Komplikationen bei peripherer Regionalanästhesie

Minimum effective concentration of ropivacaine for ultrasound-guided transmuscular quadratus lumborum block in total hip arthroplasty: a randomized clinical trial

OBJECTIVE

This trial aimed to identify the Minimum Effective Concentration (MEC90, defined as the concentration which can provide successful block in 90% of patients) of 30 mL ropivacaine for single-shot ultrasound-guided transmuscular Quadratus Lumborum Block (QLB) in patients undergoing Total Hip Arthroplasty (THA).

METHODS

A double-blind, randomized dose-finding study using the biased coin design up-and-down sequential method, where the concentration of local anesthetic administered to each patient depended on the response from the previous one. Block success was defined as a Numeric Rating Scale (NRS) score during motion ≤ 3 at 6 hours after arrival in the ward. If the block was successful, the next subject received either a 0.025% smaller dose (probability of 0.11) or the same dose (probability of 0.89); otherwise, the next subject received a 0.025% higher ropivacaine concentration. MEC90, MEC95 and MEC99 were estimated by isotonic regression, and the corresponding 95% Confidence Intervals (95% CIs) were calculated by the bootstrapping method.

RESULTS

Based on the analysis of 52 patients, MEC90, MEC95, and MEC99 of ropivacaine for QLB were estimated to be 0.352% (95% CI 0.334-0.372%), 0.363% (95% CI 0.351-0.383%), and 0.373% (95% CI 0.363-0.386%). The concentration of ropivacaine at 0.352% in a volume of 30 ml can provide a successful block in 90% of patients.

CONCLUSIONS

For ultrasound-guided transmuscular QLB in patients undergoing THA, 0.352% ropivacaine in a volume of 30 ml can provide a successful block in 90% of patients. Further dose-finding studies and large sample size are required to verify the concentration.

[Peripheral Regional Anaesthesia for Perioperative Analgesia]

Peripheral Regional Anaesthesia for Perioperative Analgesia Abstract. Peripheral regional anaesthesia is the actual gold standard of opioid-sparing perioperative analgesia and is mainly used for surgery of the shoulder, arm and leg. Well-trained anaesthesiologists are the prerequisite for the correct individual risk-benefit assessment and the performance of the nerve blocks using a combination of ultrasound guidance and peripheral nerve stimulation (dual guidance). The postoperative care of the patients requires trained staff.

[Central neurological complication of an interscalene plexus catheter]

A 78-year-old patient received an interscalene plexus catheter for perioperative pain therapy during implantation of an inverse shoulder prothesis. After stimulation-assisted puncture under sonographic control, 25 ml of local anesthetic (LA) were first administered and then the catheter was placed using the through the needle technique. Immediately after the administration of another 5 ml of local anesthetic via the inserted catheter, the patient showed symptoms of total spinal anesthesia, so that she had to be intubated and ventilated. The following computed tomographic diagnostics of the neck revealed an intrathecal misalignment of the plexus catheter, the tip of which was lying dorsal to the vertebral artery at the level of the 5/6 cervical vertebrae. The catheter could then be removed without any problems and there were no neurological sequelae. The use of ultrasound with clear identification of the nerve roots C5-C7 and the surrounding structures provides additional security when installing an intrascalene catheter. The spread of the LA should be traceable at all times using ultrasound and should otherwise be immediately terminated. Furthermore, a strict adherence to the needle position while inserting the catheter without manipulation of the needle depth is necessary. The first injection of the catheter has to be performed under controlled conditions, preferably connected to surveillance monitors with neurological monitoring of the awake patient and control of vital signs with direct access to the emergency equipment.

Careful medical interview and ultrasonography enabled detection of acute kidney injury and hematoma after lumbar trigger point injection-a case report

Background

Trigger point blocks are now widely practiced, especially in pain treatment. Among the complications of lumbar trigger point injection, reports of medically induced kidney injury are very rare, and diagnosis during emergency treatment is rare.

Case presentation

A 78-year-old woman on antiplatelet medication following a stroke was diagnosed with treatable type A aortic dissection at another hospital after undergoing lumbar trigger point injection. On arrival at our hospital, there were no signs of hemodynamic deterioration. Additional careful medical re-interview and ultrasonography by anesthesiologists enabled a definitive diagnosis of acute kidney damage and hematoma caused by lumbar trigger point injection, and aortic dissection surgery was abandoned.

Conclusion

This clinical case demonstrates the importance of awareness of potential kidney injury and hematoma during lumbar trigger point injection.

[Oberst's block anesthesia]

OBJECTIVE

Complete anesthesia of the phalanges of the fingers and toes.

INDICATIONS

All lesions distal to the metacarpophalangeal/metatarsophalangeal joint.

CONTRAINDICATIONS

Local infections at the injection site. Lesions proximal to the metacarpophalangeal/metatarsophalangeal joint.

