Tourniquet Inflation Research Articles

Limb Ischemic Conditioning Induces Oxidative Stress Followed by a Correlated Increase of HIF-1α in Healthy Volunteers

Local and remote ischemic preconditioning has been used as a protective intervention against ischemia/reperfusion (I/R) damage in several preclinical and clinical studies. However, its physiological mechanisms are not completely known. I/R increases the production of reactive oxygen species, which also serve as messengers for a variety of functions. Hypoxia-inducible factor 1 alpha (HIF-1α) is probably the most important transcription factor mediator of hypoxic signaling. We hypothesized that limb ischemic conditioning (LIC) induces a local oxidative/nitrosative stress and a correlated increase of HIF-1α plasma levels. An observational, prospective, and single-center study has been conducted in 27 healthy volunteers. LIC was applied: three cycles (5min of ischemia followed by 5min of reperfusion) using an ischemia cuff placed on the upper left arm. Time course of 8-isoprostane, nitrite, and HIF-1α levels was measured in blood plasma. Venous blood was sampled from the left arm before tourniquet inflation (basal) and after LIC: 1min and 2hr for 8-isoprostane and nitrite; and 1min, 2hr, 8hr, 24hr, and 48hr for HIF-1α. After LIC, we have found an early increase of 8-isoprostane and nitrite. HIF-1α increased at 2 and 8hr after LIC. We found a direct correlation between HIF-1α and 8-isoprostane and nitrite plasma levels. We concluded that LIC induces an early oxidative/nitrosative stress in the arm followed by an increase of HIF-1α plasma levels correlated with 8-isoprostane and nitrite levels, possibly as a local response.

Does Tranexamic Acid Reduce Knee Swelling and Improve Early Function Following Arthroscopic Meniscectomy? A Double-Blind Randomized Controlled Trial

Background:Arthroscopic meniscectomy often results in rapid recovery and return to preinjury activities; however, postoperative hemarthrosis and swelling can lead to pain, decreased range of motion, and delayed return to work and leisure activities. Tranexamic acid (TXA) is a lysine-based inhibitor of plasminogen to plasmin that has gained popularity in arthroplasty surgery for reducing blood loss and, more recently, in anterior cruciate ligament reconstruction by reducing postoperative hemarthrosis, swelling, and pain while increasing function in the short term.Purpose:To determine whether there is a role for TXA in improving the short-term results of swelling, pain, and function following arthroscopic meniscectomy.Study Design:Randomized controlled trial; Level of evidence, 2.Methods:We performed a prospective double-blinded randomized controlled trial in 41 patients undergoing arthroscopic meniscectomy by comparing patients treated with intravenous TXA with those treated with a placebo (normal saline). A single surgeon treated all patients. Following randomization, a dose of 1 g of TXA in 100 mL of normal saline (treatment group) or 100 mL of normal saline (placebo group) was given intravenously at induction prior to tourniquet inflation by the anesthetist. The anesthetist administering the TXA or placebo was not blinded, but all other clinicians involved were. Patients were evaluated by a blinded observer at postoperative days 3, 14, and 30, with the range of motion, swelling, pain levels (visual analog scale), and Lysholm and Tegner knee scores recorded.Results:Patient demographics were similar in both groups. In the treatment group, there was a nonsignificant improvement in range of motion (P = .056) and swelling (P = .384) at 14 days; however, there was a significant improvement in the Tegner score at 3 days (P = .0064). The complication profile was similar between the groups.Conclusion:The administration of 1 g of intravenous TXA in routine arthroscopic meniscectomy may improve early functional recovery without increased risk. A larger study is required to confirm these results and further evaluate any potential benefit.Registration:ACTRN12618001600235 (Australian New Zealand Clinical Trials Registry).

What should we be careful of ankle arthroscopy?

