Survey of tourniquet use in orthopaedic foot and ankle surgery

BACKGROUND: Tourniquet technique varies among foot and ankle surgeons, and to establish a standard practice guideline the current standard of care should be examined. METHODS: One hundred and forty responses were received after 253 surveys were mailed to American Orthopaedic Foot and Ankle Society (AOFAS) members, concerning type of tourniquets, location, and pressures used. RESULTS: Cuff pressures most commonly used were 301 to 350 mmHg for thigh cuffs (49% of thigh cuff users) and 201 to 250 mmHG for calf and ankle cuffs (52% of calf cuff users, 66% of ankle cuff users). A substantial number of foot and ankle surgeons who use calf and ankle cuffs frequently use pressures above 250 mmHg (41% of calf cuff users, 19% of ankle cuff users). Only 9% use limb occlusion pressure when determining cuff pressure. CONCLUSION: Based on the existing evidence-based literature these pressures may be higher than necessary for many patients, and increased adoption of optimal pressure setting techniques as reported in the literature may help reduce tourniquet pressures used and risk of tourniquet injury. Respondents reported experiencing or hearing reports of breakthrough bleeding, nerve injury, and skin injuries under the cuff.     

Continuous extradural infusion of ropivacaine for prevention of postoperative pain after major orthopaedic surgery

We studied 151 patients undergoing total hip or knee arthroplasty, or cruciate ligament reconstruction in a multicentre study in Australia and New Zealand. Patients were openly allocated randomly to one of five treatment groups or to a control group. General anaesthesia was induced after introduction of extradural block with 0.5% ropivacaine. After surgery, patients received an extradural infusion of 0.2% ropivacaine at 6, 8, 10, 12 or 14 ml h-1 or received no postoperative extradural infusion (control group). All patients had access to i.v. PCA morphine for supplementary analgesia. Morphine consumption was lower in all treatment groups compared with the control group, decreasing with increasing ropivacaine infusion rate. Median VAS scores were lower in all ropivacaine infusion groups compared with the control group for the first 10 h of the study; however by the end of the study, VAS scores were similar in all groups. The higher ropivacaine infusion rates caused a slower convergence of spread of the initial sensory block and a higher degree of motor block. The overall incidence of side effects was similar, with the exception of a higher incidence of urinary retention and hypotension in the groups receiving the higher rates of ropivacaine. The quality of treatment scores were similar for all treatment groups.      

Comparison of extradural fentanyl, bupivacaine and two fentanyl-bupivacaine mixtures for pain relief after abdominal surgery

Fentanyl 50 µg, bupivacaine 50 mg and two mixtures containingfentanyl 50 ng and bupivacaine 25 mg or 12.5 mg (0.25 and 0.125%),respectively, in a volume of 10 ml were administered via thoracicextradural catheters to 24 patients after major abdominal surgery.All patients received all four treatments, in a randomized order,so that each patient received one of the 24 possible combinationsof the four treatments. Pain relief was assessed by a linearanalogue pain scale and the Prince Henry Hospital pain score.The duration of pain relief, effects on ventilatory frequency,heart rate, arterial pressure and central venous pressure werealso recorded. Mean reductions in the analogue pain scale forfentanyl, bupivacaine, and fentanyl in 0.25% and 0.125% bupivacainewere 80 (sem 5)%, 87 (4)%, 86 (5)% and 77 (5)%, respectively(ns). Pain scores decreased by 62(6)%, 83(5)%, 77 (6)% and 72(6)%, respectively (ns). Mean arterial pressure decreased to90 (2)%, 70 (2)%, 81 (2)% and 82 (3)%, respectively, of pretreatmentvalues. In this respect, bupivacaine alone was significantlydifferent from the three other treatments (P < 0.001). Hypotension(reduction in arterial pressure greater than 25% of pretreatmentmean arterial pressure) was also more frequent after bupivacainealone (P < 0.01). Effects on ventilation, heart rate andcentral venous pressure did not differ between the four treatments.We conclude that in patients who had undergone major abdominalsurgery, analgesia after thoracic extradural injection of fentanyl50 µg did not differ significantly from analgesia after0.5% bupivacaine 10 ml, or the fentanyl-bupivacaine mixtures.Bupivacaine alone caused a greater decrease in arterial pressureand a higher incidence of hypotension than fentanyl or the fentanyl-bupivacainemixtures.     

Epinephrine decreases the dose of hyperbaric bupivacaine necessary for tourniquet pain blockade during spinal anesthesia for total knee replacement arthroplasty

Purpose

We quantified the dose-sparing effect of epinephrine by comparing the median effective dose (ED₅₀) of intrathecal hyperbaric bupivacaine co-administered with epinephrine with the ED₅₀ of intrathecal hyperbaric bupivacaine alone.

Methods

Three groups were randomly generated from 162 patients undergoing total knee replacement arthroplasty under combined spinal and epidural anesthesia: Group B (bupivacaine), Group BE1 (bupivacaine plus epinephrine 100 μg), and Group BE2 (bupivacaine plus epinephrine 200 μg). Each group was further divided by bupivacaine doses of 6, 7, 8, 9, 10, or 11 mg. The anesthesia was defined as successful if a bilateral T12 sensory block occurred within 15 min, and no intraoperative epidural supplement was required. The ED₅₀ and ED₉₅ for successful anesthesia and successful tourniquet pain blockade were determined separately by probit regression analysis.

