Surgical site infection is a common complication following pancreaticoduodenectomy and is a major source of postoperative morbidity. Surgical site infection is more common among patients who undergo preoperative biliary instrumentation, likely because of the introduction of intestinal flora into the normally sterile biliary tree. Frequently, bacterial isolates from surgical site infections after pancreaticoduodenectomy demonstrate resistance to the antibiotic agents typically used for surgical prophylaxis, suggesting that broad-spectrum coverage may be beneficial. This chapter summarizes the current evidence regarding surgical site infection following pancreatic surgery and describes the rationale and methodology underlying a multicenter randomized trial evaluating piperacillin-tazobactam compared with cefoxitin for surgical site infection prevention following pancreaticoduodenectomy. As the first U.S. randomized surgical trial to utilize a clinical registry for data collection, this study serves as proof of concept for registry-based clinical trials. The trial has successfully completed patient accrual, and study results are forthcoming.

The aim of this narrative review was to discuss the literature on β-lactam antibiotic-associated hypokalemia, a potentially life-threatening electrolyte disorder. The PubMed, Web of Science, Cochrane Library, and Scopus databases were searched for articles published between 1965 and 2023, using the following terms: \'hypokalemia\' OR \'potassium loss\' OR \'potassium deficiency\' AND \'beta-lactams\' OR \'penicillin\' OR \'penicillin G\' OR \'cephalosporins\' OR \'ceftazidime\' OR \'ceftriaxone\' OR \'flucloxacillin\' OR \'carbapenems\' OR \'meropenem\' OR \'imipenem\' OR \'cefiderocol\' OR \'azlocillin\' OR \'ticarcillin\'. Additional search terms were \'hypokalemia\' AND \'epidemiology\' AND \'ICU\' OR \'intensive care unit\' OR \'ER\' OR \'emergency department\' OR \'ambulatory\' OR \'old\' OR \'ageing population\', and experimental (animal-based) studies were excluded. A total of eight studies were selected and discussed, in addition to nine case reports and case series. Both older and currently used β-lactam antibiotics (e.g., ticarcillin and flucloxacillin, respectively) have been associated with therapy-related hypokalemia. The incidence of β-lactam antibiotic-associated hypokalemia may be as high as 40%, thus, the issue of β-lactam-associated hypokalemia remains clinically relevant. Although other causes of hypokalemia are likely to be diagnosed more frequently (e.g., due to diuretic therapy or diarrhea), the possibility of β-lactam-induced renal potassium loss should always be considered in individuals with so-called \'unexplained hypokalemia\'.

OBJECTIVE: Renal replacement therapy (RRT) plays a critical role in antimicrobial removal, particularly for low-molecular-weight drugs with low plasma protein binding, low distribution volume and hydrophilicity. Medium cut-off (MCO) membranes represent a new generation in dialysis technology, enhancing diffusive modality efficacy and increasing the cut-off from 30 to 45 kDa, crucial for middle molecule removal. This monocentric randomized crossover pilot study aimed to evaluate the impact of continuous haemodialysis with MCO membrane (MCO-CVVHD) on the removal of piperacillin, tazobactam and meropenem compared with continuous veno-venous hemodiafiltration with standard high-flux membrane (HFM-CVVHDF).
METHODS: Twenty patients were randomized to undergo MCO-CVVHD followed by HFM-CVVHDF or vice versa. Extraction ratio (ER), effluent clearance (Cleff) and treatment efficiency were assessed at various intervals. Antibiotic nadir plasma levels were measured for both treatment days.
RESULTS: HFM-CVVHDF showed greater ER compared with MCO-CVVHD for meropenem (β = - 8.90 (95% CI - 12.9 to - 4.87), p < 0.001) and tazobactam (β = - 8.29 (95% CI - 13.5 to - 3.08), p = 0.002) and Cleff for each antibiotic (meropenem β = - 10,206 (95% CI - 14,787 to - 5787), p = 0.001); tazobactam (β = - 4551 (95% CI - 7781 to - 1322), p = 0.012); piperacillin (β = - 3913 (95% CI - 6388 to - 1437), p = 0.002), even if the carryover effect influenced the Cleff for meropenem and tazobactam. No difference was observed in nadir plasma concentrations or efficiency for any antibiotic. Piperacillin (β = - 38.1 (95% CI - 47.9 to - 28.3), p < 0.001) and tazobactam (β = - 4.45 (95% CI - 6.17 to - 2.72), p < 0.001) showed lower nadir plasma concentrations the second day compared with the first day, regardless the filter type.
CONCLUSIONS: MCO demonstrated comparable in vivo removal of piperacillin, tazobactam and meropenem to HFM.

