Variations in Microcirculatory and Hemodynamic Parameters during Oncological Demolitive-Reconstructive Head and Neck Surgery: A Protocol for an Observational Study.

(1) Background: Oncological demolitive-reconstructive surgeries in the head and neck region cause significant stress on patients' biohumoural, cardiac, and vascular systems, leading to disturbances in macrocirculatory and microcirculatory parameters. Traditional monitoring addresses the symptoms, but not the underlying cause. Microcirculatory assessments complement macrocirculatory monitoring, and bladder-catheter-based technology offers a better representation of central microcirculation. Flap reconstruction surgeries involve demolitive and reconstructive phases, requiring optimal tissue perfusion. The literature lacks a consensus on macro-microcirculation coupling, and there is no agreement on the use of vasopressors during head and neck surgeries. Evidence-based guidelines are lacking, resulting in variations in vasopressor administration. (2) Methods: This is a 12-month observational, prospective study conducted in a single center. It aims to evaluate the impact of macro-microcirculation coupling on clinical complications in head and neck surgery. All consecutive patients undergoing oncologic surgery requiring flap reconstruction and meeting the inclusion criteria will be enrolled. The study will utilize standard hemodynamic monitoring and bladder catheterization for measuring urine output and temperature. (3) Conclusions: The study aims to evaluate the coupling of macro- and microcirculation in head and neck surgeries, assess hemodynamic parameters and microcirculatory changes, and investigate their association with postoperative complications. The results can enhance patient care and surgical outcomes.

A 5-year experience with midline catheters in the management of major head and neck surgery patients.

BACKGROUND: In the perioperative management of major head and neck surgery (HNS) patients, the performance of midline catheters (MCs) has been never tested. We present here our 5-year experience by reporting MC-related complications and by identifying the preoperative risk factors associated with their development. METHODS: Clinical variables were extracted and the dwell time, the number, and the type of postprocedural complications of MCs were retrieved. Complications were classified into major (needing MCs removal and including catheter-related bloodstream infection or deep vein thrombosis or catheter occlusion) and into minor (accidental dislodgement, leaking, etc.). Descriptive statistics and logistic regression models were used in order to identify the predictors of complications. RESULTS: A total of 265 patients were included, with a mean age of 67.4 years. Intraprocedural complications occurred in 1.1% of cases, while postprocedural complications occurred in 13.9% of cases (12.05/1000 days), but they were minor in more than 7.0% (5.4/1000 catheter-days). There were 19 minor complications (7.1% or 5.4/1000 catheter-days) while 18 (7%, 5.1/1000 catheter-days) patients experienced at least one major complication. Female sex (OR = 1.963, 95% CI 1.017-3.792), insertion in the right arm (OR = 2.473, 95% CI 1.150-5.318), and an ACE-27 score >1 (OR = 2.573, 95% CI 1.295-5.110) were independent predictors of major complications. CONCLUSIONS: MCs appear to represent an effective option in the setting of major HNS. The identification of patients most at risk for MC-related complications should prompt a postoperative watchful evaluation.

Hearing outcomes and patient satisfaction after stapes surgery: local versus general anaesthesia.

Objective: Otosclerosis is a frequent ear disorder causing a stapedo-ovalar ankylosis and conductive hearing loss. Stapedoplasty, performed under both general (GA) and local anaesthesia (LA), is the most advisable surgical solution. Auditory recovery relies on the patient's conditions and on the intervention itself. The aim of our work was to compare hearing outcomes with stapedoplasty performed under GA or LA and to investigate patients' compliance to both methods. Methods: Fifty-five otosclerotic patients underwent stapedoplasty both under GA (32/55) and LA (23/55). Pre- and post-operative air and bone tone audiometry threshold values as well as the air-bone gap and its closure score, were analysed. All patients filled in a satisfaction questionnaire regarding their concern and level of appreciation of the type of anaesthesia. Results and conclusions: Our data show that the auditory results with stapedoplasty are good and do not differ between LA and GA. Even considering the advantages and limits of the two methods, one cannot favour one or the other type of anaesthesia. Finally, the patient's satisfaction cannot be considered a criterion of choice, since this was found to be high in both cases.

The influence of psychological interventions on surgical outcomes: a systematic review.

