Early ß-lactam concentrations and infectious complications after lung transplantation.

Antibiotic underdosing in prophylactic antibiotic regimes after lung transplantation (LTx) can increase the risk of infection. We aimed to study whether ß-lactam concentrations achieved desirable pharmacodynamic targets in the early phase after LTx and the association between drug concentrations and the development of early infections or the acquisition of multidrug-resistant (MDR) strains. We reviewed patients in whom broad-spectrum ß-lactam levels were measured after LTx during antibiotic prophylaxis. ß-Lactam concentrations were considered "insufficient" if drug levels remained below four times the clinical breakpoint of the minimal inhibitory concentration for Pseudomonas aeruginosa. The primary outcome was the occurrence of an infection and/or acquisition of MDR pathogens in the first 14 days after transplantation. A total of 70 patients were included. "Insufficient" drug concentrations were found in 40% of patients. In 27% of patients, an early MDR pathogen was identified and 49% patients were diagnosed with an early posttransplant infection. Patients with "insufficient" drug concentrations acquired more frequently MDR bacteria and/or developed an infection than others (22/28, 79% vs. 20/42, 48% - p = .01). ß-Lactam levels were often found to be below the desired drug targets in the early phase after transplantation and may be associated with the occurrence of early infectious complications.

Colistin Use in Patients With Reduced Kidney Function.

Colistin (polymyxin E) is a mainly concentration-dependent bactericidal antimicrobial active against multidrug-resistant Gram-negative bacteria. After being abandoned over the past 30 years due to its neuro- and nephrotoxicity, colistin has been reintroduced recently as a last-resort drug for the treatment of multidrug-resistant Gram-negative bacteria infections in combination with other antimicrobials. Unfortunately, although renal toxicity is a well-known dose-related adverse effect of colistin, relatively few studies are currently available on its peculiar pharmacodynamic/pharmacokinetic properties in clinical settings at high risk for drug accumulation, such as acute or chronic kidney disease. In these specific contexts, the risk for underdosing is also substantial because colistin can be easily removed by dialysis/hemofiltration, especially when the most efficient modalities of renal replacement therapy (RRT) are used in critically ill patients. For this reason, recent recommendations in patients undergoing RRT have shifted toward higher dosing regimens, and therapeutic drug monitoring is advised. This review aims to summarize the main issues related to chemical structure, pharmacodynamics/pharmacokinetics, and renal toxicity of colistin. Moreover, recent data and current recommendations concerning colistin dosing in patients with reduced kidney function, with special regard to those receiving RRT such as dialysis or hemofiltration, are also discussed.

The Impact of Renal Failure and Renal Replacement Therapy on Outcome During Extracorporeal Membrane Oxygenation Therapy.

Acute kidney injury (AKI) is common in patients treated with veno-arterial (VA-) or veno-venous (VV-) extracorporeal membrane oxygenation (ECMO). In this setting, the use of continuous renal replacement therapy (CRRT) can help to optimize fluid status but may also negatively impact on patients' outcome. In contrast, the relationship between AKI, CRRT, and survival in critically ill adult patients receiving ECMO is not well defined. The institutional ECMO database (n = 162) from November 2008 to December 2013, excluding patients with ICU survival <24 hours was reviewed. Demographics, co-morbidities, and concomitant therapies for all patients were collected. AKI was defined according to the Acute Kidney Injury Network (AKIN) criteria. ICU mortality was noted. Data were retrieved for 135 patients (79 with VA-ECMO and 56 with VV-ECMO). Of these, 95 developed AKI, 63 (47%) of whom required CRRT; thus three groups of patients were identified: (a) no AKI; (b) AKI without CRRT (AKINOCRRT ); and (c) CRRT with AKI (AKICRRT ). AKINOCCRT patients were more likely to have preexisting heart disease, to be more severely ill, and to be treated with VA-ECMO than those without AKI. AKICRRT patients were also more likely to be treated with VA-ECMO, had more organ dysfunction at the time of ECMO insertion, and needed more transfusions and inotropic agents than patients without AKI. ICU mortality was 53% (72/135) and was similar in the three groups, even when different AKI stages or VA/VV-ECMO were analyzed separately. In this study, the use of CRRT was not associated with an increased mortality in an adult population of patients treated with ECMO, even after adjustment for confounders.

Cerebral blood flow decreases during intermittent hemodialysis in patients with acute kidney injury, but not in patients with end-stage renal disease.