Infection is one of the main causes of orthopedic implants failure, with antibiotic-resistant bacteria playing a crucial role in this outcome. In this work, antimicrobial nanogels were developed to be applied in situ as implant coating to prevent orthopedic-device-related infections. To that regard, a broad-spectrum antimicrobial peptide, Dhvar5, was grafted onto chitosan via thiol-norbornene \"photoclick\" chemistry. Dhvar5-chitosan nanogels (Dhvar5-NG) were then produced using a microfluidic system. Dhvar5-NG (1010 nanogels (NG)/mL) with a Dhvar5 concentration of 6 μg/mL reduced the burden of the most critical bacteria in orthopedic infections - methicillin-resistant Staphylococcus aureus (MRSA) - after 24 h in medium supplemented with human plasma proteins. Transmission electron microscopy showed that Dhvar5-NG killed bacteria by membrane disruption and cytoplasm release. No signs of cytotoxicity against a pre-osteoblast cell line were verified upon incubation with Dhvar5-NG. To further explore therapeutic alternatives, the potential synergistic effect of Dhvar5-NG with antibiotics was evaluated against MRSA. Dhvar5-NG at a sub-minimal inhibitory concentration (109 NG/mL) demonstrated synergistic effect with oxacillin (4-fold reduction: from 2 to 0.5 μg/mL) and piperacillin (2-fold reduction: from 2 to 1 μg/mL). This work supports the use of Dhvar5-NG as adjuvant of antibiotics to the prevention of orthopedic devices-related infections.

We evaluated the activity of piperacillin in relation to INCREASING TAZOBACTAM CONCENTRATION against ESBL-producing Enterobacterales collected from patients with bacteraemia. Increasing tazobactam concentration (4, 12 or 24 mg/L) exerted a reduction of piperacillin MICs under the clinical breakpoint in a concentration-dependent manner (0%, 60% and 90% of clinical isolates). Also, activity of piperacillin/tazobactam based at higher achievable serum concentrations (123/14 mg/L) is needed to reduce the bacterial growth in 92% of ESBL-producers. CHANGES IN THE PIPERACILLIN MIC IN RELATION TO INCREASING TAZOBACTAM SUGGEST THAT REALTIME TDM COULD BE USED FOR DRIVEN ANTIMICROBIAL THERAPY WITH PIPERACILLIN/TAZOBACTAM IN BSI DUE TO ESBL STRAINS.

