H. Kallio

Hyaluronidase as an adjuvant in bupivacaine-lidocaine mixture for retrobulbar/peribulbar block

Hyaluronidase 7.5 IU/mL added to the local anesthetic improves peribulbar block, but smaller concentrations have not been shown to be effective. In this prospective, double-blinded study, 714 consecutive ocular surgery patients were randomized into three groups: no hyaluronidase (n = 241), hyaluronidase 3.75 IU/mL (n = 244), and hyaluronidase 7.5 IU/mL (n = 229). Retrobulbar/peribulbar block was performed with two injections of a 1:1 mixture of bupivacaine 0.75% and lidocaine 2%, 6–8 mL. Patient data were collected on demographics, initial volume of local anesthetic, need for supplementary block, and akinesia of the anesthetized eye. When hyaluronidase was used (3.75 or 7.5 IU/mL), the initial block was sufficient and the anesthetized eye was akinetic significantly more often than in the group without hyaluronidase. The hyaluronidase groups (3.75 and 7.5 IU/mL) did not differ significantly in any respect. We conclude that the addition of hyaluronidase 3.75 or 7.5 IU/mL improved the success of the initial retrobulbar/peribulbar block and akinesia and reduced the need for supplementary block. Implications We conclude that the addition of hyaluronidase 3.75 or 7.5 IU/mL improved the success of the initial retrobulbar/peribulbar block and akinesia and reduced the need for supplementary block.

A comparison of intrathecal plain solutions containing ropivacaine 20 or 15 mg versus bupivacaine 10 mg

Ropivacaine, which blocks sensory nerve fibers more readily than motor fibers, is considered to be less potent than bupivacaine. Our hypothesis was that, when used in spinal anesthesia for day surgery, ropi-vacaine 15 and 20 mg would provide faster motor recovery than bupivacaine 10 mg. This prospective, randomized, double-blinded study included 90 ambulatory lower-extremity surgery patients who received 2 mL of ropivacaine 1%, ropivacaine 0.75%, or bupivacaine 0.5%. Motor block was tested with the Bromage scale, and sensory block was tested with pinprick. Ropivacaine 15 mg provided faster recovery of motor block (150 min) than did bupivacaine 10 mg (210 min; P = 0.005), but the median duration of sensory block at T10 (140 min) did not differ significantly from that with bupivacaine 10 mg (140 min). The median duration of sensory block at T10 was significantly longer with ropivacaine 20 mg (170 min) than with bupivacaine 10 mg (140 min; P =0.005), but the median recovery from motor block (210 min) did not differ significantly. We conclude that the duration of sensory block of ropivacaine was two thirds and the duration of motor block was half when compared with bupivacaine, with calculations based on the duration-per-milligram of the local anesthetic.

Measurement of surgical stress in anaesthetized children

BACKGROUND The surgical stress index (SSI), derived from a combination of heart rate (HR) and photoplethysmographic amplitude (PPGA) time series, is a novel method for continuous monitoring of intraoperative stress and has been validated in adults. The applicability of SSI and its constituents to monitoring children has not been previously evaluated. METHODS In this controlled trial, 22 anaesthetized patients, aged 4-17 yr, undergoing strabismus surgery were randomized into two groups, Group LL and Group BSS. Patients in Group LL received topical conjunctival anaesthesia with a 1:1 mixture of lidocaine 2% and levobupivacaine 0.75%, and patients in Group BSS received balanced salt solution. RESULTS Endotracheal intubation (n=22) increased median (range) SSI from 39.2 (22.6-55.6) to 53.6 (35.8-63.3) (P<0.001), decreased PPGA from 5.62 (2.79-9.69) to 5.27 (2.59-7.54)% (P=0.001), and increased the difference of response entropy (RE) and state entropy (SE) of frontal biopotentials (RE-SE) from 3.1 (0.06-9.1) to 5.7 (0.6-9.4) (P=0.01). Conventional haemodynamic variables also increased, median (range) HR from 72.9 (56.7-113.8) to 84.2 (60.4-124.8) beats min(-1) (P<0.001), and systolic non-invasive arterial pressure (S-NIBP) from 87 (78-143) to 103 (79-125) (P=0.007). When 3 min baseline before surgery was compared with 12 min of surgery, median (range) SSI increased from 43.3 (31.2-58.0) to 49.9 (39.3-57.2) (P=0.042) vs from 46.6 (26.8-57.8) to 52.1 (31.7-60.1) (P=0.024) and PPGA decreased from 6.60 (3.10-8.24) to 5.80 (3.03-7.65)% (P<0.001) vs from 5.51 (3.25-9.84) to 5.06 (3.08-8.99)% (P=0.042), in Groups LL and BSS, respectively, but SSI or other indicators did not differ significantly between the groups. CONCLUSIONS SSI, PPGA, HR, NIBP, RE, and RE-SE detect autonomic responses to nociceptive stimuli in anaesthetized children undergoing strabismus surgery.