BACKGROUND: Cerebral blood flow (CBF) may decrease during intermittent hemodialysis (IHD). Patients with acute kidney injury (AKI) may be more vulnerable to cerebral hypoperfusion than patients with end-stage renal disease (ESRD), due to concomitant critical illness and hemodynamic instability. METHODS: In this observational, prospective study, we measured mean flow velocity at the level of the middle cerebral artery by transcranial Doppler at the start, after 2 h and at the end of a hemodialysis session in 15 consecutive patients with AKI and critical illness referred to the nephrological intensive care unit of a university hospital and in 12 patients with ESRD on regular treatment thrice weekly, who served as controls. We compared end-dialysis changes from baseline in mean flow velocity between the study groups and examined the correlation between this change and that of other relevant clinical parameters. RESULTS: Mean flow velocity decreased significantly at end-dialysis in the patients with AKI, but not in those with ESRD (P = 0.02). This difference persisted after adjusting for baseline mean flow velocity and net ultrafiltration volume. No significant correlations were found in either group between changes in mean flow velocity and changes in mean blood pressure (AKI: r = -0.27, P = 0.34; ESRD: r = 0.15, P = 0.68), SUN (AKI: r = -0.33, P = 0.25; ESRD: r = 0.06, P = 0.85), plasma HCO(3)(-) (AKI: r = -0.52, P = 0.24; ESRD: r = -0.18, P = 0.59), hematocrit (AKI: r = 0.08, P = 0.71; ESRD: r = -0.19, P = 0.65) or arterial oxygen content (AKI: r = -0.17, P = 0.36; ESRD: r = -0.33, P = 0.43). CONCLUSIONS: Our data suggest that AKI patients may be more vulnerable than ESRD patients to cerebral hypoperfusion during IHD. Our findings do not support a clear-cut role of rapid changes in blood osmolarity, rheological properties or vasoreactivity of the cerebral circulation to O(2) supply in modulating CBF during hemodialysis.

Multimodal strategy to counteract vasodilation in septic shock.

Early initiation of a multimodal treatment strategy in the management of vasopressors during septic shock has been advocated to reduce delays in restoring adequate organ perfusion and to mitigate side effects associated with the administration of high-dose catecholamines. We provide a review that summarises the pathophysiology of vasodilation, the physiologic response to the vascular response, and the different drugs used in this situation, focusing on the need to combine early different vasopressors. Fluid loading being insufficient for counteracting vasoplegia, norepinephrine is usually the first-line vasopressor used to restore hemodynamics. Norepinephrine sparing is discussed in further detail through the concomitant use of adrenergic, vasopressinergic, and renin-angiotensin systems and the optimisation of endothelial reactivity with methylene blue. A blueprint for the construction of new studies is outlined to address the question of vasopressor selection and timing in septic shock.

Refractory septic shock and alternative wordings: A systematic review of literature.

BACKGROUND: We reviewed the different studies using the terms "refractory septic shock" and/or "catecholamine resistance" and/or "high dose norepinephrine" so as to highlight the heterogeneity of the definitions used by authors addressing such concepts. METHOD: A systematic review was conducted assessing the papers reporting data on refractory septic shock. We used keywords as exact phrases and subject headings according to database syntax. RESULTS: Of 276 papers initially reviewed, we included 8 studies - 3 randomized controlled trials, 3 prospective studies and 2 retrospective studies, representing a total of 562 patients with septic shock. Catecholamine resistance was generally defined as "a decreased vascular responsiveness to catecholamine independently of the administered norepinephrine dose". Refractory septic shock was broadly defined as "a clinical condition characterized by persistent hyperdynamic shock even though adequate fluid resuscitation (individualized doses) and high doses of norepinephrine (≥ 1 µg/kg/min)". Reported "high doses" of norepinephrine were often ≥1 µg/kg/min. However, wide variability was found throughout the literature on the use of these terms. DISCUSSION: Marked inconsistencies were identified in the usage of the terms for refractory septic shock. There is a pressing need to determine consensus definitions so as to establish a common language in the medical literature and to harmonize future studies.

[Ultrafiltration in heart failure]. / Ultrafiltrazione nello scompenso cardiaco.

In patients with heart failure fluid overload is clinically evident as systemic and/or pulmonary congestion, and represents a key issue in the therapeutic approach to the syndrome. Ultrafiltration, obtained by dedicated machines or standard dialysis machines (isolated ultrafiltration), or by the use of the peritoneal membrane (peritoneal ultrafiltration), has been recently proposed for fluid overload correction. This review is aimed at illustrating the operative background, safety, efficacy and cost issues of the different ultrafiltration modalities in heart failure. We retrieved all full-text non-duplicated articles documenting clinical studies on ultrafiltration in heart failure and describing patient characteristics, ultrafiltration procedures, renal outcome and adverse effects, by searching MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials up to December 31, 2011, with the terms ''heart failure'' and ''ultrafiltration OR hemofiltration'' and ''heart failure'' and "peritoneal dialysis". Isolated ultrafiltration can be considered potentially safe for the heart and the kidney in heart failure, and is efficacious for fluid overload removal. However, the available evidence does not support its widespread use as a substitute for conventional diuretic therapy. Isolated ultrafiltration should be employed neither as a quicker way to achieve mechanical diuresis nor as a remedy for an apparently inadequate response to conventional diuretic therapy. Peritoneal ultrafiltration is a promising ultrafiltration procedure that can be safely and successfully performed in heart failure; however, also in this case larger-scale randomized controlled trials are needed. The available evidence supports the concept of reserving ultrafiltration modalities for selected patients with advanced heart failure and true diuretic resistance, as part of a more integrated strategy aimed at fluid overload control.

