A knowledge pearl episode with a short case seen during intern year of residency. These three clinical entities all share a common theme; they develop quickly and need definitive management within minutes.
Fentanyl rigid chest syndrome: chest wall/abdominal/masseter rigidity following the administration of fentanyl. More commonly seen with doses >4mcg/kg but can be with ANY dose.
Risk factors: higher doses, fast push rate, extremities of age, critical illness and use of medications that alter dopamine levels.
Succinylcholine masseter muscle rigidity (MMR): whereas mild masseter rigidity and jaw stiffness is common up to a minute after giving succinylcholine, MMR presents with severe prolonged jaw stiffness after giving sux. Some of these patients will progress to outright malignant hyperthermia (MH) and management should proceed accordingly.
Risk factors: inadequate dosing of sux (<1mg/kg), children, myotonia congenita, duchenne muscular dystrophy.
Ketamine Induced Laryngospasm: laryngospasm seen after giving ketamine. Results in difficult ventilation. Can often be managed with CPAP or positive pressure ventilation using a BVM.
Risk factors: children <3 mo, pts with active URTI or asthma, larger doses, rapid push rate.