Pneumatic tourniquets are medical devices that occlude blood flow to distal part of extremities and are commonly used in upper limb surgeries to provide a dry, clean and bloodless field. To decrease pressure-related injuries and potential risk of complications subjected to the high inflation pressure of pneumatic tourniquet, minimal inflation pressures are recommended.
A new occlusion pressure mathematical model for the upper limb was established based on the correlation analysis between several possible influencing parameters and the minimal pneumatic tourniquet pressure at which the peripheral pulse disappeared was recorded using a digital plethysmograph. A prototype of an adaptive pneumatic tourniquet which automatically varies the pressure in the tourniquet cuff according to the above prediction model was developed for the upper limb which used the lowest possible inflation pressure to achieve occlusion. The prototype comprises a blood pressure monitoring module, an inflatable tourniquet cuff, and a pressure relief mechanism to maintain an optimal cuff inflation pressure. Simulation experiments were conducted to verify the function and stability of the designed adaptive pneumatic tourniquet and clinical experiments using volunteers were undertaken to evaluate the performance of the prototype design in achieving adequate haemostasis in the upper limb.
Results demonstrated that the mean arterial occlusion pressure was 152.3 ± 16.7 mmHg, obviously below the 250 to 300 mmHg previously recommended (J Bone Joint Surg Br 68:625-628, 1986 and Arthroscopy 11:307–311, 1995).
In conclusion, this adaptive method and apparatus which can provide minimal inflation pressure may be a clinically practical alternative for upper limb surgery performed with pneumatic tourniquets.
Pneumatic tourniquet; Upper limb; Arterial occlusion pressure; Microprocessor
A bloodless operative field is considered mandatory for most surgical procedures on the upper and lower extremity. This is accomplished by using either an Esmarch bandage or a pneumatic tourniquet, but a number of complications are associated with both. Nerve palsy is one of the most frequently encountered complications of this procedure. Wider cuffs have been found to cause reduced risk of tourniquet induced injury to the underlying soft tissues than the narrower ones due to the fact that lower occlusion pressures are caused by the former. To address and investigate this question, conduction in the median nerve has been measured proximal to tourniquet as well as distal to the tourniquet. Parameters of nerve conduction measured are nerve conduction velocity, latency and amplitude.
Sphygmomanometer cuffs with widths 14 cm and 7 cm were applied to the upper extremities of 20 healthy, normotensive volunteers (9 males and 11 females with age ranging from 22 to 27). Systolic blood pressure was measured first and then the cuff was inflated to about 20–30 mm Hg above it and was kept inflated for 15 minutes. Recordings were done prior to, for the period of tourniquet inflation, and following release of the tourniquet.
Nerve conduction was found to be more severely affected by the 14 cm cuff than the 7 cm cuff.
Wider cuffs resulted in more severe changes in the nerve. This brings us to the conclusion that though lower inflation pressures are required for the occlusion of the blood supply using wider cuffs, the nerve conduction is more severely affected by the wider ones. Both electrophysiological changes and occlusion pressure should be kept in mind while choosing the width of the cuff.
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.
Tourniquet; Upper limb; Limb occlusion pressure; Complications
Tourniquets are used to provide a bloodless surgical field for extremities. Hypotension due to vasodilation and bleeding after tourniquet deflation is a common event. Hemodynamic stability is modulated by the autonomic nervous system (ANS). Heart rate variability (HRV) is a sensitive method for detecting individuals who may be at risk of hemodynamic instability during general anesthesia. The purpose of this study was to investigate ANS function to predict hypotension after tourniquet deflation.
Eighty-six patients who underwent total knee replacement arthroplasty (TKRA) were studied. HRV, systolic blood pressure variability (SBPV) and baroreflex sensitivity (BRS) were analyzed. We assigned two groups depending on the lowest systolic blood pressure (SBP) or mean BP (MBP) after tourniquet release (Group H; SBP < 80 mmHg or MBP < 60 mmHg, Group S; SBP > 80 mmHg and MBP > 60 mmHg).
Fifteen patients developed severe hypotension and ten patients were treated with ephedrine. Of the parameters of HRV, SBPV, and BRS, only BRSSEQ was significant being low in Group H. BRS and high-frequency SBPV were correlated with the degree of MBP change after tourniquet deflation.