Ankle arthroscopy has been used as a standard tool by foot and ankle surgeons. To overcome the narrowness of ankle joint, a noninvasive distraction technique is used for the successful visualization in ankle arthroscopy. The aim of this study was to investigate the incidence and type of complications associated with ankle arthroscopy using a noninvasive distraction technique and to report a troublesome complication. We reviewed 514 patients' charts from 2003 to 2011. The same noninvasive distraction technique was used. Patients' demography, duration of follow-up, diagnoses, procedures, and complications related to ankle arthroscopy were analyzed. There were 388 male and 126 female; mean age was 37.2 years; mean follow-up duration was 33 months. The diagnoses were osteochondral lesion of talus, chronic ankle instability, anterolateral soft tissue impingement syndrome, and anterior bony impingement. We performed arthroscopic synovectomy, osteochondral procedure, bony spur excision, and loose body removal. The mean time of arthroscopic procedure was 47 min. There were neurologic complications (eight cases), skin necrosis of posterior thigh (three cases), instrument breakage (two cases), and superficial wound infection (one case). All complications were well resolved. The total duration of distraction plus tourniquet inflation exceeded 120 min in the three cases of skin necrosis. Skin necrosis was deemed to be resulted from the long tourniquet time. The noninvasive distraction technique is safe and effective for ankle arthroscopy. However, the distraction plus tourniquet requires attention because it can cause high pressure on posterior thigh resulting in soft tissue injury.

Minimising Tourniquet Time and Post-operative Pain During Carpal Tunnel Decompression.

BackgroundPain and discomfort at the tourniquet and wound site are recognised complications of carpal tunnel surgery. Studies have shown that longer tourniquet times lead to increased pain, local and systematic complications. We hypothesise that minimising the intraoperative tourniquet time will reduce post-operative pain and complications.ObjectiveOur aim is to present the results of our novel operative technique for carpal tunnel decompression which minimises tourniquet time.MethodThe study represented a prospective case series in which 55 consecutive and unselected patients with positive nerve conduction study results were operated on by a single surgeon at a single hospital site over a period of 12 months. The patients filled in a questionnaire based on a visual analogue score (VAS) (1-10) for pain at (1) first presentation at the clinic, (2) recovery in theatre post-operatively and (3) on discharge from care at 12 weeks post-operatively. Questions included the perception of pain at the tourniquet site and at the wound site.Results A total of 55 (female 39 and male 16) patients participated in the study. The average tourniquet time was 5 minutes 50 seconds. 98% of patients had a VAS of 1 at both the wound and tourniquet site post-operatively. One patent had a score of 3 at the tourniquet site. Eleven patients had undergone contralateral carpal tunnel decompression surgery. Of the remaining 43 patients, all said they would have the other side operated on in the same way.Conclusion We have demonstrated a safe and efficient technique to reduce post-operative pain by minimising tourniquet inflation time. Our patient cohort experienced no significant complications and minimal pain post-operatively.

Is lower tourniquet pressure during total knee arthroplasty effective? A prospective randomized controlled trial

BackgroundHigher tourniquet pressures may be associated with an increased risk of complications. We aimed to determine (1) whether a lower tourniquet pressure [systolic blood pressure (SBP) + 120 mmHg] is as effective as conventional tourniquet pressure (SBP + 150 mmHg) in providing a bloodless surgical field and decreasing blood loss, and (2) whether lowering the tourniquet pressure decreases tourniquet-related complications compared to conventional inflation pressure.MethodsOne hundred and sixty knees in 124 patients undergoing total knee arthroplasty (TKA) were randomly allocated to either conventional (n = 80) or lower inflation pressure group (n = 80). The quality of the initial surgical field and occurrence of intraoperative blood oozing, hemoglobin drop, drained volume and calculated blood loss were assessed as efficacy variables. Safety outcome variables included post-operative pain, tourniquet site skin problems (ecchymosis, bullae, skin necrosis), and other tourniquet-related complications such as nerve palsy, venous thromboembolism, and delayed rehabilitation.ResultsA comparable bloodless surgical field was successfully provided in both groups (100% vs. 99%, p = 1.000). One case in the conventional pressure group and two cases in the lower pressure group showed intraoperative blood oozing (p = 1.000), which was successfully controlled after an increase of 30 mmHg in the tourniquet inflation pressure. There was no difference in the hemoglobin drop, drained volume, and calculated blood loss. The two groups did not differ in any safety outcomes such as post-operative pain, thigh complications, and other tourniquet related complications.ConclusionThis study demonstrates that a tourniquet inflation pressure of 120 mmHg above the SBP is effective method during TKA.Trial registrationThe trial was with ClinicalTrials.gov (NCT01993758) on November 25, 2013.

