Editor's Choice - Nationwide Analysis of Patients Undergoing Iliac Artery Aneurysm Repair in the Netherlands.

OBJECTIVE: The new 2019 guideline of the European Society for Vascular Surgery (ESVS) recommends consideration for elective iliac artery aneurysm (eIAA) repair when the iliac diameter exceeds 3.5 cm, as opposed to 3.0 cm previously. The current study assessed diameters at time of eIAA repair and ruptured IAA (rIAA) repair and compared clinical outcomes after open surgical repair (OSR) and endovascular aneurysm repair (EVAR). METHODS: This retrospective observational study used the nationwide Dutch Surgical Aneurysm Audit (DSAA) registry that includes all patients who undergo aorto-iliac aneurysm repair in the Netherlands. All patients who underwent primary IAA repair between 1 January 2014 and 1 January 2018 were included. Diameters at time of eIAA and rIAA repair were compared in a descriptive fashion. The anatomical location of the IAA was not registered in the registry. Patient characteristics and outcomes of OSR and EVAR were compared with appropriate statistical tests. RESULTS: The DSAA registry comprised 974 patients who underwent IAA repair. A total of 851 patients were included after exclusion of patients undergoing revision surgery and patients with missing essential variables. eIAA repair was carried out in 713 patients, rIAA repair in 102, and symptomatic IAA repair in 36. OSR was performed in 205, EVAR in 618, and hybrid repairs and conversions in 28. The median maximum IAA diameter at the time of eIAA and rIAA repair was 43 (IQR 38-50) mm and 68 (IQR 58-85) mm, respectively. Mortality was 1.3% (95% CI 0.7-2.4) after eIAA repair and 25.5% (95% CI 18.0-34.7) after rIAA repair. Mortality was not significantly different between the OSR and EVAR subgroups. Elective OSR was associated with significantly more complications than EVAR (intra-operative: 9.8% vs. 3.6%, post-operative: 34.0% vs. 13.8%, respectively). CONCLUSION: In the Netherlands, most eIAA repairs are performed at diameters larger than recommended by the ESVS guideline. These findings appear to support the recent increase in the threshold diameter for eIAA repair.

Perioperative pharmacokinetics of cefotaxime in serum and bile during continuous and intermittent infusion in liver transplant patients.

BACKGROUND: Drug pharmacokinetics may be altered during liver transplantation. Cefotaxime (CTX), used as perioperative prophylaxis, demonstrates time-dependent killing and therefore continuous infusion might have pharmacodynamic advantages. OBJECTIVES: To determine the pharmacokinetics of CTX and desacetylcefotaxime (DCTX) in serum, bile and urine during continuous and intermittent infusion when performing liver transplantation. METHODS: Fifteen patients undergoing liver transplantation were studied after continuous infusion (CI) (4000 mg iv per 24 h following a loading dose of 1000 mg) and intermittent bolus infusion (BI) (1000 mg iv four times daily). Samples were collected during the first 48 h after liver transplantation. Concentrations of CTX and DCTX were determined by HPLC. RESULTS: During surgery, the mean concentration in serum after CI was 18 mg/L. The lowest serum concentration was 5 mg/L in the CI group and levels were undetectable in the BI group. Target serum concentrations of > or =4 mg/L were reached for 100% of the dosing interval during CI and approximately 60% during BI. Post-operatively, the mean concentration in serum after CI was 26 mg/L. The lowest serum concentration was 8 mg/L in the CI group and levels were undetectable after BI. The peroperative pharmacokinetics of CTX in this patient group were deranged and variable, mainly caused by an increased volume of distribution and decreased hepatic clearance. Metabolism was hampered, but DCTX area under the curve (AUC)/CTX AUC ratios varying between 0.7-0.9 were reached peroperatively. Post-operatively, DCTX AUC/CTX AUC ratios were higher (1.1-1.4). Unchanged CTX in bile was approximately 0.1% of the administered dose, leading to concentrations >4 mg/L throughout the dosing interval for both regimens. CONCLUSION: Although an intermittent bolus infusion of CTX 1000 mg produces t > target concentration for 60% of the dosing interval during liver transplantation, serum concentrations may be insufficient during the reperfusion phase. Continuous infusion overcomes this. Post-operatively, CTX clearance is impaired by decreased metabolic clearance and there is substantial accumulation of DCTX. In bile, sufficient concentrations of CTX and its active metabolite are reached with both regimens.

Experience with a once-daily dosing program of aminoglycosides in critically ill patients.

BACKGROUND: As aminoglycosides show concentration-dependent killing, once-daily aminoglycoside (ODA) regimens have been instituted. Data on experience with ODA regimens in critically ill patients are limited. OBJECTIVES: 1) To evaluate the ODA-program in critically ill patients; 2) to describe the pharmacokinetics of aminoglycosides (gentamicin and tobramycin); and 3) to assess the incidence of nephrotoxicity associated with an ODA regimen in this specific of group patients. DESIGN: A prospective, descriptive study. SETTING: Eighteen-bed surgical and 12-bed medical intensive care unit in a referral centre. PATIENTS: Eighty-nine critically ill patients with a suspected or confirmed infection for which gentamicin or tobramycin was indicated and a creatinine clearance > 30 ml/min were monitored. One hundred and nine pharmacokinetic profiles were gathered. INTERVENTIONS: A first dose of 7 mg/kg/24 h of gentamicin or tobramycin was given to every patient independent of renal function. Subsequent doses were chosen on the basis of the pharmacokinetic results of the first dose. MEASUREMENTS: Serum samples were collected 1 h and 6 h after start of the aminoglycoside infusion. All samples were assayed by using immunofluorescence. Pharmacokinetic parameters were estimated using a one-compartment model. RESULTS: The volume of distribution of aminoglycosides was significantly higher in critical ill patients with septic shock than in those without. Consequently, the maximum concentration reached was significantly lower in patients with septic shock. In P. aeruginosa infections the mean (SD) estimated Cmax/MIC ratio was 10.3 (3.3). In n = 17 (49%) of the patients treated > 24 h ( n = 35), a dose adjustment or lengthening of interval was necessary. The recommended dosing interval based on the Hartford Hospital nomogram and one-serum concentration at 6 h was correct in only 62% of all cases. Signs of renal impairment occurred in n = 12 (14%) of the patients; in all survivors renal function recovered completely and no haemofiltration was needed. CONCLUSIONS: An ODA-regimen of 7 mg/kg produced Cmax/MIC ratios > 10 in the majority of critically ill patients in our population. Septic shock and renal dysfunction caused an aberrant pharmacokinetic profile of aminoglycosides in these patients. Therefore, individual therapeutic drug monitoring is warranted. Signs of renal impairment were common in the presence of shock, but appeared to be reversible.