Selepressin in Septic Shock.

ABSTRACT: Sepsis and septic shock usually show a high mortality rate and frequently need of intensive care unit admissions. After fluid resuscitation, norepinephrine (NE) is the first-choice vasopressor in septic shock patients. However, high-NE doses are associated with increased rates of adverse effects and mortality. In this perspective, many authors have proposed the administration of non-adrenergic vasopressors (NAV). Selepressin is a selective vasopressin type 1A (V1A) receptor agonist and may be a valid option in this field, because it can decrease NE requirements and also limit the deleterious effects induced by high doses of catecholamines. Only few clinical data actually support selepressin administration in this setting. Here, we review the current literature on this topic analyzing some pathophysiological aspects, the rationale about the use of NAV, the possible use of selepressin differentiating animal, and human studies. Various issues remain unresolved and future trials should be focused on early interventions based on a multimodal activation of the vasopressive pathways using both alpha and V1A receptors pathways.

A Case of Spontaneous Renal Haemorrhage (Wunderlich Syndrome) in an Anticoagulated Patient.

Spontaneous renal haemorrhage is a rare but severe condition known as Wunderlich syndrome (WS). The classic presentation includes sudden-onset flank pain, a palpable flank mass and hypovolaemic shock (Lenk's triad). WS can be due to neoplasms, vascular diseases, cystic rupture, coagulopathies and infections. A contrast-enhanced CT scan of the abdomen is mandatory for diagnosis. Surgery is reserved for haemodynamically unstable patients and those with neoplastic disease. We describe a case of WS in an anticoagulated patient with chronic atrial fibrillation, diabetes mellitus type 2 and hypertension, who developed acute renal failure and severe anaemia, that completely resolved with conservative treatment and discontinuation of anticoagulation therapy. LEARNING POINTS: Wunderlich syndrome refers to spontaneous renal or perinephric haemorrhage.Contrast-enhanced CT of the abdomen is the gold standard for diagnosis.Surgery should be reserved for haemodynamically unstable patients or those with neoplastic disease.

Hyperammonemia during treatment with valproate in critically ill patients.

INTRODUCTION: Hyperammonemia (HA) is a potential side-effect of valproate (VPA) treatment, which has been described during long-term administration. The aim of this study was to evaluate the incidence, the impact and the risk factors of HA in critically ill patients. METHODS: We reviewed the data of all adult patients treated in our mixed 35-bed Department of Intensive Care over a 12-year period (2004-2015) who: a) were treated with VPA for more than 72 h and b) had at least one measurement of ammonium and VPA levels during the ICU stay; patients with Child-Pugh C liver cirrhosis were excluded. HA was defined as ammonium levels above 60 µg/dl. RESULTS: Of a total of 2640 patients treated with VPA, 319 patients met the inclusion criteria (median age 64 years; male gender 55%); 78% of them were admitted for neurological reasons and ICU mortality was 30%. Median ammonium levels were 88 [63-118] µg/dl. HA was found in 245 (77%) patients. For those patients with HA, median time from start of VPA therapy to HA was 3 [2-5] days. In a multivariable analysis, high VPA serum levels, mechanical ventilation and sepsis were independently associated with HA during VPA therapy. In 98/243 (40%) of HA patients, VPA was interrupted; VPA interruption was more frequent in patients with ammonium levels > 100 µg/dl than others (p = 0.001). HA was not an independent predictor of ICU mortality or poor neurological outcome. CONCLUSIONS: In this study, HA was a common finding during treatment with VPA in acutely ill patients. VPA levels, sepsis and mechanical ventilation were risk factors for HA. Hyperammonemia did not influence patients' outcome.

The clinical spectrum of pulmonary thromboembolism in patients with coronavirus disease-2019 (COVID-19) pneumonia: A European case series.