Effects of Pre-treatment with Ketamine and Tourniquet Application on the Prevention of the Pain Induced by Propofol Injection: A Randomized Controlled Clinical Trial

Introduction: The pain induced by propofol injection is a common adverse complications caused by propofol, which is ranked seventh among the 33 clinical symptoms of anesthesia. The present study aimed to investigate the effects of pre-treatment with ketamine and tourniquet inflation on the pain induced by propofol injection.Methods: This randomized controlled clinical trial was conducted on 120 patients with the American Society of Anesthesiologists (ASA) physical status classification I. The patients were assigned to six groups. In groups one and four, tourniquet was inflated above the angiocatheter. In groups two and five, ketamine was injected 30 seconds before propofol injection with no tourniquet. The patients in groups three and six were injected with propofol alone. To assess the severity of pain, verbal rating scores were used. Data analysis was performed in SPSS version 20.Results: In total, 74 male and 46 female patients were examined. In terms of pain severity, the lowest level of pain was experienced with the injection of ketamine before propofol with the use of a tourniquet (groups one and four). Based on the injection site, the total pain scores were higher with the injection of propofol into the veins on the dorsum of the hand. In addition, the mean pain score in groups one, two, four, and five was significantly lower compared to groups three and six (P< 0.05)Conclusion: According to the results, use of ketamine, especially with a tourniquet, could alleviate the pain induced by propofol injection.

Tourniquet-induced tissue hypoxia characterized by near-infrared spectroscopy during ankle surgery: an observational study

BackgroundPneumatic tourniquet inflation during extremity surgery leads to profound and prolonged tissue ischemia. Its effect on tissue oxygenation is inadequately studied.MethodsPatients undergoing elective ankle surgery with tourniquet application participated in this observational cohort study. Somatic and cerebral tissue oxygen saturation (SstO2 and SctO2) were monitored using tissue near-infrared spectroscopy. Oxygenation was monitored distally (SstO2-distal) and proximally to the tourniquet, on the contralateral leg, and the forehead (a total of 4 tissue beds). Tissue oxygenation at different time points was compared. The magnitude, duration, and load (product of magnitude and duration) of tissue desaturation during tourniquet inflation were correlated with tissue resaturation and hypersaturation after tourniquet deflation.ResultsData of 26 patients were analyzed. The tourniquet inflation time was 120 ± 31 mins. Following a rapid desaturation from 77 ± 8% pre-inflation to 38 ± 20% 10 mins post-inflation, SstO2-distal slowly and continuously desaturated and reach the nadir (16 ± 11%) toward the end of inflation. After deflation, SstO2-distal rapidly resaturated from 16 ± 11% to 91 ± 5% (i.e., hypersaturation); SstO2 monitored proximally to the tourniquet and on contralateral leg had significant but small desaturation (~ 2–3%, p < 0.001); in contrast, SctO2 remained stable. The desaturation load had a significant correlation with resaturation magnitude (p < 0.001); while the desaturation duration had a significant correlation with hypersaturation magnitude (p = 0.04).ConclusionsTissue dys-oxygenation following tourniquet application can be reliably monitored using tissue oximetry. Its outcome significance remains to be determined.

