Inflammatory cytokines in pediatric cardiac surgery and variable effect of the hemofiltration process

The effect of pectointercostal fascial block on stress response in open heart surgery

Background

Activation of the hypothalamus-pituitary-adrenal (HPA) axis and inflammatory processes are common forms of stress response. The increased stress response is associated with a higher chance of complications. Open hearth surgery is one of the procedures with a high-stress response. Pectointercostal fascial block (PIFB), as a new pain management option in sternotomy, has the potential to modulate the stress response.

Objective

To determine the effect of PIFB on stress response in open heart surgery.

Methods

This study was a Randomized Controlled Trial on 40 open heart surgery. Patients were divided into two groups, control (20 patients) and PIFB (20 patients). Primary parameters included basal and postoperative TNF-α, basal and post sternotomy ACTH, and basal, 0, and 24 hours postoperative NLR. Secondary parameters include the amount of opioid use, length of the post-operative ventilator, length of ICU stay, and Numeric Rating Scale (NRS) 6, 12, 24, and 48 hours postoperative.

Results

The PIFB group had a decrease in ACTH levels with an average change that was not significantly different from the control group (-57.71 ± 68.03 vs. -129.78 ± 140.98). The PIFB group had an average change in TNFα levels and an average increase in NLR 0 hours postoperative that was not significantly lower than the control group (TNFα: -0.52 ± 1.31 vs. 0.54 ± 1.76; NLR: 12.80 ± 3.51 vs. 14.82 ± 4.23). PIFB significantly reduced the amount of opioid use during surgery, NRS at 6, 12, and 24 hours, and the length of post-operative ventilator use (P < 0.05, CI: 95%).

Conclusion

PIFB has a good role in reducing the stress response of open heart surgery and producing good clinical outcomes.

Common Inflammatory Markers and Outcome After Pediatric Cardiac Surgery With High Thoracic Epidural Anesthesia: A Randomized Controlled Study

Background: High thoracic epidural analgesia (HTEA) plays a pivotal role in reducing stress and neuroendocrine response in cardiac surgeries. Aim: The primary objective is to assess the effect of HTEA, in pediatric cardiac surgery, on inflammatory markers (interleukin [IL]-6, IL-8, and tumor necrosis factor-α). The secondary objectives are to assess its effect on various organ systems, that is, pulmonary (PaO2, P/F ratio), renal (Creatinine clearance, somatic near infrared spectroscopy [NIRS], serum neutrophil gelatinase-associated lipocalin values), cardiac (cardiac index, serum Trop-I, and lactate levels), mechanical ventilation duration, and length of stay in hospital (LOS). Methods: The study included 188 pediatric patients, who underwent, on-pump cardiac surgery randomized into the Epidural Group (n = 92) and Non-Epidural Group (n = 96). After general anesthesia, a 23 G epidural catheter was placed at the T4-5 level with a Bupivacaine infusion while the Non-epidural Group received fentanyl infusion. Blood samples were collected at four-time points, T0(preop), T1(4 h), and on the first and second postoperative days (T2 and T3). Results: The inflammatory markers were reduced, while the outcomes variables of mechanical ventilation (MV) duration had lower values in the epidural group (19.5 h vs 47.3 h, P = .002). LOS was shorter (10.1 days vs 13.3 days, P = .016). pO2, PF ratio, and renal NIRS values were better in the Epidural Gp, while other parameters were comparable. Non-epidural Gp had more complications esp. Acute kidney injury requires RRT. Conclusion: HTEA use in pediatric, on-pump cardiac surgery offers a favorable profile in terms of reduction in the inflammatory markers and positive effect on the organ systems with lesser MV duration and the LOS.

Comparison of Custodiol vs warm blood cardioplegia and conditioning of donor hearts during transportation with the organ care system

Objectives

Cold crystalloid cardioplegia for donor heart harvesting and cold ischemic storage conditions during the transportation is the standard of care during heart transplantation procedure. Organ care system (OCS) was introduced for more prolonged and reliable ex vivo organ management. This study evaluated the two different techniques used for myocardial preservation during the procurement and transportation of the heart using the OCS.

