The influence of deliberate hypotension on splanchnic perfusion balance with use of either isoflurane or esmolol and nitroglycerin

[Effectiveness and safety of tranexamic acid combined with intraoperative controlled hypotension on reducing perioperative blood loss in primary total hip arthroplasty]

Objective

To evaluate the effectiveness and safety of tranexamic acid (TXA) combined with intraoperative controlled hypotension (ICH) for reducing perioperative blood loss in primary total hip arthroplasty (THA).

Methods

The clinical data of 832 patients with initial THA due to osteonecrosis of femoral head between January 2017 and July 2020 were retrospectively analyzed. All patients received TXA treatment, and 439 patients (hypotension group) received ICH treatment with an intraoperative mean arterial pressure (MAP) below 80 mm Hg (1 mm Hg=0.133 kPa) while 393 patients (normotension group) received standard general anesthesia with no special invention on blood pressure. There was no significant difference in age, gender, body mass index, American Society of Anesthesiologists (ASA) classification, basic arterial pressure, hip range of motion, internal diseases, preoperative hemoglobin (HB) and hematocrit (HCT), coagulation function, surgical approach, and TXA dosage between the two groups ( P>0.05). The perioperative blood loss and blood transfusion, anesthesia and operation time, hospitalization stay, postoperative range of motion, and complications were recorded and compared between the two groups. The patients were further divided into MAP<70 mm Hg group (group A), MAP 70-80 mm Hg group (group B), and normotension group (group C). The perioperative blood loss and postoperative complications were further analyzed to screen the best range of blood pressure.

Results

The intraoperative MAP, total blood loss, dominant blood loss, recessive blood loss, blood transfusion rate and blood transfusion volume, anesthesia time, operation time, and hospitalizarion stay in the hypotension group were significantly lower than those in the normotension group ( P<0.05). The postoperative hip flexion range of motion in the hypotension group was significantly better than that of the normotension group ( Z=2.743, P=0.006), but there was no significant difference in the abduction range of motion between the two groups ( Z=0.338, P=0.735). In terms of postoperative complications, the incidence of postoperative hypotension in the hypotension group was significantly higher than that in the normotension group ( χ ²=6.096, P=0.014), and there was no significant difference in the incidence of other complications ( P>0.05). There was no stroke, pulmonary embolism, or deep vein thrombosis in the two groups, and no patients died during hospitalization. Subgroup analysis showed that there was no significant difference in total blood loss, dominant blood loss, and recessive blood loss in groups A and B during the perioperative period ( P>0.05), which were significantly lower than those in group C ( P<0.05). There was no significant difference in blood transfusion rate, blood transfusion volume, and incidence of acute myocardial injury between 3 groups ( P>0.05); the incidence of acute kidney injury in group A was significantly higher than that in group B, and the incidence of postoperative hypotension in group A was significantly higher than that in groups B and C ( P<0.05), but no significant difference was found between groups B and C ( P>0.05).

Conclusion

The combination of TXA and ICH has a synergistic effect. Controlling the intraoperative MAP at 70-80 mm Hg can effectively reduce the perioperative blood loss during the initial THA, and it is not accompanied by postoperative complications.

Premedication for Induced Hypotension in Functional Endoscopic Sinus Surgeries: Intravenous Dexmedetomidine Infusion vs Oral Metoprolol vs Placebo: A Comparative Study

Background:

Controlled hypotension has been used to reduce bleeding and the need for blood transfusions and provide a satisfactory bloodless surgical field. In this double-blind, randomized controlled trial, we are comparing intravenous (i.v.) dexmedetomidine infusion and oral metoprolol as a premedication for controlled hypotension in functional endoscopic sinus surgery (FESS) for evaluating surgical field visibility.

Subjects and Methods:

A total of 90 patients undergoing FESS were randomly divided into three groups of 30 each. Group A received intraoperative i.v. infusion of dexmedetomidine (loading 1 μg.kg⁻¹ over 10 min followed by the maintenance of 0.2–0.5 μg.kg⁻¹.h⁻¹), Group B received oral metoprolol 50 mg on night and 2 h before surgery as a premedication, and Group C was taken as a control group and patients received oral placebo tablet as premedication and intraoperative normal saline infusion. General anesthesia was given using sevoflurane. Intraoperative target mean arterial blood pressure was set 55–65 mmHg. Various parameters were recorded and statistically compared.

Results:

The three groups were statistically comparable in demographics. Quality of surgical field was better in Group A compared to other two groups. Total blood loss was also less in Group A. The incidence of adverse reactions was more in Group A.

Conclusion:

Dexmedetomidine provides a better surgical field compared to oral metoprolol in FESS along with the desired hemodynamics with lesser blood loss and better outcome.

The effect of low central venous pressure on hepatic surgical field bleeding and serum lactate in patients undergoing partial hepatectomy: a prospective randomized controlled trial

Background

This prospective randomized controlled study was designed to evaluate the effect of fluid restriction alone versus fluid restriction + low central venous pressure (CVP) on hepatic surgical field bleeding, intraoperative blood loss, and the serum lactate concentration in patients undergoing partial hepatectomy.

