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.

Real time measurement of intramuscular pH during routine knee arthroscopy using a tourniquet

Aims Tourniquets have potential adverse effects including postoperative thigh pain, likely caused by their ischaemic and possible compressive effects. The aims of this preliminary study were to determine if it is possible to directly measure intramuscular pH in human subjects over time, and to measure the intramuscular pH changes resulting from tourniquet ischaemia in patients undergoing knee arthroscopy. Methods For patients undergoing short knee arthroscopic procedures, a sterile calibrated pH probe was inserted into the anterior fascial compartment of the leg after skin preparation, but before tourniquet inflation. The limb was elevated for three minutes prior to tourniquet inflation to 250 mmHg or 300 mmHg. Intramuscular pH was recorded at one-second intervals throughout the procedure and for 20 minutes following tourniquet deflation. Probe-related adverse events were recorded. Results A total of 27 patients were recruited to the study. Mean tourniquet time was 21 minutes (10 to 56). Tourniquet pressure was 300 mmHg for 21 patients and 250 mmHg for six patients. Mean muscle pH prior to tourniquet inflation was 6.80. Muscle pH decreased upon tourniquet inflation, with a steeper fall in the first ten minutes than for the rest of the procedure. Change in muscle pH was significant after five minutes of tourniquet ischaemia (p < 0.001). Mean muscle pH prior to tourniquet release was 6.58 and recovered to 6.75 within 20 minutes following release. No probe related adverse events were recorded. Conclusion It is possible to directly measure skeletal muscle pH in human subjects over time. Tourniquet ischaemia results in a decrease in human skeletal muscle pH over time during short procedures. Cite this article: Bone Joint Res 2021;10(6):363–369.

Personalized tourniquet pressure may be a better choice than uniform tourniquet pressure during total knee arthroplasty: a meta-analysis of randomized- controlled trials.

Background: Pneumatic tourniquets are widely used in total knee arthroplasty (TKA). Some surgeons prefer a uniform tourniquet inflation pressure (UTIP)for all patients; others use personalized tourniquet inflation pressures (PTIP) based on systolic blood pressure (SBP) and limb occlusion pressure(LOP). However, no consensus exists regarding the optimal mode of inflation pressure during TKA. This review aimed to appraise if personalized tourniquet inflation pressures are better than uniform tourniquet inflation. Methods: The databases (Web of Science，Embase，PubMed，Cochrane Controlled Trials Register,、Cochrane Library、Highwire、CBM、CNKI、VIP、Wanfang) were searched on March 2021 to systematically identify and screen the literature for randomized controlled trials (RCTs) involving PTIP and UTIP during total knee arthroplasty.Results: Thirteen randomized controlled trials, involving 1204 TKAs (1201 patients) were included in the systematic review. The meta-analysis identified a trend toward less Visual Analogue Scale (VAS) score at rest with PTIP group at one day（P=0.002），2-3day（P=0.01）, and less VAS score at activity 1day (P＜0.0001 ),2-3 days after the operation (P＜0.00001 )and discharge (P＜0.0001). No significant difference was found between the groups in terms of VAS score at rest when discharge (P=1.0). We also found no significant difference in terms of intraoperative blood loss（P=0.48）, total blood loss（P=0.15）, lower limb vein thrombosis （P=0.42）and thigh bullae（P=0.17）. However, in the PTIP group, we found a significant higher Hospital for Special Surgery (HSS) score （P=0.007）,broader knee Range of motion(ROM)（P=0.02）,less rate of thigh ecchymosis（P=0.00001）and shorter thigh circumference at one day(P=0.006), 2-3day (P=0.0005), and discharge(P=0.02).Conclusion: PTIP provides a similar bloodless surgical field compared with the conventional UTIP. Furthermore, PTIP provides less pain intensity, thigh circumference, rate of thigh ecchymosis, higher HSS and better initial recovery of knee flexion in total knee arthroplasty. Therefore, we recommend using a PTIP method during TKA. More adequately powered and better-designed randomized controlled trials （RCTs）studies with long-term follow-up are required to produce evidence-based guidelines regarding the PTIP method.

Personalized Tourniquet Inflation Pressure or Conventional Uniform Tourniquet Inflation Pressure During Total Knee Arthroplasty: A Meta-analysis of Randomized- Controlled Trials.

Background： Pneumatic tourniquets are widely used in total knee arthroplasty (TKA). Some surgeons prefer a uniform tourniquet inflation pressure (UTIP)for all patients; others use personalized tourniquet inflation pressures (PTIP). However, no consensus exists regarding the optimal mode of inflation pressure during TKA. This review aimed to appraise if personalized tourniquet inflation pressures are better than uniform tourniquet inflation. Methods：The databases (Web of Science，Embase，PubMed，Cochrane Controlled Trials Register,、Cochrane Library、Highwire、CBM、CNKI、VIP、Wanfang) were searched on August 2020 to systematically identify and screen the literature for randomized controlled trials (RCTs) involving PTIP and UTIP during total knee arthroplasty.Results: Nine randomized controlled trials, involving 840 TKAs (837 patients) were included in the systematic review. The meta-analysis identified a trend toward less Visual Analogue Scale (VAS) score at rest with PTIP group at one day（P＜0.00001），2-3day（P=0.01）, and less VAS score at activity 1day (P＜0.0001 ),2-3 days after the operation (P＜0.00001 )and discharge (P＜0.0001). No significant difference was found between the groups in terms of VAS score at rest when discharge (P=1.0), intraoperative blood loss（P=0.9）, total blood loss（P=0.3）, Hospital for Special Surgery (HSS) score （P=0.05）, lower limb vein thrombosis （P=0.42）and thigh bullae（P=0.17）. However, in the PTIP group, we found a significant broader knee Range of motion(ROM)（P=0.02）and a reduction in the rate of thigh ecchymosis（P=0.0003）and thigh circumference at one day(P=0.006), 2-3day (P=0.0005), and discharge(P=0.02). Conclusion: PTIP provides a similar bloodless surgical field compared with the conventional UTIP. Furthermore, PTIP provides less pain intensity, thigh circumference, rate of thigh ecchymosis, and better initial recovery of knee flexion in total knee arthroplasty. Therefore, we recommend using a PTIP method during TKA. More adequately powered and better-designed randomized controlled trials （RCTs）studies with long-term follow-up are required to produce evidence-based guidelines regarding the PTIP method.