TECHNIQUE

A subcutaneous deposit of a 0.5-2% local anesthetic is administered dorsoradially and dorsoulnarly at the base of the metacarpophalangeal/metatarsophalangeal joint. With the cannula advanced to palmar, an additional 0.5-1.5 ml is then administered to achieve complete anesthesia.

POSTOPERATIVE MANAGEMENT

The effect of the local anesthesia is self-limiting.

RESULTS

The Oberst block results in reliable anesthesia of the finger and toe. All surgical procedures distal to the metacarpophalangeal/metatarsophalangeal joint can be performed without pain.

[Infiltration anesthesia]

OBJECTIVE

Complete anesthesia of any skin and soft tissue area by intradermal, subcutaneous, or intramuscular injections.

INDICATIONS

Small injuries or incisions in limbs or trunk, minor surgery on the face/jaw (e.g., on the teeth), or postoperative analgesia (local infiltration anesthesia, LIA).

CONTRAINDICATIONS

Local infections at the injection site.

SURGICAL TECHNIQUE

By means of intradermal, subcutaneous or intramuscular administration, a grandeur arises, here the local anesthetic blocks nerve transmission. If anesthetized distal to end arteries, vasoconstrictors (e.g., epinephrine) should be avoided. Proximal to end arteries, localized ischemia may facilitate operative care.

POSTOPERATIVE MANAGEMENT

The effect of local anesthesia is self-limiting.

RESULTS

By means of infiltration anesthesia or "field block", larger areas of skin are easily accessible for surgical treatment. The amount to be applied has to be adapted to the extent of the operation and the maximal dose. Postoperatively, after knee or hip arthroplasty, analgesia consumption can be reduced, and early mobilization promoted using LIA.

Regionale Nervenblockaden

Periphere Nervenblockaden werden hervorgerufen durch die Injektion eines Lokalanästhetikums in die unmittelbare Nähe von Einzelnerven, Nervenstämmen oder Nervengeflechten. Das Lokalanästhetikum diffundiert zur Innenseite des Nervs und blockiert vorübergehend die spannungsabhängigen Natriumkanäle. Hierdurch entsteht eine lokal begrenzte Anästhesie, die sich eng auf das für eine Operation erforderliche Gebiet beschränkt. Die Auswirkungen auf die übrigen Körperfunktionen sind gering, v. a. werden die Atmung und Herz-Kreislauf-Funktion nicht beeinträchtigt. Die Nerven werden mit Elektrostimulation oder Ultraschall aufgesucht; Parästhesien sollten hierfür nicht ausgelöst werden. Komplikationen durch periphere Blockaden sind sehr selten. Nervenschäden, Gefäßpunktionen und Hämatome, Lokalanästhetikaintoxikation und Infektionen treten v. a. bei Kathetertechniken auf.

A comparison of the onset time of complete blockade of the sciatic nerve in the application of ropivacaine and its equal volumes mixture with lidocaine: a double-blind randomized study

BACKGROUND

The purpose of the current study is to create a new mixture of local anesthetics-one with a short time of block development and short action term (5 ml of 1% lidocaine solution) and another with a longer time of anesthesia development and a long analgetic effect (5 ml of 0.75% ropivacaine)-for use during surgical operations on extremities. The primary end point was the development of the complete sensory block of the sciatic nerve.

METHODS

Sixty blocks of sciatic nerve were used in a double-blind randomized research, under ultrasonic guidance, using an electric stimulator with the peripheral nerves. Sixty patients were divided into 3 equal groups. In the first group, a sciatic nerve block was performed with 5 ml of 0.75% ropivacaine solution (37.5 mg); in the second group, 10 ml of 0.75% ropivacaine solution (75 mg) was used and, in the third group, a mixture of 5 ml of 0.75% ropivacaine (as above) and 5 ml of 1% lidocaine solution (50 mg) was used. The assessment of the time required for developing sensory and motor blocks was carried out from the beginning of local anesthetic solution injection in the fascial sheath of the sciatic nerve.

RESULTS

Demographic data of patients were identical in the three sample groups. The time required for achieving a complete motor and sensory block was reduced due to the mix of the 1% lidocaine solution with the 0.75% ropivacaine solution. The time required for achieving a complete sensory block in groups treated with 5 and 10 ml ropivacaine was 45 (40-48) and 30 (28-30) min, respectively, in contrast with 12 (10-13) min when the mixture of anesthetics was applied (P < 0.01). There was no difference in analgesic duration in the postoperative period among groups at P > 0.05.

CONCLUSIONS

The mixture of 5 ml of 1% lidocaine with 5 ml of 0.75% ropivacaine leads to a reduction in the time required for the development of complete sensory and motor blocks of the sciatic nerve, without reducing postoperative analgesia time.