RESUMO
Background and objectives: The effect of initiating continuous renal replacement therapy (CRRT) on urine output, fluid balance and mean arterial pressure (MAP) in adult intensive care unit (ICU) patients is unclear. We aimed to evaluate the impact of CRRT on urine output, MAP, vasopressor requirements and fluid balance, and to identify factors affecting urine output during CRRT. Design: Retrospective cohort study using data from existing databases and CRRT machines. Setting: Medical and surgical ICUs at a single university-associated centre. Participants: Patients undergoing CRRT between 2015 and 2018. Main outcome measures: Hourly urine output, fluid balance, MAP and vasopressor dose 24 hours before and after CRRT commencement. Missing values were estimated via Kaplan smoothing univariate time-series imputation. Mixed linear modelling was performed with noradrenaline equivalent dose and urine output as outcomes. Results: In 215 patients, CRRT initiation was associated with a reduction in urine output. Multivariate analysis confirmed an immediate urine output decrease (-0.092 mL/kg/h; 95% confidence interval [CI], -0.150 to -0.034 mL/kg/h) and subsequent progressive urine output decline (effect estimate, -0.01 mL/kg/h; 95% CI, -0.02 to -0.01 mL/kg/h). Age and greater vasopressor dose were associated with lower post-CRRT urine output. Higher MAP and lower rates of net ultrafiltration were associated with higher post-CRRT urine output. With MAP unchanged, vasopressor dose increased in the 24 hours before CRRT, then plateaued and declined in the 24 hours thereafter (effect estimate, -0.004 µg/kg/ min per hour; 95% CI, -0.005 to -0.004 µg/kg/min per hour). Fluid balance remained positive but declined towards neutrality following CRRT implementation. Conclusions: CRRT was associated with decreased urine output despite a gradual decline in vasopressor and a positive fluid balance. The mechanisms behind the reduction in urine output associated with commencement of CRRT requires further investigation.
RESUMO
Objective: Traumatic brain injury (TBI) patients with prolonged intensive care unit (ICU) stay are at risk of secondary intracranial haemorrhage (ICH) and venous thromboembolism (VTE). We aimed to study VTE prophylaxis, secondary ICH, and VTE prevalence and outcomes in this population. Design: Retrospective observational study. Setting: Level 1 trauma centre ICU. Patients: One hundred TBI patients receiving prolonged ICU treatment (≥ 7 days). Interventions: We collected data from medical records, pathology and radiology systems, and hospital and ICU admission databases. We analysed patient characteristics, interventions, episodes and types of secondary ICH and VTE, and timing and dosage of VTE prophylaxis. Results: Data from the 100 patients in our study showed that early use of compression stockings and pneumatic calf compression was common (75% and 91% in the first 3 days, respectively). VTE chemoprophylaxis, however, was only used in 14% of patients by Day 3 and > 50% by Day 10. We observed VTE in 12 patients (10 as pulmonary embolism), essentially all after Day 6. Radiologically confirmed secondary ICH occurred in 43% of patients despite normal coagulation. However, 72% of ICH events (42/58) were radiologically mild, and the median time of onset of ICH was Day 1, when only 3% of patients were on chemical prophylaxis. Moreover, 82% of secondary ICH events (48/58) occurred in the first 3 days, with no severe ICH thereafter. Conclusions: In TBI patients receiving prolonged ICU treatment, early chemical VTE prophylaxis was uncommon. Early secondary ICH was common and mostly radiologically mild, whereas later secondary ICH was essentially absent. In contrast, early VTE was essentially absent, whereas later VTE was relatively common. Earlier chemical VTE prophylaxis and/or ultrasound screening in this population appears logical.
