Association of Intraoperative Hypotension With Delayed Graft Function Following Kidney Transplant: A Single Centre Retrospective Cohort Study.

BACKGROUND: Intraoperative hypotension is associated with acute kidney injury after surgery. However, the definition (duration and magnitude) of hypotension during kidney transplantation (KT) surgery on early graft function remains unclear. METHODS: We conducted a retrospective cohort study of KT recipients from December 1, 2009, to December 31, 2019. Exposure to intraoperative hypotension was characterized as the duration (minutes) of mean arterial pressure (MAP) <55, <65, <75, and <85 mmHg. Our co-primary outcomes were DGF-creatinine reduction ratio (DGF-CRR, <30% creatinine reduction, postoperative days 1 and 2), and DGF-dialysis (DGF-D, required dialysis within the week of KT for deceased donor recipients). Logistic regression models were fitted to assess this relationship between MAP and DGF. RESULTS: We included 1602 KT (939 deceased donors, 663 living donors) and 23 were excluded. DGF-CRR occurred in 33% of patients. DGF-CRR was associated with MAP < 65 (>5 min: OR 1.77, 95% confidence interval [CI]: 1.39-2.30; 6-10 min: OR 1.67, 95% CI: 0.97-2.86; 11-20 min: OR 2.18, 95% CI: 1.31-3.63) in unadjusted and <55 mmHg (5 min: OR 1.85, 95% CI: 1.47-2.32; 5-10 min: OR 2.41, 95% CI: 1.65-3.53; 11-20 min: OR 2.36, 95% CI: 1.60, 3.48) in adjusted models. There was also a signal for increased risk of DGF-CRR at MAP < 75 (>5 min: OR 1.69, 95% CI: 1.02-2.80). DGF-D (incidence 35%) in deceased donor KT was not associated with hypotension. CONCLUSIONS: We found an association between intraoperative hypotension and DGF-CRR at a threshold MAP of 55 mmHg, with a consistent signal toward increased risk at both 65 and 75 mmHg, as indicated by unadjusted models.

Intraoperative hypotension and the risk of acute kidney injury following liver transplantation.

BACKGROUND: Acute kidney injury (AKI) is a frequent adverse outcome following liver transplantation (LT) with a multifactorial etiology. It is critical to identify modifiable risk factors to mitigate the risk. One key area of interest is the role of intraoperative hypotension, which remains relatively unexplored in liver transplant cohorts. METHODS: This was a retrospective observational cohort study of 1292 adult patients who underwent LT (between 2009 and 2019). Multivariable logistic regression analysis was used to explore the association between intraoperative hypotension, quantified by time duration (in min) under various mean arterial pressure (MAP) thresholds, and the primary outcome of early postoperative AKI according to the KDIGO criteria. RESULTS: AKI occurred in 40% of patients and was independently associated with greater than 20 min spent below MAP thresholds of 55 mm Hg (adjusted OR = 1.866; 95% CI = 1.037-3.44; P = 0.041) and 50 mm Hg (adjusted OR = 1.801; 95% CI = 1.087-2.992; P = 0.023). Further sensitivity analyses demonstrated that the association between intraoperative hypotension and postoperative AKI was accentuated after restricting the analysis to patients with a normal preoperative renal function. CONCLUSIONS: Prolonged (>20 min) intraoperative hypotension (below a MAP of 55 mm Hg) was independently associated with AKI following LT, after adjusting for several known confounders.

Impact of goal-directed hemodynamic therapy on perioperative outcomes in head and neck free flap surgery: A before-and-after pilot study.

Background: Free flap reconstruction for head and neck cancer is associated with a high risk of perioperative complications. One of the modifiable risk factors associated with perioperative morbidity is intraoperative hypotension (IOH). The main aim of this pilot study is to determine if the intraoperative use of goal-directed hemodynamic therapy (GDHT) is associated with a reduction in the number of IOH events in this population. Methods: A before-and-after study design. The patients who had intraoperative GDHT were compared to patients from a previous period before the implementation of GDHT. The primary outcome was the number of IOH episodes defined as five or more successive minutes with a mean arterial pressure <65 mmHg. The secondary outcomes included major postoperative morbidity and 30-day mortality. Results: A total of 414 patients were included. These were divided into two groups. The control group (n = 346; January 1, 2018, to December 31, 2019), and the monitored group (n = 68; January 1, 2020, to May 1, 2021). The median intraoperative administered fluid volume was similar between the control and monitored groups (2250 interquartile range [IQR] [1607-3050] vs. 2210 IQR [1700-2807] mL). The monitored group was found to have an increased use of norepinephrine and dobutamine (respectively, 1.2% vs. 5.9% and 2.4% vs. 30.9%; p < 0.05). When adjusting for confounders (comorbidities, estimated blood loss, and duration of anesthesia) the incidence rate ratio (95% confidence interval) of number of IOH events was 0.94 (0.86-1.03), p = 0.24. The rate of postoperative flap and medical complications did not differ between the two groups. Conclusions: Even though the use of vasopressors/inotropes was higher in the monitored group, the number of IOH episodes and postoperative morbidity and mortality were similar between the two groups. Further change in hemodynamic management will require the use of specific blood pressure targets in the GDHT fluid algorithm.

Ready-to-use thermally stable mastermix pills for molecular biology applications.

Rolling circle amplification (RCA), polymerase chain reaction (PCR), and loop-mediated isothermal amplification (LAMP), are powerful tools that can be used for gene manipulation, pathogen detection, and infectious disease diagnostics. However, these techniques require trained personnel, as the pipetting steps involved can lead to contamination and, consequently, erroneous results. Furthermore, many of the reagents used in molecular biology are thermally labile and must be kept within a cold-chain. In this article, we present a simple and cost-effective method that allows molecular biology reagents to be thermally stabilized into ready-to-use mastermixes via drying in pullulan and trehalose films. Our experimental results demonstrate that this method is capable of preserving the activity of RCA, PCR, LAMP, ligase, polynucleotide kinase, and Klenow fragment mastermixes for at least 3 months at ambient conditions. Thus, stabilizing reagents via drying in pullulan and trehalose film may allow for a drastic reduction in the number of pipetting steps and the elimination of the need for a cold chain. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 35: e2764, 2019.