PURPOSE: To describe the clinical characteristics and outcomes of coronavirus disease-2019 (COVID-19)-associated pulmonary thromboembolism (PTE). MATERIALS AND METHODS: A case series of five patients, representing the clinical spectrum of COVID-19 associated PTE. Patients were admitted to four hospitals in Germany, Italy, and France. Infection with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) was confirmed using a real-time reverse transcription polymerase chain reaction test. RESULTS: The onset of PTE varied from 2 to 4 weeks after the occurrence of the initial symptoms of SARS-CoV-2 infection and led to deterioration of the clinical picture in all cases. PTE was the primary reason for hospital admission after a 2-week period of self-isolation at home (1 patient) and hospital readmission after initial uncomplicated hospital discharge (2 patients). Three of the patients had no past history of clinically relevant risk factors for venous thromboembolism (VTE). Severe disease progression was associated with concomitant increases in IL-6, ferritin, and D-Dimer levels. The outcome from PTE was related to the extent of vascular involvement, and associated complications. CONCLUSION: PTE is a potential life-threatening complication, which occurs frequently in patients with COVID-19. Intermediate therapeutic dose of anticoagulants and extend thromboprophylaxis are necessary after meticulous risk-benefit assessment.

Pulmonary embolism in patients with coronavirus disease-2019 (COVID-19) pneumonia: a narrative review.

BACKGROUND: Preliminary reports have described significant procoagulant events in patients with coronavirus disease-2019 (COVID-19), including life-threatening pulmonary embolism (PE). MAIN TEXT: We review the current data on the epidemiology, the possible underlying pathophysiologic mechanisms, and the therapeutic implications of PE in relation to COVID-19. The incidence of PE is reported to be around 2.6-8.9% of COVID-19 in hospitalized patients and up to one-third of those requiring intensive care unit (ICU) admission, despite standard prophylactic anticoagulation. This may be explained by direct and indirect pathologic consequences of COVID-19, complement activation, cytokine release, endothelial dysfunction, and interactions between different types of blood cells. CONCLUSION: Thromboprophylaxis should be started in all patients with suspected or confirmed COVID-19 admitted to the hospital. The use of an intermediate therapeutic dose of low molecular weight (LMWH) or unfractionated heparin can be considered on an individual basis in patients with multiple risk factors for venous thromboembolism, including critically ill patients admitted to the ICU. Decisions about extending prophylaxis with LMWH after hospital discharge should be made after balancing the reduced risk of venous thromboembolism (VTE) with the risk of increased bleeding events and should be continued for 7-14 days after hospital discharge or in the pre-hospital phase in case of pre-existing or persisting VTE risk factors. Therapeutic anticoagulation is the cornerstone in the management of patients with PE. Selection of an appropriate agent and correct dosing requires consideration of underlying comorbidities.

The relation between the incidence of hypernatremia and mortality in patients with severe traumatic brain injury.

INTRODUCTION: The study was aimed at verifying whether the occurrence of hypernatremia during the intensive care unit (ICU) stay increases the risk of death in patients with severe traumatic brain injury (TBI). We performed a retrospective study on a prospectively collected database including all patients consecutively admitted over a 3-year period with a diagnosis of TBI (post-resuscitation Glasgow Coma Score < or = 8) to a general/neurotrauma ICU of a university hospital, providing critical care services in a catchment area of about 1,200,000 inhabitants. METHODS: Demographic, clinical, and ICU laboratory data were prospectively collected; serum sodium was assessed an average of three times per day. Hypernatremia was defined as two daily values of serum sodium above 145 mmol/l. The major outcome was death in the ICU after 14 days. Cox proportional-hazards regression models were used, with time-dependent variates designed to reflect exposure over time during the ICU stay: hypernatremia, desmopressin acetate (DDAVP) administration as a surrogate marker for the presence of central diabetes insipidus, and urinary output. The same models were adjusted for potential confounding factors. RESULTS: We included in the study 130 TBI patients (mean age 52 years (standard deviation 23); males 74%; median Glasgow Coma Score 3 (range 3 to 8); mean Simplified Acute Physiology Score II 50 (standard deviation 15)); all were mechanically ventilated; 35 (26.9%) died within 14 days after ICU admission. Hypernatremia was detected in 51.5% of the patients and in 15.9% of the 1,103 patient-day ICU follow-up. In most instances hypernatremia was mild (mean 150 mmol/l, interquartile range 148 to 152). The occurrence of hypernatremia was highest (P = 0.003) in patients with suspected central diabetes insipidus (25/130, 19.2%), a condition that was associated with increased severity of brain injury and ICU mortality. After adjustment for the baseline risk, the incidence of hypernatremia over the course of the ICU stay was significantly related with increased mortality (hazard ratio 3.00 (95% confidence interval: 1.34 to 6.51; P = 0.003)). However, DDAVP use modified this relation (P = 0.06), hypernatremia providing no additional prognostic information in the instances of suspected central diabetes insipidus. CONCLUSIONS: Mild hypernatremia is associated with an increased risk of death in patients with severe TBI. In a proportion of the patients the association between hypernatremia and death is accounted for by the presence of central diabetes insipidus.