BACKGROUND: An amplified and/or prolonged surgical stress response might overcome the organs' functional reserve, thus leading to postoperative complications. The aim of this systematic literature review is to underline how specific psychological interventions may contribute to improve surgical outcomes through the positive modulation of the surgical stress response in surgical patients. METHODS: We conducted a comprehensive literature search in the Cochrane Register of Controlled Trials, PubMed, EMBASE, Scopus, PsycINFO, and CINAHL databases. Only studies published in English from Jan 2000 to Apr 2022 and reporting pain and/or anxiety among outcome measures were included in the review. The following psychological interventions were considered: (1) relaxation techniques, (2) cognitive-behavioral therapies, (3) mindfulness, (4) narrative medicine, (5) hypnosis, and (6) coping strategies. RESULTS: Among 3167 records identified in the literature, 5 papers were considered eligible for inclusion in this review because reporting the effects that psychological features have on neurochemical signaling during perioperative metabolic adaptation and those metabolic and clinical effects that the psychological interventions had on the observed population. CONCLUSION: Our findings confirm that psychological interventions may contribute to improve surgical outcomes via the positive influence on patients' metabolic surgical stress response. A multidisciplinary approach integrating physical and non-physical therapies can be considered a good strategy to successfully improve surgical outcomes in the perioperative period.

Risk factors for difficult Laryngeal Mask Airway LMA-Supreme™ (LMAS) placement in adults: a multicentric prospective observational study in an Italian population.

BACKGROUND: Supraglottic airway devices (SADs) are precious tools for airway management in both routine and rescue situations; few studies have analyzed the risk factors for their difficult insertion. METHODS: The aim of this study was to identify the risk factors for difficult insertion for a specific SAD, the Laryngeal Mask Airway LMA-Supreme™ (LMAS). This was a prospective multicentric observational study on a cohort of Italian adult patients receiving general anesthesia for elective surgery. The possible causes of difficulty in LMAS placement (difficulty in insertion or unsatisfactory ventilation) were identified based on literature and on the opinion of international airway management experts. A dedicated datasheet was prepared to collect patients' data, including anthropometric-parameters and parameters for the prediction of difficult airway management, as well as technical choices for the use of LMAS. Data were analyzed to discover the risk factors for difficult LMAS placement and the association between each risk factor and the proportion of incorrect positioning was evaluated through the relative risk and its confidence interval. RESULTS: Four hundred thirty-two patients were enrolled; seventy required two or more attempts to insert the LMAS; nine required a change of strategy. At multivariate analysis, the following factors were significantly associated with difficult LMAS placement: Mallampati III-IV with either phonation or not; inter-incisor distance < 3 cm; reduced neck mobility; no administration of neuromuscular blocking agents (NMBAs). CONCLUSIONS: The alignment of the laryngeal and pharyngeal axes seems to facilitate the procedure, together with NMBA administration; on the contrary, Mallampati grade III-IV are associated with difficult LMAS placement.

Evaluation of diaphragm thickening by diaphragm ultrasonography: a reproducibility and a repeatability study.

PURPOSE: We have focused on the two-dimensional (B-mode) and the time-motion (M-mode) analysis of the zone of apposition to determine the reliability of diaphragm ultrasonography in the clinical environment. METHODS: Ten healthy volunteers were enrolled and studied by three operators with different skills in ultrasonography. For every volunteer, each operator acquired three images of the diaphragm for each side, both in B-mode and in M-mode. Then a fourth operator calculated the thickening fraction (TF), by means of the formula TF = (TEI - TEE)/TEE (TEI is the thickness at end inspiration and TEE the thickness at end expiration). Afterwards, intraclass correlation coefficients (ICCs) were computed on TF to establish reproducibility and repeatability both in the B- and M-modes. A Coefficient of Repeatability or repeatability (CR) ≤ 0.3 was considered acceptable. RESULTS: Both B-mode (CRs 0.16-0.26) and M-mode (CRs 0.10-0.15) were sufficiently repeatable to assess TF, except for the less experienced operator (CRs B-Mode 0.20-0.32). Reproducibility was moderate to good between operators with CRs much narrower for the M-Mode (0.13-0.14). CONCLUSIONS: The results of our study have shown that diaphragm ultrasound is repeatable and reproducible when carried out by a radiologist or an intensivist with a basic curriculum in ultrasonography. The method is more accurate when using the M-mode for less experienced operators, and in this case, repeatability and reproducibility are not sufficient to make clinical decisions. No TF value lower than 36% was obtained using both techniques. This suggests the existence of a cut-off value that could be used as an initial tool to discriminate healthy subjects from those affected by diaphragmatic dysfunction. CLINICAL TRIAL REGISTRATION: EUDRACT 2015-004635-12.

