Hydroxyethyl starch for perioperative goal-directed fluid therapy in 2020: a narrative review

Prophylactic norepinephrine combined with 6% hydroxyethyl starch (130/0.4) co-load infusion for preventing postspinal anesthesia hypotension during cesarean section: a randomized, controlled, dose-finding trial

PURPOSE

Colloid and/or co-load may be more effective than crystalloid for preventing postspinal anesthesia hypotension. We tested five different prophylactic norepinephrine dosages combined with colloid co-load infusion in patients receiving cesarean section and spinal anesthesia.

METHODS

Patients were randomly allocated to receive different prophylactic norepinephrine dosages (0 [NE 0 group], 0.025 [NE 25 group], 0.05 [NE 50 group], 0.075 [NE 75 group], or 0.1 [NE 100 group] µg/kg/min) combined with 500 mL 6% hydroxyethyl starch (130/0.4) immediately following spinal anesthesia (n = 35 per group). The primary endpoint was the incidence of postspinal anesthesia hypotension (systolic blood pressure [SBP] < 80% of baseline). Secondary endpoints included severe hypotension, bradycardia, nausea or vomiting, hypertension, SBP stability control versus baseline, the 50% (effective dose, ED50) and 90% (ED90) dose effective for preventing postspinal anesthesia hypotension, Apgar scores, and umbilical cord blood gases.

RESULTS

The incidence of postspinal anesthesia hypotension was 48.6%, 31.3%, 17.1%, 14.3%, and 5.7% in the respective groups. As the prophylactic norepinephrine dosage increased, the incidence of postspinal anesthesia hypotension declined (p < 0.001), and SBP remained stable relative to baseline (median performance error [MDPE], p < 0.001; median absolute performance error [MDAPE], p = 0.001). The ED50 and ED90 values were -0.006 (95% CI -0.046-0.013) and 0.081 (95% CI 0.063-0.119) µg/kg/min. Other endpoints were comparable across the groups.

CONCLUSION

An initial prophylactic norepinephrine dosage of 0.05 µg/kg/min combined with 500 mL 6% hydroxyethyl starch (130/0.4) co-load infusion was optimal for preventing postspinal anesthesia hypotension during cesarean section.

TRIAL REGISTRATION

NCT05133817, registration date: 12 Nov, 2021.

Perioperative Fluid and Vasopressor Therapy in 2050: From Experimental Medicine to Personalization Through Automation

Intravenous (IV) fluids and vasopressor agents are key components of hemodynamic management. Since their introduction, their use in the perioperative setting has continued to evolve, and we are now on the brink of automated administration. IV fluid therapy was first described in Scotland during the 1832 cholera epidemic, when pioneers in medicine saved critically ill patients dying from hypovolemic shock. However, widespread use of IV fluids only began in the 20th century. Epinephrine was discovered and purified in the United States at the end of the 19th century, but its short half-life limited its implementation into patient care. Advances in venous access, including the introduction of the central venous catheter, and the ability to administer continuous infusions of fluids and vasopressors rather than just boluses, facilitated the use of fluids and adrenergic agents. With the advent of advanced hemodynamic monitoring, most notably the pulmonary artery catheter, the role of fluids and vasopressors in the maintenance of tissue oxygenation through adequate cardiac output and perfusion pressure became more clearly established, and hemodynamic goals could be established to better titrate fluid and vasopressor therapy. Less invasive hemodynamic monitoring techniques, using echography, pulse contour analysis, and heart-lung interactions, have facilitated hemodynamic monitoring at the bedside. Most recently, advances have been made in closed-loop fluid and vasopressor therapy, which apply computer assistance to interpret hemodynamic variables and therapy. Development and increased use of artificial intelligence will likely represent a major step toward fully automated hemodynamic management in the perioperative environment in the near future. In this narrative review, we discuss the key events in experimental medicine that have led to the current status of fluid and vasopressor therapies and describe the potential benefits that future automation has to offer.

