Axelle Ferry

Chloride toxicity in critically ill patients: What's the evidence?

Crystalloids have become the fluid of choice in critically ill patients and in the operating room both for fluid resuscitation and fluid maintenance. Among crystalloids, NaCl 0.9% has been the most widely used fluid. However, emerging evidence suggests that administration of 0.9% saline could be harmful mainly through high chloride content and that the use of fluid with low chloride content may be preferable in major surgery and intensive care patients. Administration of NaCl 0.9% is the leading cause of metabolic hyperchloraemic acidosis in critically ill patients and side effects might target coagulation, renal function, and ultimately increase mortality. More balanced solutions therefore may be used especially when large amount of fluids are administered in high-risk patients. In this review, we discuss physiological background favouring the use of balanced solutions as well as the most recent clinical data regarding the use of crystalloid solutions in critically ill patients and patients undergoing major surgery.

Muscle diffusion of liposomal amphotericin B and posaconazole in critically ill burn patients receiving continuous hemodialysis.

Dear Editor, Mucormycoses are opportunistic fungal infections, which occur in patients with impaired host defenses and are associated with very high mortality [1]. Therapeutic management of mucormycosis includes surgical debridement of necrotic lesions and intravenous liposomal amphotericin B (L-AMB), possibly in combination with posaconazole (PSC). Because antifungal drug concentration both in plasma and tissue remains uncertain in burn patients (as a result of large positive fluid balance with increase of volume of distribution, renal replacement therapy (RRT), gut dysfunction), we measured plasma and tissue concentration of L-AMB and posaconazole in three critically ill burn patients with proven invasive subcutaneous mucormycosis due to Mucor circinelloides. They had a median age of 45 years (28–54), a mean total burn body surface area of 80 % (min 60–max 96), and simplified acute physiology score II 42 (min 36–max 49). Mucormycosis was diagnosed 16 days (min 12–max19) after burn injury. They all received continuous venovenous hemodialysis with a multifiltrate monitor (dialysate rate of 2000 ml/h and a blood flow rate of 100 ml/min and regional citrate anticoagulation). Patients received L-AMB 10 mg/ kg once daily from diagnosis, in combination with PSC 400 mg oral suspension twice daily for patient 1. Plasma trough concentrations were collected at steady state and muscle biopsies harvested simultaneously, in non-necrotic areas, during a routine debridement surgical procedure. Plasma samples were immediately centrifuged at 4000g for 10 min. Plasma and biopsies were stored at -20 C until measurements. Weighed tissues were homogenized in water over an ice bath using a Polytron for 2.5 min. Then, plasma and muscle concentrations of L-AMB and PSC were assayed using a validated liquid chromatography method. The limit of quantification (LOQ) was 0.1 mg/l for both. L-AMB concentrations in muscle were assessed 14 (min 12–max 15) days after initiation of treatment. L-AMB median concentration was 44 lg/g [18–81], exceeding plasma concentration in all patients (Table 1). PSC plasma and tissue concentrations were measured in patient 1 and both were lower than the LOQ. Despite mucormycosis infection being considered under control in patients 2 and 3, all patients died from multiple organ dysfunction. Our study demonstrates good tissue diffusion of L-AMB in skeletal muscles, as previously reported in other tissues (lung, liver, kidney) [2], reaching 10to 20-fold higher concentrations than in plasma after infusion of high doses of L-AMB. However PSC concentration monitoring revealed a very poor bioavailability resulting in very low plasma and tissue concentrations. Because of highly variable PSC absorption after oral administration of PSC solution, extreme between-patient variability in PSC exposure was observed in a previous study [3]. These results are not expected to result from RRT removal, which has been described to be low [4]. To conclude, our data show good muscular tissue diffusion of L-AMB in critically ill burn patients receiving CVVHD. Tissue diffusion does not appear to be the limiting factor in controlling mucormycosis and efforts should probably be directed towards others factors (i.e., timing of treatment initiation, immune system

Undetectable haptoglobin is associated with major adverse kidney events in critically ill burn patients

BackgroundIntravascular haemolysis has been associated with acute kidney injury (AKI) in different clinical settings (cardiac surgery, sickle cell disease). Haemolysis occurs frequently in critically ill burn patients. The aim of this study was to assess the predictive value of haptoglobin at admission to predict major adverse kidney events (MAKE) and AKI in critically ill burn patients.MethodsWe conducted a retrospective, single-centre cohort study in a burn critical care unit in a tertiary centre, including all consecutive severely burned patients (total burned body surface > 20% and/or shock and/or mechanical ventilation at admission) from January 2012 to April 2017 with a plasmatic haptoglobin dosage at admission.ResultsA total of 130 patients were included in the analysis. Their mean age was 49 (34–62) years, their median total body surface area burned was 29% (15–51%) and the intensive care unit (ICU) mortality was 25%. Early haemolysis was defined as an undetectable plasmatic haptoglobin at admission. We used logistic regression to identify MAKE and AKI risk factors. In multivariate analysis, undetectable haptoglobin was associated with MAKE and AKI (respectively, OR 6.33, 95% CI 2.34–16.45, p < 0.001; OR 8.32, 95% CI 2.86–26.40, p < 0.001).ConclusionsUndetectable plasmatic haptoglobin at ICU admission is an independent risk factor for MAKE and AKI in critically ill burn patients. This study provides a rationale for biomarker-guided therapy using haptoglobin in critically ill burn patients.

