Anesthesiological approach to the floppy child

Children with symptoms of hypotonia (reduction of postural tone of lower limbs and trunk with or without changes in phasic tone) are frequently anesthetized for diagnostic and therapeutic interventions. This review outlines the underlying causes and classifications, and the anesthesiologic pre- and peri-operative management of hypotonic children. Hypotonia may have a large range of etiologies that are categorized into central and peripheral hypotonia. A multidisciplinary approach towards the (differential) diagnosis of the underlying cause of the symptoms in cooperation with a pediatrician and/or pediatric neurologist is emphasized. Anesthetic management involves the anticipation of an increased risk in difficult airway management because of macroglossia, reduced mouth opening, obesity and limited neck mobility, which increases with age. There are no specific restrictions towards the use of intravenous or inhalational anesthetics. Short acting opioids and hypnotics, avoiding neuromuscular blockade, and locoregional techniques are preferred. Most patients are sensitive to the cardiac and depressive effects of anesthetics and all dystrophic myopathies are considered at risk of malignant hyperthermia. Depolarizing neuromuscular blockers are contraindicated. The use of a peripheral nerve stimulator is recommended to detect the severity of muscle relaxation before extubating. Accurate control and management of IV fluids, electrolytes and temperature is mandatory. Adequate postoperative pain treatment is essential to limit stress and metabolic alteration. Preferably a locoregional technique is used to reduce the increased risk of respiratory depression. A multidisciplinary preoperative approach taking into account the differential diagnosis of the underlying disease of the floppy child is recommended.