The relationship between tourniquet duration and Il-6, d-dimer and visual analogue scale in Total knee arthroplasty

Introduction: Total knee arthroplasty (TKA) is commonly done with tourniquet device placed around the thigh. The use of tourniquet during TKA, aside, from having several advantages, is also accompanied by several risks. Some of these complications are increasing pain due to tourniquet inflation, reperfusion syndrome that leads to the increase of several pro inflammatory cytokines, such as IL-6, as well as increasing D-dimer as a marker for thromboembolic events. Methods: This study is a cross-sectional analytical experimental research performed in patients with primary osteoarthritis of the knee who failed conservative treatment and agreed to undergo Total Knee Arthroplasty. Blood samples were taken from the patients and IL-6 cytokine and D-dimer levels were identified using ELISA method. Visual Analogue Scale (VAS) was assessed at 12 hours and 24 hours post operation. Results: The result of this study showed a positive correlation between the length of tourniquet used with IL-6 at 12 hours post operation (r=0.359) and 24 hours post operation (r=0.658); with D-dimer at 12 hours post operation (r=0.491) and 24 hours post operation (r=0.483); and with VAS at 12 hours post operation (r=0.647) and 24 hours post operation (r=0.507) with p < 0,05. Conclusion: A positive correlation was found between tourniquet time and the level of IL-6 and D-dimer, and VAS. The duration of tourniquet cut-off time of more than 122.5 minutes elevated IL-6 and D-Dimer levels which increased the risk for SIRS and DVT

Comparison of lower limb lifting and squeeze exsanguination before tourniquet inflation during total knee arthroplasty

BackgroundDuring total knee arthroplasty(TKA), tourniquet is widely used by most surgeons whereas the optimal application is still controversial. With this prospective randomized controlled study, we intend to investigate the effect of lower limb lifting and squeeze exsanguination methods on clinical outcomes in a series of TKAs.MethodsProspectively enrolled a total of 236 TKA patients from March, 2012 to November, 2016. Of which 118 patients randomly constitute Group A with lower limb lifting exsanguination technique; and the other 118 patients comprise Group B with squeeze exsanguination method. A year’s follow-up measurements were recorded in detail for analysis.ResultsThe pre-tourniquet time of Group A was significantly shorter than that in Group B (P < 0.001). Significant difference was found on skin tension blister, 3 happened in Group A and 11 happened in Group B (P = 0.031), which resulted in a difference in total complications (P = 0.039). The VAS score was significantly lower in Group A at one and seven days postoperatively, P < 0.001 and P = 0.011, respectively. No significant differences were found regarding all other clinical outcome measurements.ConclusionThe lower limb lifting exsanguination is a safe and effective technique. Compared with squeeze exsanguination method, it could decrease the incidence of skin tension blister and alleviate early postoperative pain reaction, no additional risks occurred regarding other clinical outcomes. Thus, it might have the potentiality to be commonly utilized in TKA procedure.Trial registrationClinicalTrials.gov Identifier: ChiCTR1800020471. Registered on 31 December 2018 Retrospectively registered.

The effect of pregabalin on tourniquet-induced ischemia-reperfusion injury: a prospective randomized study

Background/aim The aim of this study was to investigate the efficacy of pregabalin on ischemia-reperfusion injuries.Materials and methods Fifty-four patients were randomly assigned into 2 groups. A 150-mg tablet of pregabalin was given the night before and then 1 h before the operation for patients in Group P (pregabalin group, n = 27). A placebo was given to patients in Group C (control group, n = 27) at the same times. After combined spinal-epidural anesthesia was performed, venous blood samples were taken before tourniquet inflation (t1), just before tourniquet deflation (t2), and 20 min after tourniquet deflation (t3) for the analysis of total antioxidant status (TAS), total oxidant status (TOS), catalase (CAT), and ischemia-modified albumin (IMA).Results There was no significant difference in TAS levels between the groups for the t3 period. However, the TAS in Group P was significantly higher in the t3 period than the t2 period (mean ± SD, 0.46 ± 0.1 vs. 0.38 ± 0.2 mmol of Trolox equivalent/L, respectively; P < 0.05). The CAT level in the t3 period was significantly higher in Group P than Group C (mean ± SD, 53.04 ± 32.1 vs. 35.46 ± 17.2 µmol/formaldehyde, respectively; P < 0.05). In the t3 period, the TOS was significantly lower in Group P than Group C (mean ± SD, 11.97 ± 5 vs. 18.29 ± 9.9 pg/mL, respectively; P < 0.05). The TOS in Group P was significantly lower in the t3 period than the t2 period (mean ± SD, 11.97 ± 5 vs. 18.98 ± 10.7 pg/mL, respectively; P < 0.0001).Conclusion Pregabalin has no marked antioxidant activity, but it contributes to the antioxidant defense system of an organism.