Assessment of dyspnoea in the emergency department by numeric and visual scales: A pilot study

OBJECTIVE(S) Dyspnoea is a common and often debilitating symptom that affects up to 50% of patients admitted to acute tertiary care hospitals. The primary purpose of this study was to compare the numeric rating scale (NRS) and the visual analogue scale (VAS) for dyspnoea evaluation in the ED setting. STUDY DESIGN AND PATIENTS This was a cohort study of patients admitted to the ED in a university hospital, with dyspnoea as the chief complaint. METHODS The agreement of the two dyspnoea scales was assessed using the intraclass correlation coefficient (ICC). RESULTS One hundred and seventeen patients were included in this analysis. The median age for the whole study population was 67 years and 42% of patients were male. The aetiology of dyspnoea was acute heart failure (AHF) in 35% of patients. There was good agreement between the two scores (ICC=0.795; 95% CI=0.717-0.853; P<0.001). CONCLUSIONS This pilot study demonstrated that numerical rating and visual analogue scales agree well when assessing the severity of dyspnoea in the ED. Further studies with larger cohorts of patients are needed to confirm these preliminary results.

Prediction of major adverse kidney events in critically ill burn patients

OBJECTIVE We aimed at assessing the predictive value of plasmatic Neutrophil Gelatinase Associated Lipocalin (pNGAL) at admission and severity scores to predict major adverse kidney events (MAKE, defined as death and/or need for renal replacement therapy (RRT) and/or non-renal recovery at day 90) in critically ill burn patients. MATERIAL AND METHODS Single-center cohort study in a burn critical care unit in a tertiary center, including all consecutive severely burn patients (total burned body surface >20%) from January 2012 until January 2015 with a pNGAL dosage at admission. Reclassification of patients was assessed by Integrated Discrimination Improvement (IDI). MEASUREMENTS AND RESULTS 87 patients were included. Mean age was 47.7 (IQ 25-75: 33.4-65.2) years; total burn body surface area was 40 (IQ 25-75: 30-55) % and ICU mortality 36%. 39 (44.8%) patients presented a MAKE, 32 (88.9%) patients died at day 90. pNGAL was higher in the MAKE group (423 [IQ 25-75: 327-518]pg/mL vs 184 [IQ 25-75: 147-220]pg/mL, p<0.001). In multivariate analysis, pNGAL and abbreviated burn severity index (ABSI) remained associated with MAKE (OR 1.005 [CI 95% 1.0005-1.009], p=0.03 and OR 1.682 [CI95%1.038-2.726], p=0.035 respectively). Adding pNGAL to abbreviated burn severity index, simplified organ failure assessment and the simplified acute physiology score 2 did outperform clinical scores for the prediction of MAKE and AKI and for most severe forms of AKI and allowed a statistically significant reclassification of patients compared to ABSI for MAKE, RRT, AKI at Day 7 and AKI during hospitalization with a number of patients needed to screen to detect one extra episode of MAKE was 44, 13 for severe AKI and 15 for AKI. CONCLUSIONS pNGAL at admission is associated with the risk of MAKE in this population, and outperform severity scores when associated. Interventional studies are now needed to assess if impact of biomarkers-guided strategies would improve outcome.

Cross-talk phenomenon during femoral transpulmonary thermodilution in a critically ill patient.

Transpulmonary thermodilution (TPTD) can be used to guide fluid management in critically ill patients by measuring the cardiac (CI), extra-vascular lung water (EVLWI) and global end diastolic volume (GEDVI) indices [1]. A thermodilution cold saline bolus through a superior vena cava access is the gold standard for TPTD [2]. However, central venous and arterial catheters are often inserted in the femoral site in intensive care unit (ICU) patients. In this case, ipsilateral insertion of venous and arterial femoral catheters for TPTD has been suggested to induce error measurements due to ‘‘the cross-talk phenomenon’’ between venous and arterial sites with a biphasic TPTD curve. For example, a cold saline bolus injected through the femoral central venous catheter (CVC) may induce early significant temperature changes in the nearby femoral artery by contiguity, therefore altering the signal and leading to an erroneous cardiac output measurement [3–5]. This case report describes the impact of CVC insertion ipsilateral to an arterial line (AL) for femoral TPTD on the shape of the thermodilution curve and CI measurement values in a trauma patient admitted to the ICU with severe burn injury and traumatic brain injury (TBI). A previously healthy 18-year-old male suffered a fall from approximately three meters after an electrical arc burn injury