A New Solution for Routine Endoscopic Aerosol-Generating Procedures (AGPs) in the COVID-19 Pandemic.

INTRODUCTION: There is urgent need to find a swift and cheap way to safely perform routine endoscopic procedures during the otolaryngological and anesthesiological practice. We want to share our experience of a novel device, inspired by the pediatric head box experience. MATERIALS AND METHODS: Five otolaryngologists and four anesthesiologists were asked to visualize the glottic plane by using the device. A total of 15 attempts was allowed to reach the vocal folds within 60 seconds after entering the box. Student's t-test for unpaired samples was used to compare groups. RESULTS: Transnasal laryngoscopy through our endobox could be successfully performed by all the physicians involved and the mean number of attempts before visualizing and passing the glottis for the first time was 2.8 (range 1-5) in the otolaryngologists' group versus 3.2 (range 1-6) in the anesthesiologists' group (P=0.583). Out of the 15 attempts, the group of otolaryngologists reached the glottis 10.2 times, on average, against 9.7 in the other group (P=0.692). CONCLUSIONS: Our endobox seems a practical and feasible strategy to control droplets diffusion during standard ear, nose, and throat and anesthesiological practice.

Some Suggestions from PK/PD Principles to Contain Resistance in the Clinical Setting-Focus on ICU Patients and Gram-Negative Strains.

The containment of the phenomenon of resistance towards antimicrobials is a priority, especially in preserving molecules acting against Gram-negative pathogens, which represent the isolates more frequently found in the fragile population of patients admitted to Intensive Care Units. Antimicrobial therapy aims to prevent resistance through several actions, which are collectively known as "antimicrobial stewardship", to be taken together, including the application of pharmacokinetic/pharmacodynamic (PK/PD) principles. PK/PD application has been shown to prevent the emergence of resistance in numerous experimental studies, although a straight translation to the clinical setting is not possible. Individualized antibiotic dosing and duration should be pursued in all patients, and even more especially when treating intensive care unit (ICU) septic patients in whom optimal exposure is both difficult to achieve and necessary. In this review, we report on the available data that support the application of PK/PD parameters to contain the development of resistance and we give some practical suggestions that can help to translate the benefit of PK/PD application to the bedside.

TRPA1 mediates damage of the retina induced by ischemia and reperfusion in mice.

Oxidative stress is implicated in retinal cell injury associated with glaucoma and other retinal diseases. However, the mechanism by which oxidative stress leads to retinal damage is not completely understood. Transient receptor potential ankyrin 1 (TRPA1) is a redox-sensitive channel that, by amplifying the oxidative stress signal, promotes inflammation and tissue injury. Here, we investigated the role of TRPA1 in retinal damage evoked by ischemia (1 hour) and reperfusion (I/R) in mice. In wild-type mice, retinal cell numbers and thickness were reduced at both day-2 and day-7 after I/R. By contrast, mice with genetic deletion of TRPA1 were protected from the damage seen in their wild-type littermates. Daily instillation of eye drops containing two different TRPA1 antagonists, an oxidative stress scavenger, or a NADPH oxidase-1 inhibitor also protected the retinas of C57BL/6J mice exposed to I/R. Mice with genetic deletion of the proinflammatory TRP channels, vanilloid 1 (TRPV1) or vanilloid 4 (TRPV4), were not protected from I/R damage. Surprisingly, genetic deletion or pharmacological blockade of TRPA1 also attenuated the increase in the number of infiltrating macrophages and in the levels of the oxidative stress biomarker, 4-hydroxynonenal, and of the apoptosis biomarker, active caspase-3, evoked by I/R. These findings suggest that TRPA1 mediates the oxidative stress burden and inflammation that result in murine retinal cell death. We also found that TRPA1 (both mRNA and protein) is expressed by human retinal cells. Thus, it is possible that inhibition of a TRPA1-dependent pathway could also attenuate glaucoma-related retinal damage.

