Ultrasound-guided approach to nerves (direct vs. tangential) and the incidence of intraneural injection: a cadaveric study.

This study evaluated the incidence of nerve puncture and intraneural injection based on the needle approach to the nerve (direct vs. tangential). Two expert operators in regional anaesthesia performed in-plane ultrasound-guided nerve blocks (n = 158) at different levels of the brachial plexus in cadavers, aiming either directly for the nerve (n = 77) or tangentially inferior to the nerve (n = 81). After reaching the outer limit of the nerve, the needle was intentionally advanced approximately 1 mm in both approaches, and 0.2-0.5 ml of saline was injected. Each operator classified (in real time) the needle tip and injectate as intraneural or not. Video clips showing the final position of the needle and the injection were evaluated in the same manner by seven independent expert observers who were blinded to the aims of this study. In addition, 20 injections were performed with ink for histological evaluation. Intraneural injections of saline were observed by the operator in 58% (45/77) of cases using the direct approach and 12% (10/81) of cases using the tangential approach (p < 0.001). The independent observers agreed with the operator in a substantial number of cases (Cohen's kappa index 0.65). Histological studies showed intraneural spread in 83% (5/6) of cases using the direct approach and in 14% (2/14) of cases using the tangential approach (p = 0.007). No intrafascicular injections were observed. There was good agreement between the operators' assessment and subsequent histological evaluation (Cohen's kappa = 0.89). Simulation of an unintentional/accidental advancement of the needle 'beyond the edge' of the nerve suggests significantly increased risk of epineural perforation and intraneural injection when a direct approach to the nerve is used, compared with a tangential approach.

Serratus plane block: a novel ultrasound-guided thoracic wall nerve block.

We present a novel ultrasound-guided regional anaesthetic technique that may achieve complete paraesthesia of the hemithorax. This technique may be a viable alternative to current regional anaesthetic techniques such as thoracic paravertebral and central neuraxial blockade, which can be technically more challenging and have a higher potential side-effect profile. We performed the serratus block at two different levels in the midaxillary line on four female volunteers. We recorded the degree of paraesthesia obtained and performed fat-suppression magnetic resonance imaging and three-dimensional reconstructions of the spread of local anaesthetic in the serratus plane. All volunteers reported an effective block that provided long-lasting paraesthesia (750-840 min). There were no side-effects noted in this initial descriptive study. While these are preliminary findings, and must be confirmed in a clinical trial, they highlight the potential for the serratus plane block to provide analgesia following surgery on the thoracic wall. We suggest that this novel approach appears to be safe, effective, and easy to perform, and is associated with a low risk of side-effects.

Comparison of the Baska(®) mask with the single-use laryngeal mask airway in low-risk female patients undergoing ambulatory surgery.

We compared the Baska(®) mask with the single-use classic laryngeal mask airway (cLMA) in 150 females at low risk for difficult tracheal intubation in a randomised, controlled clinical trial. We found that median (IQR [range]) seal pressure was significantly higher with the Baska mask compared with the cLMA (40 (34-40 [16-40]) vs 22 (18-25 [14-40]) cmH2O, respectively, p < 0.001), indicating a better seal. In contrast, the first time success rate for insertion of the Baska mask was lower than that seen with the cLMA (52/71 (73%) vs 77/99 (98%), respectively, p < 0.001). There were no differences in overall device insertion success rates (78/79 (99%) vs 68/71 (96%), respectively, p = 0.54). The Baska mask proved more difficult to insert, requiring more insertion attempts, taking longer to insert and had higher median (IQR [range]) insertion difficulty scores (1.6 (0.8-2.2 [0.1-5.6]) vs 0.5 (0.3-1.4 [0.1-4.0]), respectively, p < 0.001). There was also an increased rate of minor blood staining of the Baska mask after removal, but there were no differences in other complication rates, such as laryngospasm, or in the severity of throat discomfort. In conclusion, in clinical situations where the seal with the glottic aperture takes priority over ease of insertion, the Baska mask may provide a useful alternative to the cLMA.

Stellate ganglion blockade for analgesia following upper limb surgery.

We report the successful use of a stellate ganglion block as part of a multi-modal postoperative analgesic regimen. Four patients scheduled for orthopaedic surgery following upper limb trauma underwent blockade of the stellate ganglion pre-operatively under ultrasound guidance. Patients reported excellent postoperative analgesia, with postoperative VAS pain scores between 0 and 2, and consumption of morphine in the first 24 h ranging from 0 to 14 mg. While these are preliminary findings, and must be confirmed in a clinical trial, they highlight the potential for stellate ganglion blockade to provide analgesia following major upper limb surgery.

Trunk blocks for abdominal surgery.

In this review, we discuss the central non-neuraxial regional anaesthesia blocks of the abdomen, including intercostal and intrapleural blocks, rectus sheath and ilioinguinal-iliohypogastric blocks, transversus abdominis plane blocks and paravertebral blocks.

A comparison of direct and indirect laryngoscopes and the ILMA in novice users: a manikin study.

Direct laryngoscopic tracheal intubation using the Macintosh laryngoscope is taught to many healthcare professionals as it is a potentially life-saving procedure. However, it is a difficult skill to acquire and maintain. Several alternative intubation devices exist that may provide a better view of the glottis and require less skill to use. We conducted a prospective, randomised trial of four different laryngoscopes and the ILMA in 30 medical students who had no prior airway management experience. The devices were tested in both normal and cervical immobilisation laryngoscopy scenarios. Following brief didactic instruction, each participant took turns performing laryngoscopy and intubation using each device under direct supervision. Each student was allowed up to three intubation attempts with each device, in each scenario. The Airtraq, McCoy, and the ILMA each demonstrated advantages over the Macintosh laryngoscope. In both the easy and difficult airway scenarios, the Airtraq, McCoy, and the ILMA reduced the number of intubation attempts, and reduced the number of optimisation manoeuvres required. The Airtraq and ILMA reduced the severity of dental trauma in both scenarios. The performance of the other devices studied was more variable. Overall, participants found that only the Airtraq was less difficult to use and they were more confident using it compared to the Macinosh laryngoscope.

The Airtraq as a rescue airway device following failed direct laryngoscopy: a case series.

We report the successful use of the Airtraq as a rescue device following failed direct laryngoscopy, in patients deemed at increased risk for difficult tracheal intubation. In a series of seven patients, repeated attempts at direct laryngoscopy with the Macintosh blade, and the use of manoeuvres to aid intubation, such as the gum elastic bougie placement, were unsuccessful. In contrast, with the Airtraq device, each patient's trachea was successfully intubated on the first attempt. This report underlines the utility of the Airtraq device in these patients.