Mass transfer, clearance and plasma concentration of procalcitonin during continuous venovenous hemofiltration in patients with septic shock and acute oliguric renal failure

Effect of CytoSorb Coupled with Hemodialysis on Interleukin-6 and Hemodynamic Parameters in Patients with Systemic Inflammatory Response Syndrome: A Retrospective Cohort Study

Excessive release of cytokines during systemic inflammatory response syndrome (SIRS) often leads to refractory hypotension and multiple organ failure with high mortality. Cytokine removal with hemoadsorption has emerged as a possible adjuvant therapy, but data on interleukin-6 (IL-6) reduction and outcomes in clinical practice are scarce. We aimed to evaluate the effect of CytoSorb hemoadsorption on laboratory and clinical outcomes in shocked patients with SIRS. We designed a retrospective analysis of all patients with SIRS treated with CytoSorb in intensive care units (ICU). IL-6, laboratory and hemodynamic parameters were analyzed at approximate time intervals during CytoSorb treatment in the whole cohort and in a subgroup with septic shock. Observed and predicted mortality rates were compared. We included 118 patients with various etiologies of SIRS (septic shock 69%, post-resuscitation shock 16%, SIRS with acute pancreatitis 6%, other 9%); in all but one patient, CytoSorb was coupled with renal replacement therapy. A statistically significant decrease in IL-6 and vasopressor index with an increase in pH and mean arterial pressure was observed from 6 h onward. The reduction of lactate became significant at 48 h. Results were similar in a subgroup of patients with septic shock. Observed ICU and in-hospital mortalities were lower than predicted by Sequential Organ Failure Assessment (SOFA) (61% vs. 79%, p = 0.005) and Acute Physiology and Chronic Health Evaluation (APACHE) II (64% vs. 78%, p = 0.031) scores. To conclude, hemoadsorption in shocked patients with SIRS was associated with a rapid decrease in IL-6 and hemodynamic improvement, with improved observed vs. predicted survival. These results need to be confirmed in a randomized study.

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.

Efficacy of Coupled Plasma Filtration Adsorption in Treating Patients with Severe Intra-Abdominal Infection: A Retrospective Study

Background: Coupled plasma filtration adsorption (CPFA) is an extracorporeal treatment based on plasma filtration associated with an adsorbent cartridge and hemofiltration. CPFA is able to remove inflammatory mediators and it has been used to treat severe sepsis and multiple organ dysfunction. Limited experience exists on the use of CPFA in treating intra-abdominal infection (IAI). Methods: In this study, the efficacy of CPFA in treating patients with severe IAI and liver failure was evaluated in a retrospective analysis of 76 cases. Results: The survival rate of patients treated with CPFA was 82.6%, with effective removal of endotoxin and inflammatory mediators. Conclusion: Our data suggest that CPFA can be safely and effectively used to lower morbidity and mortality rates of patients with severe IAI and liver failure.

Effects of zero-balanced ultrafiltration on procalcitonin and respiratory function after cardiopulmonary bypass

The abnormal conditions to which blood is subjected during cardiopulmonary bypass (CPB) trigger an activation of the inflammatory response and cause pulmonary dysfunction. It has been suggested that high-volume, zero-balanced ultrafiltration (ZBUF) facilitates clearance of inflammatory mediators and improves post-operative pulmonary function. Procalcitonin, a newly discovered inflammatory mediator, has been found to be increased after CPB and has been proven to be an appropriate parameter for predicting pulmonary dysfunction secondary to CPB. The aim of this study was to investigate the effects of zero-balanced ultrafiltration (ZBUF) on procalcitonin (PCT) and respiratory function of infants with Tetralogy of Fallot (TOF) after CPB. Twenty infants with TOF undergoing open-heart total surgical correction were randomly assigned to two groups. The trial group was given ZBUF (50 ml/kg) and conventional ultrafiltration (CUF), while the control group was given CUF only. Plasma PCT and pulmonary function were monitored and compared between the two groups before the operation (T1), before rewarming (T2), at the end of the operation (T3), and at 12 h, 24 h and 48 h after the operation (T4-T6). PCT was decreased in the trial group between 12 h and 48 h post-operatively, but the differences did not reach statistical significance. The trial group's pulmonary compliance was higher at 12 h post-operatively ( p < 0.05). Oxygenation index was increased in the trial group at the end of the operation and 12 h post-operatively ( p > 0.05). Intubation time was shorter in the trial group ( P < 0.01). A positive correlation was found between peak PCT concentration and intubation time. ZBUF appeared to improve ventilation and shorten intubation time. The improved respiratory function may be due to the lower plasma PCT. Perfusion (2007) 22, 339—343.

