Is procalcitonin a reliable marker of sepsis in critically ill septic patients undergoing continuous veno-venous hemodiafiltration with "high cut-off" membranes (HCO-CVVHDF)?

Kinetics of serum procalcitonin in patients with acute mesenteric ischemia and bowel infarction after cardiac surgery

BACKGROUND

The present study reports perioperative changes in PCT levels occuring in cardiac patients with acute mesenteric ischemia (AMI) undergoing laparotomy. The aim of this study was to demonstrate that PCT kinetics may confirm the presence of AMI after cardiac surgery, distinguishing between bowel infarction and diffuse ischemia.

METHODS

PCT values from adult patients undergoing laparotomy for AMI after elective or urgent cardiac surgery (January 2010 - December 2019) were determinated at the ICU admission after cardiac surgery, 24 hours later and at the onset of clinical symptoms. Patients affected by diffuse intestinal ischemia with no need for bowel resection were allocated to Group A (n.8), patients presented with intestinal necrosis requiring small or large bowel resection were allocated to Group B (n.12).

RESULTS

At the beginning of the abdominal symptoms, PCT levels increased in both group, compared to those immediately after cardiac surgery. The PCT increasing resulted much more evident in patients presenting with intestinal necrosis - Group B (20.65 ng/ml [IQR8.47-34.5] vs. 4.31 ng/ml [IQR 8.47-34.5], p <0.05), rather than in those with diffuse ischemia - Group A (13.25 ng/ml [IQR 5.97-27.65] vs. 10.4 ng/ml [IQR 3.68-14.05], p 0.260). This trend was confirmed in the subgroup of patients undergoing CVVHD and in patients who experience AMI recurrence.

CONCLUSIONS

Increasing PCT values after cardiac surgery are proportional to the severity of wall ischemia and high levels of PCT are predictive of intestinal necrosis. Routine PCT monitoring after cardiac surgery should be considered extremely useful in suggesting the possibility of abdominal complications, alerting medical staff to the need of prompt treatment.

Procalcitonin in special patient populations: Guidance for antimicrobial therapy

PURPOSE

Procalcitonin (PCT) is an endogenous hormone that increases reliably in response to bacterial infection, and measurement of serum PCT levels is recommended to help guide antimicrobial therapy. The utility of PCT assessment in special patient populations (eg, patients with renal dysfunction, cardiac compromise, or immunocompromised states and those undergoing acute care surgery) is less clear. The evidence for PCT-guided antimicrobial therapy in special populations is reviewed.

SUMMARY

In the presence of bacterial infection, nonneuroendocrine PCT is produced in response to bacterial toxins and inflammatory cytokines, resulting in markedly elevated levels of serum PCT. Cytokine induction in nonbacterial inflammatory processes activated by acute care surgery may alter the interpretation of PCT levels. The reliability of PCT assessment has also been questioned in patients with renal dysfunction, cardiac compromise, or immunosuppression. In many special populations, serum PCT may be elevated at baseline and increase further in the presence of infection; thus, higher thresholds for diagnosing infection or de-escalating therapy should be considered, although the optimal threshold to use in a specific population is unclear. Procalcitonin-guided antimicrobial therapy may be recommended in certain clinical situations.

CONCLUSION

Procalcitonin may be a reliable marker of infection even in special populations with baseline elevations in serum PCT. However, due to unclear threshold values and the limited inclusion of special populations in relevant clinical trials, PCT levels should be considered along with clinical criteria, and antibiotics should never be initiated or withheld based on PCT values alone. Procalcitonin measurement may have a role in guiding de-escalation of antibiotic therapy in special populations; however, the clinician should be aware of disease states and concomitant therapies that may affect interpretation of results.

Removal of Procalcitonin and Selected Cytokines during Continuous Veno-Venous Hemodialysis Using High Cutoff Hemofilters in Patients with Sepsis and Acute Kidney Injury

INTRODUCTION

The purpose of this study was to evaluate the impact of continuous veno-venous hemodialysis (CVVHD) using high cutoff (HCO) hemofilters on the removal of procalcitonin (PCT), and other inflammatory markers in the treatment of patients during septic shock with acute kidney injury (AKI).