Methods

We performed prospective analysis of 43 patients with heart failure undergoing heart transplantation and using the OCS for donor organ transport. Donor hearts were arrested using blood cardioplegia and conditioning (n = 30) or standard Custodiol (SC) solution ( n = 13). Perfusion and cardiac function parameters were continuously monitored while the donor hearts were perfused in the OCS. Impact of preservation techniques on biochemical parameters and clinical outcomes were evaluated.

Results

All donor hearts had stable perfusion and lactate characteristics in the OCS, with similar measures between the two groups at the beginning of the ex vivo perfusion. Ex vivo heart perfusion mean ending concentration of Interleukin (IL)‐6 and IL‐8 was significantly lower in the blood cardioplegia group compared to the standard care group. Clinical outcomes were comparable between the two groups of patients.

Conclusions

The use of blood cardioplegia and conditioning could be a safe method for myocardial protection in distant procurement and preservation of donor hearts in the OCS.

Modified ultrafiltration during cardiopulmonary bypass and postoperative course of pediatric cardiac surgery

Context:

The use of cardiopulmonary bypass (CPB) provokes the inflammatory responses associated with ischemic/reperfusion injury, hemodilution and other agents. Exposure of blood cells to the bypass circuit surface starts a systemic inflammatory reaction that may causes post-CPB organ dysfunction, particularly in lungs, heart and brain.

Evidence Acquisition:

We investigated in the MEDLINE, PUBMED, and EMBASE databases and Google scholar for every available article in peer reviewed journals between 1987 and 2013, for related subjects to CPB with conventional or modified ultrafiltration (MUF) in pediatrics cardiac surgery patients.

Results:

MUF following separation from extracorporeal circulation (ECC) provides well known advantages in children with improvements in the hemodynamic, pulmonary, coagulation and other organs functions. Decrease in blood transfusion, reduction of total body water, and blood loss after surgery, are additional benefits of MUF.

Conclusions:

Consequently, MUF has been associated with attenuation of morbidity after pediatric cardiac surgery. In this review, we tried to evaluate the current evidence about MUF on the organ performance and its effect on post-CPB morbidity in pediatric patients.

Techniques of extracorporeal cytokine removal: a systematic review of human studies

BACKGROUND AND AIMS

Hypercytokinemia is believed to be harmful and reducing cytokine levels is considered beneficial. Extracorporeal blood purification (EBP) techniques have been studied for the purpose of cytokine reduction. We aimed to study the efficacy of various EBP techniques for cytokine removal as defined by technical measures.

METHOD

We conducted a systematic search for human clinical trials which focused on technical measures of cytokine removal by EBP techniques. We identified 41 articles and analyzed cytokine removal according to clearance (CL), sieving coefficient (SC), ultrafiltrate (UF) concentration and percentage removed.

RESULTS

We identified the following techniques for cytokine removal: standard hemofiltration, high volume hemofiltration (HVHF), high cut-off (HCO) hemofiltration, plasma filtration techniques, and adsorption techniques, ultrafiltration (UF) techniques relating to cardiopulmonary bypass (CPB), extracorporeal liver support systems and hybrid techniques including combined plasma filtration adsorption. Standard filtration techniques and UF techniques during CPB were generally poor at removing cytokines (median CL for interleukin 6 [IL-6]: 1.09 mL/min, TNF-alpha 0.74 mL/min). High cut-off techniques consistently offered moderate cytokine removal (median CL for IL-6: 26.5 mL/min, interleukin 1 receptor antagonist [IL-1RA]: 40.2 mL/min). Plasma filtration and extracorporeal liver support appear promising but data are few. Only one paper studied combined plasma filtration and adsorption and found low rates of removal. The clinical significance of the cytokine removal achieved with more efficacious techniques is unknown.

