Despite near ubiquity, information regarding fluids consumption at a health care systems level, and patient exposure at an individual level, is surprisingly limited in the medical literature. The epidemiology of the foundational medical intervention of intravenous fluid administration is incredibly complex, with millions of patients being exposed internationally every year. Fluid is being given for different reasons, to different targets, following different triggers, by different specialties in different countries, and any observations that can be made are thought to have limited external validity to other jurisdictions and patient groups. The independent effects of fluid administration and fluid accumulation are very hard to separate from other markers of illness severity and aspects of the process of care. Fluid accumulation can result in organ injury, even when the fluid is being given to purportedly ameliorate or prevent such injury, and if it were independently associated with mortality then would be an easily accessible and modifiable risk factor for subsequent morbidity or death. Despite their ubiquity, it is clear that we have limited understanding of the effects of the intravenous fluids we use daily in the most vulnerable of patient groups. The research agenda in this field is large and urgent.
Delivery of Health Care ; Epidemiology ; Humans ; Mortality ; Resuscitation ; Risk Factors

Urinary examination has formed part of patient assessment since the earliest days of medicine. Current definitions of oliguria are essentially arbitrary, but duration and intensity of oliguria have been associated with an increased risk of mortality, and this risk is not completely attributable to the development of concomitant acute kidney injury (AKI) as defined by changes in serum creatinine concentration. The increased risk of death associated with the development of AKI itself may be modified by directly or indirectly by progressive fluid accumulation, due to reduced elimination and increased fluid administration. None of the currently extant major illness severity scoring systems or outcome prediction models use modern definitions of AKI or oliguria, or any values representative of fluid volumes variables. Even if a direct relationship with mortality is not observed, then it is possible that fluid balance or fluid volume variables mediate the relationship between illness severity and mortality in the renal and respiratory physiological domains. Fluid administration and fluid balance may then be an important, easily modifiable therapeutic target for future investigation. These relationships require exploration in large datasets before being prospectively validated in groups of critically ill patients from differing jurisdictions to improve prognostication and mortality prediction.
Acute Kidney Injury ; Creatinine ; Critical Illness ; Dataset ; Humans ; Mortality ; Oliguria* ; Prospective Studies ; Water-Electrolyte Balance

Despite near ubiquity, information regarding fluids consumption at a health care systems level, and patient exposure at an individual level, is surprisingly limited in the medical literature. The epidemiology of the foundational medical intervention of intravenous fluid administration is incredibly complex, with millions of patients being exposed internationally every year. Fluid is being given for different reasons, to different targets, following different triggers, by different specialties in different countries, and any observations that can be made are thought to have limited external validity to other jurisdictions and patient groups. The independent effects of fluid administration and fluid accumulation are very hard to separate from other markers of illness severity and aspects of the process of care. Fluid accumulation can result in organ injury, even when the fluid is being given to purportedly ameliorate or prevent such injury, and if it were independently associated with mortality then would be an easily accessible and modifiable risk factor for subsequent morbidity or death. Despite their ubiquity, it is clear that we have limited understanding of the effects of the intravenous fluids we use daily in the most vulnerable of patient groups. The research agenda in this field is large and urgent.
Delivery of Health Care ; Epidemiology ; Humans ; Mortality ; Resuscitation ; Risk Factors

Urinary examination has formed part of patient assessment since the earliest days of medicine. Current definitions of oliguria are essentially arbitrary, but duration and intensity of oliguria have been associated with an increased risk of mortality, and this risk is not completely attributable to the development of concomitant acute kidney injury (AKI) as defined by changes in serum creatinine concentration. The increased risk of death associated with the development of AKI itself may be modified by directly or indirectly by progressive fluid accumulation, due to reduced elimination and increased fluid administration. None of the currently extant major illness severity scoring systems or outcome prediction models use modern definitions of AKI or oliguria, or any values representative of fluid volumes variables. Even if a direct relationship with mortality is not observed, then it is possible that fluid balance or fluid volume variables mediate the relationship between illness severity and mortality in the renal and respiratory physiological domains. Fluid administration and fluid balance may then be an important, easily modifiable therapeutic target for future investigation. These relationships require exploration in large datasets before being prospectively validated in groups of critically ill patients from differing jurisdictions to improve prognostication and mortality prediction.
Acute Kidney Injury ; Creatinine ; Critical Illness ; Dataset ; Humans ; Mortality ; Oliguria ; Prospective Studies ; Water-Electrolyte Balance