DNase Treatment Prevents Cerebrospinal Fluid Block in Early Experimental Pneumococcal Meningitis.

OBJECTIVE: Streptococcus pneumoniae is the most common cause of bacterial meningitis, a disease that, despite treatment with antibiotics, still is associated with high mortality and morbidity worldwide. Diffuse brain swelling is a leading cause of morbidity in S pneumoniae meningitis. We hypothesized that neutrophil extracellular traps (NETs) disrupt cerebrospinal fluid (CSF) transport by the glymphatic system and contribute to edema formation in S pneumoniae meningitis. METHODS: We used DNase I treatment to disrupt NETs and then assessed glymphatic function by cisterna magna injections of CSF tracers in a rat model of S pneumoniae meningitis. RESULTS: Our analysis showed that CSF influx into the brain parenchyma, as well as CSF drainage to the cervical lymph nodes, was significantly reduced in the rat model of S pneumoniae meningitis. Degrading NETs by DNase treatment restored glymphatic transport and eliminated the increase in brain weight in the rats. In contrast, first-line antibiotic treatment had no such effect on restoring fluid dynamics. INTERPRETATION: This study suggests that CSF accumulation is responsible for cerebral edema formation and identifies the glymphatic system and NETs as possible new treatment targets in S pneumoniae meningitis. ANN NEUROL 2021;90:653-669.

Mechanical complications after central venous catheterisation in the ultrasound-guided era: a prospective multicentre cohort study.

BACKGROUND: Limited data are available on the incidence of mechanical complications after ultrasound-guided central venous catheterisation. We aimed to determine the incidence of mechanical complications in hospitals where real-time ultrasound guidance is clinical practice for central venous access and to identify variables associated with mechanical complications. METHODS: All central venous catheter insertions in patients ≥16 yr at four emergency care hospitals in Sweden from March 2, 2019 to December 31, 2020 were eligible for inclusion. Every insertion was monitored for complete documentation and occurrence of mechanical complications within 24 h after catheterisation. Multivariable logistic regression analyses were used to determine associations between predefined variables and mechanical complications. RESULTS: In total, 12 667 catheter insertions in 8586 patients were included. The incidence (95% confidence interval [CI]) of mechanical complications was 7.7% (7.3-8.2%), of which 0.4% (0.3-0.5%) were major complications. The multivariable analyses showed that patient BMI <20 kg m-2 (odds ratio 2.69 [95% CI: 1.17-5.62]), male operator gender (3.33 [1.60-7.38]), limited operator experience (3.11 [1.64-5.77]), and increasing number of skin punctures (2.18 [1.59-2.88]) were associated with major mechanical complication. Subclavian vein catheterisation was associated with pneumothorax (5.91 [2.13-17.26]). CONCLUSIONS: The incidence of major mechanical complications is low in hospitals where real-time ultrasound guidance is the standard of care for central venous access. Several variables independently associated with mechanical complications can be used for risk stratification before catheterisation procedures, which might further reduce complication rates. CLINICAL TRIAL REGISTRATION: NCT03782324.

Non-corticosteroid adjuvant therapies for acute bacterial meningitis.