Effects of stellate ganglion block on the circulation stability of lower extremity tourniquet and endotracheal intubation

Objective To examine the effect of ultrasound-guided stellate ganglion block (SGB) on the tourniquet reaction of the lower limbs. Methods A total of sixty patients undergoing unilateral knee replacement surgery under general anesthesia were divided into 2 groups (n=30): control group and group SGB. The age of patients was 18-75 years old with ASA gradeⅠ,Ⅱ. Before general anesthesia, 1% lidocaine (10 ml) was injected into the right deltoid muscle in control group, but in the right cervical stellate ganglion in group SGB. HR, SBP, BIS and drug doses were recorded at various time points: before induction of anesthesia (T0), before intubation (T1), 1 min after intubation (T2), before tourninquet inflated (T3), tourniquet inflatable 30 min (T4), tourniquet inflation 1 h (T5), tourniquet deflation(T6), tourniquet deflation 3 min (T7) and tourniquet deflation 30 min (T8) after discharge. Results Compared with control group, group SGB showed significantly lower SBP at T2, T5, T6 and T7 (P 0.05). There was no significant difference in the BIS, the doses of propofol, remifentanil, ephedrine and phenylephrine between the two groups, while the dose of urapidil in group SGB was significantly less than control group. Conclusions SGB can reduce the cardiovascular response to the tourniquet and maintain stable perioperative circulation. Key words: Stellate ganglion block; Tourniquet

Effect of Tourniquet Inflated for All the Surgery Versus Tourniquet Inflated Only at the Time of Cementation on Early Blood Loss at Total Knee Arthroplasty

Effect of Tourniquet Inflated for All the Surgery Versus Tourniquet Inflated Only at the Time of Cementation on Early Blood Loss at Total Knee Arthroplasty

Intravenous Versus Topical Tranexamic Acid in Total Knee Arthroplasty: Both Effective in a Randomized Clinical Trial of 640 Patients.

Tranexamic acid (TXA) reduces bleeding and the need for transfusion after total knee arthroplasty. Most literature has focused on intravenous (IV) administration of TXA, with less data available on the efficacy of topically administered TXA. This multicenter randomized clinical trial specifically assessed the efficacy of topical TXA compared with IV TXA as measured by calculated blood loss, drain output, and transfusion rates. Complications, including venous thromboembolism (VTE), were reported. A total of 640 patients who underwent primary unilateral total knee arthroplasty for osteoarthritis at 2 large academic centers were randomized to receive 1 g of IV TXA prior to tourniquet inflation and 1 g at closure, or 3 g of TXA diluted in 45 mL of normal saline solution (total volume of 75 mL) and topically applied after cementation. Age, sex, body mass index, American Society of Anesthesiologists (ASA) score, and preoperative hemoglobin level were similar between the groups. Univariate, multiple linear regression, and multiple logistic regression analyses were performed. Patients who received topical TXA had significantly greater calculated blood loss compared with those who received IV TXA (mean of 324 compared with 271 mL; p = 0.005). Drain output was significantly higher in the topical TXA group compared with the IV TXA group (mean of 560 compared with 456 mL; p < 0.0001). The rate of transfusion was low in the topical and IV groups, with no significant difference on univariate analysis (1.6% compared with 0.6%, respectively; p = 0.45); however, on multiple logistic regression analysis, patients who received topical TXA were 2.2-fold more likely to receive a transfusion (p < 0.0001). The topical and IV TXA groups did not differ significantly with respect to the rate of thrombotic events (0.6% compared with 1.6%, respectively; p = 0.45). In this large, randomized clinical trial involving patients undergoing total knee arthroplasty, both IV and topical TXA were associated with a low rate of transfusion. While IV TXA was associated with less calculated blood loss, lower drain output, and fewer transfusions, the small differences between the groups may not be clinically important. Given the low prevalence of thrombotic complications, the relative safety of one formulation of TXA over the other cannot be definitely established. Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Ultrasound-guided adductor canal block: a cadaver study investigating the effect of a thigh tourniquet