Use of Fluoride as a Marker Solute to Quantify the Current Effective Delivered Dose in Continuous Renal Replacement Therapy: An "in vitro" Study.

BACKGROUND: The current effective delivered dose is a quality indicator for continuous renal replacement therapy. Its periodic assessment might enable physicians to deliver personalised treatments. Yet, its quantification as by extracorporeal urea clearance (Cl) is cumbersome and thus often neglected in routine practice. The aim of this in vitro study is to demonstrate the non-inferior effectiveness of assessing the current effective delivered dose using a simpler, cheaper and faster approach based on measurement of fluoride rather than urea extracorporeal Cl. METHODS: We compared urea and fluoride removal in 3 post-dilution continuous veno-venous haemofiltration (CVVH) and 3 continuous veno-venous haemodialysis (CVVHD) in vitro experimental models. Experiments ran for 180 min, using 3 L of human blood, heparin anticoagulation and a machine dose of 30 mL/kg/h. Urea and fluoride were measured in the inflow, outflow and effluent lines to compare sieving coefficients (SC), saturation coefficients (SA) and transmembrane Cls. RESULTS: In CVVH, the median SC values were 1.06 (1.02-1.07) and 1.02 (1.01-1.04) for fluoride and urea, respectively (discrepancy of 4.3%), while transmembrane convective Cls were 31.28 (30.01-31.31) mL/kg/h and 30.30 (29-31.85) mL/kg/h (discrepancy of 3.13%), respectively. In CVVHD, the median SA values were 1.01 (0.96-1.02) and 1 (0.95-1.01) for fluoride and urea, respectively (discrepancy of 1.6%), while transmembrane dialytic Cls were 30.26 (29.52-31.32) mL/kg/h and 31.16 (30-31.75) mL/kg/h (discrepancy of -2.97%), respectively. CONCLUSION: Fluoride transmembrane removal was close to that observed with urea, in terms of SC, SA and transmembrane Cl. Fluoride seems as much accurate as urea in assessing the current effective delivered dose during both CVVH and CVVHD and might therefore be adopted for dose measurement. Besides accuracy, fluoride bedside assessment could present many advantages over urea, particularly in terms of availability, costs, time requirement and rapidity of assessment.

Comparison of neostigmine vs. sugammadex for recovery of muscle function after neuromuscular block by means of diaphragm ultrasonography in microlaryngeal surgery: A randomised controlled trial.

BACKGROUND: Postoperative residual curarisation (PORC) is a risk directly related to the use of neuromuscular blocking agents during surgical procedures. Acceleromyography is distressing for conscious patients when assessing PORC. Diaphragm ultrasonography could be a valid alternative. OBJECTIVES: The primary objective was to achieve a 28% lower incidence of PORC in patients who, after rocuronium administration, received neostigmine or sugammadex at 30 min after surgery. To assess PORC, diaphragm ultrasonography was used, and thickening fractioning [the difference of thickness at the end of inspiration (TEI) and at the end of expiration (TEE), normalised for TEE (TEI - TEE/TEE)] was measured. PORC was defined as thickening fractioning of 0.36 or less. The secondary object was the comparison, in the two treatment groups, of the return to baseline thickening fractioning at 30 min after surgery (ΔTF30). DESIGN: Randomised, double-blind, single-centre study. SETTING: University Hospital Careggi, Florence, Italy. PATIENTS: Patients of American Society Anesthesiologists' physical status 1 or 2, 18 to 80 years, receiving rocuronium during microlaryngeal surgery. INTERVENTIONS: At the end of surgery participants were randomised to receive neostigmine (NEO group) or sugammadex (SUG group) as the reversal drug. Thickening fractioning and ΔTF30 were evaluated at baseline and at 0, 10 and 30 min after surgery. MAIN OUTCOME MEASURES: TEE and TEI at each time point. RESULTS: A total of 59 patients with similar demographic characteristics were enrolled. An association between lack of recovery (thickening fractioning ≤0.36) and drug treatment was only observed at 0 min (SUG vs. NEO, P < 0.05). Concerning ΔTF, at 30 min more patients in the SUG group returned to baseline than those in the NEO group (P < 0.001), after adjusting for side (P = 0.52), baseline thickening fractioning (P < 0.0001) and time of measurement (P < 0.01). CONCLUSION: We found an early (0 min) but not long-lasting (30 min) association between diaphragm failure and treatment allocation; a full recovery in baseline diaphragm function was observed only in patients receiving sugammadex. We cannot exclude that further differences have not been found due to interpatients variability in assessing diaphragm contractility by ultrasonography. TRIAL REGISTRATION: EudraCT Identifier: 2013-004787-62, Clinicaltrials.gov Identifier: NCT02698969.