BACKGROUND: Acute bacterial meningitis is a bacterial infection of the membranes that surround and protect the brain, known as the meninges. The primary therapy for bacterial meningitis is antibiotics and corticosteroids. Although these therapies significantly improve outcomes, bacterial meningitis still has a high risk of death and a high risk of neurological sequelae in survivors. New adjuvant therapies are needed to further reduce the risk of death and neurological sequelae in bacterial meningitis. OBJECTIVES: To assess the effects of non-corticosteroid adjuvant pharmacological therapies for mortality, hearing loss, and other neurological sequelae in people with acute bacterial meningitis. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, CINAHL, and LILACS databases and ClinicalTrials.gov and WHO ICTRP trials registers up to 30 September 2021, together with reference checking, citation searching, and contact with study authors to identify additional studies. SELECTION CRITERIA: We included randomised controlled trials (RCTs) of any pharmacological adjuvant therapy for acute bacterial meningitis. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed and extracted data on methods, participants, interventions, and outcomes. We assessed risk of bias of studies with the Cochrane risk of bias tool and the certainty of the evidence using the GRADE approach. We presented results using risk ratios (RR) and 95% confidence intervals (CI) when meta-analysis was possible. All other results are presented in a narrative synthesis. MAIN RESULTS: We found that five different adjuvant therapies have been tested in RCTs for bacterial meningitis. These include paracetamol (3 studies, 1274 participants who were children); immunoglobulins (2 studies, 49 participants; one study included children, and the other adults); heparin (1 study, 15 participants who were adults); pentoxifylline (1 study, 57 participants who were children); and a mixture of succinic acid, inosine, nicotinamide, and riboflavin mononucleotide (1 study, 30 participants who were children). Paracetamol may make little or no difference to mortality (paracetamol 35.2% versus placebo 37.4%, 95% CI 30.3% to 40.8%; RR 0.94, 95% CI 0.81 to 1.09; 3 studies, 1274 participants; I² = 0%; low certainty evidence); hearing loss (RR 1.04, 95% CI 0.80 to 1.34; 2 studies, 901 participants; I² = 0%; low certainty evidence); neurological sequelae other than hearing loss (RR 1.56, 95% CI 0.98 to 2.50; 3 studies, 1274 participants; I² = 60%; low certainty evidence); and severe hearing loss (RR 0.96, 95% CI 0.67 to 1.36; 2 studies, 901 participants; I² = 0%; low certainty evidence). Paracetamol may lead to slightly more short-term neurological sequelae other than hearing loss (RR 1.99, 95% CI 1.40 to 2.81; 2 studies, 1096 participants; I² = 0%; low certainty evidence) and slightly more long-term neurological sequelae other than hearing loss (RR 2.32, 95% CI 1.34 to 4.04; 2 studies, 901 participants; I² = 0%; low certainty evidence). No adverse events were reported in either group in any of the paracetamol studies (very low certainty evidence). Two paracetamol studies had a low risk of bias in most domains, and one had low or unclear risk of bias in all domains. We judged the certainty of evidence to be low for mortality due to limitations in study design (unclear risk of bias in at least one domain and imprecision (high level of uncertainty in absolute effects), and low for all other outcomes due to limitations in study design (unclear risk of bias in at least one domain), and imprecision (low sample size and few events) or inconsistency in effect estimates (heterogeneity). We were not able to perform meta-analysis for any of the other adjuvant therapies due to the limited number of included studies. It is uncertain whether immunoglobulins, heparin, or pentoxifylline improves mortality outcomes due to the very low certainty of the evidence. Zero adverse events were reported for immunoglobulins (very low certainty evidence), and allergic reactions occurred at a rate of 3.3% in participants receiving a mixture of succinic acid, inosine, nicotinamide, and riboflavin mononucleotide (intervention group) (very low certainty evidence). None of our other outcomes (hearing loss, neurological sequelae other than hearing loss, severe hearing loss, and short-term or long-term neurological sequelae other than hearing loss) were reported in these studies, and all of these studies were judged to have a high risk of bias. All reported outcomes for all included adjuvant therapies, other than paracetamol, were graded as very low certainty of evidence due to limitations in study design (unclear or high risk of bias in at least four domains) and imprecision (extremely low sample size and few events). AUTHORS' CONCLUSIONS: Few adjuvant therapies for bacterial meningitis have been tested in RCTs. Paracetamol may make little or no difference to mortality, with a high level of uncertainty in the absolute effects (low certainty evidence). Paracetamol may make little or no difference to hearing loss, neurological sequelae other than hearing loss, and severe hearing loss (all low certainty evidence). Paracetamol may lead to slightly more short-term and long-term neurological sequelae other than hearing loss (both outcomes low certainty evidence). There is insufficient evidence to determine whether any of the adjuvant therapies included in this review (paracetamol, immunoglobulins, heparin, pentoxifylline, or a mixture of succinic acid, inosine, nicotinamide, and riboflavin mononucleotide) are beneficial or detrimental in acute bacterial meningitis.

Effects of different mean arterial pressure targets on plasma volume, ANP and glycocalyx-A randomized trial.

BACKGROUND: Arterial haematocrit (Hct) has been shown to decrease after anaesthesia induction, most probably because of an increased plasma volume (PV). The primary objective was to quantify change in PV if mean arterial pressure (MAP) was kept at baseline level or allowed to decrease to 60 mm Hg. Our secondary objective was to evaluate underlying mechanisms of this response. METHODS: Twenty-four coronary artery bypass patients were randomized to a higher (90 mm Hg, intervention group) or lower (60 mm Hg, control group) MAP by titration of norepinephrine. During the experimental procedure, no fluids were administered. Baseline PV was measured by 125 I-albumin and the change in PV was calculated from the change in Hct. Changes in MAP, plasma 125 I-albumin, colloid osmotic pressure, albumin, Mid Regional-pro Atrial Natriuretic Peptide (MR-proANP) and endothelial glycocalyx components were measured from baseline to 50 minutes after anaesthesia induction. RESULTS: The MAP during the trial was 93 ± 9 mm Hg in the intervention group and 62 ± 5 mm Hg in the control group. PV increased with up to 420 ± 180 mL in the control group and 45 ± 130 mL in the intervention group (P < .001). Albumin and colloid osmotic pressure decreased significantly more in the control group. MR-proANP increased in the control group but no shedding of the glycocalyx layer was detected in either of the groups. CONCLUSION: Allowing mean arterial pressure to fall to 60 mm Hg during anaesthesia induction, increases the plasma volume due to reabsorption of interstitial water, with no ANP-induced degradation of the endothelial glycocalyx.

