Effects of Catecholamines on Microcirculation During General Inhalation Anesthesia

Association Between Intraoperative Noradrenaline Infusion and Outcomes in Older Adult Patients Undergoing Major Non-Cardiac Surgeries: A Retrospective Propensity Score-Matched Cohort Study

Background

Noradrenaline (NA) is commonly used intraoperatively to prevent fluid overload and maintain hemodynamic stability. Clinical studies provided inconsistent results concerning the effect of NA on postoperative outcomes. As aging is accompanied with various diseases and has the high possibility of the risk for postoperative complications, we hypothesized that intraoperative NA infusion in older adult patients undergoing major non-cardiac surgeries might potentially exert adverse outcomes.

Methods

In this retrospective propensity score-matched cohort study, older adult patients undergoing major non-cardiac surgeries were selected, 1837 receiving NA infusion during surgery, and 1072 not receiving NA. The propensity score matching was conducted with a 1:1 ratio and 1072 patients were included in each group. The primary outcomes were postoperative in-hospital mortality and complications.

Results

Intraoperative NA administration reduced postoperative urinary tract infection (OR:0.124, 95% CI:0.016-0.995), and had no effect on other postoperative complications and mortality, it reduced intraoperative crystalloid infusion (OR:0.999, 95% CI:0.999-0.999), blood loss (OR: 0.998, 95% CI: 0.998-0.999), transfusion (OR:0.327, 95% CI: 0.218-0.490), but increased intraoperative lactate production (OR:1.354, 95% CI:1.051-1.744), and hospital stay (OR:1.019, 95% CI:1.008-1.029).

Conclusion

Intraoperative noradrenaline administration reduces postoperative urinary tract infection, and does not increase other postoperative complications and mortality, and can be safely used in older adult patients undergoing major non-cardiac surgeries.

Effect of intravenous low-dose norepinephrine on blood loss in non-tourniquet total knee arthroplasty under general anesthesia: a randomized, double-blind, controlled, single-center trial

OBJECTIVE

This prospective trial aimed to evaluate the effects of low-dose intravenous norepinephrine (NE) on intraoperative blood loss and bleeding from osteotomy sites during non-tourniquet total knee arthroplasty (TKA) under general anesthesia.

METHODS

A total of 120 patients who underwent TKA between December 2020 and May 2022 were enrolled and randomly assigned to the intravenous low-dose NE Group (NE Group) or the control group (C Group). During surgery, NE Group received 0.05-0.1 μg/(kg min) of NE intravenously to raise and maintain the patient's mean arterial pressure (MAP). C Group received the same dose of saline as placebo. Intraoperative blood loss, bleeding score at osteotomy sites, Δlactate levels (Lac), postoperative complications, and transfusion rate during hospitalization were compared between groups.

RESULTS

Intraoperative and osteotomy blood loss was significantly lower in the NE Group than in the C Group (P < 0.001). No significant difference was observed in ΔLac between groups (P > 0.05). There was no significant difference in complications between the groups 3 days after surgery (P > 0.05). In addition, there was no significant difference in blood transfusion rates between the two groups during hospitalization (P > 0.05).

CONCLUSION

In non-tourniquet TKA under general anesthesia, low-dose intravenous NE safely and effectively reduced intraoperative blood loss and provided a satisfactory osteotomy site while maintaining a higher MAP.

Hemodynamics and cutaneous microcirculation during induction of general anesthesia with and without esketamine

OBJECTIVE

Currently, there are limited data on the effect of macrocirculatory hemodynamic changes on human microcirculation, especially during the induction of general anesthesia (GA).

METHODS

We performed a non-randomized observational trial on patients receiving GA for elective surgery. In the control group (CG), for GA induction sufentanil, propofol, and rocuronium was administered. Patients assigned to the esketamine group (EG) received additional esketamine for GA induction. Invasive blood pressure (IBP) and pulse contour cardiac output (CO) measurement were performed continuously. Microcirculation was assessed using cutaneous Laser Doppler Flowmetry (forehead and sternum LDF), peripheral and central Capillary Refill Time (pCRT, cCRT), as well as brachial temperature gradient (Tskin-diff) at baseline, 5, 10 and 15 minutes after induction of GA.