Pediatric perioperative fluid management

The purpose of perioperative fluid management in children is to maintain adequate volume status, electrolyte level, and endocrine system homeostasis during the perioperative period. Although hypotonic solutions containing glucose have traditionally been used as pediatric maintenance fluids, recent studies have shown that isotonic balanced crystalloid solutions lower the risk of hyponatremia and metabolic acidosis perioperatively. Isotonic balanced solutions have been found to exhibit safer and more physiologically appropriate characteristics for perioperative fluid maintenance and replacement. Additionally, adding 1-2.5% glucose to the maintenance fluid can help prevent children from developing hypoglycemia as well as lipid mobilization, ketosis, and hyperglycemia. The fasting time should be as short as possible without compromising safety; recent guidelines have recommended that the duration of clear fluid fasting be reduced to 1 h. The ongoing loss of fluid and blood as well as the free water retention induced by antidiuretic hormone secretion are unique characteristics of postoperative fluid management that must be considered. Reducing the infusion rate of the isotonic balanced solution may be necessary to avoid dilutional hyponatremia during the postoperative period. In summary, perioperative fluid management in pediatric patients requires careful attention because of the limited reserve capacity in this population. Isotonic balanced solutions appear to be the safest and most beneficial choice for most pediatric patients, considering their physiology and safety concerns.

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.

Perioperative colloids: From theory to practice

INTRODUCTION

Fluid administration is the cornerstone in hypovolemic patient's reanimation. Clinical guidelines restrict colloid administration favouring crystalloids. Currently, we don't know exactly which is the daily clinical practice during the perioperative period. The objective of this study is to describe perioperative use of colloids analysing possible reasons aiming to use them.

MATERIAL AND METHODS

Prospective, cross-section, national, multicentre observational study. Fluid Day sub-study. We enrolled all patient's older than 18 years old who underwent surgery during the 24 h of the 2-days study (February, 2019, 18th and 20th). We registered demographic data, comorbidities, anaesthetic and surgical procedure data, fluids administered, perioperative bleeding and monitoring type used during the perioperative period.

RESULTS

A total of 5928 cases were analysed and 542 patients (9.1%) received any type of colloids, being hydroxiethyl-starch the most frequently used (5.1%). Patients receiving colloids suffered more longing surgery (150 [90-255] vs. 75 [45-120] min), were urgently operated (13.7 vs. 7.5%) and were more frequent classified as high risk (22 vs. 4.8%). Their recovery was mostly in critical care units (45.1 vs.15.8%). Patients with bleeding less than 500 ml received colloids in a percentage of 5.9 versus 45.9% when this figure was overcome. Patients who received colloids were anaemic more frequently: 29.4 vs. 16.3%. Colloids administration had a higher risk for transfusion (OR 15.7). Advanced monitoring also increased the risk for receiving colloids (OR 9.43).

CONCLUSIONS

In our environment with routine clinical practice, colloids administration is limited and close linked to perioperative bleeding.

Effects of Different Types of Early Restrictive Fluid Resuscitation on Immune Function and Multiorgan Damage on Hemorrhagic Shock Rat Model in a Hypothermic Environment

Objective

This study was aimed at investigating the effects of different types of fluid restriction fluid resuscitation on the immune dysfunction and organ injury of hemorrhagic shock rats under a hypothermic environment.

Methods

SD rats were divided into sham operation group (SHAM), hemorrhagic shock model group (HS), crystal liquid limited resuscitation group (CRLLR), colloidal liquid limited resuscitation group (COLLR), and nonlimited resuscitation group (NLR); rats in each group were placed in a low-temperature environment of 0-5°C for 30 min, and then, a hemorrhagic shock rat model was prepared. Sodium lactate Ringer's restricted resuscitation solution, hydroxyethyl starch restricted resuscitation solution, and hydroxyethyl starch were used for resuscitation, and hemodynamic examination was performed. The mortality rate, inflammatory factors, oxidative stress factors, and immune function were detected by ELISA. The dysfunction and injury of the intestinal, lung, liver, and kidney were examined by histological methods.

Results

Hemorrhagic shock resulted in decreased immune function and activation of inflammation. Unrestricted fluid infusion further activated the inflammatory response. The crystalloid-restricted fluid infusion performed effectively to regulate inflammatory response, promote antioxidative activity, and reduce the immunosuppressive reaction. Rehydration could regulate the coagulation. The hydroxyethyl starch reduced the expression of platelet glycoproteins Ib and IIb/IIIa and blocked the binding of fibrinogen to activated platelets, thereby inhibiting intrinsic coagulation and platelet adhesion and aggregation. Rats in the CRLLR group showed to relieve the injury of the lung, liver, kidney, and intestine from hemorrhagic shock in low-temperature environment.

Conclusion

The early application of restrictive crystalloid resuscitation in hemorrhagic shock rats in hypothermic environment showed the best therapy results. Early LR-restrictive fluid replacement promotes the balance of inflammatory response and the recovery of immunosuppressive state, resists oxidative stress, stabilizes the balance of coagulation and fibrinolysis, improves coagulation function, and relieves organ injury.