Markers of renal function at admission and mortality in hip fracture patients - a single center prospective observational study.

Plasma cystatin C and shrunken pore syndrome (SPS) are associated with increased mortality in older adults. The objective was to assess the association between these markers of kidney function at admission and mortality in hip fracture patients. Hip fracture patients presenting at Lund University Hospital were eligible for inclusion. Cox regression was used to assess association between plasma cystatin C, creatinine, cystatin C- or creatinine-based estimations of glomerular filtration rate (eGFRCYS and eGFRCREA), or SPS (defined as eGFRCYS/eGFRCREA < 0.7) and mortality during one year follow up. Improvement in discrimination relative to the Nottingham Hip fracture score was assessed by Receiver Operational Characteristics (ROC) analysis and calculation of Net Reclassification Index (NRI). 996 patients were included in the study. Cystatin C, creatinine, eGFRCYS and eGFRCREA were associated with one-year mortality in both unadjusted and adjusted analyses. The association with mortality was stronger for cystatin C and for eGFRCYS than for creatinine and eGFRCREA. Patients with SPS had doubled mortality compared with patients without SPS (43.7 and 20.2%, respectively, p < .001). Hazard ratio for SPS in the adjusted analysis was 1.66 (95%CI; 1.16-2.39, p = .006). None of the markers improved discrimination compared to the Nottingham Hip Fracture Score using ROC analysis whereas eGFRCYS and eGFRCREA improved NRI. Our conclusion is that plasma concentrations of creatinine or cystatin C, eGFRCYS or eGFRCREA or SPS at admission in hip fracture patients are associated with mortality when known risk factors are accounted for. Identification of high risk patients may be improved by eGFRCYS or eGFRCREA.

Interventions for treatment of COVID-19: A living systematic review with meta-analyses and trial sequential analyses (The LIVING Project).

BACKGROUND: Coronavirus disease 2019 (COVID-19) is a rapidly spreading disease that has caused extensive burden to individuals, families, countries, and the world. Effective treatments of COVID-19 are urgently needed. METHODS AND FINDINGS: This is the first edition of a living systematic review of randomized clinical trials comparing the effects of all treatment interventions for participants in all age groups with COVID-19. We planned to conduct aggregate data meta-analyses, trial sequential analyses, network meta-analysis, and individual patient data meta-analyses. Our systematic review is based on Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) and Cochrane guidelines, and our 8-step procedure for better validation of clinical significance of meta-analysis results. We performed both fixed-effect and random-effects meta-analyses. Primary outcomes were all-cause mortality and serious adverse events. Secondary outcomes were admission to intensive care, mechanical ventilation, renal replacement therapy, quality of life, and nonserious adverse events. We used Grading of Recommendations Assessment, Development and Evaluation (GRADE) to assess the certainty of evidence. We searched relevant databases and websites for published and unpublished trials until August 7, 2020. Two reviewers independently extracted data and assessed trial methodology. We included 33 randomized clinical trials enrolling a total of 13,312 participants. All trials were at overall high risk of bias. We identified one trial randomizing 6,425 participants to dexamethasone versus standard care. This trial showed evidence of a beneficial effect of dexamethasone on all-cause mortality (rate ratio 0.83; 95% confidence interval [CI] 0.75-0.93; p < 0.001; low certainty) and on mechanical ventilation (risk ratio [RR] 0.77; 95% CI 0.62-0.95; p = 0.021; low certainty). It was possible to perform meta-analysis of 10 comparisons. Meta-analysis showed no evidence of a difference between remdesivir versus placebo on all-cause mortality (RR 0.74; 95% CI 0.40-1.37; p = 0.34, I2 = 58%; 2 trials; very low certainty) or nonserious adverse events (RR 0.94; 95% CI 0.80-1.11; p = 0.48, I2 = 29%; 2 trials; low certainty). Meta-analysis showed evidence of a beneficial effect of remdesivir versus placebo on serious adverse events (RR 0.77; 95% CI 0.63-0.94; p = 0.009, I2 = 0%; 2 trials; very low certainty) mainly driven by respiratory failure in one trial. Meta-analyses and trial sequential analyses showed that we could exclude the possibility that hydroxychloroquine versus standard care reduced the risk of all-cause mortality (RR 1.07; 95% CI 0.97-1.19; p = 0.17; I2 = 0%; 7 trials; low certainty) and serious adverse events (RR 1.07; 95% CI 0.96-1.18; p = 0.21; I2 = 0%; 7 trials; low certainty) by 20% or more, and meta-analysis showed evidence of a harmful effect on nonserious adverse events (RR 2.40; 95% CI 2.01-2.87; p < 0.00001; I2 = 90%; 6 trials; very low certainty). Meta-analysis showed no evidence of a difference between lopinavir-ritonavir versus standard care on serious adverse events (RR 0.64; 95% CI 0.39-1.04; p = 0.07, I2 = 0%; 2 trials; very low certainty) or nonserious adverse events (RR 1.14; 95% CI 0.85-1.53; p = 0.38, I2 = 75%; 2 trials; very low certainty). Meta-analysis showed no evidence of a difference between convalescent plasma versus standard care on all-cause mortality (RR 0.60; 95% CI 0.33-1.10; p = 0.10, I2 = 0%; 2 trials; very low certainty). Five single trials showed statistically significant results but were underpowered to confirm or reject realistic intervention effects. None of the remaining trials showed evidence of a difference on our predefined outcomes. Because of the lack of relevant data, it was not possible to perform other meta-analyses, network meta-analysis, or individual patient data meta-analyses. The main limitation of this living review is the paucity of data currently available. Furthermore, the included trials were all at risks of systematic errors and random errors. CONCLUSIONS: Our results show that dexamethasone and remdesivir might be beneficial for COVID-19 patients, but the certainty of the evidence was low to very low, so more trials are needed. We can exclude the possibility of hydroxychloroquine versus standard care reducing the risk of death and serious adverse events by 20% or more. Otherwise, no evidence-based treatment for COVID-19 currently exists. This review will continuously inform best practice in treatment and clinical research of COVID-19.

