Tourniquet-induced hypertension correlates with autonomic nervous system changes detected by power spectral heart rate analysis

Comparison of bolus administration effects of lidocaine on preventing tourniquet-induced hypertension in patients undergoing general anesthesia: a randomized controlled trial

Background

This study assessed the effect of a single bolus administration of lidocaine on the prevention of tourniquet-induced hypertension (TIH) and compared the effect of lidocaine to that of ketamine in patients undergoing general anesthesia.

Methods

This randomized, controlled, double-blind study included 75 patients who underwent lower limb surgery using a tourniquet. The patients were administered lidocaine (1.5 mg/kg, n = 25), ketamine (0.2 mg/kg, n = 25) or placebo (n = 25). The study drugs were administered intravenously 10 min before tourniquet inflation. Systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) were measured before tourniquet inflation, after tourniquet inflation for 60 min at 10 min intervals, and immediately after tourniquet deflation. The incidence of TIH, defined as an increase of 30% or more in SBP or DBP during tourniquet inflation, was also recorded.

Results

SBP, DBP, and HR increased significantly over time in the control group compared to those in the lidocaine and ketamine groups for 60 min after tourniquet inflation (P < 0.001, P < 0.001, and P = 0.007, respectively). The incidence of TIH was significantly lower in the lidocaine (n = 4, 16%) and ketamine (n = 3, 12%) group than in the control group (n = 14, 56%) (P = 0.001).

Conclusion

Single-bolus lidocaine effectively attenuated blood pressure increase due to tourniquet inflation, with an effect comparable to that of bolus ketamine.

Femoral artery block (FAB) attenuates thigh tourniquet-induced hypertension: a prospective randomized, double-blind, placebo-controlled trial

INTRODUCTION

Prolonged tourniquet inflation during surgery frequently leads to tourniquet hypertension (TH), which is thought to arise from compression of A-δ fibers leading to sympathetically mediated C fiber activation. In the lower extremity, C fibers and other sympathetic nerve fibers are carried along the femoral artery. We hypothesized that blockade of these fibers at the femoral artery would decrease the incidence of TH.

METHODS

Thirty American Society of Anesthesia 1-3 patients aged 18-75 undergoing total ankle arthroplasty were randomized to receive 15 mL of injectate (mepivacaine 1.5% or saline placebo) at the anteromedial aspect of the common femoral artery at the level of the inguinal crease under ultrasound guidance. Both groups received preoperative popliteal sciatic and saphenous nerve blocks for analgesia and a standardized general anesthetic. Esmolol was administered if systolic blood pressure rose >30% above baseline. Incidence of TH was the primary outcome.

RESULTS

TH was present in 93.3% of sham patients versus 33.3% of block patients. Mean systolic pressure at 120 min and 150 min of tourniquet time was significantly higher in the sham group compared with the block group. Esmolol requirement (95.3+107.6 v 8.0+14.2, p=<0.001) was also significantly higher in the sham group. No differences were noted in pain scores or opioid consumption, and no patient experienced sensory or motor block of the femoral nerve.

DISCUSSION

Under these experimental conditions, injection of local anesthetic around the femoral artery reduced the incidence of TH and intraoperative esmolol requirement.

TRIAL REGISTRATION NUMBER

www.clinicaltrials.gov (NCT03390426; December 28, 2017).

A single blind randomised controlled trial of the impact on patient-reported pain of arm elevation versus exsanguination prior to tourniquet inflation

AIMS

The aim of this study was to compare the pain caused by the application of a tourniquet after exsanguination of the upper limb with that occurring after simple elevation.

PATIENTS AND METHODS

We used 26 healthy volunteers (52 arms), each of whom acted as their own matched control. The primary outcome measure was the total pain experienced by each volunteer while the tourniquet was inflated for 20 minutes. This was calculated as the area under the pain curve for each individual subject. Secondary outcomes were pain at each time point; the total pain experienced during the recovery phase; the ability to tolerate the tourniquet and the time for full recovery after deflation of the tourniquet.

