Free-breathing magnetic resonance imaging with radial k-space sampling for neonates and infants to reduce anesthesia.

BACKGROUND: Conventional chest and abdominal MRI require breath-holds to reduce motion artifacts. Neonates and infants require general anesthesia with intubation to enable breath-held acquisitions. OBJECTIVE: We aimed to validate a free-breathing approach to reduce general anesthesia using a motion-insensitive radial acquisition with respiratory gating. MATERIALS AND METHODS: We retrospectively enrolled children <3 years old who were referred for MRI of the chest or abdomen. They were divided into two groups according to MRI protocol: (1) breath-held scans under general anesthesia with T2-weighted single-shot fast spin-echo (SSFSE) and contrast-enhanced T1-weighted modified Dixon, and (2) free-breathing scans using radial sequences (T2-W MultiVane XD and contrast-enhanced T1-W three-dimensional [3-D] Vane XD). Two readers graded image quality and motion artifacts. RESULTS: We included 23 studies in the free-breathing cohort and 22 in the breath-hold cohort. The overall imaging scores for the free-breathing radial T2-W sequence were similar to the scores for the breath-held T2-W SSFSE sequence (chest, 3.6 vs. 3.2, P=0.07; abdomen, 3.9 vs. 3.7, P=0.66). The free-breathing 3-D radial T1-W sequence also had image quality scores that were similar to the breath-held T1-W sequence (chest, 4.0 vs. 3.0, P=0.06; abdomen, 3.7 vs. 3.9, P=0.15). Increased motion was seen in the abdomen on the radial T2-W sequence (P<0.001), but increased motion was not different in the chest (P=0.73) or in contrast-enhanced T1-W sequences (chest, P=0.39; abdomen, P=0.15). The mean total sequence time was longer in free-breathing compared to breath-held exams (P<0.01); however, this did not translate to longer overall exam times (P=0.94). CONCLUSION: Motion-insensitive radial sequences used for infants and neonates were of similar image quality to breath-held sequences and had decreased sedation and intubation.

A retrospective cohort study of children with spinal muscular atrophy type 2 receiving anesthesia for intrathecal administration of nusinersen.

INTRODUCTION: Spinal muscular atrophy is characterized by loss of motor neurons in the anterior horn of the spinal cord with resultant proximal muscle weakness. Intrathecal nusinersen has revolutionized the treatment of spinal muscular atrophy. We reviewed the perioperative care of 61 anesthetics performed on eight patients with spinal muscular atrophy type 2 who received nusinersen over 30 months in conjunction with nusinersen's phase 3 clinical trials. METHODS: Anesthesia was induced in all patients with sevoflurane, nitrous oxide, and oxygen (30%) via facemask. A peripheral intravenous line was placed after the loss of consciousness in all but three procedures. General anesthesia was maintained in 58 anesthetics with a propofol infusion at 250-300 µg/kg/min, while the remainder was maintained with inhalational anesthetics. The airway was managed via facemask or nasal cannula in all but two procedures, in whom a laryngeal mask airway was placed. We analyzed patient demographics, duration of anesthesia and of postanesthesia care unit stay, discharge destination, preprocedure oxygen saturation (SaO2 ), postanesthesia care unit discharge oxygen saturation, and occurrence of unanticipated admission or postdischarge hospitalization. RESULTS: Eight American Society of Anesthesiologists physical status three patients (3 male: 5 female) with a median age of 4.1 (2.1-7.8) years and median weight of 13.2 (10-24.7) kg, underwent 61 anesthetics for nusinersen administration or sham procedure. There were no intraoperative anesthetic complications of unanticipated cardiovascular instability, major neurologic events, respiratory failure, or death. Anesthesiologists performed 83% of the procedures. CONCLUSION: Nusinersen has revolutionized the care of patients with spinal muscular atrophy type 2 and anesthesiologists will be involved in its administration. We found that routine anesthetic care was safe and effective.

Fatal hyponatremia in a 7-year-old girl with cloacal exstrophy after cystoscopy for a bladder stone.

A case of fatal hyponatremia in a 7-year-old girl following a percutaneous cystolithotomy is presented. Stone removal by percutaneous cystolithotomy is considered a safe and effective procedure, but this may depend on the type of solution used for irrigation. In this case less than 2L of sterile water was used as irrigation in an augmented bladder causing a drop in sodium to 120 mmol/L in 30 min. The result was a massive shift of water into the cerebral tissue, cerebral edema and death.