Novel biomarkers for prediction of outcome in hip fracture patients-An exploratory study.

BACKGROUND: Little is known about the value of biomarkers for prognostication in hip fracture patients. The main objective of the present study was to assess if biomarkers add useful information to an existing risk score for prediction of 30-day mortality in patients suffering from out of hospital hip fractures. METHODS: In a prospective observational single centre study, association between plasma concentration of ninety-two biomarkers at admission and 30-day mortality was analysed using logistic regression adjusted for risk factors included in Nottingham Hip Fracture Score (NHFS). Biomarkers associated with the outcome in the adjusted analysis were further evaluated by calculating the net reclassification improvement (NRI) and the change in area under the receiver operating characteristics curve (AUC) relative to the NHFS. RESULTS: 997 patients were included. Sixty-two patients died within 30 days (6.2%). Eleven biomarkers were associated with 30-day mortality in adjusted analysis. Of these biomarkers Growth Differentiation Factor-15 (GDF-15) had NRI for the primary outcome (12.1%; 95% CI: 1.2-23.3) and Carbohydrate Antigen 125 (CA-125) improved the AUC relative to NHFS (improvement: 0.05; 95% CI: 0.01-0.10, P = .027). Both CA-125 and GDF-15 improved the AUC for a composite outcome of 30-day mortality and cardiovascular complications. CONCLUSIONS: Adding GDF-15 or CA-125 to the Nottingham Hip Fracture Score improves the discrimination with regard to predicting 30-day mortality and may help to identify a subgroup of hip fracture patients with a particularly poor prognosis. The value of these biomarkers should be explored in further studies to confirm clinical utility.

Albumin infusion rate and plasma volume expansion: a randomized clinical trial in postoperative patients after major surgery.