Closed-Loop Controlled Fluid Administration Systems: A Comprehensive Scoping Review

Physiological Closed-Loop Controlled systems continue to take a growing part in clinical practice, offering possibilities of providing more accurate, goal-directed care while reducing clinicians’ cognitive and task load. These systems also provide a standardized approach for the clinical management of the patient, leading to a reduction in care variability across multiple dimensions. For fluid management and administration, the advantages of closed-loop technology are clear, especially in conditions that require precise care to improve outcomes, such as peri-operative care, trauma, and acute burn care. Controller design varies from simplistic to complex designs, based on detailed physiological models and adaptive properties that account for inter-patient and intra-patient variability; their maturity level ranges from theoretical models tested in silico to commercially available, FDA-approved products. This comprehensive scoping review was conducted in order to assess the current technological landscape of this field, describe the systems currently available or under development, and suggest further advancements that may unfold in the coming years. Ten distinct systems were identified and discussed.

Protective Effect of Targeted Fluid Therapy on Patients with One-Lung Ventilation

Objective

To evaluate the protective effect of target-directed fluid therapy on the lungs and postoperative rehabilitation in elderly patients with single-lung ventilation undergoing total endoscopic radical resection of esophageal cancer.

Methods

Seventy elderly patients who underwent total endoscopic radical resection of esophageal cancer from January 2017 to December 2019 in our hospital were selected and divided into two groups by the random number table method: the goal-directed fluid treatment group (group G, n = 35) and the control group (group C, n = 35). Venous blood was extracted before surgery (T1), at the end of free esophagus (T2) by thoracoscopy, at the end of abdominal surgery (T3), and at the end of surgery (T4). IL-6 and IL-10 levels were detected by ELISA. The clinical pulmonary infection score (CIPS) was used to evaluate the pulmonary inflammation on the second day after surgery and the occurrence of complications. Duration of antibiotic use and length of hospital stay were recorded.

Results

At T1, there were no significant differences in IL-6 and IL-10 levels between the two groups (P > 0.05). At T2, the IL-6 level in group G increased to 26.65 ± 1.80 pg/ml but was significantly lower than that in group C (32.28 ± 3.22 pg/ml) (P < 0.01). At T3 and T4, IL-6 and IL-10 levels in group G were significantly lower than those in group C (P < 0.01). The CIPS score of group G was lower than that of group C (1.5 ± 1.0 vs 2.7 ± 1.4), and the duration of antibiotic use in group G was shorter than that in group C (211.2 ± 15.4 vs 232.6 ± 18.7 h), with statistical significance (P < 0.01). The incidence of complications in group G was lower than that in group C (28.6% vs 40.0%), and the length of hospital stay in group G was shorter than that in group C (10.5 ± 1.7 vs 11.2 ± 1.9 days), but there was no significant difference between the two groups (P > 0.05).

Conclusion

Target-directed fluid therapy inhibited inflammatory cytokine levels and had better lung protection, but no significant benefit in the complications or the length of hospital stay was observed.

Hydroxyl Ethyl Starch (HES) Preserves Intrarenal Microcirculatory Perfusion Shown by Contrast-Enhanced Ultrasound (Ceus), and Renal Function in a Severe Hemodilution Model in Pigs

ABSTRACT

Acute normovolemic hemodilution (ANH) is associated with low oxygen carrying capacity of blood and purposed to cause renal injury in perioperative setting. It is best accomplished in a perioperative setting by a colloid such as hydroxyl ethyl starch (HES) due its capacity to fill the vascular compartment and maintain colloidal pressure. However, alterations of intra renal microvascular perfusion, flow and its effects on renal function and damage during ANH has not been sufficiently clarified. Based on the extensive use of HES in the perioperative setting we tested the hypothesis that the use of HES during ANH is able to perfuse the kidney microcirculation adequately without causing renal dysfunction and injury in pigs. Hemodilution (n = 8) was performed by stepwise replacing blood with HES to hematocrit (Hct) levels of 20% (T1), 15% (T2), and 10% (T3). Seven control animals were investigated. Systemic and renal hemodynamics were monitored. Renal microcirculatory perfusion was visualized and quantified using contrast-enhanced ultrasound (CEUS) and laser speckle imaging (LSI). In addition, sublingual microcirculation was measured by handheld vital microscopy (HVM). Intrarenal mean transit time of ultrasound contrast agent (IRMTT-CEUS) was reduced in the renal cortex at Hct 10% in comparison to control at T3 (1.4 ± 0.6 vs. 2.2 ± 0.7 seconds, respectively, P < 0.05). Although renal function was preserved, the serum neutrophil gelatinase-associated lipocalin (NGAL) levels was higher at Hct 10% (0.033 ± 0.004 pg/μg protein) in comparison to control at T3 (0.021 ± 0.002 pg/μg protein. A mild correlation between CO and IRMTT (renal RBC velocity) (r -0.53; P = 0.001) and CO and NGAL levels (r 0.66; P = 0.001) was also found. Our results show that HES induced ANH is associated with a preserved intra renal blood volume, perfusion, and function in the clinical range of Hct (<15%). However, at severely low Hct (10%) ANH was associated with renal injury as indicated by increased NGAL levels. Changes in renal microcirculatory flow (CEUS and LSI) followed those seen in the sublingual microcirculation measured with HVM.