MATERIALS AND METHODS

Thirty-six patients with septic shock and AKI were included in the study. Before and after the 24-h HCO-CVVHD, PCT, native C-reactive protein (CRP) and cytokines (interleukin-1β, interleukin-6, interleukin-12, interleukin-17, tumor necrosis factor-α) in serum and effluent were assessed.

RESULTS

After the HCO-CVVHD serum concentrations of PCT, CRP and selected cytokines were significantly lower. The decrease in PCT was bigger than in CRP (p = 0.007). The change in PCT concentration was significantly influenced by PCT and IL-17 clearances (R2 = 0.525; p < 0.001).

CONCLUSION

In contrast to the native CRP, monitoring of PCT during HCO-CVVHD is less useful because it reflects the clearance of this marker and anti-inflammatory effectiveness of the method.

Organ dysfunction during continuous veno-venous high cut-off hemodialysis in patients with septic acute kidney injury: A prospective observational study

Background

Continuous veno-venous hemodialysis with high cut-off membranes (HCO-CVVHD) removes inflammatory mediators involved in organ dysfunction during sepsis. The aim of the present study was to assess the variations in SOFA score and identify early predictors of short-term mortality in a cohort of patients with septic shock, treated with HCO-CVVHD for acute kidney injury (AKI).

Methods

An observational prospective multicenter cohort study was conducted in four mixed medical-surgical ICUs. Thirty-eight patients with septic shock and AKI (KDIGO stage≥1) treated with HCO-CVVHD have been included in this study. Patients were divided into Survivors and non-Survivors according to mortality observed at 72^nd hr of treatment. The variation of SOFA scores and clinical/biochemical parameters were described over time for the entire population and specifically for Survivors and non-Survivors. Similarly, circulating inflammatory mediators (as IL-6, TNF-a and IL-10) were described over time. A logistic regression analysis was used to identify the baseline clinical and biochemical parameters associated with 72 hrs-ICU mortality.

Results

Overall, the mean SOFA score was 12±3 at baseline, 10.9±3 at 6hrs, 9.8±3 at 12hrs, 8.9±3.3 at 24 hrs, and 8±3.5 at 48 hrs after HCO-CVVHD initiation; and 6.5±2.7 at 24 hrs and 6.6±3 at 48 hrs after HCO-CVVHD discontinuation. In the multivariate regression analysis, baseline serum lactate levels and AKI stage independently correlated with short-term mortality during HCO-CVVHD. A significant reduction was observed in circulating levels of TNFα and IL-6 among Survivors.

Conclusions

SOFA score significantly decreased early after initiation of HCO-CVVHD in patients with septic AKI. Baseline lactate levels and the AKI stage resulted to be associated to 72 hrs-ICU-mortality.

Presepsin teardown - pitfalls of biomarkers in the diagnosis and prognosis of bacterial infection in cirrhosis

AIM

To evaluate the diagnostic and prognostic value of presepsin in cirrhosis-associated bacterial infections.

METHODS

Two hundred and sixteen patients with cirrhosis were enrolled. At admission, the presence of bacterial infections and level of plasma presepsin, serum C-reactive protein (CRP) and procalcitonin (PCT) were evaluated. Patients were followed for three months to assess the possible association between presepsin level and short-term mortality.

RESULTS

Present 34.7 of patients had bacterial infection. Presepsin levels were significantly higher in patients with infection than without (median, 1002 pg/mL vs 477 pg/mL, P < 0.001), increasing with the severity of infection [organ failure (OF): Yes vs No, 2358 pg/mL vs 710 pg/mL, P < 0.001]. Diagnostic accuracy of presepsin for severe infections was similar to PCT and superior to CRP (AUC-ROC: 0.85, 0.85 and 0.66, respectively, P = NS for presepsin vs PCT and P < 0.01 for presepsin vs CRP). At the optimal cut-off value of presepsin > 1206 pg/mL sensitivity, specificity, positive predictive values and negative predictive values were as follows: 87.5%, 74.5%, 61.8% and 92.7%. The accuracy of presepsin, however, decreased in advanced stage of the disease or in the presence of renal failure, most probably because of the significantly elevated presepsin levels in non-infected patients. 28-d mortality rate was higher among patients with > 1277 pg/mL compared to those with ≤ 1277 pg/mL (46.9% vs 11.6%, P < 0.001). In a binary logistic regression analysis, however, only PCT (OR = 1.81, 95%CI: 1.09-3.01, P = 0.022) but neither presepsin nor CRP were independent risk factor for 28-d mortality after adjusting with MELD score and leukocyte count.