Preoperative low BRS is associated with hypotension after tourniquet deflation, suggesting the importance of baroreflex regulation for intraoperative hemodynamic stability.
Baroreflex sensitivity; Heart rate variability; Hypotension; Systolic blood pressure variability; Tourniquet deflation
This study reports the results of the clinical use of a new tourniquet system for surgery of foot and ankle that can determine tourniquet pressure in synchrony with systolic blood pressure (SBP). We prospectively applied additional pressure of 100 mmHg based on the SBP recorded before the skin incision in 100 consecutive procedures. There were 34 open reduction internal fixation procedures, 26 lateral colateral ligament repair or reconstruction, 16 Achilles tendon repairs, nine arthroscopic procedures such as removal of loose body or accessory bone and synovectomy, seven corrective osteotomy and eight others such as removal of tumour, ankle fusion, and bone graft. The average initial tourniquet pressure was 211 mmHg. The average maximum SBP change during surgery was 28 mmHg. All cases maintained an excellent operative field without measurable bleeding and there were no postoperative complications. Fifty-five cases had a lower intra-operative SBP than the initial value. Since a tourniquet should be applied at the lowest pressure possible for maintaining a bloodless surgical field, the new system appears to be practical and reasonable, as compared to conventional tourniquets, which maintain the initial pressure.
Tourniquets are commonly used in limb surgeries, be it orthopedic or plastic surgeries. But the inflation pressures, the duration, and release guidelines are still not clear. According to a survey, majority of orthopedic surgeons inflate the tourniquet to fixed pressures for the upper and the lower limbs without considering the baseline blood pressure of the patient on whom the tourniquets are being applied. This review was designed to recall and review the safe use of tourniquets and the various techniques that can be employed to minimize the complications of tourniquet use. Google, science direct, and pubmed were searched for appropriate literature and relevant articles were identified.
Tourniquet; orthopaedic surgery; tourniquet and complications
A pneumatic tourniquet is generally used to achieve a bloodless operation field in hand surgery. However, this has changed with tumescent solution-based wide-awake surgery. This study is a preliminary prospective case series study to elaborate the formula and indications of the tumescent technique in hand surgery without a tourniquet.
Seven patients (age range, 4 months to 37 years) underwent hand or upper extremity surgery for conditions such as nerve palsy, electric burn defect, fingertip injury, contracture, constriction ring syndrome, or acrosyndactyly. A "one-per-mil" tumescent solution (epinephrine 1:1,000,000+20 mg lidocaine/50 mL saline) was used to create a bloodless operating field without a tourniquet. Observation was performed to document the amount of solution injected, the operation field clarity, and the postoperative pain.
The "one per mil" epinephrine solution showed an effective hemostatic effect. The tumescent technique resulted in an almost bloodless operation field in the tendon and in the constriction ring syndrome surgeries, minimal bleeding in the flap and contracture release surgeries, and acceptable bleeding in acrosyndactyly surgery. The amount of solution injected ranged from 5.3 to 60 mL. No patient expressed significant postoperative pain. Flap surgeries showed mixed results. One flap was lost, while the others survived.
Epinephrine 1:1,000,000 in saline solution is a potential replacement for a tourniquet in hand surgery. Further studies are needed to delineate its safety for flap survival.
Epinephrine; Lidocaine; Upper extremity
Tourniquets are commonly used in penile surgery to achieve a bloodless operating field or produce artificial erections intraoperatively. Several techniques have been described, but there is a paucity of data and a lack of guidelines to direct their safe use. In penile surgery, it is the local rather than systemic effects of tourniquet use that are the main concern. Tourniquet time should be kept to a minimum, as the limited data available suggests that reperfusion injury can occur even after short periods of ischaemia. High risk groups such as diabetics and arteriopaths are at particular risk. Further studies are needed to determine safe tourniquet times and pressures.
hypospadia; ischaemia; penile surgery; reperfusion injury; tourniquet
Surgical tourniquets are commonplace in lower limb surgery. Several studies have shown that tourniquets can be a potential source of microbial contamination but have not compared the use of sterile versus non-sterile tourniquets in the same procedures.