Postoperative pain after vitreo-retinal surgery is influenced by surgery duration and anesthesia conduction.

BACKGROUND: The control of postoperative pain (POP) is a key component of perioperative care. POP after vitreo-retinal surgery (VRS) has been under-investigated, and its incidence remains elusive. METHODS: In order to assess POP after VRS, the associated risk factors and efficacy of the analgesic protocol in use at our institution, we made a one-year retrospective study on patients undergoing VRS. Patients aged >18 years, ASA Class I-III undergoing VRS entered the study. POP was evaluated by measuring a Numerical Rating Scale (NRS), and analgesic consumption. RESULTS: A total of 782 patients entered the study. Patients received locoregional (LRA) or general anesthesia (GA) with supplemental block. Twenty-two percent of patients needed analgesics (acetaminophen in 97% of cases), mostly between two and six hours after surgery. The univariate analysis showed a positive association between POP and duration of surgery (P<0.0001) and glaucoma (P=0.04), and a negative association with age (P=0.008), analgesic administration at the end of surgery (P=0.005) and the intraoperative administration of remifentanil for surgery under LRA (P=0.02); sedation to execute the block for LRA did not reduce POP. Patients treated with GA with supplemental block had less pain compared to those treated with LRA with/without remifentanil (P=0.03, P=0.002, respectively). The multivariate analysis confirmed a positive correlation between POP and duration of surgery (P=0.0007) and a negative correlation with the intraoperative remifentanil administration during LRA (P=0.04), and with GA with supplemental block (P=0.01). CONCLUSIONS: The incidence of POP after VRS is low but not absent, especially for long procedures, it does not require postoperative opioids and can be modified by anesthesiologic choices.

Recovery of muscle function after deep neuromuscular block by means of diaphragm ultrasonography and adductor of pollicis acceleromyography with comparison of neostigmine vs. sugammadex as reversal drugs: study protocol for a randomized controlled trial.

BACKGROUND: The extensive use of neuromuscular blocking agents (NMBAs) during surgical procedures still leads to potential residual paralyzing effects in the postoperative period. Indeed, neuromuscular monitoring in an intra-operative setting is strongly advocated. Acetylcholinesterase inhibitors can reverse muscle block, but their short half-life may lead to residual curarization in the ward, especially when intermediate or long-acting NMBAs have been administered. Sugammadex is the first selective reversal drug for steroidal NMBAs; it has been shown to give full and rapid recovery of muscle strength, thus minimizing the occurrence of residual curarization. Acceleromyography of the adductor pollicis is the gold standard for detecting residual curarization, but it cannot be carried out on conscious patients. Ultrasonography of diaphragm thickness may reveal residual effects of NMBAs in conscious patients. METHODS/DESIGN: This prospective, double-blind, single-center randomized controlled study will enroll patients (of American Society of Anesthesiologists physical status I-II, aged 18-80 years) who will be scheduled to undergo deep neuromuscular block with rocuronium for ear, nose, or throat surgery. The study's primary objective will be to compare the effects of neostigmine and sugammadex on postoperative residual curarization using two different tools: diaphragm ultrasonography and acceleromyography of the adductor pollicis. Patients will be extubated when the train-of-four ratio is > 0.9. Diaphragm ultrasonography will be used to evaluate the thickening fraction, which is the difference between the end expiratory thickness and the end inspiratory thickness, normalized to the end expiratory thickness. Ultrasonography will be performed before the initiation of general anesthesia, before extubation, and 10 and 30 min after discharging patients from the operating room. The secondary objective will be to compare the incidence of postoperative complications due to residual neuromuscular block between patients who receive neostigmine and those who receive sugammadex. DISCUSSION: Postoperative residual curarization is a topic of paramount importance, because its occurrence can cause complications and increase the length of stay in hospital and the related costs. Diaphragm ultrasound assessment may become a bedside integrative tool in the neuromuscular monitoring field to detect concealed residual curarization in surgical patients who have received paralyzing agents. TRIAL REGISTRATION: EudraCT, 2013-004787-62. Registered on 18 June 2014, as "Evaluation of muscle function recovery after deep neuromuscular blockade by acceleromyography of the adductor pollicis or diaphragmatic echography: comparison between sugammadex and neostigmine." ClinicalTrials.gov, NCT02698969 . Registered on 15 February 2016, as "Recovery of Muscle Function After Deep Neuromuscular Block by Means of Diaphragm Ultrasonography and Adductor Pollicis Acceleromyography: Comparison of Neostigmine vs. Sugammadex as Reversal Drugs."