Extreme Procalcitonin Elevation without Proven Bacterial Infection Related to Amphetamine Abuse

Systemic inflammatory response with rhabdomyolysis and consequent multiorgan failure is a known sequela of psychotropic drug abuse. However, in cases with uncertain past medical history the initial diagnosis can be challenging. Here we report the case of a 21-year-old male who was admitted to the intensive care unit with severe neurological impairment caused by amphetamine intoxication. First laboratory investigations revealed extremely high serum procalcitonin (PCT) levels reaching a maximum concentration of 1640 ng/mL on the second day of observation. Although PCT has high sensitivity and specificity in differentiating bacterial sepsis from nonbacterial inflammation, our case report shows for the first time that it can be extremely elevated following serious amphetamine intoxication without bacterial infection.

The effect of Prometheus device on laboratory markers of inflammation and tissue regeneration in acute liver failure management

Prometheus, based on modified fractionated plasma separation and adsorption (FPSA) method, is used in the therapy of acute liver failure as a bridge to liver transplantation. As the therapeutic effect of Prometheus is caused not only by the elimination of terminal metabolites, the aim of the study was to identify the effect of FPSA on the levels of cytokines and markers of inflammation and liver regeneration. Previous studies assessing cytokine levels involved mostly acute-on-chronic liver failure patients. Data concerning markers of inflammation and liver regeneration are not published yet. Eleven patients (three males, eight females) with acute liver failure were investigated. These patients underwent 37 therapeutic sessions on Prometheus device. Before and after each treatment, the plasma levels of selected cytokines, tumor necrosis factor alpha (TNFα), C-reactive protein (CRP), procalcitonin (PCT), hepatocyte growth factor (HGF), and α(1) fetoprotein, were measured, and the kinetics of their plasma concentrations was evaluated. Before the therapy, elevated levels of interleukin (IL)-6, IL-8, IL-10, TNFα, CRP, and PCT were detected. The level of TNFα, CRP, PCT, and α(1) fetoprotein decreased significantly during the therapy. In contrast, an increase of HGF was detected. The decline of IL-6, IL-8, and IL-10 concentrations was not significant. Our results show that Prometheus is highly effective in clearing inflammatory mediators responsible for systemic inflammatory response syndrome and affects the serum levels of inflammatory and regeneration markers important for management of acute liver failure.

Allergic airway inflammation initiates long-term vascular remodeling of the pulmonary circulation

BACKGROUND

Asthma and allergic airway inflammation are associated with persistent structural alterations in the bronchi, i.e. airway remodeling. Previous studies have shown that during allergic airway inflammation, similar structural alterations may also be evoked in the pulmonary circulation. However, it remained unknown whether remodeling of the pulmonary circulation is as persistent as airway remodeling. The aim of this study is to investigate the reversibility and resolution of vascular remodeling, induced by allergic airway inflammation.

METHODS

A validated mouse model of allergic airway inflammation, utilizing ovalbumin as allergen, was employed. Animals were sacrificed 1 day, 1 week or 1 month after the last allergen exposure, and different parameters of remodeling (smooth muscle mass, proliferation of smooth muscle cells and endothelial cells as well as number of myofibroblasts and procollagen-I-producing cells) were investigated and quantified histologically.

