WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT • Gentamicin pharmacokinetics show wide inter‐individual variability across all age groups and impaired gentamicin clearance is associated with impaired creatinine clearance in older people. • Changes in body composition and renal function with old age and frailty are likely to affect the pharmacokinetics of gentamicin. • There is current debate on whether the Modification of Diet in Renal Disease (MDRD) equation estimate of glomerular filtration rate (GFR) should replace the Cockcroft Gault equation estimate of creatinine clearance for calculation of doses of renally excreted drugs. WHAT THIS STUDY ADDS • The volume of distribution of gentamicin is not significantly lower in frail than in non frail older people. • The correlation between volume of distribution of gentamicin and actual bodyweight is poor in frail and moderate in non frail older people. • Gentamicin clearance is significantly lower in frail than in non frail older people. • The Cockcroft Gault calculation of creatinine clearance, calculated using ideal bodyweight, gave the best estimate of gentamicin clearance in this population of frail and non frail older people. • The MDRD estimate of GFR and Cockcroft Gault estimate of creatinine clearance, calculated using actual bodyweight, overestimate gentamicin clearance in frail and non frail older people. AIMS Frailty, a syndrome of decreased physiological reserve that is prevalent in old age, impacts on clinical pharmacology. The aims of the study were to (1) determine whether frailty affects the pharmacokinetics of gentamicin and (2) assess the accuracy of different estimates of body size and renal clearance as estimates of gentamicin pharmacokinetics in older inpatients. METHODS This was an observational study of gentamicin pharmacokinetics in a cohort of Australian hospital inpatients aged ≥65 years, who were administered prophylactic intravenous gentamicin. RESULTS Of the 31 participants, 14 were frail and 17 non frail on the Reported Edmonton Frail Scale. The mean volume of distribution of gentamicin was 14.8 ± 1.4 l in frail participants and 15.3 ± 2.2 l in non frail (NS). Volume of distribution correlated best with lean bodyweight. Gentamicin clearance was significantly lower in frail participants (46.6 ± 10.7 ml min−1) than in non frail (58.2 ± 12.4 ml min−1, P= 0.01). The Cockcroft Gault estimate of creatinine clearance calculated using ideal bodyweight gave the best estimate of gentamicin clearance (mean error – 0.15 ml min−1, 95% CI −2.67, 2.39). The Cockcroft Gault creatinine clearance calculated using actual bodyweight and the estimated glomerular filtration rate from the modified diet in renal disease equation overestimated gentamicin clearance, with mean errors of −10.15 ml min−1 (95%CI −13.60, −6.71) and −18.86 ml min−1 (95% CI −22.45, −15.27), respectively. The Cockcroft Gault creatinine clearance calculated using lean bodyweight underestimated gentamicin clearance (mean error 6.54 ml min−1, 95% CI 4.18, 8.90). CONCLUSIONS Frail older people...

BackgroundIn the intensive care unit (ICU), critical illness delirium occurs in the context of multiple comorbidities, multi-organ failure, and invasive management techniques, such as mechanical ventilation, sedation, and lack of sleep. Delirium is characterized by an acute confusional state defined by fluctuating mental status, inattention, and either disorganized thinking or an altered level of consciousness. The long-term cognitive and psychosocial function of patients that experience delirium in the ICU is of crucial interest because preliminary data suggest a strong association between ICU-related delirium and long-term cognitive impairment.ObjectiveThe aim of this study is to explore the relationship between delirium in the ICU and adverse outcomes by following mechanically ventilated patients for one year following their discharge from the ICU and collecting data on their long-term cognition and psychosocial function.MethodsThis study will be conducted by enrolling patients in two tertiary ICUs in Australia. We aim to recruit 200 patients who have been mechanically ventilated for more than 24 hours. Data will be collected at the following three time points: (1) at discharge where they will be administered the Mini-Mental State Examination (MMSE); (2) at 6 months after discharge from the ICU discharge where the Impact of Events Scale Revised (IES-R) and the Telephone Inventory for Cognitive Status (TICS) tests will be administered; and (3) at 12 months after discharge from the ICU where the patients will be administered the TICS and IES-R tests, as well as the Informant Questionnaire for Cognitive Decline in the Elderly (IQCODE). The IQCODE will be administered to their “person responsible” or the significant other of the patient.ResultsLong-term cognition and psychosocial function will be the primary outcome of this study. Mortality will also be investigated as a secondary outcome. Active enrollment will take place until the end of September 2016 and data collection will conclude at the end of September 2017. The analysis and results are expected to be available by March 2018.ConclusionDelirium during mechanical ventilation has been linked to longer ICU and hospital stays, higher financial burdens, increased risks of long-term cognitive impairment (ie, dementia), poor functional outcomes and quality of life, and decreased survival. However, delirium during mechanical ventilation in the ICU is not well understood. This study will advance our knowledge of the comprehensive, long-term effects of delirium on cognitive and psychosocial function.Trial RegistrationAustralian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12616001116415; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=371216 (Archived by WebCite at http://www.webcitation.org/ 6nfDkGTcW)