Melbourne is the coffee capital of the world (according to me at least). It’s the city that is home of the deconstructed latte and coffee bars can be found on most street corners. Every morning I am woken at 5-ish by one of my children calling out to me. After the yell of “Daaaaaddy”, the second word she utters is “Coffee”. Perhaps she is a little too young for her first espresso shot?
You are never to young for your first coffee?
Apnoea of prematurity can occur in a quarter of all preterm infants less than 2500g within the first 10 days or so after birth. This is aggressively managed in order to prevent possible downstream sequelae such as hypoxic brain injury. The basic approach to management is very similar to the way in which my children try to get me out of bed in the morning – tactile stimulation (prodding me), adjustment of ambient temperature (pulling the duvet off me) an assisted ventilation (a kiss on the cheek if I’m lucky). When these approaches to apnoea of prematurity fail then methylxanthines come in to play.
Why does apnoea of prematurity occur?
There are number of theories, but one suggestion is that there is altered sensitivity of central and peripheral chemoreceptors to either carbon dioxide or oxygen. Xanthines, in the form of theophylline or caffeine, act as central respiratory stimulants with the later having fewer peripheral effects than theophylline. Caffeine therapy reduces the frequency of apnoeic episodes and reduces the need for mechanical ventilation. It has also been shown to reduce the incidence of bronchopulmonary dysplasia as a form of ventilator induced lung injury. Its use may also reduce the incidence of retinopathy of prematurity (again due to decreased ventilation/oxygen exposure). But it is not without potential harms.
Adenosine has been shown to preserve cerebral ATP levels and be neuro-protective in hypoxic animal models. Could the use of adenosine receptor blocking agents (e.g. caffeine) have long term deleterious effects on brain function? One study of over 900 infants found no increase in ultrasonographic indices of brain damage between neonates that receives caffeine and those that did not.
Are there any other uses for caffeine?
Just as stimulants are used in the treatment of hyper-activity disorders, caffeine has been trialed for use in children who display post-sedation paradoxical hyperactivity. Although relatively uncommon the degree or irritability and agitation can be a challenge to manage. In a study of children that received sedation for radiological imaging, those that received either IV caffeine recovered from their agitation much faster than those that were left alone to recover naturally.
So how much caffeine is bad for you?
Regular caffeine consumption can be a cause of headaches in young children and so it is worthwhile asking a dietary history when one presents to the ED. A series from a specialist headache clinic found 36 children over a five year period that had chronic daily headaches secondary to caffeine consumption. These were children that were drinking up to a 1.5 litres of cola a day – the equivalent of 192.88mg per day. Examining the trends of caffeinated beverage consumption, 73% of US children consume such a drink on any given day. Scarily 63% of children in the 2 to 5 year age group consume them too. These are mainly soda-based drinks (62%), followed by tea then coffee and energy drinks.
Caffeine has a dose dependent effect on the human body with moderate doses (200-300mg) producing effects of improved concentration and improved energy levels. Higher doses, over 400mg, lead to the jitters and nausea. These effects may be ameliorated in habitual drinkers.
There is also the problem of sugar. Most caffeinated energy drinks and colas have a high sugar content with all of its attendant adverse effects.
But what if they… just…can’t…stop!
Given that such a large number of children drink caffeinated drinks what happens when they try to stop? Just as in adults, caffeine withdrawal leads to self-reported headaches and increased levels of drowsiness. These effects are apparent after about 24 hours of abstinence. The muzziness can persist for up to a week after the cessation of caffeine.
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