RESULTS

42 patients were included in the analysis (CG n = 22, EG n = 20). pCRT, cCRT, Tskin-diff, forehead and sternum LDF decreased following GA induction in both groups. IBP and CO were significantly more stable in esketamine group. However, the changes in the microcirculatory parameters were not significantly different between the groups.

CONCLUSIONS

The addition of esketamine for GA induction warranted better hemodynamic stability for the first five minutes, but had no significant effect on any of the cutaneous microcirculatory parameters measured.

Effects of Different Anesthetic and Analgesic Methods on Cellular Immune Function and Stress Hormone Levels in Patients Undergoing Esophageal Cancer Surgery

The change of perioperative immune function in patients with esophageal cancer is mainly caused by the joint action of surgical trauma and anesthesia. In our study, we aimed to investigate the effects of different anesthetic methods on the changes of T lymphocyte subsets and cytokines in peripheral blood of patients with esophageal cancer surgery. 50 patients with esophageal cancer were divided into the study group and the control group. Among them, the patients in the control group chose intravenous anesthesia and received self-controlled intravenous analgesia after surgery. Patients in the study group chose thoracic epidural anesthesia combined with general anesthesia, undergoing self-controlled epidural analgesia after surgery; serum interleukin-2 (IL-2) and soluble interleukin-2 receptor (sIL-2R) were measured by ELISA. Serum stress hormones GH and sIL-8 were measured by radioimmunoassay. Both groups of patients achieved significant postoperative analgesia, but the VAS score in the study group at the T2-T4 time point was lower than that in the control group. The serum GH concentration in the study group increased at T1 and reached its highest peak at T2, then decreased. The serum IL-8 concentration of the two groups showed a downward trend from T1 to T4. Thoracic epidural anesthesia combined with general anesthesia for postoperative epidural analgesia can relieve the degree of cellular immunosuppression during and after surgery. Moreover, the thoracic epidural block combined with general anesthesia for esophageal cancer surgery and epidural analgesia after surgery for patients are anesthetic and analgesic methods with clinically significant effects. Our research results have a positive effect on the promotion of postoperative rehabilitation in patients with malignant cell tumors.

The effect of moderate intraoperative blood loss and norepinephrine therapy on sublingual microcirculatory perfusion in patients having open radical prostatectomy: An observational study

BACKGROUND

It is not clear whether moderate intraoperative blood loss and norepinephrine used to restore the macrocirculation impair the microcirculation and affect microcirculation/macrocirculation coherence.

OBJECTIVE

We sought to investigate the effect of moderate intraoperative blood loss and norepinephrine therapy administered to treat intraoperative hypotension on the sublingual microcirculation.

DESIGN

Prospective observational study.

SETTING

University Medical Center Hamburg-Eppendorf, Hamburg, Germany, from November 2018 to March 2019.

PATIENTS

Thirty patients scheduled for open radical prostatectomy and 29 healthy volunteer blood donors.

INTERVENTION

Simultaneous assessment of the macrocirculation using a noninvasive finger-cuff method and the sublingual microcirculation using vital microscopy.

MAIN OUTCOME MEASURES

The main outcome measures were changes in the sublingual microcirculation caused by moderate intraoperative blood loss and norepinephrine therapy.

RESULTS

General anaesthesia decreased median [IQR] mean arterial pressure from 100 [90 to 104] to 79 [69 to 87] mmHg (P < 0.001), median heart rate from 69 [63 to 79] to 53 [44 to 62] beats per minute (P < 0.001), median cardiac index from 2.67 [2.42 to 3.17] to 2.09 [1.74 to 2.49] l min-1 m-2 (P < 0.001), and median microvascular flow index from 2.75 [2.66 to 2.85] to 2.50 [2.35 to 2.63] (P = 0.001). A median blood loss of 600 [438 to 913] ml until the time of prostate removal and norepinephrine therapy to treat intraoperative hypotension had no detrimental effect on the sublingual microcirculation: There were no clinically important changes in the microvascular flow index, the proportion of perfused vessels, the total vessel density, and the perfused vessel density. Blood donation resulted in no clinically important changes in any of the macrocirculatory or microcirculatory variables.