Methods

One hundred forty patients undergoing partial hepatectomy with intraoperative portal triad clamping were randomized into a fluid restriction group (Group F) or fluid restriction + low CVP group (Group L). Both groups received limited fluid infusion before the liver lesions were removed. Ephedrine was administered if the systolic blood pressure (SBP) decreased to <90 mmHg for 1 min. When the urine output was <20 ml/h or the SBP was <90 mmHg for 1 min more than three times, an additional 200 ml of crystalline solution was quickly infused within 10 min. In addition to fluid restriction, patients in Group L received continuous nitroglycerin and esmolol infusion to maintain a low CVP. The duration of portal triad clamping, frequency of additional fluid infusion, frequency of ephedrine administration, intraoperative blood loss, extent of liver resection, and bleeding score of the hepatic surgical field were recorded. Arterial blood gas analysis was performed before anesthesia (T1), after liver dissection and immediately before liver resection (T2), 10 min after removal of the liver lesion (T3), and before the patient was discharged from the postanesthesia care unit (T4).

Results

Being in the fluid restriction Group (Group F) (odds ratio = 5.04) and cirrhosis (odds ratio = 3.28) were risk factors for hepatic surgical field bleeding. Factors contributing to intraoperative blood loss were the operation time, duration of portal triad clamping, and extent of resection. No significant between-group difference was observed for blood loss or blood transfusion. The serum lactate concentration peaked at T3 in both groups.

Conclusions

Maintaining a lower CVP during hepatectomy provides an optimal surgical field but has no significant effect on intraoperative blood loss. Moreover, lower CVP does not increase the serum lactate concentration.

Trial registration

“A comparative study of the effect fluid restriction and low CVP pressure on the oozing of blood in liver wounds and blood lactate in patients undergoing partial hepatectomy” was prospectively registered as a trial (registration number: ChiCTR-INR-17014172, date of registration: 27 December 2017).

The effect of magnesium sulfate on surgical field during endoscopic sinus surgery: A meta-analysis of randomized controlled trials

INTRODUCTION

The benefits of magnesium sulfate for surgical field during endoscopic sinus surgery remain controversial. We conduct a systematic review and meta-analysis to explore the influence of magnesium sulfate versus placebo on surgical field during endoscopic sinus surgery.

METHODS

We search PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases through November 2018 for randomized controlled trials (RCTs) assessing the effect of magnesium sulfate versus placebo on surgical field during endoscopic sinus surgery. This meta-analysis is performed using the random-effect model.

RESULTS

Four RCTs and 404 patients are included in the meta-analysis. Overall, compared with control group endoscopic sinus surgery, magnesium sulfate has remarkably positive impact on surgical field scores (MD = -1.76; 95% CI = -2.33 to -1.18; P < .00001), and intraoperative blood loss (MD = -89.09; 95% CI = -163.20 to -14.97; P = .02), but shows no markedly effect on surgery duration (MD = -7.08; 95% CI = -21.38 to 7.22; P = .33), fentanyl (MD = -0.64; 95% CI = -1.97 to 0.70; P = .35), and vecuronium (MD = -3.64; 95% CI = -10.99 to 3.70; P = .33).

CONCLUSIONS

Magnesium sulfate exerts positive impact on surgical field and blood loss reduction for endoscopic sinus surgery.

Comparison of esmolol to nitroglycerine in controlling hypotension during nasal surgery

OBJECTIVE

The aim of this study was to compare esmolol to nitroglycerine in terms of effectiveness in controlling hypotension during nasal surgery.

MATERIALS AND METHODS

After approval by our institutional Ethics Committee, 40 patients were recruited and randomized into two drug groups: esmolol (Group E) and nitroglycerine (Group N). In group E, a bolus dose of 500 μg/kg esmolol was administered over 30 sec followed by continuous administration at a dose of 25-300 μg/ kg/min to maintain systolic arterial pressure at 80 mmHg. In group N, nitroglycerine was administered at a dose of 0.5-2 μg/kg/min.

RESULTS

During the hypotensive period, systolic arterial pressure, diastolic arterial pressure, mean arterial pressure, and heart rate were decreased 24%, 33%, 27% and 35%, respectively, in group E (p<0.001, p<0.001, p<0.001, p<0.001) and were decreased 30%, 33%, 34% and 23%, respectively, in group N (p<0.001, p<0.001, p<0.001, p<0.001). The decrease in heart rate was higher in group E during the hypotensive period (p=0.048). During the recovery period, diastolic arterial pressure and heart rate were decreased 9% and 18%, respectively, in group E (p=0.044, p<0.001). Systolic arterial pressure, diastolic arterial pressure, and mean arterial pressure were decreased 7%, 3% and 7%, respectively, in group N (p=0.049, p=0.451, p=0.045).

CONCLUSION

Esmolol provides hemodynamic stability and good surgical field visibility and should be considered as an alternative to nitroglycerine.