OBJECTIVE: Piperacillin/tazobactam is extensively used off-label to treat late-onset neonatal sepsis, but safety and pharmacokinetic data in this population are limited. Additionally, the organic immaturity of the newborns contributes to a high piperacillin pharmacokinetic variability. This affects the clinical efficacy of the antibiotic treatment and increases the probability of developing drug resistance. This study aimed to evaluate the predictive performance of reported piperacillin population pharmacokinetic models for their application in a model-informed precision dosing strategy in preterm and term Mexican neonatal intensive care patients.
METHODS: Published population pharmacokinetic models for piperacillin which included neonates in their study population were identified. From the reference models, structured models, population pharmacokinetic parameters, and interindividual and residual variability data were extracted to be replicated in pharmacokinetic software (NONMEM® version 7.4). For the clinical study, a sampling schedule was designed, and 2-3 blood samples of 250 µL were taken from neonates who met the inclusion criteria. Piperacillin plasma concentrations were determined by liquid chromatography/tandem mass spectrometry. The clinical treatment data were collected, and piperacillin plasma concentrations were estimated using reference pharmacokinetic models for an a priori or Bayesian approach. Statistical methods were used in terms of bias and precision to evaluate the differences between observed and estimated neonatal piperacillin plasma concentrations with the different approaches and to identify the pharmacokinetic model that best fits the neonatal data.
RESULTS: A total of 70 plasma samples were collected from 25 neonatal patients, of which 15 were preterm neonates. The overall median value (range) postnatal age, gestational age, body weight, and serum creatinine at the sampling collecting day were 12 (3-26) days, 34.2 (26-41.1) weeks, 1.78 (0.08-3.90) Kg, 0.47 (0.20-0.90) mg/dL, respectively. Three population pharmacokinetic models for piperacillin in infants up to 2 months were identified, and their predictive performance in neonatal data was evaluated. No pharmacokinetic model was suitable for our population using an a priori approach. The model published by Cohen-Wolkowiez et al. in 2014 with a Bayesian approach showed the best performance of the pharmacokinetic models evaluated in our neonatal data. The procedure requires two blood samples (predose and postdose), and, when applied, it predicted 66.6% of the observations with a relative median absolute predicted error of less than 30%.
CONCLUSIONS: The population pharmacokinetic model developed by Cohen-Wolkowiez et al. in 2014 demonstrated superior performance in predicting the plasma concentration of piperacillin in preterm and term Mexican neonatal intensive care patients. The Bayesian approach, including two different piperacillin plasma concentrations, was clinically acceptable regarding bias and precision. Its application for model-informed precision dosing can be an option to optimize the piperacillin dosage in our population.

OBJECTIVE: We evaluated the usefulness of prophylactic mini-tracheostomy (PMT) and perioperative administration of tazobactam/piperacillin (TAZ/PIPC) in high-risk patients after esophagectomy.
METHODS: We retrospectively studied 89 consecutive high-risk patients who underwent esophagectomy for esophageal cancer between January 2013 and December 2021. We defined patients with two or more of the following factors as high risk: age ≥70 years, performance status ≥1, respiratory dysfunction, liver dysfunction, cardiac dysfunction, renal dysfunction, diabetes mellitus, albumin <3.5 g/dl, and Brinkman index >600. Standard management was administered to the first 50 patients (standard group). PMT and TAZ/PIPC were administered to the next 39 patients (combination group). Patient characteristics and short-term outcomes were compared before and after propensity-score matching.
RESULTS: Before propensity-score matching, 24-hour urine creatinine clearance, retrosternal route, 3-field lymph node dissection, and open abdominal approach were more common, postoperative pneumonia (13% vs. 36%, p=0.045) and complications of grade ≥3b (2.6% vs. 22%, p=0.01) were less frequent, and the postoperative hospital stay was shorter (median: 23 vs. 28 days, p=0.022) in the combination group than in the standard group. In propensity-score matching, patient characteristics, except for 24-h creatinine clearance and reconstructive route, were matched for 23 paired patients. Postoperative pneumonia (8.7% vs. 39%, p=0.035) and complications of grade ≥3b (0% vs. 26%, p=0.022) were less frequent and postoperative hospital stay was shorter (median: 22 vs. 25 days, p=0.021) in the combination group than in the standard group.
CONCLUSIONS: PMT with TAZ/PIPC can potentially prevent postoperative pneumonia in high-risk patients after esophagectomy.

BACKGROUND: The investigation of drug disposition in tissues is critical to improving dosing strategy and maximizing treatment effectiveness, yet developing a multi-tissue bioanalytical method could be challenging due to the differences among various matrices. Herein, we developed an LC-MS/MS method tailored for the quantitation of piperacillin (PIP), cefazolin (CFZ), and cefoxitin (CFX) in rat plasma and 12 tissues, accompanied by validation data for each matrix according to the FDA and EMA guidelines.
RESULTS: The method required only a small sample volume (5 μL plasma or 50-100 μL tissue homogenates) and a relatively simple protocol for simultaneous quantitation of PIP, CFZ, and CFX within different biological matrices. Mobile phase A was composed of 5 mM ammonium formate and 0.1 % formic acid in water, while mobile phase B contained 0.1 % formic acid in acetonitrile. The mobile phase was pumped through a Synergi Fusion-RP column equipped with a guard column with a gradient elution program at a 0.3 mL/min flow rate. The mass spectrometer was operated in positive ionization mode (ESI+) using multiple reaction monitoring.
CONCLUSIONS: The validated method has been successfully applied to quantify PIP, CFZ, and CFX from the plasma and tissue samples collected in a pilot rat study and will further be used in a large pharmacokinetic study. To our knowledge, this is also the first report presenting long-term, freeze-thaw, and autosampler stability data for PIP, CFZ, and CFX in rat plasma and multiple tissues.