CONCLUSION

Presepsin is a valuable new biomarker for defining severe infections in cirrhosis, proving same efficacy as PCT. However, it is not a useful marker of short-term mortality.

Linezolid extracorporeal removal during haemodialysis with high cut-off membrane in critically ill patients

Continuous venovenous haemodialysis with high cut-off membrane (HCO-CVVHD) is often used in critically ill septic patients with acute kidney injury (AKI) to sustain renal function and to remove circulating inflammatory mediators. The aim of this study was to analyse the extracorporeal removal of linezolid and related alterations in pharmacokinetic/pharmacodynamic (PK/PD) parameters during HCO-CVVHD. Three critically ill septic patients with AKI, treated with linezolid and HCO-CVVHD, were prospectively observed. To calculate the extracorporeal clearance of linezolid and the PK parameters, effluent, pre-filter and post-filter samples were contemporaneously collected before linezolid infusion, just after 1-h infusion (maximum serum concentration; C(max)), at 3 h and 6 h after dosing, and before the next dose (trough serum concentration; C(min)). Linezolid C(max) and C(min) (pre-filter) ranged from 10.4-23.5 mg/L and from 2.9-10.3 mg/L. The dialysate saturation coefficient was 0.66-0.85 and the extracorporeal clearance with a diffusive dose of 35 m L/kg/h ranged from 2.1-2.5 L/h. Total linezolid clearance was between 1.7 L/h and 6.3 L/h. The total area under the plasma concentration-time curve (AUC0-∞) ranged from 95.1 mgh/L to 352.9 mgh/L, in accordance with the different clinical conditions. AUCfree/MIC ratios were always <85 for an MIC of 4.0 mg/L, and two of three patients did not reach the optimal PK/PD target of ≥85 even when using an MIC of 2.0 mg/L. Although extracorporeal clearance may affect linezolid total clearance, the clinical features of critically ill septic patients appear to be mainly responsible for the high variability of linezolid serum concentrations.

Role of hemodialysis with high cut-off membranes in a patient with a non-recognized leishmaniasis

BACKGROUND

We report here a case of a woman affected by fever, weight loss, splenomegaly, and leucopenia associated with trombocytopenia, transferred to the intensive care unit with acute kidney injury and septic shock.

METHODS

Patient was treated with high cut-off continuous veno-venous hemodialysis (HCO-CVVHD).

RESULTS

During treatment, the patient experienced a stable improvement in the hemodynamic, pulmonary function and tissue perfusion parameters. After 48 h of treatment, significant reductions in SOFA score (from 12, before starting the procedure, to 6) and in serum inflammatory mediators (as IL-6, from 599-568 pg/ml) were observed. Leishmania infection was identified as responsible of the septic condition only 48 h after removing hemodialysis. Antiprotozoal therapy was begun and the patient discharged.

CONCLUSIONS

By supporting the renal function and reducing systemic inflammation, HCO-CVVHD could be a useful bridge therapy. This procedure allowed the medical team to gain sufficient time to diagnose the type of infection and begin an etiological therapy.

Cytokine removal with high cut-off membrane: review of literature

During the last decade, blood purification therapies have been proposed as an effective therapy to control the cytokines dysregulation in systemic inflammatory syndromes. Among them, the treatment with high cut-off membranes is characterized by larger pore size and more effective clearance for middle molecular weight molecules (cytokines). In this paper, we performed a thoughtful review of the literature on HCO being used for blood purification indications in all systemic inflammation syndromes. Clinical and experimental studies show that the use of high effluent flows in a pure diffusive treatment effectively removes serum cytokines with a safe profile in albumin clearance. In clinical studies, the removal of these inflammatory mediators is associated with a significant improvement in hemodynamic condition, oxygenation indices, and organ dysfunction.