Ultrasonographic guided axillary plexus blocks with low volumes of local anaesthetics: a crossover volunteer study

Our study group recently evaluated an ED(95) local anaesthetic volume of 0.11 ml.mm(-2) cross-sectional nerve area for the ulnar nerve. This prospective, randomised, double-blind crossover study investigated whether this volume is sufficient for brachial plexus blocks at the axillary level. Ten volunteers received an ultrasonographic guided axillary brachial plexus block either with 0.11 ('low' volume) or 0.4 ('high' volume) ml.mm(-2) cross-sectional nerve area with mepivacaine 1%. The mean (SD) volume was in the low volume group 4.0 (1.0) and 14.8 (3.8) ml in the high volume group. The success rate for the individual nerve blocks was 27 out of 30 in the low volume group (90%) and 30 out of 30 in the high volume group (100%), resulting in 8 out of 10 (80%) vs 10 out of 10 (100%) complete blocks in the low vs the high volume groups, respectively (NS). The mean (SD) sensory onset time was 25.0 (14.8) min in the low volume group and 15.8 (6.8) min in the high volume group (p < 0.01). The mean (SD) duration of sensory block was 125 (38) min in the low volume group and 152 (70) min in the high volume group (NS). This study confirms our previous published ED(95) volume for mepivacaine 1% to block peripheral nerves. The volume of local anaesthetic has some influence on the sensory onset time.

[Examination reports on survived strangulation cases]

Clinical-forensic examination of strangulation victims is an increasing part of the routine of many forensic pathology institutes. The cases examined between 2004 and 2008 at the Institute of Legal Medicine of the Hanover Medical School were retrospectively analysed. In total, the study material comprised 218 victims (175 females and 43 males). In 80.7 %, the clinical-forensic examination was performed within 24 hours after the incident. In the overwhelming number of cases, the alleged perpetrator was no stranger. 128 victims (58.7 %) had strangulation marks, 32 victims (14.7 %) ligature marks and 65 victims (29.8 %) nail marks. Four victims showed injuries of the laryngeal and pharyngeal structures (reddening, hematomas, swelling and in one case a fracture of the cricoid cartilage on both sides). Extensive petechiae were predominantly seen in the conjunctivae, the buccal mucosa and the skin of the face in cases where the victims suffered a loss of consciousness. 87 cases (39.9% were classified as potentially life-threatening and 30 cases (13.8 %) as acute life-threatening events. This classification is of legal relevance for the penalty. In addition, 60 victims experienced sexual violence. These results suggest that early clinical-forensic examination is crucial for documenting forensic evidence in support of police investigations and may deliver significant details relevant in court.

Newly designed, self-coiling catheters for regional anesthesia--an imaging study

A major concern with the use of continuous peripheral nerve block is the difficulty encountered in placing the catheters close enough to the nerves to accomplish effective analgesia. The aim of this study was to investigate if a self-coiling catheter would remain close to the sciatic nerve once introduced through needles placed under ultrasound guidance and if contrast dye injected through the pigtail catheter made direct contact to the nerves.

Malignant pheochromocytomas and paragangliomas: a diagnostic challenge

Malignant pheochromocytomas (PCCs) and paragangliomas (PGLs) are rare disorders arising from the adrenal gland, from the glomera along parasympathetic nerves or from paraganglia along the sympathetic trunk. According to the WHO classification, malignancy of PCCs and PGLs is defined by the presence of metastases at non-chromaffin sites distant from that of the primary tumor and not by local invasion. The overall prognosis of metastasized PCCs/PGLs is poor. Surgery offers currently the only change of cure. Preferably, the discrimination between malignant and benign PCCs/PGLs should be made preoperatively.

Randomized clinical trial of the i-gel™ and Magill tracheal tube or single-use ILMA™ and ILMA™ tracheal tube for blind intubation in anaesthetized patients with a predicted difficult airway

The single-use supraglottic airway device i-gel™ has been described in several case reports as a conduit for intubation, but no prospective data about success rates of blind intubation are available. Therefore, we performed this prospective randomized controlled trial to compare the success rate of blind tracheal intubation with a Magill PVC tube through the i-gel™ with intubation using an sILMA™ PVC tube through the single-use intubating laryngeal mask airway (sILMA™).

Auditory Imagery and the Poor-Pitch Singer

The vocal imitation of pitch by singing requires one to plan laryngeal movements on the basis of anticipated target pitch events. This process may rely on auditory imagery, which has been shown to activate motor planning areas. As such, we hypothesized that poor-pitch singing, although not typically associated with deficient pitch perception, may be associated with deficient auditory imagery. Participants vocally imitated simple pitch sequences by singing, discriminated pitch pairs on the basis of pitch height, and completed an auditory imagery self-report questionnaire (the Bucknell Auditory Imagery Scale). The percentage of trials participants sung in tune correlated significantly with self-reports of vividness for auditory imagery, although not with the ability to control auditory imagery. Pitch discrimination was not predicted by auditory imagery scores. The results thus support a link between auditory imagery and vocal imitation.