Patients undergoing elective orthopaedic lower limb surgery were randomised prospectively to use of non-sterile pneumatic tourniquet or sterile elastic exsanguination tourniquet (S-MART™, OHK Medical Devices, Haifa, Israel). Samples were taken from the ties of the non-sterile tourniquet prior to surgery and from the sterile tourniquets at the end of the operation in a sterile fashion. These were then sealed in universal containers and immediately analysed by the microbiology department on agar plates, cultured and incubated.
Thirty-four non-sterile tourniquets were sampled prior to surgical application, twenty-three of which were contaminated with sev-eral different organisms including coagulase-negative Staphylococcus spp, Staphylococcus aureus, Sphingomonas pau-cimobilis, Bacillus spp, and coliforms. Thirty-six sterile tourniquets were used, with no associated contamination.
There was significant contamination of 68% of orthopaedic surgical tourniquets. These are used regularly in proce-dures involving the placement of prosthesis and metalwork, and can act as a potential source of infection. We recommend the use of sterile single-use disposable tourniquets where possible. The availability of an alternative should now set the new standard of care and we rec-ommend adopting this as a current NICE guideline for control of surgical site infection.
Tourniquet; Equipment contamination; Orthopedic equipment; Lower extremity; Agar plate
Pneumatic tourniquets are used frequently in orthopaedic theatres to provide a bloodless field whilst operating on the extremities. Their use has given rise to complications and preventable damage due to over-pressurisation and prolonged application. We designed a questionnaire to assess the knowledge on tourniquet use among operating department assistants (ODAs) and specialist registrars (SpRs) in orthopaedic surgery.
SUBJECTS AND METHODS
A questionnaire was constructed using set guidelines from the Association of periOperative Registered Nurses (AORN) for recommended practice of tourniquet application. This was distributed to orthopaedic registrars with varying levels of experience and ODAs from five different NHS hospitals. The unpaired, two tailed t-test was used to test for statistical significance of results.
A total of 54 completed questionnaires were collected for analysis. The study population included 29 orthopaedic SpRs and 25 ODAs. The mean score for the orthopaedic SpRs as a group was 41.3% (SD 6.85; range, 29.0–54.8%). The mean score for the ODAs was 46.7% (SD 9.64; range, 23.3–62.9%) with a P-value of 0.024.
Most surgeons are taught how to use pneumatic tourniquets by their senior colleagues as no formal teaching is given. Most of the complications are infrequent and preventable. However, their consequences can be devastating to the patient with medicolegal implications. Our results show suboptimal knowledge of tourniquets and their use among SpRs and ODAs. This study highlights the need for amendments in training to improve the knowledge and awareness of medical practitioners on the application and use of tourniquets to prevent adverse events and improve patient safety.
Tourniquets; Education; Extremities; Orthopaedics; Ischaemia
The aim of the present study was to compare the pain levels resulting from the use of a silicone ring tourniquet (SRT) to those resulting from the use of a classic pneumatic cuff tourniquet (PT) in patients undergoing carpal tunnel release under local anesthesia.
Materials and methods
Fifty patients that underwent carpal tunnel release under local anesthesia were randomized using the technique of stratified randomization by minimization. A forearm tourniquet was applied: a standard PT was used in 25 patients, and an SRT was used in the other 25 patients (the model of SRT used was selected according to the standard systolic blood pressure). Patient demographics and complications were recorded. Pain levels were assessed with the visual analogue scale and were recorded (a) just after tourniquet application, (b) 5 min after tourniquet application, and (c) just before tourniquet removal.
There was no statistical significant difference in patient demographics between the two groups. The mean tourniquet time was similar for both groups (p = 1.000). The difference between the mean final pain level and the mean initial pain level was statistically significant for the SRT group (p = 0.010) and highly statistically significant for the PT group (p < 0.001). The mean final pain level for the PT group was higher than that for the SRT group (p = 0.043).
According to the findings of this study, in patients who underwent carpal tunnel release under local anesthesia, the pain levels at the end of the operation and those just before the removal of the tourniquet were higher in the PT group than in the SRT group of patients.