BackgroundPlacement of local anaesthetic within the adductor canal using ultrasonography is an alternative to femoral nerve blocks for postoperative pain relief after knee joint replacement surgery. However, the effect of an inflated thigh tourniquet on the distribution of local anaesthetic within the adductor canal is unknown. The aim of this cadaveric study was to compare the distribution of radio-opaque dye within the adductor canal in the presence or absence of an inflated thigh tourniquet. MethodsBilateral ultrasound-guided adductor canal blocks were performed on the thawed lower limbs of five fresh frozen human cadavers. The left and right lower cadaver limbs were randomised to receive or not receive a thigh tourniquet inflated to 300 mm Hg for 1 h. X-rays with iohexol radio-opaque dye were obtained in four views, and fiducial markers inserted as reference points. Virtual editing technology was used to recreate outlines representing the distribution of the radio-opaque dye and superimpose these on anatomical images. ResultsRadio-opaque dye was distributed on the medial aspect of the thighs with entire and well circumscribed margins. The majority of the radio-opaque dye was confined within the adductor canal. Superior-inferior dye distribution was 315 mm [95% confidence intervals (CI) 289–342] and 264 mm (95% CI 239–289) in the presence and absence of an inflated thigh tourniquet, respectively (diff 95% CI −80.46 to −22.22, P=0.0081). Image analysis using the recreated radio-opaque outlines suggested that the most proximal point of the radio-opaque dye was 100 mm (95% CI 82–117) or 117 mm (95% CI 62–171) below the inguinal ligament in the presence and absence of an inflated thigh tourniquet, respectively (diff 95% CI −38 to 72, P=0.456). ConclusionsApplication and inflation of thigh tourniquets significantly increased the combined superior–inferior dye distribution within the adductor canal of cadaveric limbs. There was insufficient evidence to suggest significant proximal spread of 25 ml of local anaesthetic to involve the motor branches of the femoral nerve. In some patients, the local anaesthetic may reach the popliteal fossa in close approximation to the sciatic nerve.

Tourniquet pressure settings based on limb occlusion pressure determination or arterial occlusion pressure estimation in total knee arthroplasty? A prospective, randomized, double blind trial

ObjectiveThe aim of this study was to compare the limb occlusion pressure (LOP) determination and arterial occlusion pressure (AOP) estimation methods for tourniquet pressure setting in adult patients undergoing knee arthroplasty under combined spinal-epidural anesthesia. MethodsNinety-three patients were randomized into two groups. Pneumatic tourniquet inflation pressures were adjusted based either on LOP determination or AOP estimation in Group 1 (46 patients, 38 female and 8 male; mean age: 67.71 ± 9.17) and Group 2 (47 patients, 40 female and 7 male; mean age: 70.31 ± 8.27), respectively. Initial and maximal systolic blood pressures, LOP/AOP levels, required time to estimate AOP/determinate LOP and set the cuff pressure, initial and maximal tourniquet pressures and tourniquet time were recorded. The effectiveness of the tourniquet was assessed by the orthopedic surgeons using a Likert scale. ResultsInitial and maximal systolic blood pressures, determined LOP, estimated AOP, duration of tourniquet and the performance of the tourniquet were not different between groups. However, the initial (182.44 ± 14.59 mm Hg vs. 200.69 ± 15.55 mm Hg) and maximal tourniquet pressures (186.91 ± 12.91 mm Hg vs. 200.69 ± 15.55 mm Hg) were significantly lower, the time required to estimate AOP and set the tourniquet cuff pressure was significantly less (23.91 ± 4.77 s vs. 178.81 ± 25.46 s) in Group II (p = 0.000). No complications that could be related to the tourniquet were observed during or after surgery. ConclusionTourniquet inflation pressure setting based on AOP estimation method provides a bloodless surgical field that is comparable to that of LOP determination method with lower pneumatic inflation pressure and less required time for cuff pressure adjustment in adult patients undergoing total knee arthroplasty under combined spinal epidural anesthesia.

