Depth of insertion of right internal jugular central venous catheter: Comparison of topographic and formula methods

Background: Central venous catheters (CVCs) are inserted in many critically ill patients, but there is no gold standard in estimating their approximate depth of insertion. Many techniques have been described in literature. In this study, we compare the topographic method with the standard formula technique. Materials and Methods: 260 patients, in whom central venous catheterization was warranted, were randomly assigned to either topographic method or formula method (130 in each group). The position of the CVC tip in relation to carina was measured on a postprocedure chest X-ray. The primary endpoint was the need for catheter repositioning. Results: The majority of the CVCs tips positioned by the formula method were situated below the carina, and 68% of these catheters required repositioning after obtaining postprocedure chest X-ray (P < 0.001). Conclusion: The topographic method is superior to formula approach in estimating the depth of insertion of right internal jugular CVCs

Transient brachial monoparesis following epidural anesthesia for cesarean section

Monoparesis following lumbar epidural block is a rare occurrence, with few cases reported in the literature. We report development of transient brachial monoparesis following epidural anesthesia in a parturient for cesarean section. The patient received a mixture of 15 mL of 2% lignocaine with 50 mcg fentanyl epidurally to achieve a blockade up to T6 level. She remained hemodynamically stable throughout the procedure, with no respiratory distress or desaturation. However, near the end of surgery, she developed weakness in the right upper limb. The weakness lasted for 90 min, followed by complete neurological recovery. Subsequent hospital stay was uneventful

Inaccurate level of intervertebral space estimated by palpation: The ultrasonic revelation

Background: Spinal cord injury resulting from spinal anesthesia is a rare, but an alarming scenario. The most likely cause is believed to be misjudged level of intervertebral space (IVS). We evaluated the accuracy of palpation method to locate IVS with the ultrasonography. Materials and Methods: A total of 109 patients undergoing spinal anesthesia were included in this observational, double-blind study. First anesthesiologist was asked to mark IVS using palpation method. It was followed by ultrasonographic assessment by another anesthesiologist who was unaware of the level estimated for the mark. We evaluated the accuracy of palpation method in sitting and lateral position as well as the impact of the anesthesiologist′s experience (Trainee/Consultant). Statistical Analysis Used: Association between the gender, anthropometric parameters, type of anesthesiologists assessing the IVS, and the level of agreement were identified using Chi-square test. The agreement between palpation method and ultrasound assessment of IVS was analyzed using kappa statistic. P < 0.05 was defined as statistical significance. Results: The IVS located by palpation method was in agreement with ultrasound location in 37.14% of the patients. There were no statistically significant differences found in terms of demographic data (sex, age, height, weight, or body mass index [BMI]) between agreement and disagreement group. The rate of errors was found to be significantly higher (P = 0.01) among the trainees (74.51%) than the consultants (51.86%). The rate of errors was not different between the sitting and lateral position. The frequency of errors was more common in cephalad direction (53.31.5%) compared to caudal direction (9.52%). The misidentified spaces were as high as three spaces above the intended space while in caudal direction it differed by only one space. Conclusion: The accuracy of palpation method controlled by ultrasound is 37.14% and differs by 1-3 IVS in cephalad direction (53.31%). The accuracy is affected by anesthesiologist′s experience but remains unaffected by age, sex height, BMI, and patient positioning

Sonographic detection of tracheal or esophageal intubation: A cadaver study

Background: The correct position of the endotracheal tube is confirmed by various modalities, most of which are not entirely reliable. Ultrasound is now increasingly available to anesthesiologists in the operating theater and is an attractive alternative. To investigate the usefulness of sonography in identifying the correct tracheal tube position in human cadavers. Materials and Methods: Endotracheal tubes placed randomly into trachea or esophagus was identified with a linear ultrasound probe placed transversely just above the suprasternal notch by a single anesthesiologist. Results: Of the 100 intubations performed at random, 99 were correctly identified to give a sensitivity of 100% and a specificity of 97.9%. Conclusion: Sonography is a useful technique to identify correct position of the tracheal tube

The Brain Processing of Scratching

Neuroimaging studies have examined the neural networks activated by pruritus but not its behavioral response, scratching. In this study, we examine the central sensory effects of scratching using blood oxygen level-dependent functional magnetic resonance imaging (fMRI) in 13 healthy human subjects. Subjects underwent functional imaging during scratching of the right lower leg. Scratching stimulus was started 60seconds after initiation of fMRI acquisition and was cycled between 30-second duration applications of scratching and 30-second duration applications of no stimuli. Our results show that repetitive scratching induces robust bilateral activation of the secondary somatosensory cortex, insular cortex, prefrontal cortex, inferior parietal lobe, and cerebellum. In addition, we show that the same stimulus results in robust deactivation of the anterior and posterior cingulate cortices. This study demonstrates brain areas (motor, sensory, and non-sensory) activated and deactivated by repetitive scratching. Future studies that investigate the central effects of scratching in chronic itch conditions will be of high clinical relevance