Tourniquet; Pneumatic tourniquet; Silicon ring tourniquet; Tourniquet pain
A small pneumatic cuff inflated around the knee was used to produce tourniquet paralysis in baboons. A cuff pressure of 1,000 mm Hg maintained for one to three hours produced paralysis of distal muscles lasting up to three months. Nerve conduction studies showed that most of the motor fibres to the abductor hallucis muscle were blocked at the level of the cuff and that they conducted impulses normally in their distal parts. There was a significant correlation between the duration of compression and that of the subsequent conduction block. When tested two to three weeks after the tourniquet, the amplitude of the response of m. abductor hallucis to nerve stimulation distal to the cuff was usually slightly reduced compared with the precompression figure. This was assumed to mean that a small proportion of the motor fibres had undergone Wallerian degeneration as a result of compression. Maximal motor conduction velocity was reduced in recovering nerves. It was also reduced when a cuff pressure of 500 mm Hg was used, which was insufficient to produce persistent conduction block. In such cases a reduced velocity without evidence of block could be demonstrated 24 hours after compression. Ascending nerve action potentials were recorded from the sciatic nerve in the thigh, with stimulation at the ankle. Before compression the fastest afferent fibres had a significantly higher velocity than the fastest motor fibres in the same nerve trunk. Results after compression suggested that the high-velocity afferent fibres had a susceptibililty to the procedure similar to that of the fastest motor fibres.
A prospective randomised trial of 50 patients was carried out to assess the autoclavable Lofquist cuff (Boazal, Sweden) as a tourniquet in varicose vein surgery and determine the effect on bleeding, bruising, cosmesis and patient pain and activity. Patients undergoing unilateral long saphenous vein ligation, stripping and avulsions were randomised to tourniquet or no tourniquet. Lofquist cuffs were applied after inflation to 120 mmHg to the upper thigh for the duration of the surgery. Varicose vein grade, duration of surgery, blood loss, extent of bruising at 7 days, pain and activity scores over the first week, and wound complications and cosmetic result at 6 weeks were recorded. Patients' age, sex, and varicose vein grade were similar in the two groups. Peroperative blood loss (median, range) was significantly reduced in the tourniquet group (0 ml, 0-20 ml) compared to the no tourniquet group (125 ml, 20-300; P < 0.01). Operative time and thigh bruising (median, range) were also reduced in the tourniquet group (30 min, 11-47 min; 72 cm2, 30-429 cm2), respectively, compared to the no tourniquet group (37 min, 18-50 min; 179 cm2, 24-669 cm2) both (P < 0.01). There was no difference in pain and activity scores in the two groups and cosmetic results were also similar. The use of the Lofquist cuff tourniquet during varicose vein surgery reduces peroperative blood loss, operative time and postoperative bruising without any obvious drawbacks.
The common causes of rhabdomyolysis include trauma, hypoxia, drugs, toxins, infections and hyperthermia. Operative insults, including direct trauma and ischemia, have the potential to cause the development of rhabdomyolysis. Pneumatic tourniquets used during arthroscopic knee surgery to prevent blood loss have led to many complications such as nerve paralysis and vascular injuries. Rhabdomyolysis can also be caused by prolonged pneumatic tourniquet application without a midapplication release, and also from an increased application pressure, but the actual incidence of this is low. In order to prevent rhabdomyolysis, the clinicians must be aware of such risks and follow strict guidelines for the application time, the midapplication release and also the inflation pressure. Vigorous hydration and postoperative patient surveillance are helpful to prevent rhabdomyolysis. We have recently experienced a case of rhabdomyolysis after the arthroscopic knee surgery, and the rhabdomyolysis could have been associated with the use of a pneumatic tourniquet.
Rhabdomyolysis; Tourniquets; Kidney failure, acute
Tourniquets are employed widely in orthopaedic surgery. The use of the same tourniquet on a repetitive basis without a standard protocol for cleaning may be a source of cross-infection. This study examines the contamination of the tourniquets in our institution.
MATERIALS AND METHODS
Agar plates were used to take samples from 20 tourniquets employed in orthopaedic procedures. Four sites on each tourniquet were cultured and incubated at 37°C for 48 h.
