The impact of a cadaver-based airway lab on critical care fellows' direct laryngoscopy skills.

This study sought to determine the impact of a cadaver-based airway lab on critical care medicine fellows' direct laryngoscopy skills and hypothesised that fellows can improve their self-reported percentage of glottic opening (POGO) scores in cadaver models to achieve POGO scores similar to that of expert faculty. Nineteen fellows attended an airway management skills laboratory utilising five modified cadavers. Initial fellow POGO (POGOi) visualised was recorded at the onset with direct laryngoscopy. Maximum fellow POGO score with optimised direct laryngoscopy was recorded after two additional hours of teaching and also during a testing phase several days later. Data was assessed for significant differences between trainee POGO scores at each time interval and between trainee POGO scores and expert scores. A departmental procedural database was utilised to examine success rates of intubation as a clinical correlation. Fellows' mean POGOi scores, averaged across all five specimens, were significantly lower than both their maximum POGO scores and their testing phase POGO scores. Mean POGOi scores for fellows, averaged over all five cadavers, were lower than the instructors' POGOi scores. There was no difference between fellows' and instructors' mean maximum POGO or mean testing phase POGO scores. Clinical success rates of intubation were over 98%. A short training session using modified cadavers can be utilised to teach new critical care medicine fellows additional techniques for airway management and assist them in obtaining higher POGO scores, similar to those of expert instructors. Success rates of clinical intubations were favourable in the wake of this training.

The impact of local anesthetic distribution on block onset in ultrasound-guided interscalene block.

BACKGROUND: Recent investigations of local anesthetic distribution in the lower extremity have revealed that completely surrounding the sciatic nerve with local anesthetic provides the advantage of more rapid and complete anesthesia in the territory served by the nerve. We hypothesized that a pattern of distribution that entirely envelops the targeted nerve roots during interscalene block would provide similar benefits of more rapid anesthesia onset. METHODS: During interscalene block guided by ultrasound with nerve stimulator confirmation, the pattern of local anesthetic distribution was recorded and later classified as complete or incomplete envelopment of the visible nerve elements in 50 patients undergoing ambulatory shoulder arthroscopic surgery. The pattern was then compared with the extent of block setup at pre-determined intervals, as well as to post-operative pain levels and block duration. RESULTS: Twenty-two patients (44%) had complete envelopment of the nerves in the plane of injection during ultrasound imaging of the interscalene block. There was no difference in the fraction of blocks that were fully set-up at 10 min with regards to complete or incomplete envelopment of the nerves by local anesthetic. All of the patients had complete setup of the block by 20 min. In addition, the post-operative pain levels and duration of block did not vary among the two groups with complete vs. incomplete local anesthetic distribution around the nerves. CONCLUSION: The presence or absence of complete envelopment of the nerve elements in the interscalene groove by local anesthetic did not determine the likelihood of complete block effect at pre-determined time intervals after the procedure.

Sonoanatomy of the vasculature at the supraclavicular and interscalene regions relevant for brachial plexus block.

BACKGROUND: Our aim in this observational study was to utilize ultrasound, as well as anatomic dissection, to document the frequency with which branches of the subclavian vessels are found in close association with the brachial plexus at the locations of supraclavicular and interscalene brachial plexus block. METHODS: Ultrasound was utilized to document the presence of branches of the subclavian vein and artery, adjacent to the brachial plexus in the supraclavicular and in the interscalene region in 50 patients undergoing shoulder surgery. The position, depth, and dimensions of the vessels were described, and the origin determined when possible. In addition, the posterior triangle of the neck on both sides of three non-preserved cadavers was dissected to evaluate the vascular anatomy and correlate the ultrasound findings. RESULTS: Ultrasound scanning revealed an arterial branch adjacent to, or passing directly through, the brachial plexus in the supraclavicular region in 43/50 (86%) patients. Within the interscalene region, an artery was identified coursing in a lateral direction in 45/50 (90%) of cases, while a corresponding small vein, coursing medial to lateral in this area, was noted in 23/50 (46%) of cases. CONCLUSIONS: Small branch vessels from the subclavian artery and vein were frequently evident, on ultrasound imaging, in close association with the nerve elements of the brachial plexus in the supraclavicular and interscalene regions. Appreciation of the presence of these vessels and their likely origin and course will aid the anesthesiologist in planning a safe nerve block.

Ultrasound decreases the failed labor epidural rate in resident trainees.

BACKGROUND: Epidural analgesia is widely used for pain relief during labor. The purpose of this study was to determine if ultrasound measurement of the depth from skin to epidural space before the epidural technique decreases the failure rate of labor analgesia. A secondary objective was to correlate ultrasound depth to the epidural space with actual depth of the needle at placement. METHODS: In this prospective, randomized, non-blinded study, 370 parturients requesting labor epidural analgesia were randomized to receive their epidural technique by first year anesthesia residents with or without prior ultrasound determination of epidural space depth. Outcome variables included the incidence of epidural catheter replacement for failed analgesia and the number of epidural attempts and accidental dural punctures. RESULTS: The ultrasound group had fewer epidural catheter replacements (P<0.02), and epidural placement attempts (P<0.01) compared to the control group. Pearson's correlation coefficients comparing the actual versus ultrasound estimated depth to the epidural space in the longitudinal median and transverse planes were 0.914 and 0.909, respectively. Pearson's correlation coefficient comparing the ultrasound estimated depths to the epidural space in the transverse and longitudinal median planes was 0.940. No significant differences were noted with respect to staff interventions, top-ups, accidental dural punctures, and delivery outcome. CONCLUSIONS: Ultrasound measurement of the epidural space depth before epidural technique placement decreases the rate of epidural catheter replacements for failed labor analgesia, and reduces the number of epidural attempts when performed by first year residents and compared to attempts without ultrasound guidance.

Intravenous adenosine therapy accelerating rate of paroxysmal supraventricular tachycardia.

Two cases of paroxysmal supraventricular tachycardia are reported in which the administration of adenosine produced sustained elevation of the rate of paroxysmal supraventricular tachycardia. In each case, sinus rhythm was restored readily through the use of intravenous verapamil. This adverse reaction to adenosine has not been previously described.

Post-traumatic intracerebral pneumatocele: case report.

Pneumocephalus occurs in 0.5 to 1.0% of head trauma, but may also occur after neurologic surgery, or as a result of eroding infection or neoplasm. The pathophysiology involves the presence of craniodural fistula allowing ingress of air. A ball-valve mechanism may allow air to enter but not exit the cranium, or CSF leak permits air entrance as fluid leaves the intracranial space. While a "succession splash" is considered diagnostic of pneumocephalus, most patients have nonspecific signs and symptoms such as headache. Therefore, a high index of suspicion in a patient with recent head trauma is necessary. The diagnosis is made radiographically by CT scan. This is generally performed to rule out intracranial hematoma or cerebral contusion in head trauma, but will reveal even very small quantities of air to the unsuspecting physician. Therapy is often noninvasive, allowing the craniodural defect to heal spontaneously. Selected situations require immediate operative repair of the fistula.