All TBPBs were performed according to a standardized procedure using a nerve stimulator (Stimuplex® HNS 11, B. Braun Melsungen AG, Melsungen, Germany) and a 19-gauge × 60 mm stimulation cannula (Meier Plexolong® set, Pajunk AG, Geislingen, Germany)<!—AQ3: Kindly check whether the change made to this sentence is OK.—>. The electrical current of the nerve stimulator was initially set at 2 mA with a stimulation frequency of 2 Hz and a pulse duration of 0.1 ms.
After skin disinfection, sterile covering and local anesthesia of the insertion site, the stimulation cannula was carefully advanced from the puncture site below the middle scalene muscle (or through this muscle) in the direction of the anatomical target. If the middle scalene muscle was palpable, the cannula was advanced beneath this muscle using nerve stimulation. A contraction of the ipsilateral biceps (3), triceps muscles (4) or deltoid muscle (3) was obtained at an electrical intensity of 0.2–0.8 mA. Once the cannula tip reached the brachial plexus, an assistant administered a weight-dependant dose of 10–20 mL mepivacaine 1% and 20–30 mL ropivacaine 0.75% via a tubing catheter through the fixed cannula.
A successful block was defined as the absence of cold and pinprick response by a standard sterile 19-gauge Quincke needle in the shoulder and upper arm area (sensory block) and paresis of the upper arm (motorblock). Paresis of the upper arm was tested as the inability to lift or abduct the arm. In case of a humerus fracture, the upper arm had to be pain free during passive movement for surgical preparation and positioning.
In most cases, the brachial plexus was localized at a depth of 2–4 cm. The needle was withdrawn to the skin if no muscle contraction was noted after inserting the cannula to a depth of 4 cm and stimulating with an electrical current of 2 mA. In this case, the needle tip was then redirected dorsally about 10°–20° and advanced again in the direction of the lateral aspect of the sternocleidomastoid muscle insertion at the clavicle. (Figs. 1 and 2).
The age range of the 27 patients was between 34 and 72 years. In 23 of the 27 patients (85.2%), TBPB resulted in successful intraoperative analgesia without the need for additional analgesics. Two patients (7.4%) required IV sufentanil (10 μg and 15 μg, respectively) in addition to the TBPB for complete intraoperative analgesia. In two additional patients (7.4%) analgesia was inadequate and general anesthesia was necessary.
None of the patients undergoing a TBPB experienced respiratory distress or a decrease in oxygen saturation after the plexus block. There were no vascular punctures or persistent pain at the insertion sites. Two patients (7.4%) experienced an ipsilateral reversible recurrent laryngeal nerve blockade, whereas one patient (3.7%) experienced a reversible Horner syndrome. Both of those side effects were temporary and resolved completely. No additional serious regional or systemic side effects or complications were observed.
The puncture site for a brachial plexus block should be as far away as possible from the cervical vertebra and as cranial to the lung as possible in order to avoid or diminish the risk of potentially serious and dangerous complications of interscalene brachial plexus blocks, such as cervical and thoracic epidural blockade (5), total spinal anesthesia (6–8) associated with persistent neurologic damage (9,10), inadvertent injection into the vertebral artery (11), and pneumothorax during a supraclavicular brachial plexus block (12,13). Additionally, the puncture needle should be directed slightly more medial and from dorsal to ventral.
More serious complications, such as total spinal anesthesia, cervical and thoracic epidural blockade, or intravertebral artery injection, can be potentially avoided with techniques as described by Borgeat et al. (14) and Pham Dang et al. (15,16) by choosing an insertion technique with a medial to lateral approach. Borgeat et al. reported in a series of 700 adult patients undergoing a modified lateral approach, an incidence of Horner syndrome of 6% and an incidence of recurrent laryngeal nerve blockade of 0.9% (14). However, Pham Dang et al. observed, in their series of 150 patients with a novel supraclavicular approach, a relatively high rate of transient neurologic deficits, including asymptomatic phrenic nerve blockade in 60%, a transient Horner syndrome in 10%, and a transient laryngeal nerve blockade in 1.3% of patients, which amounts to a total complication rate of more than 71% for transient neurological deficits. Additionally misplacement into the subclavian vein was observed in one patient (0.6%) (15). The neurological complications such as phrenic nerve blockade and Horner syndrome, as described in Pham Dang et al.'s series, were transient and none of the patients showed any saturation respiratory distress (15). Hence, they did not change the overall long term course of the anesthetic procedure.
In comparison, we experienced, in our smaller series of 27 patients, that 7.4% of patients had an ipsilateral reversible recurrent laryngeal nerve blockade and 3.7% had a reversible Horner syndrome as the only adverse effect. The asymptomatic phrenic nerve block should be included in further comparative studies.
