on 30-day mortality, the risk of developing LCOS and the requirement for inotropes, vasopressors and intra-aortic balloon pumps in patients with severe left ventricular dysfunction.

METHODS

Patient with severe left ventricular dysfunction and an ejection fraction <25% undergoing coronary artery bypass grafting with CPB were admitted 24 h before surgery and were randomly assigned to receive levosimendan (loading dose 10 μg/kg followed by a 23 h continuous infusion of 0.1μg/kg/min) or a placebo.

RESULTS

From December 1, 2002 to June 1, 2008, a total of 252 patients were enrolled (127 in the levosimendan group and 125 in the control group). Individuals treated with levosimendan exhibited a lower incidence of complicated weaning from CPB (2.4% versus 9.6%; P<0.05), decreased mortality (3.9% versus 12.8%; P<0.05) and a lower incidence of LCOS (7.1% versus 20.8%; P<0.05) compared with the control group. The levosimendan group also had a lower requirement for inotropes (7.9% versus 58.4%; P<0.05), vasopressors (14.2% versus 45.6%; P<0.05) and intra-aortic balloon pumps (6.3% versus 30.4%; P<0.05).

CONCLUSION

Patients with severe left ventricle dysfunction (ejection fraction <25%) undergoing coronary artery bypass grafting with CPB who were pretreated with levosimendan exhibited lower mortality, a decreased risk for developing LCOS and a reduced requirement for inotropes, vasopressors and intra-aortic balloon pumps. Studies with a larger number of patients are required to confirm whether these findings represent a new strategy to reduce the operative risk in this high-risk patient population.