All sampled tourniquets were contaminated with colony counts varying from 9 to > 385. Coagulase-negative Staphylococcus spp. were the most commonly grown organisms from the tourniquets (96%).Some tourniquets had growths of important pathogens including methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas spp., and S. aureus. On cleaning five tourniquets with Clinell (detergent and disinfectant) wipes (GAMA Healthcare Ltd, London, UK), there was a 99.2% reduction in contamination of the tourniquets 5 min after cleaning.
In addition to the manufacturers' guidelines, we recommend the cleaning of tourniquets with a disinfectant wipe before every case.
Tourniquet; Agar plate; Colony count; Contamination
Activation of the endothelium, complement activation and generation of cytokines are known events during ischemia-reperfusion (I/R) that mediate tissue injury. Our aim was to elucidate their respective participation at the onset of the reperfusion phase. Tourniquet application in hand surgery causes short-term ischemia, followed by reperfusion and was therefore used as the model in this study.
Ten patients were included in the study after obtaining informed consent. A tourniquet was placed on the upper arm and inflated to 250 mmHg for 116 ± 16 min, during which the surgery was performed. Venous blood and tissue samples from the surgical area were taken at baseline as well as 0, 2, and 10 min after reperfusion and analyzed for the following parameters: Endothelial integrity and/or activation were analyzed by measuring heparan sulfate and syndecan-1 in serum, and vWF, heparan sulfate proteoglycan as well as CD31on tissue. Complement activation was determined by C3a and C4d levels in plasma, levels of C1-inhibitor in serum, and IgG, IgM, C3b/c, and C4b/c deposition on tissue. Cytokines and growth factors IL-5, IL-6, IL-7, IL-8, IL-10, IL-17, G-CSF, GM-CSF, MCP-1, TNFα, VEGF, and PDGF bb were measured in the serum. Finally, CK-MM levels were determined in plasma as a measure for muscle necrosis.
Markers for endothelial activation and/or integrity as well as complement activation showed no significant changes until 10 min reperfusion. Among the measured cytokines, IL-6, IL-7, IL-17, TNFα, GM-CSF, VEGF, and PDGF bb were significantly increased at 10 min reperfusion with respect to baseline. CK-MM showed a rise from baseline at the onset of reperfusion (p < 0.001) and dropped again at 2 min (p < 0.01) reperfusion, suggesting ischemic muscle damage.
In this clinical model of I/R injury no damage to the endothelium, antibody deposition or complement activation were observed during early reperfusion. However, an increase of pro-inflammatory cytokines and growth factors was shown, suggesting a contribution of these molecules in the early stages of I/R injury.
Tourniquet; Hand surgery; Ischemia; Reperfusion injury; Cytokines; Complement; Endothelium; Glycocalyx
Purpose. Tourniquet-induced nerve injuries have been reported in the literature, but even if electromyography abnormalities in knee surgery are frequent, only two cases of permanent femoral nerve palsies have been reported, both after prolonged tourniquet time. We report a case of tourniquet-related permanent femoral nerve palsy after knee surgery. Case Report. We report a case of a 58-year-old woman who underwent surgical treatment of a patella fracture. Tourniquet was inflated to 310 mmHg for 45 minutes. After surgery, patient complained about paralysis of the quadriceps femoris with inability to extend the knee. Electromyography and nerve conduction study showed a severe axonal neuropathy of the left femoral nerve, without clinical remission after several months. Discussion. Even if complications are not rare, safe duration and pressure for tourniquet use remain a controversy. Nevertheless, subtle clinical lesions of the femoral nerve or even subclinical lesions only detectable by nerve conduction and EMG activity are frequent, so persistent neurologic dysfunction, even if rare, may be an underreported complication of tourniquet application. Elderly persons with muscle atrophy and flaccid, loose skin might be in risk for iatrogenic nerve injury secondary to tourniquet.