Obese patients require higher, but not high pneumatic tourniquet inflation pressures using a novel technique during total knee arthroplasty.

This study aims to investigate the effect of obesity on pneumatic tourniquet inflation pressures determined with a novel formula during total knee arthroplasty (TKA). Data of 208 patients (19 males, 199 females; mean age 69.8 years; range, 53 to 84 years) who were performed TKA between January 2013 and December 2016 were evaluated prospectively. Patients were divided into two groups as non-obese (body mass index [BMI] ≤30.0 kg/m2) and obese (BMI >30.0 kg/m2) according to BMI. Tourniquet inflation pressures were set using arterial occlusion pressure (AOP) estimation method and adding 20 mmHg of safety margin to AOP value. All patients were assessed intra- and postoperatively with outcome measures such as systolic blood pressure, AOP, tourniquet pressure and its effectiveness. The quality of the surgical field and complications were assessed by the surgical team in a blinded fashion. The study included 118 and 90 lower extremity operations in obese and non-obese groups, respectively. Compared to non-obese group; extremity circumference, initial and maximal systolic blood pressures, AOP values, initial and maximal tourniquet pressures were higher in obese group. The performance of the tourniquet was assessed as "excellent" and "good" at almost all stages of the surgical procedure in all patients in both groups. No complication occurred intra- or postoperatively. Compared to non-obese patients, higher tourniquet inflation pressure is required in obese patients during TKA due to their wider extremity circumference and higher systolic blood pressure profile.

The Role of the Tourniquet and Patella Position on the Compartmental Loads During Sensor-Assisted Total Knee Arthroplasty

BackgroundAn inflated tourniquet may diminish the natural excursion of the extensor mechanism and alter compartmental loads, affecting the surgeon's ability to accurately assess ligament balance during total knee arthroplasty (TKA). In addition, patella position (reduced, lateralized, or everted) has also been known to affect compartmental loads. This study used intraoperative sensing to assess how a combination of tourniquet inflation and patella position may affect medial and lateral compartmental loads during sensor-assisted TKA. MethodsFifty-six patients (13 men) with a mean age of 66 years (standard deviation, 8.66) and mean BMI of 31 kg/m2 (standard deviation, 6.66) undergoing primary cemented TKA for primary osteoarthritis were enrolled. After final prosthetic implantation, with the tourniquet inflated, medial and lateral compartment loads were obtained in the 10°, 45°, and 90° of flexion with the patella in reduced, lateralized, or everted positions. The tourniquet was deflated and this process repeated. Surgeons were blinded to the values as to not influence medial and lateral stressing of the knee. Linear regression was used to evaluate absolute loads. ResultsTourniquet inflation did not significantly alter compartmental loads regardless of knee flexion or patella position. Lateral compartment loads significantly increased as the patella moved from the reduced, to the lateralized, to the everted position with the tourniquet inflated or deflated. ConclusionTourniquet inflation did not significantly alter compartmental loads during sensor-assisted TKA. However, irrespective of tourniquet use, a lateralized or everted patellar position significantly increased lateral compartment loads.

Determination of Pneumatic Tourniquet Pressure of Lower Limb by Ultrasonic Doppler.