Postmortem ventilation: A new method for improved detection of pulmonary pathologies in forensic imaging

Postmortem imaging has gained prominence in the field of forensic pathology. Even with experience in this procedure, difficulties arise in evaluating pathologies of the postmortem lung. The effect of postmortem ventilation with applied pressures of 10, 20, 30 and 40mbar was evaluated in 10 corpses using simultaneous postmortem computed tomography (pmCT) scans. Ventilation was performed via a continuous positive airway pressure mask (n=5), an endotracheal tube (n=4) and a laryngeal mask (n=1) using a portable home care ventilator. The lung volumes were measured and evaluated by a segmentation technique based on reconstructed CT data. The resulting changes to the lungs were analyzed. Postmortem ventilation at 40mbar induced a significant (p<0.05) unfolding of the lungs, with a mean volume increase of 1.32l. Small pathologies of the lung such as scarring and pulmonary nodules as well as emphysema were revealed, while inner livores were reduced. Even though lower ventilation pressures resulted in a significant (p<0.05) volume increase, pathologies were best evaluated when a pressure of 40mbar was applied, due to the greater reduction of the inner livores. With the ventilation-induced expansion of the lungs, a decrease in the heart diameter and gaseous distension of the stomach was recognized. In conclusion, postmortem ventilation is a feasible method for improving evaluation of the lungs and detection of small lung pathologies. This is because of the volume increase in the air-filled portions of the lung and reduced appearance of inner livores.

Prospective randomized trial comparing sutured with sutureless mesh fixation for Lichtenstein hernia repair: long-term results

Following Lichtenstein hernia repair, up to 25% of patients experience prolonged postoperative and chronic pain as well as discomfort in the groin. One of the underlying causes of these complaints are the compression or irritation of nerves by the sutures used to fixate the mesh. We compared the level and rate of chronic pain in patients operated with the classical Lichtenstein technique fixated by sutures to patients with sutureless mesh fixation technique.

Objective hypoesthesia and pain after transabdominal preperitoneal hernioplasty: a prospective, randomized study comparing tissue adhesive versus spiral tacks

Irritation of inguinal nerves with laparoscopic hernia repair may cause chronic neuralgia and hypoesthesia. Hypoesthesia in particular is generally not assessed objectively. We objectively investigated hypoesthesia and chronic pain after transabdominal preperitoneal inguinal hernia repair (TAPP) with titanium spiral tacks (STs) compared with tissue adhesive (TA) for mesh fixation.

Anatomic study of the superficial sural artery and its implication in the neurocutaneous vascularized sural nerve free flap

Combined extended nerve and soft tissue defects of the upper extremity require nerve reconstruction and adequate soft tissue coverage. This study focuses on the reliability of the free vascularized sural nerve graft combined with a fasciocutaneous posterior calf flap within this indication. An anatomical study was performed on 26 cadaveric lower extremities that had been Thiel fixated and color silicone injected. Dissection of the fasciocutaneous posterior calf flap involved the medial sural nerve and superficial sural artery (SSA) with its septocutaneous perforators, extended laterally to include the lateral cutaneous branch of the sural nerve and continued to the popliteal origin of the vascular pedicle and the nerves. The vessel and nerves diameter were measured with an eyepiece reticle at 4.5× magnification. Length and diameter of the nerves and vessels were carefully assessed and reported in the dissection book. A total of 26 flaps were dissected. The SSA originated from the medial sural artery (13 cases), the popliteal artery (12 cases), or the lateral sural artery (one case). The average size of the SSA was 1.4 ± 0.4 mm. The mean pedicle length before the artery joined the sural nerve was 4.5 ± 1.9 cm. A comitant vein was present in 21 cases with an average diameter of 2.0 ± 0.8 mm, in 5 cases a separate vein needed to be dissected with an average diameter of 3.5 ± 0.4 mm. The mean medial vascularized sural nerve length was 21.2 ± 8.9 cm. Because of inclusion of the vascularized part of the lateral branch of the sural nerve (mean length of 16.7 ± 4.8 cm), a total of 35.0 ± 9.6 cm mean length of vascularized nerve could be gained from each extremity. The free vascularized sural nerve graft combined with a fasciocutaneous posterior calf flap pedicled on the SSA offers a reliable solution for complex tissue and nerve defect. Clin. Anat. 2012. © 2012 Wiley Periodicals, Inc.