We set out to determine if arthroscopic knee surgery was acceptable to patients and their surgeon when carried out using a local anaesthetic infiltration technique. Patients awaiting arthroscopy were randomly allocated to have either a local or a general anaesthetic. The same surgeon (NPT) carried out all the procedures. The demographic profile was similar in the two groups, as were the diagnosis and the surgical procedures. The only difference between the two groups was that those performed under local anaesthesia did not have a limb tourniquet inflated. The time spent in the theatre suite was similar in each group. This did not include the recovery time in the general anaesthetic group. The duration of the operation was longer in the local anaesthetic group (P = 0.05). A simple 0 to 10 scoring system indicated that patients preferred a local anaesthetic but the surgeon preferred to have the patient asleep (P > 0.05). Those having a local anaesthetic required less physiotherapy (P = 0.025) and more of them returned to work and sport earlier (P = 0.05). We attributed this to not having sustained pressure-induced tissue damage to the thigh muscle as they did not have a tourniquet inflated. We had a 4% failure rate in the local anaesthetic group. Arthroscopic surgery is already a well-established day case procedure and our findings have a financial implication (a saving of 25 pounds per case) as well as identifying a safer technique in the medically unfit. Unfortunately, this technique is not suitable for the investigation and treatment of all knee problems. There are certain constraints, viz the very anxious patient, acute problems, children, larger arthroscopic procedures and the inability to perform an examination under anaesthetic but, overall, it is a useful and effective way of performing a common surgical procedure.
Extra-articular extravasation of irrigation fluid is relatively common around entry incisions and is usually limited to the subcutaneous tissue. Very rarely, extravasation occurs above the knee, in the thigh and even up into the pelvis. We are reporting the second case of irrigation fluid extravasation during a knee arthroscopy, which spread up to the thigh, groin and perineum during anterior cruciate ligament reconstruction, whilst the tourniquet was inflated. In our case, we think that the extravasation was caused by a fault in the pressure sensor due to the fact that the reservoir was over-filled. The irrigation pressure was therefore too high, and the irrigation fluid was able to diffuse, despite the presence of a pneumatic tourniquet, up past the thigh.
Knee; Aneterior cruciate ligament; Complications
A 25 yr old 60 kg haemoglobin SS male presented with a 3 year history of a discharging sinus in the left upper arm. His last crisis was ten years earlier; while his stable haemoglobin concentration was 10 g/dl.
Examination revealed healthy looking, well hydrated man. He had left upper arm chronic osteomyelitis which was diagnosed radiologically. He was scheduled for an elective saucerization and sequestrectomy. Tourniquet was applied to reduce blood loss and maintain a relatively bloodless field at surgery; and nitrous oxide/oxygen/halothane relaxant technique of anaesthesia was adopted.
No perioperative problems were encountered and the patient made remarkable improvement and was discharged home. At post surgical review a few weeks after, he was stable and well.
To evaluate the usefulness of the tourniquet placed at the distal forearm, 30 patients were operated with the tourniquet set at the distal forearm using nerve-block anaesthesia. Pain during surgery, flexion of the fingers, bloodless field, and general complications during surgery and 18 months thereafter were recorded. The mean time of ischemia was 19.6±7.5 (10–50) min. A bloodless field was achieved in all cases, and pain during operation was low. Flexion of the fingers were found in most cases but was reducible and not annoying for the surgeon. There were no serious complications during surgery or at follow-up. The tourniquet placed at the distal forearm is painless, safe, and useful in hand surgery.
The relative importance of ischaemic and direct mechanical injury to nerves compressed by a tourniquet, in the pathogenesis of tourniquet paralysis in man has not been established. To investigate this question, conduction in ulnar or median nerve fibres has been measured in healthy subjects both at the level of the pneumatic tourniquet and distal to the tourniquet. Measurement was prior to, for the period of tourniquet inflation, and following release of the tourniquet. The earliest conduction delays and block were observed at the level of the tourniquet, particularly across the proximal tourniquet border zone. However, a proximal to distal progression in conduction abnormalities distal to the tourniquet suggested that the earlier conduction abnormalities at the level of the tourniquet were primarily ischaemic in origin. Mechanical compression, however, probably contributed to disproportionate conduction delays and blocks across the border zones of the tourniquet.
Inflation and deflation of a pneumatic tourniquet used in total knee replacement surgery induces various changes in patient's hemodynamic and metabolic status, which may result in serious complications, especially in aged patients. Near-infrared spectroscopy (NIRS) is a monitoring device designed to estimate the regional cerebral oxygen saturation. We evaluated the effect of tourniquet deflation on hemodynamics and regional cerebral oxygen saturation in aged patients undergoing total knee replacement surgery, using NIRS.