BACKGROUND: Optimal infusion rate of colloids in patients with suspected hypovolemia is unknown, and the primary objective of the present study was to test if plasma volume expansion by 5% albumin is greater if fluid is administered slowly rather than rapidly. METHODS: Patients with signs of hypoperfusion after major abdominal surgery were randomized to intravenous infusion of 5% albumin at a dose of 10 ml/kg (ideal body weight) either rapidly (30 min) or slowly (180 min). Plasma volume was measured using radiolabeled albumin at baseline, at 30 min, and at 180 min after the start of infusion. Primary outcome was change in plasma volume from the start of infusion to 180 min after the start of infusion. Secondary outcomes included the change in the area under the plasma volume curve and transcapillary escape rate (TER) for albumin from 180 to 240 min after the start of albumin infusion. RESULTS: A total of 33 and 31 patients were included in the analysis in the slow and rapid groups, respectively. The change in plasma volume from the start of infusion to 180 min did not differ between the slow and rapid infusion groups (7.4 ± 2.6 vs. 6.5 ± 4.1 ml/kg; absolute difference, 0.9 ml/kg [95%CI, - 0.8 to 2.6], P = 0.301). Change in the area under the plasma volume curve was smaller in the slow than in the rapid infusion group and was 866 ± 341 and 1226 ± 419 min ml/kg, respectively, P < 0.001. TER for albumin did not differ and was 5.3 ± 3.1%/h and 5.4 ± 3%/h in the slow and in the rapid infusion groups, respectively, P = 0.931. CONCLUSIONS: This study does not support our hypothesis that a slow infusion of colloid results in a greater plasma volume expansion than a rapid infusion. Instead, our result of a smaller change in the area under the plasma volume curve indicates that a slow infusion results in a less efficient plasma volume expansion, but further studies are required to confirm this finding. A rapid infusion has no effect on vascular leak as measured after completion of the infusion. TRIAL REGISTRATION: EudraCT2013-004446-42 registered December 23, 2014.

Mechanical complications of central venous catheter insertions: A retrospective multicenter study of incidence and risks.

BACKGROUND: Incidence and risk factors for complications after insertion of central venous catheters have previously been reported for smaller cohorts. The aim of this observational multicenter study was to study risk factors for mechanical complications in a large, recently collected cohort of patients. METHODS: Records of central venous catheter insertions from 8 hospitals in southern Sweden from 2013 to 2016 were collected from the regional chart system. Data on blood coagulation tests, use of ultrasonography, central venous catheter location, bore size, number of needle passes, arterial puncture, the chronological order of the central venous catheter insertion, and mechanical complications were extracted. Only one insertion/patient was included using worst-case selection criteria. Predefined primary outcome was mechanical complications defined as bleeding, pneumothorax, nerve injury, or malignant arrhythmia. Severe mechanical complications were defined as bleeding requiring intervention or transfusion, pneumothorax, persistent nerve injury, or non-self-limiting arrhythmias. RESULTS: We included 10 949 insertions and identified 118 (1.1%) incidents of mechanical complication, of which 85 (0.8%) were bleedings, 21 (0.2%) were pneumothoraces, 7 (0.06%) were transient nerve injuries, and 5 (0.05%) were self-limiting arrhythmias. Severe mechanical complications occurred in 23 (0.2%) cases. CONCLUSIONS: In this retrospective, multicenter observational study on 10 949 central venous catheter insertions, mechanical complications were rare. Preprocedural coagulopathy, number of needle passes, and arterial puncture were associated with grade 2-4 bleeding. Subclavian vein insertions, arterial puncture, and chronological order of the central venous catheter insertion were associated with pneumothorax.

Glomerular hyperpermeability after acute unilateral ureteral obstruction: effects of Tempol, NOS, RhoA, and Rac-1 inhibition.

It is well known that proteinuria following urinary tract obstruction is mainly of a tubular nature. However, it is unknown whether there are also changes in glomerular permeability. In this study, we compared glomerular sieving coefficients (θ) of polydisperse fluorescein isothiocyanate (FITC)-Ficoll 70/400 following a 120- or 180-min unilateral ureteral obstruction (UUO) in anesthetized Sprague-Dawley rats. Samples were collected from the obstructed kidney at 5, 15, and 30 min postrelease and analyzed by means of high-pressure size-exclusion chromatography. After 120-min UUO, mean θ for Ficoll70Å was increased ( P < 0.01) from 2.2 ± 0.5 × 10-5 (baseline) to 10.6 ± 10 × 10-5 15 min postrelease (highest value). After 180-min UUO, mean θ for Ficoll70Å was further increased ( P < 0.001) from 1.4 ± 0.5 × 10-5 (baseline) to 40 ± 10 × 10-5 at 5 min postrelease (highest value). Administration of a reactive oxygen species (ROS) scavenger (Tempol; 1 mg·kg-1·min-1) partly abrogated the permeability effects following 120-min UUO but not after 180 min. Moreover, administration of the RhoA kinase inhibitor Y-27632, the nitric oxide synthase inhibitor NG-nitro-l-arginine methyl ester, or Rac-1 inhibition did not ameliorate glomerular hyperpermeability following 180-min UUO. We show, for the first time, that acute UUO results in marked elevations in glomerular permeability. In addition, our data suggest a time-dependent pathophysiology of UUO-induced hyperpermeability, where reactive oxygen species generation may play an important role in the early stages.