The latency distribution of motor evoked potentials in patients with multiple sclerosis

OBJECTIVE: To compare the individual latency distributions of motor evoked potentials (MEP) in patients with multiple sclerosis (MS) to the previously reported results in healthy subjects (Firmin et al., 2011). METHODS: We applied the previously reported method to measure the distribution of MEP latencies to 16 patients with MS. The method is based on transcranial magnetic stimulation and consists of a combination of the triple stimulation technique with a method originally developed to measure conduction velocity distributions in peripheral nerves. RESULTS: MEP latency distributions in MS typically showed two peaks. The individual MEP latency distributions were significantly wider in patients with MS than in healthy subjects. The mean triple stimulation delay extension at the 75% quantile, a proxy for MEP latency distribution width, was 7.3ms in healthy subjects and 10.7ms in patients with MS. CONCLUSIONS: In patients with MS, slow portions of the central motor pathway contribute more to the MEP than in healthy subjects. The bimodal distribution found in healthy subjects is preserved in MS. SIGNIFICANCE: Our method to measure the distribution of MEP latencies is suitable to detect alterations in the relative contribution of corticospinal tract portions with long MEP latencies to motor conduction.

Acute pulmonary edema and airway hemorrhage in a goat during sevoflurane anesthesia

A goat was scheduled for experimental surgery under general anesthesia. The first attempt of performing endotracheal intubation failed and provoked laryngeal spasm. After repeated succesful intubation of inhalation anesthesia was delivered in high concentrations of sevoflurane. Suddenly hypertension and tachycardia were observed, followed by foamy airway secretion and then severe airway hemorrhage. The authors hypothesize that laryngeal spasm provoked respiratory distress and pulmonary edema. The delivered high concentrations of sevoflurane probably enhanced a hyperadrenergic response, predisposing to the development of airway hemorrhage.

Pulmonary edema at recovery after colic operation with in-situ nasogastric tube in a horse

After an uneventful general anesthesia, in a horse negative pressure pulmonary edema developed due to acute upper airway obstruction during the anesthetic recovery phase after colic surgery. No pathologic alteration of respiration was observed until the horse stood up and began suffocating. The horse had recovered with the nasogastric tube in situ. This, together with the postmortem diagnosis of laryngeal hemiplegia resulted in impairment of airflow through the larynx and development of pulmonary edema. Our objective is to alert clinicians about the possible hazard of recovery with an in-situ nasogastric tube.

The distribution of E-cadherin expression in listeric rhombencephalitis of ruminants indicates its involvement in Listeria monocytogenes neuroinvasion

AIM: To investigate the expression of E-cadherin, a major host cell receptor for Listeria monocytogenes (LM) internalin A, in the ruminant nervous system and its putative role in brainstem invasion and intracerebral spread of LM in the natural disease. METHODS: Immunohistochemistry and double immunofluorescence was performed on brains, cranial nerves and ganglia of ruminants with and without natural LM rhombencephalitis using antibodies against E-cadherin, protein gene product 9.5, myelin-associated glycoprotein and LM. RESULTS: In the ruminant brain, E-cadherin is expressed in choroid plexus epithelium, meningothelium and restricted neuropil areas of the medulla, but not in the endothelium. In cranial nerves and ganglia, E-cadherin is expressed in satellite cells and myelinating Schwann cells. Expression does not differ between ruminants with or without listeriosis and does not overlap with the presence of microabscesses in the medulla. LM is observed in phagocytes, axons, Schwann cells, satellite cells and ganglionic neurones. CONCLUSION: Our results support the view that the specific ligand-receptor interaction between LM and host E-cadherin is involved in the neuropathogenesis of ruminant listeriosis. They suggest that oral epithelium and Schwann cells expressing E-cadherin provide a port of entry for free bacteria offering a site of primary intracellular replication, from where the bacterium may invade the axonal compartment by cell-to-cell spread. As E-cadherin expression in the ruminant central nervous system is weak, only very locally restricted and not related to the presence of microabscesses, it is likely that further intracerebral spread is independent of E-cadherin and relies primarily on axonal spread.

Neuropathogenesis of naturally occurring encephalitis caused by Listeria monocytogenes in ruminants

Listeriosis is a serious food-borne disease with increasing frequency in humans and ruminants. Despite the facts that in both hosts, listeriosis can occur as rhombencephalitis and ruminants are a reservoir of Listeria monocytogenes (LM) strains pathogenic for humans, little work has been done on the pathogenesis in ruminants. This study investigates the neuropathogenesis of listeric encephalitis in over 200 natural cases in cattle, sheep and goats by analyzing anatomical distribution, severity, bacterial load and temporal evolution of the lesions. Our results suggest that LM gains access to the brainstem of all three species via axonal migration not only along the trigeminal nerve, but also along other nerves. The ensuing encephalitis does not remain restricted to the brainstem. Rather, LM spreads further from the brainstem into rostral brain regions likely by intracerebral axonal migration. Significant differences in severity of the lesions and bacterial load were found between cattle and small ruminants, which may be caused by species-specific properties of antibacterial immune responses. As histopathological lesions of human rhombencephalitis caused by LM strongly resemble those of ruminants, the disease likely has a similar pathogenesis in both hosts.