RESULTS

There was a significant difference in the area under the pain curves in favour of exsanguination (mean difference 8.4; 95% confidence interval (CI) 3.0 to 13.7, p = 0.004). There was no difference between the dominant and non-dominant arms (mean difference -0.2; 95% CI -23.2 to 22.8, p = 0.99). The area under both recovery curves were similar (mean difference 0.7; 95% CI -6.0 to 4.6, p = 0.78). There was no statistical difference in recovery time, the actual mean difference being 30 seconds longer in the elevation group (p = 0.06).

CONCLUSION

Many orthopaedic and plastic surgery procedures are done under local anaesthetic or regional block where a bloodless field and a motionless patient are essential. Optimising patient comfort during surgery with the tourniquet inflated is thus a priority. This study is useful in that it compares two common methods of preparation of the upper limb prior to tourniquet inflation and which have not previously been compared in this context. Following on the results of this study, we can confidently conclude that exsanguinating the upper limb before inflating a tourniquet is more comfortable than simply elevating the arm for patients undergoing a procedure under local or regional block, both during the procedure and in the recovery phase.

TAKE HOME MESSAGE

Exsanguination rather than elevation is recommended in order to minimise patient discomfort and optimise the surgical field.

Comparison of ketorolac and low-dose ketamine in preventing tourniquet-induced increase in arterial pressure

BACKGROUND AND AIMS

Application of tourniquet during orthopaedic procedures causes pain and increase in blood pressure despite adequate anaesthesia and analgesia. In this study, we compared ketorolac with ketamine in patients undergoing elective lower limb surgery with tourniquet in order to discover if ketorolac was equally effective or better than ketamine in preventing tourniquet-induced hypertension.

METHODS

Approval was granted by the Institutional Ethics Review Committee and informed consent was obtained from all participants. A randomised double-blinded controlled trial with 38 patients each in the ketamine and ketorolac groups undergoing elective knee surgery for anterior cruciate ligament repair or reconstruction was conducted. Induction and maintenance of anaesthesia were standardised in all patients, and the minimum alveolar concentration of isoflurane was maintained at 1.2 throughout the study period. One group received ketamine in a dose of 0.25 mg/kg and the other group received 30 mg ketorolac 10 min before tourniquet inflation. Blood pressure was recorded before induction of anaesthesia (baseline) and at 0, 10, 20, 30, 40, 50, and 60 min after tourniquet inflation.

RESULTS

The demographic and anaesthetic characteristics were similar in the two groups. At 0 and 10 min, tourniquet-induced rise in blood pressure was not observed in both groups. From 20 min onward, both systolic and diastolic blood pressures were significantly higher in ketorolac group compared to ketamine group.

CONCLUSION

We conclude that ketamine is superior to ketorolac in preventing tourniquet-induced increases in blood pressure.

Tourniquet in surgery of the limbs: a review of history, types and complications

CONTEXT

A tourniquet is a device that is used frequently in most orthopaedic surgeries but this routine device can lead to serious complications so we decided to review and declare it for safe instruction and use.

EVIDENCE ACQUISITION

We searched the word "tourniquet" in PubMed and Google and reviewed all full text English articles and abstracts of non-English articles. In addition, we read all the reference pages of articles to find the new references.

RESULTS

The use of tourniquet in orthopedic surgery can lead to serious but rare complications that can be prevented by its correct knowledge and use.

CONCLUSIONS

At present, there is not enough evidence to discontinue the routine uses of tourniquets.

Tourniquet use in upper limb surgery

Tourniquets are compressive devices that occlude venous and arterial blood flow to limbs and are commonly used in upper limb surgery. With the potential risk of complications, there is some debate as to whether tourniquets should continue to be routinely used. In this review, we first look at the different designs, principles, and practical considerations associated with the use of tourniquets in the upper limb. The modern pneumatic tourniquet has many design features that enhance its safety profile. Current literature suggests that the risk of tourniquet-related complications can be significantly reduced by selecting cuff inflation pressures based on the limb occlusion pressure, and by a better understanding of the actual level of pressure within the soft tissue, and the effects of cuff width and contour. The evidence behind tourniquet time, placement, and limb exsanguination is also discussed as well as special considerations in patients with diabetes mellitus, hypertension, vascular calcification, sickle cell disease and obesity. We also provide an evidence-based review of the variety of local and systemic complications that may arise from the use of upper limb tourniquets including pain, leakage, and nerve, muscle, and skin injuries. The evidence in the literature suggests that upper limb tourniquets are beneficial in promoting optimum surgical conditions and modern tourniquet use is associated with a low rate of adverse events. With the improvement in knowledge and technology, the incidence of adverse events should continue to decrease. We recommend the use of tourniquets in upper limb surgery where no contraindications exist.