RESULTS

Allergen exposure resulted in allergic airway inflammation characterized by a transient leukocyte infiltration and in structural alterations in both airway and vascular compartments. The increase in vascular smooth muscle mass and endothelial proliferation persisted at 1 month after the last allergen exposure. The other parameters and cellular inflammatory response returned to baseline within 1 month after the last allergen challenge.

CONCLUSIONS

Based on the findings in this study, we conclude that acute allergic airway inflammation, although being initiated from the airways, is able to evoke similar long-term structural alterations in pulmonary vessels as described for bronchi.

Hemofiltration in sepsis and systemic inflammatory response syndrome: the role of dosing and timing

INTRODUCTION

The benefit of hemofiltration (HF) as an adjunctive treatment of sepsis or the systemic inflammatory response syndrome (SIRS) in critically ill patients is a subject of severe debate. Firm conclusions on this subject are hampered by the heterogeneity in study populations and HF treatments, and the lack of adequately sized randomized controlled clinical trials. The aim of this review was to determine the importance of ultrafiltration dose and timing on the physiologic and clinical effects of HF in sepsis and SIRS. In addition, we discuss the issue of filter pore size.

METHODS

Literature search was done in Embase and PubMed database for animal and human studies.

RESULTS

Animal studies suggest beneficial effects of HF on hemodynamics; gas exchange; sepsis-induced immunoparalysis; histology of gut, lung, and kidney; and (short-term) survival. These effects were more prominent with "very high" ultrafiltrate rates (> or =100 mL/kg per hour) and early initiation of HF (ie, before or very early after the septic challenge). Three small randomized studies and 3 observational studies in patients with sepsis or SIRS show beneficial effects of short-term or pulse HF using very high ultrafiltrate rates and/or early initiation of HF on physiologic endpoints and survival. However, the studies were underpowered for survival. The first observations of high permeability HF (pore size, about 10 nm; in vitro cutoff, 100 kd) are promising, but so far, it has not been sufficiently examined to allow strong conclusions.

CONCLUSION

Human and animal studies suggest that early initiation and high ultrafiltrate volumes are determinants of the beneficial physiologic and clinical effect of HF in sepsis and SIRS. As yet, the evidence in humans is too low to recommend HF as an adjunctive therapy for critically ill patients with sepsis or SIRS. Regarding the many uncertainties about optimal volume (high or very high) and type of membrane, clinical studies should first focus on endpoints as recovery from organ failure and length of treatment before survival studies are started.

Year in review: Critical Care 2004 - nephrology

We summarize all original research in the field of critical care nephrology published in 2004 or accepted for publication in Critical Care and, when considered relevant or directly linked to this research, in other journals. Articles were grouped into four categories to facilitate a rapid overview. First, regarding the definition of acute renal failure (ARF), the RIFLE criteria (risk, injury, failure, loss, ESKD [end-stage kidney disease]) for diagnosis of ARF were defined by the Acute Dialysis Quality Initiative workgroup and applied in clinical practice by some authors. The second category is acid-base disorders in ARF; the Stewart-Figge quantitative approach to acidosis in critically ill patients has been utilized by two groups of researchers, with similar results but different conclusions. In the third category - blood markers during ARF - cystatin C as an early marker of ARF and procalcitonin as a sepsis marker during continuous venovenous haemofiltration were examined. Finally, in the extracorporeal treatment of ARF, the ability of two types of high cutoff haemofilters to influence blood levels of middle- and high-molecular-weight toxins showed promise.

Measurements in the intensive care unit: what do they mean?

Intensivists depend upon a large number of measurements to make daily decisions in the ICU. However, the reliability of these measures may be jeopardized by the effects of therapy. Moreover, in critical illness, what is normal is not necessarily optimal. Procalcitonin, a putative marker of occult infection, is emerging as a valuable diagnostic marker in the ICU. Although questions remain regarding its specificity, an increasing body of work suggests that it is reliably elevated in the setting of infection. As demonstrated by Level and colleagues in this issue of Critical Care, its utility as a diagnostic marker is not affected by concomitant hemodialysis.