CONCLUSION

Moderate intraoperative blood loss and norepinephrine therapy administered to treat intraoperative hypotension have no detrimental effect on the sublingual microcirculation and the coherence between the macrocirculation and microcirculation in patients having open radical prostatectomy.

Effects of impaired microvascular flow regulation on metabolism-perfusion matching and organ function

Impaired tissue oxygen delivery is a major cause of organ damage and failure in critically ill patients, which can occur even when systemic parameters, including cardiac output and arterial hemoglobin saturation, are close to normal. This review addresses oxygen transport mechanisms at the microcirculatory scale, and how hypoxia may occur in spite of adequate convective oxygen supply. The structure of the microcirculation is intrinsically heterogeneous, with wide variations in vessel diameters and flow pathway lengths, and consequently also in blood flow rates and oxygen levels. The dynamic processes of structural adaptation and flow regulation continually adjust microvessel diameters to compensate for heterogeneity, redistributing flow according to metabolic needs to ensure adequate tissue oxygenation. A key role in flow regulation is played by conducted responses, which are generated and propagated by endothelial cells and signal upstream arterioles to dilate in response to local hypoxia. Several pathophysiological conditions can impair local flow regulation, causing hypoxia and tissue damage leading to organ failure. Therapeutic measures targeted to systemic parameters may not address or may even worsen tissue oxygenation at the microvascular level. Restoration of tissue oxygenation in critically ill patients may depend on restoration of endothelial cell function, including conducted responses.

[Perioperative pharmacological circulatory support in daily clinical routine]

Perioperative phases of hypotension are associated with an increase in postoperative complications and organ damage. Whereas some years ago hemodynamic stabilization was primarily carried out by volume supplementation, in recent years the use and dosing of cardiovascular-active substances has significantly increased. But like intravascular volume therapy, also substances with a cardiovascular effect have therapeutic margins, and thus, potential side effects. This review article discusses indications for each cardiovascular-active agent, weighing up advantages and disadvantages. Special attention is paid to the question how to administrate them: central venous catheter vs. peripheral indwelling venous cannula. The authors come to the conclusion that it is not a question of whether it is principally allowed to apply cardiovascular-active drugs via peripheral veins but more importantly, what should be taken into consideration if a peripheral venous access is used. This article provides concise recommendations.

Preload Dependence Is Associated with Reduced Sublingual Microcirculation during Major Abdominal Surgery

Editor’s Perspective

What We Already Know about This Topic

What This Article Tells Us That Is New

Background

Dynamic indices, such as pulse pressure variation, detect preload dependence and are used to predict fluid responsiveness. The behavior of sublingual microcirculation during preload dependence is unknown during major abdominal surgery. The purpose of this study was to test the hypothesis that during abdominal surgery, microvascular perfusion is impaired during preload dependence and recovers after fluid administration.

Methods

This prospective observational study included patients having major abdominal surgery. Pulse pressure variation was used to identify preload dependence. A fluid challenge was performed when pulse pressure variation was greater than 13%. Macrocirculation variables (mean arterial pressure, heart rate, stroke volume index, and pulse pressure variation) and sublingual microcirculation variables (perfused vessel density, microvascular flow index, proportion of perfused vessels, and flow heterogeneity index) were recorded every 10 min.

Results

In 17 patients, who contributed 32 preload dependence episodes, the occurrence of preload dependence during major abdominal surgery was associated with a decrease in mean arterial pressure (72 ± 9 vs. 83 ± 15 mmHg [mean ± SD]; P = 0.016) and stroke volume index (36 ± 8 vs. 43 ± 8 ml/m2; P &lt; 0.001) with a concomitant decrease in microvascular flow index (median [interquartile range], 2.33 [1.81, 2.75] vs. 2.84 [2.56, 2.88]; P = 0.009) and perfused vessel density (14.9 [12.0, 16.4] vs. 16.1 mm/mm2 [14.7, 21.4], P = 0.009), while heterogeneity index was increased from 0.2 (0.2, 0.4) to 0.5 (0.4, 0.7; P = 0.001). After fluid challenge, all microvascular parameters and the stroke volume index improved, while mean arterial pressure and heart rate remained unchanged.

Conclusions

Preload dependence was associated with reduced sublingual microcirculation during major abdominal surgery. Fluid administration successfully restored microvascular perfusion.