Randomised comparison of hyperbaric articaine and hyperbaric low-dose bupivacaine along with fentanyl in spinal anaesthesia for day-case inguinal herniorrhaphy.

Background and objective Low-dose mixture of hyperbaric bupivacaine and fentanyl is commonly used in day-case spinal anaesthesia. Using hyperbaric articaine, the onset may be faster and duration more predictable than with bupivacaine–fentanyl. We compared these two spinal anaesthetics for inguinal herniorrhaphy. Methods Adult patients were randomised to spinal anaesthesia with hyperbaric articaine 84 mg (group A, n = 40) or hyperbaric bupivacaine 7 mg along with fentanyl 10 &mgr;g (group B+F, n = 40). A blinded observer tested the block characteristics. Aiming at sensory block spread to T10 dermatome, the operating table was tilted head-end up or down 10° (once or twice), as required. Postoperative telephone interviews were performed. Results All patients in group A had a sensory block to T10 in a median time of 4 (range 2–20) min. In group B+F, the median onset time of T10 analgesia was 10 (2–30) min (P < 0.001), but T10 analgesia was not reached in seven of 40 B+F patients. A head-up tilt was needed in 37 of 40 group A patients to prevent from too extensive cephalad spread of block, and 34 of 40 group B+F patients needed a head-down tilt to enhance cephalad spread of analgesia. To treat hypotension, 6.4 mg of ephedrine was required, on average, in group A and 1.8 mg in group B+F (P = 0.01). Median time to recovery from sensory block was significantly shorter in group A (2.5 h) than in group B+F (3 h; P = 0.002). General anaesthesia was needed in three patients (group A, two patients: sensory block too short; group B+F, one patient: sensory block too limited). Conclusion Hyperbaric articaine leads to faster onset of block and faster recovery than bupivacaine along with fentanyl. Hypotension is more common with articaine. The onset and extension of the spinal block are unpredictable when using these techniques.

spinal Hyperbaric Ropivacaine-fentanyl for Day-surgery

Background: Adequate intraoperative analgesia combined with faster mobilization might be achieved by replacing hyperbaric ropivacaine partly with fentanyl. Methods: Sixty spinal anesthesia patients were randomized into 2 groups of either fentanyl 20 μg mixed with hyperbaric ropivacaine 10 mg (group FR10) or hyperbaric ropivacaine 15 mg (group R15). Forty-five patients underwent inguinal hernia repair and 15 patients had lower extremity surgery. Sensory block was tested by pinprick, and motor block was tested by use of a modified Bromage scale at 5-minute intervals for 30 minutes, 15-minute intervals for 60 minutes, and at 30-minute intervals until full recovery. Results: The groups did not differ significantly regarding success (27 of 30 [group FR10] and 29 of 30 [group R15]), median onset time (10 [5 to 25] v 10 [5 to 20] minutes) or median duration of T10 sensory block (55 [20 to 115] v 80 [5 to 170] minutes), respectively. Recovery from spinal block was significantly quicker in group FR10 than in group R15, recorded in ability to walk (2.5 hours v 3 hours [P = .017]), full motor recovery (1 hour v 1.5 hour [P < .001]), and sensory recovery to S1 (2.5 hours v 3.3 hours [P = .026]). Pruritus occurred in 18 (60%) of group FR10 v 0 of group R15 patients (P < .001). This symptom was mild in all except 1 patient, who received ondansetron 8 mg IV. In the OR, the groups did not differ hemodynamically: 9 (30%) of the group FR10 and 10 (33%) of the group R15 patients, respectively, required medication for hypotension and/or bradycardia. Full motor block (Bromage 3) developed less frequently (P < .001) in group FR10 patients than in group R15 patients (1 [3%] v 14 [47%]), and the group FR10 patients recovered faster in a median time of 60 v 90 minutes (P < .001). In both groups, sensory and motor blocks were more extensive on the operative side compared with the nonoperative side (P < .001). Conclusion: Faster mobilization but equal onset and duration of analgesia were achieved with intrathecal hyperbaric ropivacaine 10 mg plus fentanyl 20 μg as compared with hyperbaric ropivacaine 15 mg.

Comparison of hyperbaric and plain articaine in spinal anaesthesia for open inguinal hernia repair.