Neuroprotective effects of intraoperative dexmedetomidine versus saline infusion combined with goal-directed haemodynamic therapy for patients undergoing cranial surgery: A randomised controlled trial

BACKGROUND

By inhibiting neuroinflammation dexmedetomidine may be neuroprotective in patients undergoing cranial surgery, but it reduces cardiac output and cerebral blood flow.

OBJECTIVE

To investigate whether intra-operative dexmedetomidine combined with goal-directed haemodynamic therapy (GDHT) has neuroprotective effects in cranial surgery.

DESIGN

A double-blind, single-institution, randomised controlled trial.

SETTING

A single university hospital, from April 2017 to April 2020.

PATIENTS

A total of 160 adults undergoing elective cranial surgery.

INTERVENTION

Infusion of dexmedetomidine (0.5 μg kg-1 h-1) or saline combined with GDHT to optimise stroke volume during surgery.

MAIN OUTCOME MEASURES

The proportion who developed postoperative neurological complications was compared. Postoperative disability was assessed using the Barthel Index at time points between admission and discharge, and also the 30-day modified Rankin Scale (mRS). Postoperative delirium was assessed. The concentration of a peri-operative serum neuroinflammatory mediator, high-mobility group box 1 protein (HMGB1), was compared.

RESULTS

Fewer patients in the dexmedetomidine group developed new postoperative neurological complications (26.3% vs. 43.8%; P = 0.031), but the number of patients developing severe neurological complications was comparable between the two groups (11.3% vs. 20.0%; P = 0.191). In the dexmedetomidine group the Barthel Index reduction [0 (-10 to 0)] was less than that in the control group [-5 (-15 to 0)]; P = 0.023, and there was a more favourable 30-day mRS (P = 0.013) with more patients without postoperative delirium (84.6% vs. 64.2%; P = 0.012). Furthermore, dexmedetomidine induced a significant reduction in peri-operative serum HMGB1 level from the baseline (222.5 ± 408.3 pg ml-1) to the first postoperative day (152.2 ± 280.0 pg ml-1) P = 0.0033. There was no significant change in the control group. The dexmedetomidine group had a lower cardiac index than did the control group (3.0 ± 0.8 vs. 3.4 ± 1.8 l min-1 m-2; P = 0.0482) without lactate accumulation.

CONCLUSIONS

Dexmedetomidine infusion combined with GDHT may mitigate neuroinflammation without undesirable haemodynamic effects during cranial surgery and therefore be neuroprotective.

TRIAL REGISTRATION

Clinicaltrials.gov Identifier: NCT02878707.

Hydroxyethyl Starch Curcumin Enhances Antiproliferative Effect of Curcumin Against HepG2 Cells via Apoptosis and Autophagy Induction

It is well documented that curcumin (CUR), as a polyphenol molecule originated from turmeric, has many advantages such as antioxidative, anti-inflammatory, neuroprotective, and antitumor effects. However, because of its poor water solubility and low bioavailability, the biomedical applications of CUR are limited. So, in this study, we modified CUR with conjugation to a food-derived hydrophilic hydroxyethyl starch (HES) via an ester linkage to fabricate the amphiphilic conjugate HES-CUR prior to self-assembling into uniform nanoparticles (HES-CUR NPs). And, the results of the ¹H NMR spectra and FT-IR spectrum showed successful synthesis of HES-CUR NPs; moreover, the solubility and the drug loading efficiency of CUR were significantly increased. Next, we further explored the differences on the antitumor effects between HES-CUR NPs and CUR in HepG2 cells, and the results of the CCK8-assay and cell counting experiment showed that HES-CUR NPs exhibited a more significant antiproliferative effect than that of CUR in HepG2 cells. And HepG2 cells were more sensitive to apoptosis induced by HES-CUR NPs as evidenced by flow cytometry, increased cytochrome c level, and decreased full length caspase-3 and Bcl-2 protein expressions. Additionally, we found that the efficacy of HES-CUR NPs against HepG2 cells might be related to the enhanced degree of mitochondrial damage (decrease of the mitochondrial membrane potential and ATP) and autophagy (increased levels of Beclin-1 and LC3-II proteins). So, the findings in this study suggest that HES-CUR NPs have a great application potential in antitumor efficacy and play an important role in multiple signal pathways.