Is Heparin-Binding Protein Inhibition a Mechanism of Albumin's Efficacy in Human Septic Shock?

OBJECTIVES: Our objectives were to determine first whether albumin prevents heparin-binding protein-induced increased endothelial cell permeability and renal cell inflammation and second, whether a plasma heparin-binding protein-to-albumin ratio predicts risk of acute kidney injury, fluid balance, and plasma cytokine levels in septic shock. DESIGN: In vitro human endothelial and renal cell model and observation cohort of septic shock. SETTINGS: Research laboratory and multicenter clinical trial (Vasopressin and Septic Shock Trial). PATIENTS: Adult septic shock (norepinephrine dose > 5 µg/min for > 6 hr). INTERVENTIONS: In vitro: heparin-binding protein (or thrombin) was added with or without albumin to 1) human endothelial cell monolayers to assess permeability and 2) to human renal tubular epithelial cells to assess inflammation. MEASUREMENTS AND MAIN RESULTS: Transendothelial electrical resistance-a marker of permeability-of human endothelial cells was measured using a voltohmmeter. We measured plasma heparin-binding protein-to-albumin ratio and a panel of cytokines in septic shock patients (n = 330) to define an heparin-binding protein-to-albumin ratio that predicts risk of acute kidney injury. Albumin inhibited heparin-binding protein (and thrombin-induced) increased endothelial cell permeability at a threshold concentration of 20-30 g/L but increased renal tubular cell interleukin-6 release. Patients who developed or had worsened acute kidney injury had significantly higher heparin-binding protein-to-albumin ratio (1.6 vs 0.89; p < 0.001) and heparin-binding protein (38.2 vs 20.8 ng/mL; p < 0.001) than patients without acute kidney injury. The highest heparin-binding protein-to-albumin ratio (> 3.05), heparin-binding protein quartiles (> 69.8), and heparin-binding protein > 30 ng/mL were significantly associated with development or worsening of acute kidney injury (p < 0.001) in unadjusted and adjusted analyses and were robust to sensitivity analyses for death as a competing outcome. Heparin-binding protein and heparin-binding protein-to-albumin ratio were directly associated with positive fluid balance (p < 0.001) and with key inflammatory cytokines. Increasing quartiles of heparin-binding protein-to-albumin ratio and heparin-binding protein (but not albumin) were highly significantly associated with days alive and free of acute kidney injury and renal replacement therapy (p < 0.001), vasopressors (p < 0.001), ventilation (p < 0.001), and with 28-day mortality. CONCLUSIONS: Albumin inhibits heparin-binding protein-induced increased human endothelial cell permeability and heparin-binding protein greater than 30 ng/mL and heparin-binding protein-to-albumin ratio greater than 3.01-but not serum albumin-identified patients at increased risk for acute kidney injury in septic shock.

Plasma lactate at admission does not predict mortality and complications in hip fracture patients: a prospective observational study.

Hip fractures in elderly carry a high mortality. Our objective was to test the hypothesis that plasma lactate concentration at hospital admission can be used to identify patients with a high risk for poor outcome. Hip fracture patients admitted to a university hospital in Sweden from January 2011 to August 2014 in whom a venous lactate was obtained at admission were included in this prospective observational study. Primary outcome measure was 30-d mortality and secondary outcome measure was a composite outcome of 30-d mortality and postoperative complications. Lactate concentration was evaluated as a continuous predictor using logistic regression, crude and adjusted for age, gender and American Society of Anesthesiology Physical Status (ASA PS) score. Discrimination was evaluated using receiver operating characteristics (ROC) analysis. Totally, 690 patients were included. Median age was 84 years (interquartile range [IQR] 77-90). At 30-d follow-up, mortality was 7.2%, and 45% of the patients had suffered the composite outcome. Median lactate level was 1.3 mmol/L (IQR 1.0-1.8 mmol/L). The odds ratio (OR) by each 1.0 mmol/L increase in the lactate concentration for 30-d mortality was 1.13 (95% CI 0.77-1.68) while for the composite outcome it was 1.06 (95% CI 0.85-1.3). Similar results were obtained after adjustment for age, sex and ASA PS classification for both outcomes. Area under the ROC curve for lactate as a predictor of 30-d mortality was 0.51 (95% CI 0.45-0.57). In our cohort, plasma lactate at admission does not appear to be a useful biomarker to identify high-risk patients after hip fracture.

Isolated Brain Trauma in Cats Triggers Rapid Onset of Hypovolemia.