The use of regional cerebral oximetry monitoring during controlled hypotension: a case series

Regional cerebral oximetry monitoring was used to guide nitroglycerin infusion and IV fluid administration during controlled hypotension in order to optimize each individual patient's mean arterial pressure in a series of 20 consecutive patients who underwent major open urological or abdominal surgery. Although controlled hypotension offers a definite benefit in patients undergoing complex surgery where blood loss will be elevated or would severely compromise the surgical field, it is not without risk as low arterial pressure may compromise tissue perfusion and promote ischemia. In this case series, despite an average mean arterial pressure decrease of 19.5 % (p < 0.001), cerebral oximetry values increased by an average of 22.7 % (p < 0.001) after the nitroglycerin infusion had been initiated (220 mcg/min average). Patients received an average of 3.15L crystalloid and 437 ml albumin in fluid resuscitation.

Effects of infusion of different fluids during controlled hypotension on gastric intramucosal pH and postoperative gastroenterological function

The present study was aimed to investigate the effects of infusion of different fluids combined with controlled hypotension on gastric intramucosal pH (pHi) and postoperative gastrointestinal function in patients undergoing hepatocarcinoma surgery. Forty-five patients (ASA II) scheduled for surgical resection of hepatocarcinoma undergoing controlled hypotension were randomly assigned to three groups and received infusion of 20 mL/kg Ringer's solution (R group), 6% HAES(H group) or 6% Voluven group (W group). Intragastric PgCO2, pHi, hematocrit and hemoglobin were measured. The significant decrease of pHi and increase of PgCO2 were produced at 1 and 2 h after controlled hypotension in the R group (P < 0.05 or P < 0.01). The time of bowel movement after operation was shorter in the W group than the R group. Meanwhile, we also did not find obvious difference in blood gas indexes among the three groups. The infusion of HAES and Voluven during controlled hypotension could improve gastrointestinal perfusion and accelerate the recovery of postoperative gastrointestinal function.

Induced hypotension with epidural/general anesthesia reduces transfusion in radical prostate surgery

PURPOSE

Radical prostatectomy is associated with substantial blood loss frequently requiring allogeneic blood transfusion. We investigated the efficacy of deliberate hypotension using combined epidural/general anesthesia in reducing allogeneic transfusion requirements in patients undergoing radical prostatectomy.

METHODS

In a prospective, randomized, single-blind trial, 102 patients undergoing radical prostatectomy were allocated to either an epidural group (n = 51) or a control group (n = 51). In the epidural group, deliberate hypotension was achieved with a target mean arterial pressure of 55-60 mmHg. The trigger for allogeneic blood transfusion in both groups was a hematocrit value < 0.25.

RESULTS

Operative blood loss in the epidural group was significantly less than that in the control group (955 +/- 517 mL vs 1477 +/- 823 mL respectively, P < 0.001). The percentage of patients who reached the threshold trigger for allogenic transfusion was significantly less in the epidural group (8% vs 26%, respectively, P = 0.019) and the number of patients who were actually transfused during hospitalization was also significantly less (P = 0.028). There were no serious adverse events in either group during the study.

CONCLUSION

Controlled hypotension using a combined epidural/ general anesthetic technique is associated with significantly less blood loss, and a reduction in the use of allogeneic blood in patients undergoing radical prostatectomy compared to general anesthesia alone.

Einsatz von Vasopressin und Terlipressin bei Sepsis und systemischen Entzündungsreaktionen

Vasopressin and terlipressin are increasingly used as alternative non-adrenergic vasopressors for hemodynamic support of septic patients with arterial hypotension. Despite excellent vasopressive effects, vasopressin analogues may potentially impair macro-hemodynamics, oxygen transport and microvascular blood flow. Due to those unwanted side-effects, vasopressin and terlipressin may potentially compromise organ function and possibly foster the development of multiple organ failure. This review article discusses the results of clinical and experimental studies to judge the effects of vasopressin and terlipressin on microcirculation, oxygen supply, metabolism and organ function in patients with sepsis or systemic inflammatory response syndrome (SIRS). Although vasopressin analogues are emerging as promising alternatives to treat catecholamine-refractory hypotension, there is no evidence that vasopressin receptor agonists improve outcome. To date, vasopressin and terlipressin can, therefore, not be recommended for routine clinical use.

Clinical review: splanchnic ischaemia

Inadequate splanchnic perfusion is associated with increased morbidity and mortality, particularly if liver dysfunction coexists. Heart failure, increased intra-abdominal pressure, haemodialysis and the presence of obstructive sleep apnoea are among the multiple clinical conditions that are associated with impaired splanchnic perfusion in critically ill patients. Total liver blood flow is believed to be relatively protected when gut blood flow decreases, because hepatic arterial flow increases when portal venous flow decreases (the hepatic arterial buffer response [HABR]). However, there is evidence that the HABR is diminished or even abolished during endotoxaemia and when gut blood flow becomes very low. Unfortunately, no drugs are yet available that increase total hepato-splanchnic blood flow selectively and to a clinically relevant extent. The present review discusses old and new concepts of splanchnic vasoregulation from both experimental and clinical viewpoints. Recently published trials in this field are discussed.