The puncture techniques by Borgeat et al. and Pham Dang et al. are difficult to perform in obese patients and carry a higher risk of pneumothorax, in particular in those patients with short necks (Fig. 3). In these patients, techniques with a posterior access are recommended (1,2). The Pippa et al. (1) and Boezaart et al. (2) techniques can only be performed while the patient is sitting or if positioned supine and turned to the contralateral side of the injured arm. These positions may not be sustainable in well-sedated patients or in those with recent fractures. The most serious complications such as epidural block, total spinal anesthesia and inadvertent intra-arterial injection into the vertebral artery may not be totally eliminated with either puncture technique.
Our data suggest that, despite the small number of patients enrolled (n = 27), the TBPB appears to be a likely alternative technique when compared to other brachial plexus blocks. The advantage of the classic Winnie approach to the interscalene block is familiarity, whereas that of the lateral or longitudinal approach is that the neuroforamen cannot be penetrated. The main advantages of the posterior approaches are that the vertebral artery and vein cannot be reached and injured and the neuroforamen cannot be penetrated. From an anatomical and theoretical point of view, it appears that our method may offer major advantages over the Winnie approach and the posterior approaches, but further studies are needed to compare these different techniques. Additionally, a certain subset of patients, such as the morbidly obese or those with short necks, may not have different outcomes regardless of the approach used. Further studies with more patients and a comparison to other plexus techniques are needed to evaluate whether the TBPB technique has a lower incidence of serious side effects and higher overall success rate. At this stage of research, our study can't support any safety or other advantages over other plexus techniques.
We thank Prof. Dr. W. W. Hoepker and his colleagues at the Department of Pathology, Asklepios Klinik Barmbek as well as Dr. A. D. Duong of the Department of Cardiothoracic Surgery, Asklepios Klinik St. Georg, Hamburg, for their active support.
1. Pippa P, Cominelli E, Marinelli C, Aito S. Brachial plexus block using the posterior approach. Eur J Anaesthesiol 1990;7:411–20
2. Boezaart AP, Koorn R, Rosenquist RW. Paravertebral approach to the brachial plexus: an anatomic improvement in technique. Reg Anesth Pain Med 2003;28:241–4
3. Silverstein WB, Saiyed MU, Brown AR. Interscalene block with a nerve stimulator: a deltoid motor response is a satisfactory endpoint for successful block. Reg Anesth Pain Med 2000;25:356–9
4. Borgeat A, Ekatodramis G, Kalberer F, Benz C. Acute and nonacute complications associated with interscalene blocks and shoulder surgery: a prospective study. Anesthesiology 2001;95:875–80
5. Kumar A, Battit GE, Froese AB, Long MC. Bilateral cervical and thoracic epidural blockade complicating interscalene brachial plexus block: report of two cases. Anesthesiology 1971;35:650–2
6. Dutton RP, Eckhardt WF III, Sunder N. Total spinal anesthesia after interscalene blockade of the brachial plexus. Anesthesiology 1994;80:939–41
7. Iocolano CF. Total spinal anesthesia after an interscalene block. J Perianesth Nurs 1997;12:163–70
8. Norris D, Klahsen A, Milne B. Delayed bilateral spinal anaesthesia following interscalene brachial plexus block. Can J Anaesth 1966;43:303–5
9. Benumof JL. Permanent loss of cervical spinal cord function associated with interscalene block performed under general anesthesia. Anesthesiology 2000;93:1541–4
10. Passannante AN. Spinal anesthesia and permanent neurologic deficit after interscalene block. Anesth Analg 1996;82:873–4
11. Durrani Z, Winnie AP. Brainstem toxicity with reversible locked-in syndrome after intrascalene brachial plexus block. Anesth Analg 1991;72:249–52
12. Hamelberg W. Pneumothorax following brachial plexus block. Anesth Analg 1959;38:251–3
13. Wishart HY. Pneumothorax complicating brachial plexus block anaesthesia. Br J Anaesth 1954;26:120–3
14. Borgeat A, Dullenkopf A, Ekatodramis G, Nagy L. Evaluation of the lateral modified approach for continuous interscalene block after shoulder surgery. Anesthesiology 2003;99:436–42
15. Pham Dang C, Gunst JP, Gouin F, Poirier P, Touchais S, Meunier JF, Kick O, Drouet JC, Bourreli B, Pinaud M. A novel supraclavicular approach to brachial plexus block. Anesth Analg 1997;85:111–6
© 2007 International Anesthesia Research Society
16. Pham Dang C. Correct needle direction in the intersternocleidomastoid approach to the brachial plexus. Reg Anesth Pain Med 2005;30:595–6