Santhanam Suresh

ASRA Practice Advisory on Neurologic Complications in Regional Anesthesia and Pain Medicine

Neurologic complications associated with regional anesthesia and pain medicine practice are extremely rare. The ASRA Practice Advisory on Neurologic Complications in Regional Anesthesia and Pain Medicine addresses the etiology, differential diagnosis, prevention, and treatment of these complications. This Advisory does not focus on hemorrhagic and infectious complications, because they have been addressed by other recent ASRA Practice Advisories. The current Practice Advisory offers recommendations to aid in the understanding and potential limitation of neurologic complications that may arise during the practice of regional anesthesia and pain medicine.

Anesthetic Neurotoxicity — Clinical Implications of Animal Models

Some anesthetics and sedatives have been shown to cause neurotoxic effects in laboratory animals. The FDA collaboration SmartTots recommends undertaking large-scale clinical studies and avoiding nonurgent surgical procedures requiring anesthesia in children younger than 3 years of age.

Pediatric Regional Anesthesia Network (PRAN): a multi-institutional study of the use and incidence of complications of pediatric regional anesthesia.

BACKGROUND: Regional anesthesia is increasingly used in pediatric patients to provide postoperative analgesia and to supplement intraoperative anesthesia. The Pediatric Regional Anesthesia Network was formed to obtain highly audited data on practice patterns and complications and to facilitate collaborative research in regional anesthetic techniques in infants and children. METHODS: We constructed a centralized database to collect detailed prospective data on all regional anesthetics performed by anesthesiologists at the participating centers. Data were uploaded via a secure Internet connection to a central server. Data were rigorously audited for accuracy and errors were corrected. All anesthetic records were scrutinized to ensure that every block that was performed was captured in the database. Intraoperative and postoperative complications were tracked until their resolution. Blocks were categorized by type and as single-injection or catheter (continuous) blocks. RESULTS: A total of 14,917 regional blocks, performed on 13,725 patients, were accrued from April 1, 2007 through March 31, 2010. There were no deaths or complications with sequelae lasting >3 months (95% CI 0–2:10,000). Single-injection blocks had fewer adverse events than continuous blocks, although the most frequent events (33% of all events) in the latter group were catheter-related problems. Ninety-five percent of blocks were placed while patients were under general anesthesia. Single-injection caudal blocks were the most frequently performed (40%), but peripheral nerve blocks were also frequently used (35%), possibly driven by the widespread use of ultrasound (83% of upper extremity and 69% of lower extremity blocks). CONCLUSIONS: Regional anesthesia in children as commonly performed in the United States has a very low rate of complications, comparable to that seen in the large multicenter European studies. Ultrasound may be increasing the use of peripheral nerve blocks. Multicenter collaborative networks such as the Pediatric Regional Anesthesia Network can facilitate the collection of detailed prospective data for research and quality improvement.

A comparison of three doses of a commercially prepared oral midazolam syrup in children.

Midazolam is widely used as a preanesthetic medication for children. Prior studies have used extemporaneous formulations to disguise the bitter taste of IV midazolam and to improve patient acceptance, but with unknown bioavailability. In this prospective, randomized, double-blinded study we examined the efficacy, safety, and taste acceptability of three doses (0.25, 0.5, and 1.0 mg/kg, up to a maximum of 20 mg) of commercially prepared Versed® syrup (midazolam HCl) in children stratified by age (6 mo to <2 yr, 2 to <6 yr, and 6 to <16 yr). All children were ASA class I–III scheduled for elective surgery. Subjects were continuously observed and monitored with pulse oximetry. Ninety-five percent of patients accepted the syrup, and 97% demonstrated satisfactory sedation before induction. There was an apparent relationship between dose and onset of sedation and anxiolysis (P < 0.01). Eight-eight percent had satisfactory anxiety ratings at the time of attempted separation from parents, and 86% had satisfactory anxiety ratings at face mask application. The youngest age group recovered earlier than the two older age groups (P < 0.001). There was no relationship between midazolam dose and duration of postanesthesia care unit stay. Before induction, there were no episodes of desaturation, but there were two episodes of nausea and three episodes of emesis. At the time of induction, during anesthesia, and in the postanesthesia care unit, there were several adverse respiratory events. Oral midazolam syrup is effective for producing sedation and anxiolysis at a dose of 0.25 mg/kg, with minimal effects on respiration and oxygen saturation even when administered at doses as large as 1.0 mg/kg (maximum, 20 mg) as the sole sedating medication to healthy children in a supervised clinical setting.

Ultrasound imaging for regional anesthesia in infants, children, and adolescents: a review of current literature and its application in the practice of extremity and trunk blocks.

Complementary to a previous publication related to pediatric extremity and trunk blockade, the authors present a comprehensive narrative review of the literature pertaining to techniques described and outcomes evaluated for ultrasound imaging in pediatric neuraxial anesthesia. The sonoanatomy related to each block is also described and illustrated to serve as a foundation for better understanding the block techniques described. For neuraxial blockade, ultrasound may fairly reliably predict the depth to loss of resistance and can enable a dynamic view of the needle and catheter after entry into the spinal canal. Particularly, in young infants, direct visualization of the needle and catheter tip may be possible, whereas in older children surrogate markers including the displacement of dura mater by the injection of fluid may be necessary for confirming needle and catheter placement. More outcome-based, prospective, randomized, controlled trials are required to prove the benefits of ultrasound when compared with conventional methods.