The aim of this study was to investigate the clinical effect of tourniquet inflation pressure setting by ultrasonic Doppler on lower limb operation. Ninety-six patients with total knee arthroplasty were selected in this study from January 2015 to December 2015. The patients were randomly divided into the study group and the control group with 48 cases in each group. In the control group, the tourniquet pressure is determined by the doctor's request for the patient's condition, but all the tourniquet pressure values should be 80 KPa or less. In the study group, ultrasonic Doppler was used to monitor the popliteal artery blood flow of surgery limb with the maximum systolic velocity in artery as a reference value. The pressure of pneumatic tourniquet gradually increased until the maximum systolic velocity was reduced to 0. At this time, the popliteal artery blood flow was not present. The 2 groups of patients with lower extremity tourniquet pressure, hemostatic effect of intraoperative tourniquet, and the incidence of adverse reaction using tourniquets were observed and recorded. In the study group, the lower extremity tourniquet pressure and the incidence of adverse reaction using tourniquets were all better than that in control group; the difference between 2 groups was significant (P < 0.05). There was no significant difference between the 2 groups in the effect of hemostasis and the time of tourniquet operation (P > 0.05). The method of ultrasonic Doppler setting lower extremity tourniquet pressure during the operation could not only ensure the hemostatic effect, but it could also provide the optimum individual pneumatic tourniquet pressure value for patients. In the meanwhile, it could reduce the incidence of adverse reaction using tourniquets effectively as well as improve the safety of the tourniquet. This method played an important role in the recovery of patients.

The Effects of Timing of Ankle Blocks in Forefoot, Midfoot, or Hindfoot Reconstruction With the Use of an Ankle Tourniquet.

Ankle blocks are used in the ambulatory surgery setting to control postoperative pain, which is often worst in the first 24 hours after surgery. We conducted a trial to determine whether the timing of ankle block administration in relation to ankle tourniquet inflation has an effect on perceived pain and narcotic consumption. A prospective randomized study was conducted between August 2015 and January 2016. Patients were assigned to three groups. In group A, an ankle block was performed before ankle tourniquet inflation; in group B, immediately after ankle tourniquet inflation; and in group C, immediately after ankle tourniquet inflation with additional local anesthetic placed around the incision at the end of the procedure. Pain was assessed by a visual analogue scale (VAS) score, which was recorded at discharge, 24 hours, 48 hours, and 2 weeks after surgery. Narcotic consumption was recorded at 24 and 48 hours after surgery. The only statistically significant difference in mean VAS scores occurred at 24 hours, when patients who received an ankle block after tourniquet inflation with local incisional anesthetic at closure (group C) had a mean VAS score 2.8 points lower (3.5 vs 6.3; P = .025) than those who received only an ankle block after tourniquet inflation (group B). There was no difference in narcotic consumption between groups at 24 and 48 hours. The timing of ankle block in relation to tourniquet inflation did not have an effect on pain control in forefoot, midfoot, and hindfoot reconstruction. The synergistic effect of an ankle block with additional incisional anesthetic at closure, is more effective than ankle block alone and is the ideal combination for postoperative pain control in foot surgery. Therapeutic, Level II: Prospective, comparative trial.

Ceftriaxone concentration at the surgical site following systemic and isolated upper limb injection.

Background and Aims:This study was conducted to find out the equipotent dose of isolated upper limb injection of ceftriaxone in the upper limb (IUL) surgeries under tourniquet that would attain a peak bone marrow concentration (Cmax) similar to systemic (ST) 1 g injection.Material and Methods:Patients were allocated into two groups – ST and IUL. ST group (n = 5) received 1 g of ceftriaxone 20 min before tourniquet inflation, and IUL group received calculated dose (n = 5 in each dosage, i.e., 200, 100, 75, and 50 mg) diluted in 50 mL of normal saline distally after tourniquet inflation. Venous and bone marrow samples were collected at various time intervals intra- and post-operatively. Ceftriaxone concentration was analyzed by high-performance liquid chromatography.Results:There was no significant difference between Cmax following ST 1 g injection and IUL injection with 75 mg (155.8 ± 2.1 vs 158.5 ± 3.1 μg/mL, respectively; P = 0.1). There was significant difference in area under curve (AUC) and t½ between ST 1 g injection and IUL injection with 75 mg of ceftriaxone (AUC 1285 ± 67 vs 784.4 ± 28 μg/mL/h, respectively; P < 0.001), (t½ 5.2 ± 0.5 vs 4.7 ± 0.3 h, respectively; P < 0.001). None of the patients in the ST and IUL groups had post-operative infection up to a period of 1 week duration.Conclusion:IUL injection with 75 mg of ceftriaxone can be equipotent and as effective as ST 1 g injection in upper limb orthopedic surgeries under tourniquet.