Incidence of clinically symptomatic pneumothorax in ultrasound-guided infraclavicular and supraclavicular brachial plexus block.

The use of periclavicular brachial plexus block as regional anaesthesia for surgical procedures on the upper extremity is common. However, the proximity of the pleura results in a risk of pneumothorax. Without ultrasound monitoring, the pneumothorax risk has been reported to be as high as 6.1%. We conducted a prospective, observational study to examine the risk of pneumothorax in 6366 ultrasound-guided periclavicular plexus blocks. All patients with a clinically manifest and radiologically confirmed pneumothorax were analysed. Clinically symptomatic pneumothorax occurred in four patients (0.06%; 95% CI 0.001-0.124), in three of them after a two-day latency period. Ultrasound guidance does therefore appear to reduce the risk of pneumothorax. Although all of the anaesthesiologists involved in the complications had previously performed fewer than 20 blocks, we are not able to confirm that a block experience ≤ 20 is a significant risk factor. Faulty image-setting, inability to obtain a view of the needle tip and inadequate supervision are likely to be important risk factors.

[Ultrasound-guided peripheral regional anesthesia : placement and dosage of local anesthetics]. / Ultraschallgesteuerte periphere Regionalanästhesie : Applikationsort und Dosierung des Lokalanästhetikums.

Ever since the use of ultrasound guidance in regional anesthesia became more and more popular in recent years, it seemed obvious that so-called intraneural puncture and injection of local anesthetics was much more common than previously assumed. However, neurologic damage was not seen very often. The ultrasound-guided imaging of the nerves showed that intraneural injection has to be seen as an overall term. This term must be characterized in more detail in accordance with nerve anatomy and morphology. Various studies demonstrated that if intraneural puncture occured the needle usually took a path away from the fascicles (intraneural perifascicular), while intraneural transfascicular puncture seemed relatively rare and intraneural intrafascicular placement of the needle even more uncommon. As long as the needle is placed intraneurally but in an extrafascicular fashion a safe injection and the absence of neurologic damage can be assumed. However, if nerve fascicles are affected neurologic dysfunction can occur. In studies investigating the minimal effective local anesthetic volume needed for successful nerve block, a relevant reduction of injected volume was still achieved by intentionally applying the local anesthetic circumferentially around the outermost nerve layer rather than injecting it into neural structures. As an intraneural -intrafascicular injection carries the risk of nerve injury associated with a decrease in quality of life, the potential of ultrasound guidance in regional anesthesia should be considered. Circumferential administration of local anesthetic rather than creating a single point injection appears to be advantageous.

Analgesia and pulmonary function after lung surgery: is a single intercostal nerve block plus patient-controlled intravenous morphine as effective as patient-controlled epidural anaesthesia? A randomized non-inferiority clinical trial.

BACKGROUND: Thoracic epidural anaesthesia (EDA) is regarded as the 'gold standard' for postoperative pain control and restoration of pulmonary function after lung surgery. Easier, less time-consuming, and, perhaps, safer is intercostal nerve block performed under direct vision by the surgeon before closure of the thoracotomy combined with postoperative i.v. patient-controlled analgesia with morphine. We hypothesized that this technique is as effective as thoracic EDA. METHODS: The study was designed as a single-centre, open labelled, randomized non-inferiority trial. A total of 92 patients undergoing elective lung surgery were randomly assigned to the epidural (n=47) or intercostal group (n=45), and 83 patients completed the study. Pain scores, inspiratory vital capacity, forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), and peak expiratory flow rate (PEFR) were assessed during the first four postoperative days. RESULTS: Median treatment differences regarding pain scores at rest failed to demonstrate non-inferiority of the intercostal nerve block at the first postoperative day. Patients of the intercostal group reported significantly higher pain scores on coughing during the first and second postoperative days. The epidural group had a significantly higher median FVC, FEV1, and PEFR values on the second postoperative day. No difference was found in pulmonary complications, length of hospital stay, or in-hospital deaths. CONCLUSIONS: In patients undergoing lung surgery, single intercostal nerve block plus i.v. patient-controlled analgesia with morphine is not as effective as patient-controlled EDA with respect to pain control and restoration of pulmonary function.