Vol. 15 •Issue 4 • Page 29
Respiratory Flutter Syndrome
May Be More Prevalent Than Previously Thought
BY Shawn Proctor
Everyone gets the hiccups at one time or another. Generally it is no big deal. Take Charles Osborne, for example. In 1922, the Iowa man began a hiccup fit that lasted through two marriages and eight children, a whopping 78 years, according to the Guinness Book of World Records. Witnesses insist Osborne led a normal life despite his hiccups.
However, hiccups’ lesser known cousin, Respiratory Flutter Syndrome (RFS), poses a very real threat to infants, according a recent case series in the American Journal of Respiratory and Critical Care Medicine.
“RFS is a fluttering of the upper airway and inspiratory muscles, including the diaphragm,” noted Eliot S. Katz, MD, lead author of the article. “There appears to be a window of vulnerability that neonates have during which they are intolerant of diaphragmatic or inspiratory muscle dysfunction.”
While there are significant differences between the two conditions, they share one thing in common: neither has a defined cause. “Flutter Syndrome’s in general have multiple etiologies,” Katz explained from his office in the Division of Respiratory Science at Children’s Hospital in Boston. “It can be a problem localized to the brainstem, which is what we postulated in these children, because they had associated findings of swallowing dysfunction. However, anything that traumatizes the phrenic nerve or irritates the diaphragmatic directly can give rise to flutter.”
Generally, RFS presents clinically with an infant emitting a rapid squeaking or fluttering sound with an upper airway origin, he said. In some cases, it might appear as if the patient could be suffering from vocal cord dysfunction.
If RFS appears to be a foreign term, don’t be alarmed. Reasons abound for its anonymity. For starters, the condition is thought to be somewhat rare, although that is far for certain, according to Katz. “The diagnosis of three infants with this presentation during an 18-month period suggests this may be a more frequent cause of respiratory failure in newborns than previously recognized,” he said.
RFS also has the potential to go unreported because it is difficult to detect. “It can mimic a number of other disorders,” he noted.
Hospitals that use impedance-type respiratory monitoring might miss the subtleness of the tell-tale inspiratory motion because of the low frequency response, he said. In one case, the rapid fluctuations operated at a rate of 300 per minute during inspiration.
“Most children in newborn nurseries are monitored with an impedance-type monitor,” said Katz. “That might not be sufficient, because the fluttering in two of our three children was not evident on this monitor.”
Consider instead respiratory inductive plethysmography (RIP), which offers a higher frequency response, he explained. In the case studies, the fluttering was clearly more evident when using RIP.
Katz found CPAP therapy could stabilize the fluttering pattern. However, he admitted, it can be difficult to apply CPAP to an active infant long term. He likewise found that if CPAP was interrupted, it could lead the patient to respiratory failure. Also, CPAP weaning was ineffective, as noted in the case study.
In all cases, Katz, et al., used Chlorpromazine, a major tranquilizer, as the treatment drug of choice. “We actually decided to treat the respiratory flutter with (the drug) based on its utility in recalcitrant hiccups,” he said.
The drug halted RFS symptoms within 12 hours and all three children were weaned from their ventilators within 24 hours, according to Katz. “For children with RFS in respiratory failure, I think it presents a reasonable treatment option.”
Follow-ups with the three patients have been encouraging, he said. All are intellectually and developmentally normal one to two years later with no signs of any relapses or ill effect. Katz said future RFS studies might focus on routine RIP monitoring of neonates to help determine if there are more cases than previously diagnosed.
His advice to RTs is singular: be attentive to the patient and be aware that RFS could happen. “The important take-home message is to have a high index of suspicion,” he said. “When you observe young neonates making fluttering respiratory movements or squeaky upper respiratory sounds, they may, in fact, have RFS.”
You can reach Shawn Proctor at [email protected].