Effects of dobutamine, dopamine, phenylephrine and noradrenaline on systemic haemodynamics and intestinal perfusion in isoflurane anaesthetised horses

BACKGROUND

In the horse, effects of cardiovascular-active drugs on local perfusion of the gastrointestinal tract are poorly understood.

OBJECTIVES

To determine the effect of drugs commonly used to support blood pressure, on local intestinal blood flow and tissue oxygenation under isoflurane anaesthesia.

STUDY DESIGN

In vivo randomised crossover experiment.

METHODS

Ten horses were anaesthetised with isoflurane. After 90 min of equilibration three doses (μg/kg bwt/min) of dobutamine (DOB 0.5/1/3), dopamine (DA 1/2/5), noradrenaline (NA 0.1/0.2/0.5) and phenylephrine (PHE 0.5/1/3) were infused for 15 min, in a randomised order, with a 45 min washout-period. Blood flow and tissue oxygenation (sO₂ ) of jejunum, colon and stomach were measured using white light remission spectrophotometry and laser doppler flowmetry; heart rate (HR), mean arterial blood pressure (MAP), cardiac output (CO) were measured and systemic vascular resistance (SVR) calculated.

RESULTS

Compared to baseline high dose dobutamine significantly increased CO, HR, MAP (P<0.001) and blood flow to the jejunum (+47 ± 26%, P = 0.001) and colon (+29 ± 15%, P<0.001) (mean ± s.d.). Dopamine (DA5) increased CO but decreased colonic blood flow (-39 ± 21% from baseline, P<0.001), as well as SVR and MAP compared to baseline (P<0.001). Noradrenaline had no significant influence on intestinal perfusion, but increased MAP and SVR from baseline (P<0.001). Phenylephrine (PHE3) caused a significant decrease in blood flow and sO₂ , most profoundly at the colon compared to baseline (flow -44 ± 21%; sO₂ -16 ± 3%, P<0.001), while MAP and SVR increased and CO and HR decreased (P<0.001).

MAIN LIMITATIONS

The measurement technique only allows for flow measurements in arbitrary units, which can limit comparability to other techniques.

CONCLUSION

At the investigated doses dobutamine improved systemic and peripheral haemodynamics, while dopamine decreased MAP and peripheral perfusion. Noradrenaline increased MAP and SVR while peripheral blood flow was maintained, phenylephrine increased MAP, but reduced both local and systemic perfusion.

Effect of Prewarming during Induction of Anesthesia on Microvascular Reactivity in Patients Undergoing Off-Pump Coronary Artery Bypass Surgery: A Randomized Clinical Trial

Background

General anesthesia may induce inadvertent hypothermia and this may be related to perioperative cardiovascular complications. Microvascular reactivity, measured by the recovery slope during a vascular occlusion test, is decreased during surgery and is also related to postoperative clinical outcomes. We hypothesized that microvascular changes during surgery may be related to intraoperative hypothermia. To evaluate this, we conducted a randomized study in patients undergoing off-pump coronary artery bypass surgery, in which the effect of prewarming on microvascular reactivity was evaluated.

Methods

Patients scheduled for off-pump coronary artery bypass surgery were screened. Enrolled patients were randomized to the prewarming group to receive forced-air warming during induction of anesthesia or to the control group. Measurement of core and skin temperatures and vascular occlusion test were conducted before anesthesia induction, 1, 2, and 3 h after induction, and at the end of surgery.

Results

In total, 40 patients were enrolled and finished the study (n = 20 in the prewarming group and n = 20 in the control group). During the first 3 h of anesthesia, core temperature was higher in the prewarming group than the control group (p < 0.001). The number of patients developing hypothermia was lower in the prewarming group than the control group (4/20 vs. 13/20, p = 0.004). However, tissue oxygen saturation and changes in recovery slope following a vascular occlusion test at 3 h after anesthesia induction did not differ between the groups. There was no difference in clinical outcome, including perioperative transfusion, wound infection, or hospital stay, between the groups.

Conclusions

Prewarming during induction of anesthesia decreased intraoperative hypothermia, but did not reduce the deterioration in microvascular reactivity in patients undergoing off-pump coronary artery bypass surgery.

Trial Registration

ClinicalTrials.gov NCT02186210