Effect of fentanyl on hemodynamic changes connected with a thigh tourniquet during knee arthroscopic surgery

BACKGROUND

The use of a tourniquet can produce pain and increase in blood pressure. It is known that fentanyl reduces central sensitization, however its effect on blood pressure increase due to tourniquet is unknown. So we investigated the effect of fentanyl on tourniquet-induced changes of mean arterial blood pressure (MBP), heart rate (HR), and cardiac index (CI).

METHODS

ASA physical status I and II, who were scheduled for knee arthroscopic surgery using a tourniquet, were assigned into control (n = 30) and fentanyl group (n = 30). Anesthesia was maintained with enflurane, N2O and O2. Fentanyl was injected 1.5 ug/kg at 10 min before inflation of the tourniquet in the fentanyl group. Changes of the MBP, HR, CI were measured before and 10, 20, 30, 40, 50, 60 min after inflation of the tourniquet.

RESULTS

There were no differences in the baseline values. MBP was increased at 40, 50, 60 min in the control group. At 60 min, MBP was lower in the fentanyl than the control group. HR was decreased at 10 min in the fentanyl group. CI was decreased in all groups after tourniquet inflation. At 60 min, CI was more decreased in the control than the fentanyl group.

CONCLUSIONS

Fentanyl injection prior to tourniquet inflation can attenuate the tourniquet induced hemodynamic changes in the knee arthroscopic surgery patients.

Preoperative oral dextromethorphan vs. clonidine to prevent tourniquet-induced cardiovascular responses in orthopaedic patients under general anaesthesia

BACKGROUND AND OBJECTIVE

Preoperative oral dextromethorphan and intravenous clonidine attenuate arterial pressure and heart rate increases during tourniquet inflation under general anaesthesia. The effect of preoperative oral clonidine on these variables has not been investigated.

METHODS

We designed this study to compare the effect of preoperative oral dextromethorphan or clonidine on haemodynamic changes during tourniquet inflation in 75 patients undergoing lower limb surgery under general anaesthesia. Patients were randomly assigned into three groups: dextromethorphan 30 mg (n = 25), clonidine 3 microg kg(-1) (n = 25) and placebo (n = 25). Anaesthesia was maintained with isoflurane 1.2% and N2O 50% in oxygen with endotracheal intubation. Dextromethorphan, clonidine or placebo was given orally in a double-blinded fashion 90 min before induction of anaesthesia. Systolic, diastolic and mean arterial pressure and heart rate were measured at 0, 30, 45, 60 min after the start of tourniquet inflation, before tourniquet release and 20 min after tourniquet deflation.

RESULTS

Systolic, diastolic and mean arterial pressure were significantly lower in the clonidine group compared with control after 45, 60 min tourniquet inflation and before tourniquet release (P < 0.05). Twenty minutes after deflation, diastolic and mean arterial pressure in the control group were still increased and significantly higher compared with the clonidine group (P < 0.05). Development of more than a 30% increase in systolic arterial pressure during tourniquet inflation was more frequent in the control group than in the other groups.

CONCLUSIONS

Preoperative oral clonidine 3 microg kg(-1) significantly prevented tourniquet-induced systemic arterial pressure increase in patients under general anaesthesia better than oral dextromethorphan.