CONCLUSION

Human clinical trials indicate that high cut-off hemofiltration techniques, and perhaps plasma filtration and extracorporeal liver support techniques are likely more efficient in removing cytokines than standard techniques.

Bicarbonate-buffered ultrafiltration during pediatric cardiac surgery prevents electrolyte and acid-base balance disturbances

Pediatric cardiopulmonary bypass is still a challenge because of electrolyte disturbances and inflammation. Many investigations deal with different types of hemofiltration to reduce these potentially harmful side effects. We tested the hypothesis of whether bicarbonate-buffered hemofiltration of the priming solution minimizes electrolyte and acid-base disturbances during the initiation of cardiopulmonary bypass and whether bicarbonate-buffered hemofiltration performed during cardiopulmonary bypass could reduce cytokine levels. Twenty children younger than 2 years of age (mean age 166 ± 191 days; mean weight 6.42 ± 3.22 kg) scheduled for pediatric cardiac surgery with cardiopulmonary bypass were enrolled in this prospective clinical study. Cardiopulmonary bypass circuits were primed with a bicarbonate-buffered hemofiltration solution, gelatin and 1 unit of packed red blood cells. The priming was hemofiltered using an ultrahemofilter until approximately 1000 mL of ultrafiltrate was restored with the buffered solution. Further hemofiltration was performed throughout the whole bypass time, especially during rewarming. Blood gas analyses and inflammatory mediators were monitored during the operation. Blood gas analysis results after initiation of cardiopulmonary bypass and throughout the entire study remained within the physiologic ranges. Even potassium decreased from 4.0 ± 0.3 to 3.4 ± 0.4 mmol.l−1 after initiation of cardiopulmonary bypass. Plasma levels of tumor necrosis factor alpha decreased significantly (47 ± 44 vs. 24 ± 21 pg.mL−1) whereas complement factor C3a (5.0 ± 2.9 vs. 16.8 ± 6.6 ng.mL−1) and interleukin-6 (7.3 ± 15.2 vs. 110 ± 173 pg.mL−1) increased despite hemofiltration. In conclusion, this study shows that bicarbonate-buffered ultrafiltration is an efficient, simple and safe method for performing hemofiltration, both of the priming solution and during the entire bypass time. The use of a physiological restitution solution prevents electrolyte and acid-base balance disturbances. The elimination of inflammatory mediators seems to be as effective as other ultrafiltration methods.

Cardiac Surgery and Sickle Cell Disease

Three patients with homozygous sickle cell disease underwent successful open heart surgery for multivalvular lesions. Details of the surgical technique and the necessary precautions are described. Exchange transfusion was implemented in all cases. Crucial issues in cardiac surgical management to avoid or at least minimize vasoocclusive crisis and associated complications are discussed.

Continuous hemodiafiltration during cardiopulmonary bypass in infants

The homologous blood prime in cardiopulmonary bypass circuits contributes a significant electrolyte and metabolite load in small infants. The efficacy of hemofiltration and continuous hemodiafiltration of the blood prime in preventing metabolic disturbances in small infants was compared in two groups of 60 patients each. Blood pH, base excess, and calcium concentrations decreased during cardiopulmonary bypass in the hemofiltration group. The acid-base balance was well preserved during cardiopulmonary bypass by continuous hemodiafiltration. This therapeutic strategy may confer an advantage in maintaining more physiological conditions during cardiopulmonary bypass in small infants.

Effect of inhaled corticosteroid on pulmonary injury and inflammatory mediator production after cardiopulmonary bypass in children

OBJECTIVE

To determine whether inhaled steroid administration after cardiopulmonary bypass will attenuate pulmonary inflammation and improve lung compliance and oxygenation.

DESIGN

Randomized, prospective, double-blind, placebo-controlled clinical trial.

