Peri-operative goal-directed therapy: A definitive answer remains elusive

Perioperative Neurological Evaluation and Management to Lower the Risk of Acute Stroke in Patients Undergoing Noncardiac, Nonneurological Surgery: A Scientific Statement From the American Heart Association/American Stroke Association

Perioperative stroke is a potentially devastating complication in patients undergoing noncardiac, nonneurological surgery. This scientific statement summarizes established risk factors for perioperative stroke, preoperative and intraoperative strategies to mitigate the risk of stroke, suggestions for postoperative assessments, and treatment approaches for minimizing permanent neurological dysfunction in patients who experience a perioperative stroke. The first section focuses on preoperative optimization, including the role of preoperative carotid revascularization in patients with high-grade carotid stenosis and delaying surgery in patients with recent strokes. The second section reviews intraoperative strategies to reduce the risk of stroke, focusing on blood pressure control, perioperative goal-directed therapy, blood transfusion, and anesthetic technique. Finally, this statement presents strategies for the evaluation and treatment of patients with suspected postoperative strokes and, in particular, highlights the value of rapid recognition of strokes and the early use of intravenous thrombolysis and mechanical embolectomy in appropriate patients.

Personalised haemodynamic management targeting baseline cardiac index in high-risk patients undergoing major abdominal surgery: a randomised single-centre clinical trial

BACKGROUND

Despite several clinical trials on haemodynamic therapy, the optimal intraoperative haemodynamic management for high-risk patients undergoing major abdominal surgery remains unclear. We tested the hypothesis that personalised haemodynamic management targeting each individual's baseline cardiac index at rest reduces postoperative morbidity.

METHODS

In this single-centre trial, 188 high-risk patients undergoing major abdominal surgery were randomised to either routine management or personalised haemodynamic management requiring clinicians to maintain personal baseline cardiac index (determined at rest preoperatively) using an algorithm that guided intraoperative i.v. fluid and/or dobutamine administration. The primary outcome was a composite of major complications (European Perioperative Clinical Outcome definitions) or death within 30 days of surgery. Secondary outcomes included postoperative morbidity (assessed by a postoperative morbidity survey), hospital length of stay, mortality within 90 days of surgery, and neurocognitive function assessed after postoperative Day 3.

RESULTS

The primary outcome occurred in 29.8% (28/94) of patients in the personalised management group, compared with 55.3% (52/94) of patients in the routine management group (relative risk: 0.54, 95% confidence interval [CI]: 0.38 to 0.77; absolute risk reduction: -25.5%, 95% CI: -39.2% to -11.9%; P<0.001). One patient assigned to the personalised management group, compared with five assigned to the routine management group, died within 30 days after surgery (P=0.097). There were no clinically relevant differences between the two groups for secondary outcomes.

CONCLUSIONS

In high-risk patients undergoing major abdominal surgery, personalised haemodynamic management reduces a composite outcome of major postoperative complications or death within 30 days after surgery compared with routine care.

CLINICAL TRIAL REGISTRATION

NCT02834377.

Continuous Noninvasive Hemoglobin Monitoring Reflects the Development of Acute Hemodilution After Consecutive Fluid Challenges

BACKGROUND

Consecutive fluid challenges (FCs) are frequently administered to maximize the stroke volume (SV) as part of a goal-directed therapy (GDT) strategy. However, fluid administration may also cause acute hemodilution that might lead to an actual paradoxical decrease in oxygen delivery (DO2). The aim of this study was to examine whether continuous noninvasive hemoglobin (SpHb) monitoring can be used to detect the development of acute hemodilution after graded fluid administration.

METHODS

In 40 patients who underwent major vascular or gastrointestinal surgery, an FC, consisting of 250 mL colloid solution, was administered. When the SV increased by ≥10%, the FC was repeated up to a maximum of 3 times. Laboratory-measured hemoglobin concentrations (BHb), SpHb, SV, cardiac output (CO), and DO2 values were recorded after each FC.

RESULTS

All 40 patients received the first FC, 32 patients received the second FC, and 20 patients received the third FC (total of 750 mL). Out of the 92 administered FCs, only 55 (60%) caused an increase in SV ≥10% ("responders"). The first and the second FCs were associated with a significant increase in the mean CO and DO2, while the mean SpHb and BHb decreased significantly. However, the third and last FC was associated with no statistical difference in CO and SV, a further significant decrease in mean SpHb and BHb, and a significant decrease in DO2 in these patients. Compared to their baseline values (T0), BHb and SpHb decreased by a mean of 5.3% ± 4.9% and 4.4% ± 5.2%, respectively, after the first FC (T1; n = 40), by 9.7% ± 8.4% and 7.9% ± 6.9% after the second FC (T2; n = 32), and by 14.5% ± 6.2% and 14.6% ± 5.7% after the third FC (T3; n = 20). Concordance rates between the changes in SpHb and in BHb after the administration of 250, 500, and 750 mL colloids were 83%, 90%, and 100%, respectively.

CONCLUSIONS

Fluid loading aimed at increasing the SV and the DO2 as part of GDT strategy is associated with acute significant decreases in both BHb and SpHb concentrations. When the administration of an FC is not followed by a significant increase (≥10%) in the SV, the DO2 decreases significantly due to the development of acute hemodilution. Continuous noninvasive monitoring of SpHb does not reflect accurately absolute BHb values, but may be reliably used to detect the development of acute hemodilution especially after the administration of at least 500 mL of colloids.

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.