BACKGROUND: Hemodynamic instability responsive to fluid resuscitation is common after a traumatic brain injury (TBI), also in the absence of systemic hemorrhage. The present study tests if an isolated severe TBI induces a decrease in plasma volume (PV). METHODS: The study was performed in three groups of anesthetized and tracheostomized male cats (n = 21). In one group (n = 8), the cats were prepared with a cranial borehole (10 mm i.d) used to expose the brain to a fluid percussion brain injury (FPI) (1.90-2.20 bar), and two smaller cranial boreholes (4 mm i.d) for insertion of an intracranial pressure (ICP) and a microdialysis catheter. To differentiate the effect of FPI from that of the surgical preparation, a sham group was exposed to the same surgical preparation but no FPI trauma (n = 8). A control group had no brain trauma and no surgical preparation (n = 5). PV was determined by a 125I-albumin dilution technique. PV, electrolytes, pH, BE (base excess), hematocrit (Hct), PaO2, and PaCO2 were measured at baseline and after 3 h. Mean arterial pressure (MAP) was measured continuously. ICP was measured in the FPI and the sham group. RESULTS: In the FPI group, PV decreased by 11.2 mL/kg from 31.7 mL/kg (p < 0.01) with a simultaneous increase in Hct and decrease in pH. In the sham group, PV decreased by 5.7 mL/kg from 32.7 mL/kg (p < 0.01). The control group showed no PV reduction. CONCLUSIONS: The results support that an isolated severe head trauma triggers a significant and rapid reduction in PV, most likely due to vascular leak.

Will This Hemodynamically Unstable Patient Respond to a Bolus of Intravenous Fluids?

IMPORTANCE: Fluid overload occurring as a consequence of overly aggressive fluid resuscitation may adversely affect outcome in hemodynamically unstable critically ill patients. Therefore, following the initial fluid resuscitation, it is important to identify which patients will benefit from further fluid administration. OBJECTIVE: To identify predictors of fluid responsiveness in hemodynamically unstable patients with signs of inadequate organ perfusion. DATA SOURCES AND STUDY SELECTION: Search of MEDLINE and EMBASE (1966 to June 2016) and reference lists from retrieved articles, previous reviews, and physical examination textbooks for studies that evaluated the diagnostic accuracy of tests to predict fluid responsiveness in hemodynamically unstable adult patients who were defined as having refractory hypotension, signs of organ hypoperfusion, or both. Fluid responsiveness was defined as an increase in cardiac output following intravenous fluid administration. DATA EXTRACTION: Two authors independently abstracted data (sensitivity, specificity, and likelihood ratios [LRs]) and assessed methodological quality. A bivariate mixed-effects binary regression model was used to pool the sensitivities, specificities, and LRs across studies. RESULTS: A total of 50 studies (N = 2260 patients) were analyzed. In all studies, indices were measured before assessment of fluid responsiveness. The mean prevalence of fluid responsiveness was 50% (95% CI, 42%-56%). Findings on physical examination were not predictive of fluid responsiveness with LRs and 95% CIs for each finding crossing 1.0. A low central venous pressure (CVP) (mean threshold <8 mm Hg) was associated with fluid responsiveness (positive LR, 2.6 [95% CI, 1.4-4.6]; pooled specificity, 76%), but a CVP greater than the threshold made fluid responsiveness less likely (negative LR, 0.50 [95% CI, 0.39-0.65]; pooled sensitivity, 62%). Respiratory variation in vena cava diameter measured by ultrasound (distensibility index >15%) predicted fluid responsiveness in a subgroup of patients without spontaneous respiratory efforts (positive LR, 5.3 [95% CI, 1.1-27]; pooled specificity, 85%). Patients with less vena cava distensibility were not as likely to be fluid responsive (negative LR, 0.27 [95% CI, 0.08-0.87]; pooled sensitivity, 77%). Augmentation of cardiac output or related parameters following passive leg raising predicted fluid responsiveness (positive LR, 11 [95% CI, 7.6-17]; pooled specificity, 92%). Conversely, the lack of an increase in cardiac output with passive leg raising identified patients unlikely to be fluid responsive (negative LR, 0.13 [95% CI, 0.07-0.22]; pooled sensitivity, 88%). CONCLUSIONS AND RELEVANCE: Passive leg raising followed by measurement of cardiac output or related parameters may be the most useful test for predicting fluid responsiveness in hemodynamically unstable adults. The usefulness of respiratory variation in the vena cava requires confirmatory studies.

Perioperative changes in PIVKA-II.

