Neuromuscular diseases in children: a practical approach

Anesthesia of the Patient with Zhu-Tokita-Takenouchi-Kim (ZTTK) Syndrome: A Case Report

Zhu-Tokita-Takenouchi-Kim (ZTTK) syndrome is an extremely rare multiorgan disorder, first described in 2015. Nowadays, about 50 patients with ZTTK syndrome have been reported, but there are no data about management during anesthesia. ZTTK syndrome patients can be indicated for surgery of musculoskeletal deformations and corrections of cardiovascular or urogenital malformations. This syndrome can be challenging for the anesthetic team based on the clinical manifestation of the syndrome. Because there are no recommendations for the management of these patients, anesthesiologists have to study typical symptoms, anatomy and possible expected changes in pathophysiology in perioperative period. One of the most dreaded anesthetic complications, the scenario "can not intubate, can not ventilate" could occur in these patients. The goal of this publication is to show options for anesthetic and perioperative management of this new rare syndrome with no published studies about management and approach in the perioperative period. The anesthetic team should choose the safest available approach. We present the first case report of anesthesia of a patient with ZTTK syndrome, a 7-year-old boy indicated for posterior neuromuscular scoliosis correction and fusion. This case describes the author's experiences with anesthetic management and mentions possible early postoperative complications. Adequate understanding of this syndrome can reduce perioperative complications and improve patient outcomes after surgery.

Multidisciplinary Perioperative Care for Children with Neuromuscular Disorders

Children with neuromuscular diseases present unique challenges to providing safe and appropriate perioperative care. Given the spectrum of disease etiologies and manifestations, this is a population that often requires specialized multidisciplinary care from pediatricians, geneticists, neurologists, dieticians, and pulmonologists which must also be coordinated with surgeons and anesthesiologists when these patients present for surgery. Several of these diseases also have specific pharmacologic implications for anesthesia, most notably mitochondrial disease and muscular dystrophies, which put them at additional risk during the perioperative period particularly in patients presenting without a formal diagnosis. Techniques and strategies to fully evaluate and optimize these patients preoperatively, manage them safely intraoperatively, and return them to their baseline status postoperative are particularly important in this vulnerable group of patients. Utilizing a review of inherited neuromuscular conditions, generalized perioperative concerns, and specific complications related to anesthesia, this article provides an overview of pertinent considerations and recommends a framework for management of these patients.

Anesthesia-induced rhabdomyolysis or malignant hyperthermia: is defining the crisis important?

Anesthesia-induced rhabdomyolysis and malignant hyperthermia occur in response to the same agents and present with similar clinical features. Distinguishing between these diagnoses can be challenging in a clinical crisis yet making the distinction is critical as prompt appropriate management may be life-saving, whereas delayed recognition and/or inappropriate management will almost certainly result in death. This focused review examines the differences between these conditions and focuses on the emergency management of anesthesia-induced rhabdomyolysis.

Anesthetic management of 877 pediatric patients undergoing muscle biopsy for neuromuscular disorders: a 20-year review

BACKGROUND

The objectives are to review the anesthetic management and anesthetic-related adverse events in patients undergoing muscle biopsy for a broad spectrum of neuromuscular disorders (NMD).

AIM

The study aims to assess the hypothesis that perceived awareness of potential anesthesia-induced hyperkalemia and MH in patients with NMD reduces the frequency of such events.

METHODS

A 20-year retrospective review of 877 consecutive patients undergoing muscle biopsy to establish diagnoses of NMD has been performed. Patients were categorized prebiopsy into six groups: M (myopathy and muscular dystrophy), MM (mitochondrial or metabolic myopathy), N (neurodegenerative, peripheral neuropathy or spinal muscular atrophy disorder), D (dermatomyositis), C (cardiomyopathy), or S (seizure disorder). Data were collected for demographics, anesthetic management, pre- and postoperative anesthesia-induced muscle injury, postbiopsy histopathologic diagnosis, and concordance comparisons between pre- and postbiopsy diagnoses.