SETTING

Children's Hospital of Michigan, intensive care unit.

PATIENTS

Thirty-two children <2 yrs of age with congenital heart disease requiring cardiopulmonary bypass.

INTERVENTIONS

Participants were randomly assigned to one of two groups. Group 1 (n = 16) received an inhaled steroid, Budesonide (0.25 mg/2 mL), and group 2 (n = 16) received an inhaled placebo (2 mL of inhaled 0.9% saline). The nebulizations were given at the end of cardiopulmonary bypass, 6 hrs after cardiopulmonary bypass, and 12 hrs after cardiopulmonary bypass. Two hours after each nebulization, bronchoalveolar lavage for interleukin-6 and interleukin-8 was collected.

MEASUREMENTS AND MAIN RESULTS

The concentrations of interleukin-6 and interleukin-8 in the bronchoalveolar lavage increased in both groups after cardiopulmonary bypass. Interleukin-6 peaked 2 hrs after cardiopulmonary bypass and was decreasing by 14 hrs after cardiopulmonary bypass. However, administration of corticosteroid did not affect the production of interleukin-6 when compared with the placebo group (378 +/- 728 vs. 287 +/- 583 pg/mL pre-cardiopulmonary bypass, 1662 +/- 1410 vs. 1584 +/- 1645 pg/mL at the end of cardiopulmonary bypass, 2601 +/- 3132 vs. 3677 +/- 4935 pg/mL 2 hrs after cardiopulmonary bypass, and 1792 +/- 3100 vs. 1283 +/- 1344 pg/mL 14 hrs after cardiopulmonary bypass; p > .05). Likewise, interleukin-8 in the lavage fluid was similar in both the placebo and steroid groups at all time points (570 +/- 764 vs. 990 +/- 1147 pg/mL pre-cardiopulmonary bypass, 1647 +/- 1232 vs. 1394 +/- 1079 pg/mL at the end of cardiopulmonary bypass, 1581 +/- 802 vs. 1523 +/- 852 pg/mL 2 hrs after cardiopulmonary bypass, and 1652 +/- 1069 pg/mL vs. 1808 +/- 281 pg/mL 14 hrs after cardiopulmonary bypass; p > .05). Lung compliance and oxygenation were similar in both groups.

CONCLUSIONS

Cardiopulmonary bypass is associated with a pulmonary inflammatory response. Inhaled corticosteroid did not affect the pulmonary inflammatory response as measured by interleukin-6 and interleukin-8 concentrations in the lung lavage after cardiopulmonary bypass. Pulmonary mechanics and oxygenation were not improved by the use of inhaled corticosteroid.

Extracorporeal membrane oxygenation and extracorporeal albumin dialysis in pediatric patients with sepsis and multi-organ dysfunction syndrome

Extracorporeal membrane oxygenation (ECMO) is used in managing patients with potentially reversible cardio-respiratory failure refractory to conventional methods. Multiorgan dysfunction syndrome (MODS), usually due to sepsis, remains the main cause of mortality in such patients. We report a series of six pediatric patients with sepsis-induced MODS where extracorporeal albumin dialysis (EAD) was used while the patients were on ECMO. The age of the patients ranged between 1 month and 17 years. The mean pediatric index of mortality (PIM) score at admission was 67.5%. All these patients further deteriorated with MODS and EAD was used as rescue therapy. At institution of EAD, 4 patients had dysfunction of 4 organs and 2 patients had dysfunction of 5 organs. The number of EAD cycles ranged between 1 and 3. Three out of the 6 patients (50%) survived to discharge from the intensive care unit and two of the six patients (33%) survived to hospital discharge. According to our previous experience and published results, all these patients would have been expected to die. The present results suggest that EAD may prove to have a role in the treatment of pediatric patients with sepsis-induced MODS. Further research is required to identify the group of patients who would benefit most by EAD as well as understand the clearance of inflammatory mediators and other mechanisms involved with the use of EAD.

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