Preoperative stellate ganglion blockade prevents tourniquet-induced hypertension during general anesthesia

BACKGROUND

Prolonged and excessive inflation of pneumatic tourniquets leads to a hyperdynamic circulatory response. Sympathomimetic activity is an important factor in tourniquet-induced hypertension. Stellate ganglion block specifically blunts sympathetic efferent nerves and prevents hypertension induced by sympathomimetic stimulation. The present study was performed to investigate the effects of stellate ganglion block (SGB) on arterial pressure and heart rate during prolonged tourniquet use under general anesthesia.

METHODS

Twenty patients scheduled for knee arthroscopy were either treated with 10 ml of 1% lidocaine for SGB (SGB group; n = 10), or intramuscular injection (IM group; n = 10) before tourniquet inflation. Comparisons of systolic and diastolic arterial pressure and heart rate were made before and after the induction of anesthesia, 10 min after the lidocaine treatment, every 5 min during the first 60 min after tourniquet inflation, and immediately before and 5 min following deflation. The maximum values of the circulatory variables were compared.

RESULTS

Tourniquet inflation caused increases in the circulatory variables in both groups. Systolic arterial pressure in the SGB group was significantly lower than that in the IM group after 55 min of tourniquet inflation. Diastolic arterial pressure also was significantly lower in the SGB group immediately before the deflation. The maximum values of the three hemodynamic variables were significantly lower in the SGB group. Arterial pressure significantly decreased after tourniquet deflation in the IM group.

CONCLUSION

Ipsilateral SGB attenuated the hyperdynamic response mediated by prolonged tourniquet inflation during knee arthroscopy.

Preoperative Oral Dextromethorphan Attenuated Tourniquet-Induced Arterial Blood Pressure and Heart Rate Increases in Knee Cruciate Ligament Reconstruction Patients Under General Anesthesia

The precise mechanism of tourniquet-induced arterial blood pressure increase is unknown. We determined the effect of preoperative oral dextromethorphan (DM) on arterial blood pressure and heart rate changes during tourniquet inflation in knee cruciate ligament reconstruction patients under general anesthesia. Patients in the DM group (n = 38) received oral DM 30 mg, and patients in the control group (n = 38) received oral placebo 2 h before the induction of anesthesia. Anesthesia was maintained with sevoflurane 2.0% and N(2)O in 33% oxygen, and the trachea was intubated until the end of surgery. Arterial blood pressure and heart rate were measured at 0, 30, and 60 min after the start of tourniquet inflation. Systolic arterial blood pressure and heart rate at 60 min in the control group were significantly more than those in the DM group (131.1 +/- 15.8 mm Hg versus 123.6 +/- 15.9 mm Hg [P < 0.05] and 74.1 +/- 11.3 bpm versus 67.8 +/- 8.5 bpm [P < 0.01], respectively). The percentage increase in systolic arterial blood pressure and heart rate in the DM group was also attenuated when compared with that in the control group (P < 0.05). In conclusion, preoperative oral DM 30 mg significantly attenuated arterial blood pressure and heart rate increases during tourniquet inflation under general anesthesia.

IMPLICATIONS

We demonstrated that preoperative oral dextromethorphan 30 mg significantly attenuated arterial blood pressure and heart rate increases at 60 min during tourniquet inflation in patients undergoing knee cruciate ligament reconstruction under general anesthesia.

Preoperative clonidine blunts hyperadrenergic and hyperdynamic responses to prolonged tourniquet pressure during general anesthesia

Although the mechanism of tourniquet-induced hypertension is still unclear, plasma norepinephrine concentrations continuously increase in parallel to arterial blood pressure during tourniquet inflation. Clonidine attenuates hyperadrenergic and hyperdynamic responses. We investigated the effects of clonidine on prolonged tourniquet inflation. Twenty-nine patients scheduled for elective orthopedic surgery were randomly assigned to receive IV clonidine (3 microg/kg; n = 14) or placebo (n = 15) before tourniquet inflation of the lower limbs under general anesthesia in a double-blinded manner. Arterial blood pressure, heart rate, epinephrine, and norepinephrine plasma concentrations were measured before tourniquet inflation, 60 min after tourniquet inflation, just before tourniquet deflation, and 20 min after tourniquet deflation. Mean arterial blood pressure and norepinephrine plasma-concentrations were significantly lower in the Clonidine group compared with Control after 60 min tourniquet inflation (P = 0.016; P = 0.006). Immediately before deflation of the tourniquet, the difference for mean arterial pressure between groups was even more pronounced (P = 0.005). Twenty minutes after deflation mean arterial blood pressure in the Control group was still increased and significantly higher compared with the Clonidine group (P = 0.002). In conclusion, preoperative IV clonidine blunts hyperadrenergic and hyperdynamic responses resulting from prolonged tourniquet inflation under general anesthesia in ASA class I--II patients.