BACKGROUND Fast onset and short duration are prominent properties of the amide-type local anaesthetic articaine. Similar to bupivacaine, a hyperbaric solution of articaine may produce faster onset and shorter duration of spinal anaesthesia than a plain solution. METHODS Patients undergoing open inguinal hernia repair received in random order articaine 84 mg in either hyperbaric (HyperA, n=49) or plain solution (PlainA, n=48) intrathecally. A blinded observer tested the dermatomal spread (pinprick) and motor block (Bromage scale). RESULTS Median (range) onset time to the T(10) dermatome was 2 (2-8) (n=46) and 6 (2-30) min (n=39) (P<0.001), and the duration of the sensory block at (or above) the T(10) dermatome was 86 (39-148) and 69 (15-118) min (P=0.007), in Groups HyperA and PlainA, respectively. Peak sensory block was greater in Group HyperA T(4) (L(2)-C(2)) than in Group PlainA T(8)-T(7) (L(3)-T(3)) dermatome, median (range), P<0.001. Spread of the block to the cervical dermatomes associated with hypotension occurred in three patients of Group HyperA (one patient C(2) and two C(4)). The sensory block resolved to the S(2) dermatome significantly faster in Group HyperA, 2.5 (1.5-4.5) h, than in Group PlainA, 3.5 (2.0-4.5) h (P<0.001). Median duration of the motor block was significantly shorter in Group HyperA, 2.0 (1.3-3.5) vs 3.0 (1.5-4.0) h (P<0.001). CONCLUSIONS Hyperbaric articaine 84 mg had a faster onset and shorter duration of spinal anaesthesia than the plain solution.

Hyperbaric articaine with or without fentanyl in spinal anaesthesia: patient and observer blinded comparison.

The rapid and short‐acting local anaesthetic articaine is a feasible spinal anaesthetic for day‐case open inguinal herniorrhaphy (OIH). We hypothesised that similarly to other spinal local anaesthetics, the addition of fentanyl may prolong articaine spinal analgesia without prolonging motor block.

Retrobulbar/peribulbar block with 0.2% ropivacaine or 1% lidocaine for transscleral cyclophotocoagulation or retinal panphotocoagulation☆

BACKGROUND AND OBJECTIVES Brief analgesia is needed to complete krypton laser cyclophotocoagulation for glaucoma patients and is advantageous in argon laser panphotocoagulation for diabetic retinopathy. We studied whether 0.2% ropivacaine, known for analgesia with minimal motor block or 1% lidocaine, with rapid onset and short duration of action, both supplemented with hyaluronidase, are suitable local anesthetics for retrobulbar/peribulbar block for these procedures. METHODS Seventy-four treatment sessions of 65 patients were included in this prospective, randomized, double-blind study. Data were collected on adequacy of analgesia, need for supplementary blocks and eye movements at 10 minutes after injecting the block and at the end of the treatment, and need for patching the eye at discharge. RESULTS Frequency of inadequate analgesia (24% in ropivacaine group and 32% in lidocaine group), and of supplementary blocks (11% and 14%, respectively) did not differ between the groups and exceeded our clinically acceptable level. Ropivacaine produced less motor block than lidocaine at 10 minutes (P < .001) and at the end of the treatment (P = .002). However, at discharge, the eye was significantly more often patched in the ropivacaine (70%) group than in the lidocaine group (41 %) (P = .035). In the ropivacaine group, a mobile eye did not predict inadequate intraoperative analgesia, whereas in the lidocaine group it did (P = .001). CONCLUSION According to our preliminary data, neither 0.2% ropivacaine nor 1% lidocaine reached acceptable frequencies of adequate analgesia during transscleral cyclophotocoagulation, while all retinal panphotocoagulations could be completed under the initial block.

Preliminary experience of combined peri- and retrobulbar block in surgery for penetrating eye injuries.

Background and objective: Regional anaesthesia has not been recommended as an anaesthetic method for penetrating eye injuries because it is suspected to aggravate the injury already present. After having successfully managed the treatment of a penetrating eye injury under combined peri‐ and retrobulbar block in an ASA IV patient, it was decided to evaluate this anaesthetic method further in the treatment of such emergency cases. Methods: Twenty adult patients with penetrating eye injuries with a maximum wound length of 8 mm extending up to 4 mm posteriorly from the limbus were operated on under combined peri‐ and retrobulbar anaesthesia. Eighteen patients receiving general anaesthesia served as controls. Results: The mean (range) volume injected for a satisfactory peribulbar retrobulbar block was 7.4 (6.5–8.0) mL, six patients needed an additional retrobulbar injection before surgery (2.9, range 2–4, mL). All patients receiving regional anaesthesia were satisfied with the anaesthetic method and the surgeons considered the surgical conditions as good. No problems relating to local anaesthesia were observed or reported by any of the patients. Conclusions: In the hands of an experienced anaesthesiologist and under certain conditions, regional anaesthesia appears to be suitable for adult patients having penetrating eye injuries.