Influence of OPRM1 Polymorphism on Postoperative Pain After Intrathecal Morphine Administration in Italian Patients Undergoing Elective Cesarean Section.

OBJECTIVES: The aim of this prospective observational study was to evaluate the influence of OPRM1 polymorphism on the analgesic efficacy (including visual analog scale [VAS] scores and requirement for rescue analgesia) of a standard dose of intrathecal morphine. MATERIALS AND METHODS: An Italian cohort of 63 parturients, scheduled for elective cesarean section at a tertiary University Hospital, received spinal anesthesia with hyperbaric bupivacaine and morphine 100 mcg. For the first 48 hours in the postoperative period the patients received acetaminophen 1 g IV q6hr. Incident pain was treated with ketorolac 30 mg IV. Every 6 hours the following parameters were registered: VAS at rest, VAS during movements, postoperative nausea and vomiting, pruritus, and rescue analgesic medications requirements. Age and anthropometric data, number of pregnancies, educational level, OPRM1 genotype, were also obtained. RESULTS: Of the 63 patients enrolled, 45 (71%) were homozygous genotype A/A (118A group), whereas 18 carried the G variants of OPRM1 (A/G or G/G) (118G group). No significant differences in analgesic rescue doses' administration and in incidence of moderate/severe postoperative pain (VAS>3) between the 2 groups were observed. Pruritus was more frequent in the 118A group than in the 118G group in the first 24 hours of the postoperative period. DISCUSSION: In the Italian population participating in this study there was a different incidence of pruritus in the postcesarean period in response to intrathecal opioids related to OPRM1 gene polymorphism, but not of postoperative pain.

The use of oral fosfomycin-trometamol in patients with catheter-associated urinary tract infections (CAUTI): new indications for an old antibiotic?

We present the results of a multicenter retrospective study of 35 difficult-to-treat patients with urinary tract infections associated with indwelling urinary catheters (CAUTIs). All patients received oral administration of 3 g fosfomycin trometamol once a day for two days and then with a dose of 3 g every 48 h for two weeks. The most commonly isolated strains were: Escherichia coli (65.7%) and Enterococcus spp. (25.7%); prevalence of Extended-Spectrum Beta-Lactamase strains was 48.5%. Six patients (17.1%) had a clinical response after a single dose of fosfomycin trometamol, 12 (34.2%) after two doses and 13 (37.1%) patients had a clinical response after three or more doses. Four patients (11.6%) failed prolonged antibiotic treatment with fosfomycin trometamol. During the follow-up period, 30 out of 35 (85.7%) patients were without symptomatic infections. No significant side effects were reported. In conclusion, fosfomycin trometamol seems to be a valid treatment option in patients with CAUTIs.

Changes in ceftriaxone pharmacokinetics/pharmacodynamics during the early phase of sepsis: a prospective, experimental study in the rat.