IMPLICATIONS

Tourniquet inflation is associated with a continuous increase in arterial blood pressure and sympathetic outflow. This study shows that IV clonidine effectively blunts increases of both arterial blood pressure and plasma norepinephrine concentrations.

Preoperative small-dose ketamine prevented tourniquet-induced arterial pressure increase in orthopedic patients under general anesthesia

The mechanism of tourniquet-induced arterial pressure increase is not known. We investigated the effect of preoperative ketamine on tourniquet-induced arterial pressure and heart rate changes in 85 patients undergoing knee surgery with a tourniquet under general anesthesia. Patients were randomly assigned into three groups; Large Ketamine (n = 28; ketamine 1.0 mg/kg), Small Ketamine (n = 28; ketamine 0.25 mg/kg), and Control (n = 29; normal saline) groups. Anesthesia was maintained with 1.5%-2.5% sevoflurane and 66% N(2)O in oxygen with endotracheal intubation. Ketamine or normal saline was given in a double-blinded fashion before skin incision and tourniquet inflation. Arterial pressure and heart rate were recorded every 10 min until 60 min after the start of tourniquet inflation and again after deflation. Arterial pressure and heart rate were compared among the three groups by using repeated-measures analysis of variance. In the Large and Small Ketamine groups, arterial pressure was not significantly changed, but in the Control group arterial pressure was significantly increased 40, 50, and 60 min after the start of tourniquet inflation (P < 0.05). Development of more than a 30% increase in systolic arterial pressure during tourniquet inflation was more frequent in the Control group than the other groups. The results show that preoperative IV ketamine, 0.25 mg/kg or more, significantly prevented tourniquet-induced systemic arterial pressure increase in patients under general anesthesia.

IMPLICATIONS

Preoperative small-dose ketamine, IV, significantly prevented a systemic arterial pressure increase during prolonged tourniquet inflation in patients under general anesthesia.

Heart rate variability and the prone position under general versus spinal anesthesia

STUDY OBJECTIVE

To evaluate heart rate (HR) variability in the prone position with power spectral heart rate (PSHR) analysis during spinal and general anesthesia.

DESIGN

Prospective, clinical evaluation of HR variability in the prone position.

SETTING

Tertiary care teaching hospital.

PATIENTS

20 healthy, ASA physical status I and II patients scheduled for elective lumbar spine surgery in the prone position.

INTERVENTIONS

Anesthetic technique was either a standard general anesthetic or spinal anesthetic, based on the preference of the patient. Power spectral heart rate, HR, and blood pressure (BP) readings were determined prior to anesthetic intervention and as soon as a stable PSHR reading was available in the prone position.

MEASUREMENTS AND MAIN RESULTS

Heart rate and BP were recorded at baseline prior to anesthesia and at the time of stable PSHR data in the prone position. Power spectral heart rate data included low-frequency activity (LFa), high-frequency activity (HFa), and the ratio (LFa/HFa). Spinal anesthesia level was recorded by thoracic dermatome at complete onset. Data were collected from 20 patients; 12 patients chose spinal anesthesia and 8 chose general anesthesia. The prone position resulted in significant increase in HR in the spinal group and significant decrease in BP in the general anesthesia group. Low-frequency activity and LFa/HFa ratio were unchanged in the spinal anesthesia group and were significantly decreased in the general anesthesia group. Spinal level was T8.7.

CONCLUSIONS

The association of less change in LFa activity and preservation of BP on assumption of the prone position in patients during low spinal anesthesia suggests better preservation of autonomic nervous system compensatory mechanisms during low spinal anesthesia than with general anesthesia.