Regional Anesthesia in Anesthetized or Heavily Sedated Patients

The American Society of Regional Anesthesia and Pain Medicine (ASRA) Practice Advisory on Neurologic Complications in Regional Anesthesia and Pain Medicine includes an evidence- and expert opinion-based section on performing procedures on anesthetized or heavily sedated patients. This practice advisory is based on existing scientific literature, pathophysiological principles, and expert opinion. The advisory panel examined the ability of anesthetized or heavily sedated patients to recognize and report intravascular injection of local anesthetic or impending neurologic injury. The advisory panel also considered whether or not the ability to recognize and report symptoms could actually affect the occurrence of nerve injury or local anesthetic systemic toxicity. The advisory contains recommendations pertaining to both adult and pediatric patients.

Ultrasound guided transversus abdominis plane block in infants, children and adolescents: a simple procedural guidance for their performance.

The transversus abdominis plane block (TAP) has been described recently for pain management following abdominal surgery. Although many techniques have been described using anatomical landmarks, a simple ultrasound (US) guidance technique for the block has not been described in children. An article published by Hebbard and colleagues on the use of US‐guidance for TAP blocks described the technique with the probe positioned at the midaxillary line with a needle insertion that is located further medial on the abdominal wall. This technique, although feasible in adults is not possible in children due to the need for obtaining a more thorough spread of the local anesthetic solution. We describe in this article, a user‐friendly approach to the placement of a TAP block in infants, children and adolescents. Further pharmacokinetic data has to be obtained for actual dosing for these blocks in infants and children.

The new air-Q™ intubating laryngeal airway for tracheal intubation in children with anticipated difficult airway: comment

1 Danon MJ, Oh SJ, DiMauro S et al. Lysosomal glycogen storage disease with normal acid maltase. Neurology 1981; 31: 51–57. 2 Maron BJ, Roberts WC, Arad M et al. Clinical outcome and phenotypic expression in LAMP2 cardiomyopathy. JAMA 2009; 301(12): 1253–1259. 3 Mittnacht AJC, Moung C, Lai WW. Massive cardiac hypertrophy in a patient with Danon disease: an intraoperative transesophageal echocardiographic evaluation. Anesth Analg 2007; 105(4): 963–965. 4 Nishino I, Fu J, Tanji K et al. Primary LAMP-2 deficiency causes X-linked vacuolar cardiomyopathy and myopathy (Danon disease). Nature 2000; 406: 906–910. 5 Dworzak F, Casazza F, Mora M et al. Lysosomal glycogen storage with normal acid maltase: a familial study with successful heart transplant. Neuromuscul Disord 1994; 4(3): 243–247. 6 Arad M, Maron BJ, Gorham JM et al. Glycogen storage diseases presenting as hypertrophic cardiomyopathy. N Engl J Med 2005; 352(4): 362–372. 7 Charron P, Villard E, Sebillon P et al. Danon’s disease as a cause of hypertrophic cardiomyopathy: a systematic survey. Heart 2004; 90: 842–846. 8 Yang Z, McMahon CJ, Smith LR et al. Danon disease as an underrecognized cause of hypertrophic cardiomyopathy in children. Circulation 2005; 112: 1612–1617. 9 Sugie K, Yamamoto A, Murayama K et al. Clinicopathological features of genetically confirmed Danon disease. Neurology 2002; 58: 1773–1778. 10 Balmer C, Ballhausen C, Bosshard NU et al. Familial X-linked cardiomyopathy (Danon disease): diagnostic confirmation by mutation analysis of the LAMP2 gene. Eur J Pediatr 2005; 164: 509–514. 11 Prall FR, Drack A, Taylor M et al. Opthalmic manifestations of Danon disease. Ophthalmology 2006; 113: 1010–1013. 12 Lake CL, Booker PB. Pediatric Cardiac Anesthesia, 4th edn. Philadelphia: Lippincott Williams & Wilkins, 2005: 532–534.

Opioid Tolerance in Neonates: Mechanisms, Diagnosis, Assessment, and Management

Opioid tolerance and withdrawal have been challenges for decades. The neurochemical mechanisms of tolerance and dependence are clinically important only because they can affect weaning schedules and the adjustment of doses for neonates. Analgesic effects are characterized by an increased depolarization threshold for the neuron, shorter duration of the action potential generated, and reduced release of neurotransmitters. Tolerance and withdrawal are associated with the reversal of these cellular effects. Adverse clinical effects associated with the use of opioids in neonates include respiratory depression, chest wall rigidity, urinary retention, and decreased gastrointestinal motility. The physiological systems most prominently affected by opioid withdrawal include the central nervous system, gastrointestinal system, and the autonomic nervous system. Opioid withdrawal symptoms in neonates can be assessed by using easily available scoring systems, although these need to be validated for different populations. Management of opioid withdrawal includes the use of other opioids, benzodiazepines and alpha-2 adrenergic receptor antagonist, clonidine. Careful titration of opioids with attention given to appropriate weaning schedules can reduce the incidence of withdrawal in neonates.

The new air-QTM intubating laryngeal airway for tracheal intubation in children with anticipated difficult airway: a case series: THE NEW AIR-QTM INTUBATING LARYNGEAL AIRWAY FOR ANTICIPATED DIFFICULT AIRWAY IN CHILDREN

The air‐Q intubating laryngeal airway (ILA) is a new supraglottic airway device which may overcome some limitations inherent to the classic laryngeal mask airway for tracheal intubation. We present a case series of patients with anticipated difficult airway in whom the air‐Q ILA was successfully used as a conduit for fiberoptic intubation.