Twenty-eight American Society of Anesthesiologists physical status I or II patients, over the age of sixty-five years undergoing total knee replacement surgery, were included. Under general anesthesia, the mean arterial pressure (MAP), heart rate (HR), cardiac output (CO), stroke volume (SV), and regional cerebral oxygen saturation (rSO2) were recorded before induction of anesthesia and every 2 min after tourniquet deflation for 20 min. Arterial blood gas analysis was performed 5 min before, in addition to 0, and 10 min after tourniquet deflation.
The decrease of rSO2 was not significant during 20-min deflation period. MAP, CO and SV showed significant decrease during 2 to 12, 4 to 6 and 2 to 6-min period after tourniquet deflation, respectively (P < 0.05). There was no relationship between a maximal decrease of MAP and rSO2.
In aged patients undergoing total knee replacement surgery under general anesthesia, tourniquet deflation caused significant changes in hemodynamic and metabolic status, but not in regional cerebral oxygen saturation. It is recommended to monitor neurologic status, as well as hemodynamic and metabolic status to avoid serious complications, especially in aged patients.
Aged; Hemodynamics; Near-Infrared spectroscopy; Tourniquet
Arrhythmias resulting in cardiac arrest during electroconvulsive therapy have been reported. Most reported cases of cardiac arrest had asystole as the initial rhythm. Pulseless electrical activity as an initial rhythm of cardiac arrest during electroconvulsive therapy has never been reported. Also, thromboembolism after inflation of pneumatic tourniquet during lower limb surgery has been reported but never following tourniquet inflation during an electroconvulsive therapy.
We report a case involving an 81- year- old female who presented to us for an electroconvulsive therapy for severe depression and developed pulseless electrical activity immediately after electroconvulsive therapy. She was successfully resuscitated and was later found to have bilateral pulmonary emboli with a complete occlusion of the right lower lobe pulmonary artery. The source of embolus was from her left lower extremity deep venous thrombus, which we believe, got dislodged intraoperatively after inflation of pneumatic tourniquet. Our patient not only survived the massive pulmonary embolus, but also showed significant improvement in her mental status compared to her pre-admission level at the time of discharge to a sub-acute rehabilitation centre.
We recommend that patients who are elderly and at high risk of thromboembolism should selectively undergo a preoperative doppler ultrasound for deep venous thrombosis. Also, selective application of tourniquet in the upper limb, to monitor for seizure activity, would reduce the incidence of pulmonary thrombo-embolism as embolic events are significantly less from deep venous thromboses of upper extremities when compared to lower extremities.
ECT; Pulseless electrical activity; Tourniquet; Pulmonary embolism
Aims: Prolonged tourniquet inflation produces a hyperdynamic cardiovascular response. We investigated the effect of continuous remifentanil infusion on systemic arterial pressure, heart rate, and cardiac output changes during prolonged tourniquet use in elderly patients under sevoflurane/N2O general anesthesia.
Methods: Thirty female patients scheduled for knee replacement arthroplasty were infused with either remifentanil at a target organ concentration of 2.0 ng/mL (remifentanil group, n = 15) or saline (control group, n = 15) after induction of anesthesia. Anesthesia was maintained with sevoflurane and N2O. Heart rate (HR), systolic arterial pressure (SAP), diastolic arterial pressure (DAP), cardiac index (CI), total systemic vascular resistance index (TSVRI), BIS, end-tidal sevoflurane concentration (EtSEVO), and end-tidal carbon dioxide concentration (EtCO2) were measured during the study period.
Results: There were significant differences in mean HR, SAP, DAP, and EtSEVO over time between the groups (P = 0.047, P < 0.001, P = 0.017, and P < 0.001, respectively). There was a statistically significant time trend effect (P < 0.001) in HR, SAP, DAP, and CI between the groups, with a statistically significant time-group interaction between the two groups (P = 0.02, 0.007, 0.001, 0.01, respectively).
Conclusion: The present study demonstrated that infusion with remifentanil prevented an increase in hemodynamic pressure during tourniquet inflation in elderly patients under sevoflurane/N2O general anesthesia.
general anesthesia; knee replacement arthroplasty; remifentanil; tourniquet.