Results

The ED₅₀ and ED₉₅ of intrathecal hyperbaric bupivacaine for successful anesthesia were not different among the groups: the ED₅₀ values were 7.1 mg [95 % confidence interval (95 % CI) 6.0–8.0 mg] in Group B, 6.2 mg (95 % CI 4.8–7.2 mg) in Group BE1, and 6.3 mg (95 % CI 4.9–7.2 mg) in Group BE2. However, the ED₅₀ and ED₉₅ values for tourniquet pain control were significantly smaller in Groups BE1 and BE2 than in Group B: the ED₅₀ values were 7.2 mg (95 % CI 6.3–7.9 mg), 5.5 mg (95 % CI 4.1–6.3 mg), and 5.3 mg (95 % CI 3.7–6.2 mg) in Groups B, BE1, and BE2, respectively. The incidence of tourniquet pain was significantly lower in Groups BE1 and BE2 than in Group B. The time to patients’ requests for supplemental analgesia was significantly longer in Groups BE1 and BE2 than in Group B.

Conclusions

Intrathecal epinephrine did not decrease the dose of intrathecal hyperbaric bupivacaine required for successful anesthesia. However, it reduced the dose required for tourniquet pain blockade.     

Comparison of ropivacaine and bupivacaine in extradural analgesia for the relief of pain in labour

Forty women having requested extradural analgesia for labourwere allocated randomly to receive 0.5% ropivacaine or bupivacaine10 ml as the main dose. When a top-up was requested, 0.25% ropivacaineor bupivacaine 10 ml was given (the same drug as the main dose).The study ended when a second top-up was requested or deliveryof the baby occurred. Pain from two contractions was assessedbefore extradural block by visual analogue scoring and thereafterwith every contraction. Sensory block and motor block were assessedat intervals. The only significant difference between the groupswas a shorter onset of pain relief after the main dose of bupivacaine;there were no other significant differences in duration, onsetof pain relief after top-up, quality of analgesia, spread ofsensory block and motor block between the groups. Cardiovascularchanges and neonatal outcome were similar in the two groups(Br. J. Anaesth. 1995; 74: 261–265)     

Addition of glucose to bupivacaine in spinal anesthesia increases incidence of tourniquet pain

The effect of baricity of 0.5% bupivacaine on the incidence of tourniquet pain when used for spinal anesthesia was evaluated in 60 patients undergoing orthopedic surgery. Three ml of either hyperbaric (8% glucose) or isobaric (glucose-free) solution was used. A standard 7-cm orthopedic tourniquet was applied at the thigh and was inflated to 300 mm Hg for 2 hr or until the patient experienced pain from the tourniquet. During application time, the levels of sensory block to pin prick were similar in the groups. The incidence of tourniquet pain in the glucose-free group (4/30) was significantly lower than in the hyperbaric group (11/30).     

Effects of acetylcysteine and ischaemic preconditioning on muscular function and postoperative pain after orthopaedic surgery using a pneumatic tourniquet

BACKGROUND AND OBJECTIVE: The use of a pneumatic tourniquet can induce muscular and neurological complications in the operated limb. The genesis of these injuries could involve an ischaemia/reperfusion phenomenon and a compression under the cuff. We evaluated effects of an antioxidant, acetylcysteine and ischaemic preconditioning on the rhabdomyolysis and postoperative pain following a knee ligamentoplasty using a pneumatic tourniquet. METHODS: We included 31 patients scheduled for a knee ligamentoplasty randomly assigned in three groups (control, acetylcysteine 1200 mg the day before and 600 mg at the operative day, ischaemic preconditioning). RESULTS: There was a moderate rise in myoglobin and creatinine phosphokinase with no significant difference between the three groups. The muscular functional parameters were similar in all the groups. However, the morphine consumption within the first 48 h was smaller in the treatment groups (0.22 +/- 0.31 mg kg-1 and 0.22 +/- 0.23 mg kg-1 in the preconditioning and antioxidant groups, respectively) than in the control group (0.47 +/- 0.33 mg kg-1, P <0.05). CONCLUSIONS: Acetylcysteine and ischaemic preconditioning do not decrease the extent of rhabdomyolysis related to the use of a pneumatic tourniquet and do not improve the postoperative muscle recovery. On the other hand, they allow a significant reduction in the postoperative morphine consumption.     

The effects, risks, and guidelines for radiation use in orthopaedic surgery

Radiation is used during orthopaedic surgery in more than 15 million studies performed yearly. The biologic effects of radiation have been shown to inhibit mitosis by producing irrepairable deoxyribonucleic acid double strand breaks or create structural changes by damaging the nucleus, thereby producing potential genetic transmissions. Although human cells are thought to be resistant to malignant change and no studies have shown toxic effects resulting from long-term exposure to low-dose radiation, risks still are assumed. To decrease all risks, radiographic units should undergo periodic calibration, surgeons should wear protective devices, increase their working distance from the x-ray beam, and limit their duration of radiation exposure by making certain that they follow the guidelines set forth by the National Council for Radiation Protection and Measurement.     