Restricted, optimized or liberal fluid strategy in thoracic surgery: A narrative review

Perioperative fluid balance has a major impact on clinical and functional outcome, regardless of the type of interventions. In thoracic surgery, patients are more vulnerable to intravenous fluid overload and to develop acute respiratory distress syndrome and other complications. New insight has been gained on the mechanisms causing pulmonary complications and the role of the endothelial glycocalix layer to control fluid transfer from the intravascular to the interstitial spaces and to promote tissue blood flow. With the implementation of standardized processes of care, the preoperative fasting period has become shorter, surgical approaches are less invasive and patients are allowed to resume oral intake shortly after surgery. Intraoperatively, body fluid homeostasis and adequate tissue oxygen delivery can be achieved using a normovolemic therapy targeting a “near-zero fluid balance” or a goal-directed hemodynamic therapy to maximize stroke volume and oxygen delivery according to the Franck–Starling relationship. In both fluid strategies, the use of cardiovascular drugs is advocated to counteract the anesthetic-induced vasorelaxation and maintain arterial pressure whereas fluid intake is limited to avoid cumulative fluid balance exceeding 1 liter and body weight gain (~1-1.5 kg). Modern hemodynamic monitors provide valuable physiological parameters to assess patient volume responsiveness and circulatory flow while guiding fluid administration and cardiovascular drug therapy. Given the lack of randomized clinical trials, controversial debate still surrounds the issues of the optimal fluid strategy and the type of fluids (crystalloids versus colloids). To avoid the risk of lung hydrostatic or inflammatory edema and to enhance the postoperative recovery process, fluid administration should be prescribed as any drug, adapted to the patient's requirement and the context of thoracic intervention.

Analysis on the application value of goal-directed fluid therapy in patients undergoing laparoscopy-assisted radical gastrectomy with fast-track anesthesia

OBJECTIVE

To explore the application value of goal-directed fluid therapy (GDFT) in patients undergoing laparoscopy-assisted radical gastrectomy with fast-track anesthesia.

METHODS

From December 2016 to December 2019, 74 patients who underwent laparoscopy-assisted radical gastrectomy under the concept of enhanced recovery after surgery (ERAS) in gastrointestinal Surgery department of Tongling People's Hospital were selected as research participants. They were divided into two groups: the routine group (patients were treated with conventional fluids) (n=37) and the GDFT group (patients were treated with GDFT) (n=37). In the two groups, patients were compared in terms of intraoperative fluid inflow and outflow, hemodynamic indexes before operation for 30 min (T0), after anesthesia induction for 30 min (T1), during operation for 0.5 h (T2) and 1.5 h (T3) and after operation (T4), postoperative complications, postoperative recovery, mini-mental state examination (MMSE) scores on the first day (d0) before operation and the first day (d1), the third day (d2) and the seventh day (d3) after operation, and inflammatory factor levels.

RESULTS

The amount of crystal input, colloid, blood loss, fluid replacement and urine volume in the GDFT group were significantly less than those in the routine group (P < 0.05). From T1 to T4, the values of mean arterial pressure (MAP) and central venous pressure (CVP) in the GDFT group were higher than those in the routine group (p < 0.05). The total incidence of postoperative complications in the GDFT group was lower than that in the routine group (P < 0.05). Compared with those in the routine group, the postoperative anus exhaust time, the first time of starting to eat, the time of leaving bed, the duration of stay in the postanesthesia care unit and the hospital stay were significantly shorter in the GDFT group (P < 0.05). From D1 to D3, the MMSE score in the GDFT group was higher than that in the routine group, while the levels of C-reactive protein (CPR), interleukin 6 (IL-6) and procalcitonin (PCT) were lower than those in the routine group (P < 0.05).

CONCLUSION

GDFT has a better effect on the rapid rehabilitation of patients undergoing laparoscopy-assisted radical gastrectomy during fast-track anesthesia, and it also has a positive effect on maintaining the stability of hemodynamics, reducing systemic inflammation and decreasing postoperative complications.