Marco A. Maurtua

Dexmedetomidine for deep brain stimulator placement in a child with primary generalized dystonia: case report and literature review

Dexmedetomidine, which is a relatively selective alpha2-adrenoceptor agonist, is used for sedation and analgesia in intensive care unit patients, during awake craniotomies in pediatric and adult patients, and during magnetic resonance imaging, with minimal depression of respiratory function. The successful use of dexmedetomidine in a pediatric patient undergoing bilateral deep brain stimulator placement for the treatment of generalized dystonia, is presented.

Perioperative complications of blood brain barrier disruption under general anesthesia: A retrospective review

Blood brain barrier disruption enhances drug delivery in primary central nervous system lymphoma. In this study, we report adverse events that were encountered intraoperatively and in the postoperative period in these patients. A retrospective analysis of 17 patients documenting demographic data, preprocedure medical history, intraoperative, and postoperative anesthetic complications was conducted between January 2002 and December 2004. Seventeen patients underwent 210 treatments under general anesthesia with a mean of 12.4±7.2 treatments per patient. Focal seizures occurred in 13% of patients. Generalized motor seizures occurred in 4 treatment sessions in 2 different patients. The incidence of seizures was significantly higher when the internal carotid artery was used for injection, as opposed to the vertebral artery (20.8% and 6.02%, respectively, P=0.0034). Tachycardia associated with ST segment depression occurred 9 times (4.3%) in 3 patients. One patient had significant ST segment elevation (more than 1.5 mm). Transient cerebral vasospasm after methotrexate injection occurred in 9% of patients. Postoperative nausea and vomiting were observed in 11.9% of patients. After emergence, lethargy and obtundation occurred in 7.6% of the cases. The incidence of postoperative headache and reversible motor deficits was 6% and 3.8%, respectively. Our review highlights the problems that were encountered during blood brain barrier disruption under anesthesia and in the postoperative period. Further prospective studies are required for comprehensive evaluation of intraprocedure and postprocedure complications that will allow development of an optimal anesthetic plan and will improve patient outcome by preventing potential complications.

Dosing of Remifentanil to Prevent Movement During Craniotomy in the Absence of Neuromuscular Blockade

Background In neuroanesthesia practice, muscle relaxants may at times need to be avoided to facilitate intraoperative motor pathway monitoring. Our studys objective was to determine the optimal dose of remifentanil required to prevent movement after neurosurgical stimulation. Methods After Institutional Review Board approval and written informed consent, 132 patients undergoing elective craniotomy randomly received one of 12 remifentanil dose regimens (0.10 to 0.21 μg/kg/min). Remifentanil was started before induction with propofol and succinylcholine. Anesthesia was maintained with isoflurane (0.6% end-tidal) in air/oxygen. During the study, movement was assessed on predetermined criteria by the anesthesiology, nursing, and neurosurgical teams. Heart rate and blood pressure were recorded every 5 minutes. We assessed the relationship between movement, hypotension, bradycardia, and dose using probit analysis and logistic regression. Results Sixty-five percent of the patients moved in response to surgical stimuli [95% confidence interval (CI): 49%-79%] at a remifentanil infusion rate of 0.10 μg/kg/min, and movement decreased to 21% (95% CI: 11-35) at 0.21 μg/kg/min. The probability of movement was 50% at an infusion rate (95% CI) of 0.13 (0.10 to 0.15) μg/kg/min remifentanil and decreased to 25% at an infusion rate of 0.19 (0.17 to 0.29) μg/kg/min. The probability of hypotension and bradycardia was 50% at 0.13 (0.10 to 0.15) μg/kg/min and 0.17 (0.15 to 0.21) μg/kg/min, respectively. Conclusions Higher doses of remifentanil lessen the risk of movement in the absence of muscle relaxants with surgical stimulation for elective craniotomy. Hypotension and bradycardia were common at higher doses. Even at the maximum dose (0.21 mcg/kg/min) there was a 20% chance of movement. Adjunctive therapy is needed to ablate movement reliably, and to counteract the hypotensive effect of remifentanil. These findings may be helpful for clinicians administering remifentanil and isoflurane during procedures, where muscle relaxants may not be desirable.

Use of the CTrach Laryngeal Mask Airway in adult patients: a retrospective review of 126 cases☆

STUDY OBJECTIVE To evaluate the effectiveness of the CTrach Laryngeal Mask Airway (LMA) when used electively. DESIGN Retrospective analysis. SETTING Operating room of an academic hospital. MEASUREMENTS Data from 126 patients who were electively intubated with the CTrach LMA over a 16-month period were reviewed. Each patients weight, height, ASA physical status classification, Mallampati score, thyromental distance, and cervical spine range of motion were recorded. MAIN RESULTS Successful ventilation was achieved in 100% of patients, while successful intubation was achieved in 89.7% of patients. The most common reason for failure to intubate was poor airway visualization and the inability to appropriately position the device anterior to the vocal cords. CONCLUSIONS The major advantage of the CTrach LMA is that it is the only device that allows airway visualization during patient ventilation; however, it does not have 100% success with intubation.