Single bolus compared with a fractionated dose injection technique of bupivacaine for extradural Caesarean section: effect on uteroplacental and fetal haemodynamic state

We studied 26 healthy parturients undergoing elective Caesarean section, allocated randomly to receive extradural block with 0.5% plain bupivacaine in a double-blind manner in either a single bolus or fractionated doses. After a 3-ml test dose, an additional 20 ml of bupivacaine were given over a 5-min period in the single bolus group (n = 13) and over a 25-min period in the fractionated dose group (n = 13). We studied the effects of bupivacaine on blood flow velocities in the maternal placental and non-placental uterine and fetal umbilical arteries before and four times during establishment of extradural block using a pulsed colour Doppler technique. Median sensory block reached T3 in the single-dose group compared with T4 in the fractionated-dose group. Two subjects in each group required i.v. ephedrine to correct transient hypotension (systolic arterial pressure < 90 mm Hg). Blood flow velocity waveform indices of the uterine and umbilical arteries did not differ significantly within or between groups during the study. There was no significant difference in neonatal outcome, as assessed by Apgar scores and umbilical artery pH values. In conclusion, we observed no deterioration in uteroplacental circulation after administration of a single bolus dose of bupivacaine.      

The influence of baricity on the haemodynamic effects of intrathecal bupivacaine 0.5%

This study compared the haemodynamic effects of subarachnoid block with plain bupivacaine 0.5% (dextrose-free), heavy bupivacaine 0.5% (in dextrose 8%) and a mixture of these two solutions, i.e. bupivacaine 0.5% in dextrose 4%. Thirty-six male patients, aged 55-89 years, undergoing transurethral surgery were recruited. Invasive systolic arterial and central venous pressures were recorded at 5-s intervals after the block was initiated using a computerised data-collection system. The height of sensory blockade was recorded at 5-min intervals. No preload was given and episodes of hypotension were treated with colloid (8 ml x kg(-1)) and, if this was ineffective, a metaraminol infusion. Systolic arterial and central venous pressures decreased in all three groups following block (p < 0.05). These decreases were more rapid in onset in the heavy bupivacaine group compared with plain bupivacaine group (p < 0.005). Patients in the heavy bupivacaine group also had a greater requirement for early treatment of hypotension (< 10 min) and treatment with metaraminol (p < 0.05). The onset of sensory blockade was more rapid in the heavy group compared with the mixed group, although final sensory levels were similar. The onset of haemodynamic and sensory changes are more rapid when using heavy bupivacaine intrathecally. This leads to a higher and earlier incidence of hypotension and requirement for treatment.     

Comparison of continuous and intermittent administration of extradural bupivacaine for analgesia after lower abdominal surgery

We have compared intermittent bolus and continuous infusion of extradural local anaesthetic for pain relief in a randomized, double- blind study of 48 patients who underwent major abdominal gynaecological surgery. Each patient received 5 ml of 0.375% bupivacaine hourly, either as a bolus over 5 min or as a constant infusion. Patients who received the intermittent administration technique maintained a more extensive sensory block, reported marginally better analgesia and had a lower requirement for rescue medication. The intermittent bolus technique was not associated with an increase in side effects.      

Epidural anesthesia with bupivacaine: effects of age on neural blockade and pharmacokinetics

Effects of aging after epidural administration of 0.5% bupivacaine without epinephrine were studied in two groups of patients, between 20 and 55 yr old and older than 55 yr, respectively. All patients received 95 mg bupivacaine HCl. The onset of analgesia in caudad segments decreased with age and the upper level of analgesia increased with age. Effects of age on duration of anesthesia could not be demonstrated. The total plasma clearance of bupivacaine decreased and the terminal half-life increased with age. Age had no effect on the peak plasma concentrations and time to peak concentrations.     

Shivering related to epidural blockade with bupivacaine in labour, and the influence of epidural pethidine

A prospective survey of two hundred patients who received an epidural block in labour was performed in order to determine the incidence and severity of shivering, and the influence of likely associated factors. Twenty-two of the patients who shivered took part in a double-blind trial to see if epidural pethidine 25 mg, versus saline, had any effect upon shivering. Fifty per cent of patients shivered soon after the initial dose of bupivacaine. Shivering was more common among patients who had experienced shivering before epidural block, and in those who had received nitrous oxide (P less than 0.005). Prior intramuscular injection of pethidine did not significantly affect the incidence of shivering, and it was not influenced by the concentration of epidural bupivacaine used (0.5 or 0.25%). Shiverers were more likely to feel cold than non-shiverers (P less than 0.001) but shivering was generally regarded by patients as a trivial symptom, only 13% describing it as very irritating. Shivering was abolished or considerably diminished within ten minutes in all patients who received epidural pethidine 25 mg, whereas there was no change in eight out of eleven patients who received epidural saline. These results are significant (P less than 0.01), and demonstrate that shivering following epidural blockade can be effectively treated with small epidural doses of pethidine.