BACKGROUND AND AIMS: Proteins induced by vitamin K absence for factor II (PIVKA-II) is an enzyme-linked immunosorbent assay that monitors uncarboxylated prothrombin and responds to vitamin K deficits prior to changes in the prothrombin test. The aim of this project was to study perioperative PIVKA-II changes during various types of surgery in a prospective observational study. METHODS: Patients undergoing abdominal or orthopaedic surgery were included. Blood was sampled on the day of surgery (preoperatively) and up to 5 days after surgery. The activated partial thromboplastin time, Quick and Owren prothrombin times were analyzed, together with PIVKA-II. RESULTS: Thirty-nine patients were included, 27 +male and 12 +female. All but 7 +patients had elevated PIVKA-II levels preoperatively. PIVKA-II levels had already increased significantly (p < 0.017) on day 1 after surgery as compared to presurgery plasma levels. The median PIVKA-II was highest on day 5. Routine tests were mostly normal. No significant difference in PIVKA-II was seen when comparing patients undergoing abdominal versus orthopaedic surgeries. There was no significant correlation between PIVKA-II and routine coagulation tests. Patients with anterior resection, emergency laparotomy and emergency hip fractures had higher postoperative increases, which could be linked to increased gastrointestinal recovery times, paralytic ileus, peritonitis and comorbidities. CONCLUSIONS: PIVKA-II levels increase during the perioperative period, despite mostly normal routine coagulation tests. Pre- and perioperative vitamin K supplementation in patients with elevated PIVKA-II levels should be studied, and its clinical significance be defined in future studies.

Plasma volume expansion with 5% albumin compared to Ringer's acetate during normal and increased microvascular permeability in the rat.

BACKGROUND: It is believed that the effectiveness of colloids as plasma volume expanders is dependent on the endothelial permeability for macromolecules. The objective of this study was to test the hypothesis that the plasma volume expanding effect of 5% albumin relative to that of a crystalloid solution is reduced if microvascular permeability is increased. METHODS: A control group was resuscitated with either 5% albumin (8 ml/kg) or Ringer's acetate (36 ml/kg) immediately after a hemorrhage of 8 ml/kg (n = 29). In a second group, permeability was increased by inducing sepsis through cecal ligation and incision (n = 28). Three hours after cecal ligation and incision, the animals were resuscitated with either 5% albumin in a ratio of 1:1 relative to the volume of lost plasma, or Ringer's acetate in a ratio of 4.5:1. RESULTS: In the hemorrhage group, plasma volumes at 15 min after resuscitation with albumin or Ringer's acetate had increased by 9.8 ± 2.6 ml/kg (mean ± SD) and 7.4 ± 2.9 ml/kg and were similar at 2 and 4 h. Plasma volume 3 h after cecal ligation and incision had decreased by approximately 7 ml/kg, and at 15 min after resuscitation with albumin or Ringer's acetate it had increased by 5.7 ± 2.9 and 2.4 ± 3.0 ml/kg, respectively (P < 0.05). At 2 and 4 h after resuscitation, plasma volumes did not differ between the groups. CONCLUSION: This study does not support the hypothesis that the plasma-volume-expanding effect of albumin relative to that of crystalloids is decreased under conditions characterized by increased permeability.

Blood volume in patients likely to be preload responsive: a post hoc analysis of a randomized controlled trial.

BACKGROUND: Preload responsive postoperative patients with signs of inadequate organ perfusion are commonly assumed to be hypovolemic and therefore treated with fluids to increase preload. However, preload is influenced not only by blood volume, but also by venous vascular tone and the contribution of these factors to preload responsiveness in this setting is unknown. Based on this, the objective of this study was to investigate blood volume status in preload-responsive postoperative patients. METHODS: Data from a clinical trial including postoperative patients after major abdominal surgery were analyzed. Patients with signs of inadequate organ perfusion and with data from a passive leg raising test (PLR) were included. An increase in pulse pressure by ≥ 9% was used to identify patients likely to be preload responsive. Blood volume was calculated from plasma volume measured using radiolabelled albumin and hematocrit. Patients with a blood volume of at least 10% above or below estimated normal volume were considered hyper- and hypovolemic, respectively. RESULTS: A total of 63 patients were included in the study. Median (IQR) blood volume in the total was 57 (50-65) ml/kg, and change in pulse pressure after PLR was 14 (7-24)%. A total of 43 patients were preload responsive. Of these patients, 44% were hypovolemic, 28% euvolemic and 28% hypervolemic. CONCLUSIONS: A large fraction of postoperative patients with signs of hypoperfusion that are likely to be preload responsive, are hypervolemic. In these patients, treatments other than fluid administration may be a more rational approach to increase cardiac output. Trial registration EudraCT 2013-004446-42.