BACKGROUND: Pancreatoduodenectomy is associated with an increased incidence of surgical-site infections, often leading to a significant rise in morbidity and mortality. This trend underlines the inadequacy of traditional antibiotic prophylaxis strategies. Hence, the aim of this meta-analysis was to assess the outcomes of antimicrobial prophylaxis, comparing piperacillin/tazobactam with traditional antibiotics.
METHODS: Upon registering in PROSPERO, the international prospective register of systematic reviews (CRD42023479100), a systematic search of various databases was conducted over the interval 2000-2023. This inclusive search encompassed a wide range of study types, including prospective and retrospective cohorts and RCTs. The subsequent data analysis was carried out utilizing RevMan 5.4.
RESULTS: A total of eight studies involving 2382 patients who underwent pancreatoduodenectomy and received either piperacillin/tazobactam (1196 patients) or traditional antibiotics (1186 patients) as antibiotic prophylaxis during surgery were included in the meta-analysis. Patients in the piperacillin/tazobactam group had significantly reduced incidences of surgical-site infections (OR 0.43 (95% c.i. 0.30 to 0.62); P < 0.00001) and major surgical complications (Clavien-Dindo grade greater than or equal to III) (OR 0.61 (95% c.i. 0.45 to 0.81); P = 0.0008). Subgroup analysis of surgical-site infections highlighted significantly reduced incidences of superficial surgical-site infections (OR 0.34 (95% c.i. 0.14 to 0.84); P = 0.02) and organ/space surgical-site infections (OR 0.47 (95% c.i. 0.28 to 0.78); P = 0.004) in the piperacillin/tazobactam group. Further, the analysis demonstrated significantly lower incidences of clinically relevant postoperative pancreatic fistulas (grades B and C) (OR 0.67 (95% c.i. 0.53 to 0.83); P = 0.0003) and mortality (OR 0.51 (95% c.i. 0.28 to 0.91); P = 0.02) in the piperacillin/tazobactam group.
CONCLUSIONS: Piperacillin/tazobactam as antimicrobial prophylaxis significantly lowers the risk of postoperative surgical-site infections, major surgical complications (complications classified as Clavien-Dindo grade greater than or equal to III), clinically relevant postoperative pancreatic fistulas (grades B and C), and mortality, hence supporting the implementation of piperacillin/tazobactam for surgical prophylaxis in current practice.

Cefepime and piperacillin/tazobactam are antimicrobials recommended by IDSA/ATS guidelines for the empirical management of patients admitted to the intensive care unit (ICU) with community-acquired pneumonia (CAP). Concerns have been raised about which should be used in clinical practice. This study aims to compare the effect of cefepime and piperacillin/tazobactam in critically ill CAP patients through a targeted maximum likelihood estimation (TMLE). A total of 2026 ICU-admitted patients with CAP were included. Among them, (47%) presented respiratory failure, and (27%) developed septic shock. A total of (68%) received cefepime and (32%) piperacillin/tazobactam-based treatment. After running the TMLE, we found that cefepime and piperacillin/tazobactam-based treatments have comparable 28-day, hospital, and ICU mortality. Additionally, age, PTT, serum potassium and temperature were associated with preferring cefepime over piperacillin/tazobactam (OR 1.14 95% CI [1.01-1.27], p = 0.03), (OR 1.14 95% CI [1.03-1.26], p = 0.009), (OR 1.1 95% CI [1.01-1.22], p = 0.039) and (OR 1.13 95% CI [1.03-1.24], p = 0.014)]. Our study found a similar mortality rate among ICU-admitted CAP patients treated with cefepime and piperacillin/tazobactam. Clinicians may consider factors such as availability and safety profiles when making treatment decisions.