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Provision of intravenous fluids outside of medical facilities has become an expanding business in the USA, and for several years has been marketed for pre-event and postevent hydration at various sporting events, including mass events like marathons.1 These ‘for-purchase on-demand’ intravenous services are marketed to enhance performance and postevent recovery. Typically administered in a tent or a mobile station by a nurse under the licensure of a physician, little or no preintervention medical assessment is involved.
Oral versus intravenous fluids
Since the composition of intravenous fluids can be easily reproduced in oral solutions, the benefit of intravenous fluids lies in circumventing delays with absorption of oral fluids.2 These delays can be strictly related to intestinal absorption in a healthy athlete or delays related to gastrointestinal distress (eg, vomiting or diarrhoea) in an ill athlete. Intravascular plasma volume expansion with intravenous fluids in a healthy athlete is only transiently increased when compared with oral rehydration and the benefit probably lasts for 35 min or less.2 There is little difference in plasma volume expansion after 1 hour.2 In a prerace or postrace setting, it is unlikely that this brief window of increased bioavailability with intravenous fluids would benefit a healthy athlete when compared with oral rehydration, though there may be some benefits to intravenous rehydration in the ill athlete under certain circumstances.
Use and misuse of intravenous fluids in sports
The World Anti-Doping Agency currently bans intravenous infusions and/or injections of more than a total of 100 mL per 12 hours period except when legitimately received in the course of hospital treatments, surgical procedures or clinical diagnostic investigations.3 Nevertheless, three-quarters of the National Football League teams reported routine use of intravenous fluids to ‘hyperhydrate’ players before games in 2011.4 On average, six players on each team received intravenous fluids per game.4
Some believe that pre-exercise intravenous hydration can prevent dehydration and exercise-associated muscle cramping, and postexercise intravenous hydration will speed recovery compared with oral rehydration.2 5 But, there is no evidence to support such claims in an athlete who can take fluids orally. In one small study, oral rehydration was more likely to lower perceived exertion and thirst compared with intravenous rehydration.6 While intravenous rehydration may replenish body fluid more rapidly compared with oral rehydration, the transient effect has no clinical benefits in healthy athletes.2 5
When are intravenous fluids indicated in athletes?
The most obvious scenario supporting the use of intravenous fluids is for an athlete who is unable to tolerate oral fluids (eg, altered mental status or persistent vomiting) and is severely dehydrated.7 8 However, prior to initiation of intravenous fluids, it is important that the athlete undergoes a medical assessment (eg, vital signs, mental status and possibly weight change status) since hyponatraemia and hyperthermia can be present with similar symptoms. Hypervolaemic hyponatraemia is quite common in endurance sports.7 8 Proper management of the condition involves fluid restriction and small volumes of hypertonic saline or oral salt intake, whereas administration of isotonic or hypotonic intravenous fluids could exacerbate the hyponatraemia and be fatal.7 8 In the case of hyperthermia, delay in proper management with cooling efforts could also result in serious morbidity or mortality.8
Clinicians can use a history and physical examination to assess the hydration status of an athlete, but examination findings can be unreliable following an endurance competition.7 Although urine and blood studies can be crucial in determining whether a patient is dehydrated or overhydrated, these are rarely available in the field and do not seem to be part of the typical assessment by intravenous hydration businesses.7
Conclusions
Oral rehydration is generally adequate and preferred in most cases of postexercise dehydration. In sports environments, intravenous hydration is only warranted in situations in which a severely dehydrated athlete is unable to rehydrate due to poor cognitive status or gastrointestinal symptoms preventing adequate oral hydration.8
On the other hand, the potential risks from unregulated intravenous hydration of athletes include infection, ecchymosis, electrolyte imbalance, air embolus and needle sticks to the provider.5 It is particularly concerning that intravenous isotonic and hypotonic fluids can worsen mild or asymptomatic hypervolaemic hyponatraemia, causing rapid progression to seizure.9 Without prompt diagnosis and proper treatment with hypertonic saline, significant morbidity or death could result. These intravenous hydration business ventures are unlikely to be prepared with adequate resources to properly assess and intervene if an athlete rapidly deteriorates from hyponatraemia.
Athletes are a vulnerable population in their quest to optimise performance and attain a competitive advantage. It is our opinion that intravenous hydration businesses are taking advantage of athletes through their provision of a medical intervention that is generally unwarranted and with potentially deleterious consequences when performed without proper medical oversight. We encourage state medical boards to respond with regulations (eg, requiring evaluation by a clinician prior to administration) that control these potentially dangerous business ventures who capitalise on vulnerable athletes.
Footnotes
Competing interests None declared.
Patient consent Not required.
Provenance and peer review Not commissioned; externally peer reviewed.