The use of the CTrachTM Laryngeal Mask Airway in pediatric patients: a retrospective review of 25 cases

To the Editor, The CTrach Laryngeal Mask Airway (LMA CTrach) (LMA North America, San Diego, CA, USA) was developed by Dr. Archie Brain as an improvement on the LMA Fastrach to facilitate tracheal intubation through better visualization of the vocal cords. The LMA CTrach can serve as a rescue airway or it can be used electively for routine airway management. Several adult retrospective studies report its efficacy for lung ventilation and tracheal intubation. Timmermann et al. reported lung ventilation in all patients and successful tracheal intubation in 98.3% of patients, and Liu et al. reported successful insertion in 100% of patients and successful tracheal intubation in 96% of patients. Currently, there is a lack of literature regarding the use of the LMA CTrach in pediatric patients. We present herein the cumulative experience with elective use of the LMA CTrach at our institution. We sought to assess the clinical efficacy of the LMA CTrach by focusing on the reported achievement of successful ventilation and intubation and by identifying the difficulties encountered by clinicians. This retrospective review was approved by the Cleveland Clinic Institutional Review Board. A database search limited to ages 0 mth to 18 yr yielded 25 pediatric patients who underwent surgical procedures and whose tracheas were intubated electively using the LMA CTrach. In all cases, the clinicians who used the LMA CTrach were experienced anesthesiologists who performed tracheal intubations on a regular basis. Data were collected during a 24-mth period from June 2006 to June 2008. Patient age, biometric data (weight and height), and American Society of Anesthesiologists physical status classification were obtained from the anesthesia record. The body mass index (BMI) was calculated (BMI = weight/height. The Mallampati score, thyromental distance, and cervical spine range of motion physiological data were obtained from the pre-anesthesia clinical record. When documented, the LMA CTrach efficacy in airway management is reported as statistical percentages based on successful lung ventilation, tracheal intubation attempts, and tracheal intubation outcomes. The LMA CTrach was used electively in 25 pediatric patients with diverse demographic profiles (see Table). All patients had normal cervical spine range of motion and a thyromental distance [ 6 cm. Two patients (8%) were recorded as having short necks. The majority of patients (72%) had normal BMIs, 24% were overweight, and 4% were obese. No failures to insert the LMA CTrach were recorded. Furthermore, all pediatric patients’ lungs were ventilated successfully. Tracheal intubation was successful in all 25 patients and was performed without difficulty in 23 (92%). One intubation required a second intubation attempt because of an initial blurry image in the LMA CTrach screen. During another tracheal intubation, the endotracheal tube had to be rotated 1808, as the tip advanced beyond the epiglottic lever; a second attempt was not required. Mallampati score did not affect the intubation success rate. The tracheas of patients with Mallampati scores of 1 (17 patients), 2 (six patients), 3 (one patient), and 4 (one patient) were all intubated successfully. This retrospective review shows that successful lung ventilation and tracheal intubation procedures were achieved in all 25 pediatric patients where the LMA CTrach was used. Two initial difficulties with tracheal M. A. Maurtua, MD (&) P. S. Finnegan, NREMT-B G. DeBoer, MD Cleveland Clinic, Cleveland, OH, USA e-mail: maurtum@ccf.org

The incidence of intraoperative bradycardia, postoperative electrolyte abnormalities, and delayed pacu discharge in patients undergoing endoscopic third ventriculostomy with lactated ringer’s solution irrigant

Conclusion: Our preliminary results suggest that remifentanil lessens the risk of movement in the absence of muscle relaxant with the application of head pins and surgical stimulation in patients getting remifentanil infusions greater than 0.15mg/kg/min. It is important to note that also hypotension and bradycardia were more frequent in the high dose group. These findings give the clinician a better knowledge in the administration of remifentanil combined with isoflurane during neurosurgical procedures were muscle relaxants can not be used because of their interference with intraoperative neurophysiologic monitoring. We recently completed the study and we are currently performing the statistical analysis of our findings, the information shown above will be updated with our final results. References: 1. Erhan E, Ugur G, Gunusen I, Alper I, Ozyar B. Propofol not thiopental or etomidate with remifentanil provides adequate intubating conditions in the absence of neuromuscular blockade. Can. J Anaesth. 2003;50:108–15. 2. Erhan E, Ugur G, Alper I, Gunusen I, Ozyar B. Tracheal intubation without muscle relaxants: remifentanil or alfentanil in combination with propofol. Eur. J. Anaesthesiol. 2003;20:37–43. 3. Trabold F, Casetta M, Duranteau J, Albaladejo P, Mazoit JX, Samii K, Benhamou D, Sitbon P. Propofol and remifentanil for intubation without muscle relaxant: the effect of the order of injection. Acta Anaesthesiol. Scand. 2004;48:35–9.