RESULTS

There were 513 males (58.5%) and 364 females (41.5%) (1.4:1) with 137 individuals (15.6%) operated on under 1 year of age and two-thirds by 6 years of age. NMD diagnosis was reached in 409 (46.6%) while 468 (53.4%) had no specific pathology. No patients exhibited signs of anesthesia-induced muscle injury (malignant hyperthermia, rhabdomyolysis, cardiac arrest, or postoperative deterioration of weakness). MM was the largest group pre biopsy (367, 41.8%). Anesthetic agents were: nitrous oxide in 657 (74.9%); volatile agents in 139 (15.8%); intravenous agents in 836 (95.3%) (primarily propofol, midazolam, and fentanyl); nondepolarizing muscle relaxants in 404 (46.1%); and regional anesthesia in 112 (12.8%) [most commonly spinal anesthesia in 80 (71.4%)]. Comparing preoperative diagnostic category with postoperative diagnosis, there was a concordance of 78% (319/409) between the two for cases with a definitive diagnosis and 89.7% (787/877) for all cases.

CONCLUSIONS

In this retrospective study, no patient exhibited signs or symptoms of hyperkalemia or MH probably because the incidence is very low and becomes even less likely due to the selection of the various anesthetic agents and strategies administered.

Anesthetic considerations in myofibrillar myopathy

Myofibrillar myopathy (MFM) is a relatively newly recognized genetic disease that leads to progressive muscle deterioration. MFM has a varied phenotypic presentation and impacts cardiac, skeletal, and smooth muscles. Affected individuals are at increased risk of respiratory failure, significant cardiac conduction abnormalities, cardiomyopathy, and sudden cardiac death. In addition, significant skeletal muscle involvement is common, which may lead to contractures, respiratory insufficiency, and airway compromise as the disease progresses. This study is the first report of anesthetic management of a patient with MFM. We report multiple anesthetic encounters of a child with genetically confirmed BAG3-myopathy, a subtype of MFM with severe childhood disease onset. A review of the anesthetic implications of the disease is provided, with specific exploration of possible susceptibility to malignant hyperthermia, rhabdomyolysis, and sensitivity to other anesthetic agents.

Ketofol simulations for dosing in pediatric anesthesia

BACKGROUND

Propofol mixed with racemic ketamine (or 'ketofol') is popular for short procedural sedation and analgesia. Use is creeping into anesthesia, yet neither the optimal combination nor infusion rate is known. The EC(50) of propofol's antiemetic effect is reported to be 0.343 mg·l(-1), while ketamine analgesia is thought to persist with concentrations above 0.2 mg·l(-1). We aimed to determine a ketofol dosing regimen for anesthesia 30-min and 1.5-h duration in a healthy child that did not unduly compromise recovery.

METHODS

Pharmacokinetic-pharmacodynamic parameters were used to simulate drug concentration and effect profiles over time for different ratios of propofol to ketamine ratios (1 : 1 to 10 : 1) and rates. The target effect was the 95% probability of loss of response to a 5-s transcutaneous tetanus (P05). Combined effects were additive, with a propofol EC(50) of 3.1 mg·l(-1), ketamine EC(50) of 0.64 mg·l(-1), and slope of 5.4. The time to predicted 50% probability of return of this response after ceasing infusion (P(50)) was determined for a 5-year-old 20-kg healthy child.

RESULTS

The addition of ketamine to propofol infused using a manual infusion regimen (loading dose 3 mg·kg(-1), then 15 mg·kg(-1) ·h(-1) for 15 min, 13 mg·kg(-1) ·h(-1) for 15 min, 11 mg·kg(-1) ·h(-1) for 30 min, and 10 mg·kg(-1) ·h(-1) for 1-2 h) caused prolonged postoperative sedation. The P(50) after a 1.5-h infusion using a 1 : 1 mixture was 4.5 h, 2 : 1 mixture was 3.25 h, 5 : 1 mixture was 1.6 h, and 10 : 1 mixture was 40 min. These P(50) estimates could be reduced by slowing administration infusion rates to 20%, 33%, 50%, 67%, 80%, and 90% for mixtures 1 : 1, 2 : 1, 3 : 1, 5 : 1, 6.7 : 1, and 10 : 1, respectively. These rates achieve a P(50) of approximately 20 min for 30-min duration anesthesia and 60 min for 1.5-h duration anesthesia.

CONCLUSIONS

The addition of ketamine to propofol infusion will prolong recovery unless infusion rates are decreased. We suggest an optimal ratio of racemic ketamine to propofol of 1 : 5 for 30-min anesthesia and 1 : 6.7 for 90-min anesthesia. Delivery of these ratios achieves propofol concentrations above an antiemetic threshold for longer than the ketamine concentration above the analgesic threshold during, potentially reducing postoperative nausea incidence.