BACKGROUND: Sepsis is characterized by the loss of the perm-selectivity properties of the glomerular filtration barrier (GFB) with consequent albuminuria. We examined whether the pharmacokinetics-pharmacodynamics (PK/PD) of ceftriaxone (CTX), an extensively protein-bound 3rd generation cephalosporin, is altered during early sepsis and whether an increase in urinary loss of bound-CTX, due to GFB alteration, can occur in this condition. METHODS: A prospective, experimental, randomized study was carried out in adult male Sprague-Dawley rats. Sepsis was induced by cecal ligation and puncture (CLP). Rats were divided into two groups: Sham-operated and CLP. CTX (100 mg i.p., equivalent to 1 g dose in humans) was administered in order to measure plasma and lung CTX concentrations at several time-points: baseline and 1, 2, 4 and 6 h after administration. CTX was measured by High Performance Liquid Chromatography (HPLC). The morphological status of the sialic components of the GFB barrier was assessed by lectin histo-chemistry. Monte Carlo simulation was performed to calculate the probability of target attainment (PTA >90%) for 80 and 100% of Tfree > minimum inhibitory concentration (MIC) for 80 and 100% of dosing interval. MEASUREMENTS AND MAIN RESULTS: After CLP, sepsis developed in rats as documented by the growth of polymicrobial flora in the peritoneal fluid (≤1 × 101 CFU in sham rats vs 5 × 104-1 × 105 CFU in CLP rats). CTX plasma concentrations were higher in CLP than in sham rats at 2 and 4 h after administration (difference at 2 h was 47.3, p = 0.012; difference at 4 h was 24.94, p = 0.004), while lung penetration tended to be lower. An increased urinary elimination of protein-bound CTX occurred (553 ± 689 vs 149 ± 128 mg/L, p < 0.05; % of bound/total CTX 22 ± 6 in septic rats vs 11 ± 4 in sham rats, p < 0.01) and it was associated with loss of the GFB sialic components. According to Monte Carlo simulation a PTA > 90% for 100% of the dosing interval was reached neither for sham nor CLP rats using MIC = 1 mg/L, the clinical breakpoint for Enterobacteriacee. CONCLUSIONS: Sepsis causes changes in the PK of CTX and an alteration in the sialic components of the GFB, with consequent loss of protein-bound CTX. Among factors that can affect drug pharmacokinetics during the early phases of sepsis, urinary loss of both free and albumin-bound antimicrobials should be considered.

Effects of continuous renal replacement therapy on linezolid pharmacokinetic/pharmacodynamics: a systematic review.

BACKGROUND: Major alterations in linezolid pharmacokinetic/pharmacodynamic (PK/PD) parameters might be expected in critically ill septic patients with acute kidney injury (AKI) who are undergoing continuous renal replacement therapy (CRRT). The present review is aimed at describing extracorporeal removal of linezolid and the main PK-PD parameter changes observed in critically ill septic patients with AKI, who are on CRRT. METHOD: Citations published on PubMed up to January 2016 were systematically reviewed according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement. All authors assessed the methodological quality of the studies and consensus was used to ensure studies met inclusion criteria. In-vivo studies in adult patients with AKI treated with linezolid and on CRRT were considered eligible for the analysis only if operational settings of the CRRT machine, membrane type, linezolid blood concentrations and main PK-PD parameters were all clearly reported. RESULTS: Among 68 potentially relevant articles, only 9 were considered eligible for the analysis. Across these, 53 treatments were identified among the 49 patients included (46 treated with high-flux and 3 with high cut-off membranes). Continuous veno-venous hemofiltration (CVVH) was the most frequent treatment performed amongst the studies. The extracorporeal clearance values of linezolid across the different modalities were 1.2-2.3 L/h for CVVH, 0.9-2.2 L/h for hemodiafiltration and 2.3 L/h for hemodialysis, and large variability in PK/PD parameters was reported. The optimal area under the curve/minimum inhibitory concentration (AUC/MIC) ratio was reached for pathogens with an MIC of 4 mg/L in one study only. CONCLUSIONS: Wide variability in linezolid PK/PD parameters has been observed across critically ill septic patients with AKI treated with CRRT. Particular attention should be paid to linezolid therapy in order to avoid antibiotic failure in these patients. Strategies to improve the effectiveness of this antimicrobial therapy (such as routine use of target drug monitoring, increased posology or extended infusion) should be carefully evaluated, both in clinical and research settings.