Autologous priming technique to reduce blood transfusion in pediatric cardiopulmonary bypass

Excessive hemodilution during cardiopulmonary bypass is associated with decreased oxygen carrying capacity, edema, and organ dysfunction. The use of blood products is often necessary to prime the extracorporeal circuit for pediatric cardiac surgical patients. However, the use of blood products carries serious risks both in the acute and long-term aspects of patient care. Autologous priming of the extracorporeal circuit used in conjunction with ultrafiltration, pharmacologic manipulation, and cell salvage may decrease the need for blood transfusion in the pediatric cardiac surgical population. We have developed a technique that enables us to perform transfusionless complex congenital heart repair targeting patients as small as 5 kg.     

A technique for autologous priming of the veno-venous bypass circuit during liver transplantation

Orthotopic liver transplantations (OLT) have been associated with significant blood loss and hemodilution, necessitating significant homologous blood component replacement. Increasing administration of homologous blood products has been found to be inversely related to patient and graft survival. Various methods to reduce the amount of blood products patients receive during OLT, such as antifibrinolytic therapy, thromboelastography-guided transfusion, phlebotomy, reduced central venous pressures intraoperatively, and the use of the veno-venous bypass (VVB) circuit, have been explored.The asanguineous priming volume of the VVB circuit increases the likelihood of the patient receiving homologous blood products due to hemodilution. It was reasoned that autologous priming of the VVB circuit in OLT surgery was a plausible adjunctive blood conservation technique given its application to the extracorporeal circuit during cardiac surgery. We describe our technique of modifying the VVB circuit for autologous priming. This technique adds minimal risk and a small amount of cost to the procedure, requires slightly more communication among members of the surgical team, and with proper sequencing, adds no additional length to the surgical procedure. It is recommended that this technique be considered for addition to the arsenal of blood conservation techniques when VVB is used during OLT.     

心脏手术中使用自体血回输装置与术后感染的相关性研究

目的观察在体外循环心脏直视手术中,应用自体血洗涤回输器(CellSaver)对自体血进行洗涤、浓缩后回输与术后炎症反应及感染之间的关系。方法随机选择40例体外循环直视下心脏手术患者,25例使用CellSaver作为研究组(CS组),15例未使用CellSaver作为对照组(NCS组)。结果CS组较NCS组显著减少输血量。两组各采样时点C-反应蛋白(CRP)均明显升高,以术后第2天为峰值,组间差异无统计学意义。两组间中性粒细胞绝对值及百分数、白介素-6(IL-6)及肿瘤坏死因子-α(TNF-α)、术后3d最高体温、感染率之间差异无统计学意义。细菌学资料均阴性。结论在体外循环术中应用CellSaver进行自体血回输,不会加重术后全身炎症反应,对术后感染率无明显影响。     

逆行自体血预充方法用于心肺转流先心病手术血液保护的效果

目的探讨逆行自体血预充技术(RAP)在心肺转流(CPB)先心病手术中的血液保护效果。方法 20例先心病手术患者,随机分为对照组(n=10)和RAP组(n=10)。对照组采用常规的预充方法,RAP组采用逆行自体血预充技术。记录CPB前、CPB 15min、停CPB后1h、术后24h的Hb、Hct和血乳酸(Lac),并记录预充液量、术中用血量、呼吸机辅助时间、ICU停留时间等。结果两组患者均成功进行CPB心脏手术,无患者死亡,无输血相关并发症。RAP组预充液量明显少于对照组(P0.01)。CPB 15 min和停CPB后1hRAP组Hb和Hct均明显高于对照组(P0.05);停CPB后1h和术后24hRAP组Lac明显低于对照组(P0.05)。RAP组围术期用血量明显少于对照组(P0.05)。结论在CPB先心病手术中使用RAP技术可以有效的减少预充液量,减低CPB过程中的血液稀释,改善组织灌注,减低呼吸机辅助时间,减少术中用血量。     

Rat cardiopulmonary bypass model: application of a miniature extracorporeal circuit composed of asanguinous prime

A clinically relevant rat cardiopulmonary bypass (CPB) model would be a valuable tool for investigating pathophysiological and therapeutic strategies on bypass. Previous rat CPB models have been described in the literature; however, they have many limitations, including large circuit surface area, the inability to achieve full bypass, and donor blood requirements for prime. Therefore, we have established a rat CPB model designed to overcome these limitations. The miniature circuit consisted of a filtered reservoir, heat exchanger, membrane oxygenator (surface area = 0.02 m2) with a static priming volume of 2.8 mL, and an inline blood gas monitor. The circuit was primed with 9.5+/-0.5 mL of crystalloid solution and CPB was established on male Sprague-Dawley rats (430-475 g, n = 5) by cannulating the left common carotid artery and the right external jugular vein. The animals were placed on CPB at full flow (111+/-13 mL/kg/ min) for 1 hour and were monitored for and additional 2 hours after the CPB procedure. Hemodynamics, hemoglobin concentration (Hb), and blood gases were analyzed at three time intervals: before, during, and after CPB. The circuit performance was evaluated according to prime volume, compliance, hemodynamic parameters, and gas and heat exchange as described by modified AMMI standards. Data are expressed as mean+/-SD and a repeated-measures analysis of variance with post-Hoc test was used for data comparison between the three time intervals. The ratio of oxygenator surface area to subject body weight for this model is comparable with that of current human adult CPB practice (0.05 m2/kg vs 0.057 m2/kg) Full CPB was achieved and we observed clinically acceptable PaO2, PaCO2, and SvO2 values (209+/-86 mmHg, 25+/-2 mmHg, 78+/-8%, respectively) while on CPB. The use of asanguinous prime did produce statistically significant Hg reduction (15.7+/-0.76 vs. 9.2+/-0.59 g/dL) comparable with clinical practice. No statistically significant differences between pre- and post-CPB hemodynamics and blood gases were found in our study. We have established a miniature circuit consisting of asanquineous prime for a rat CPB model that maintains clinically acceptable results regarding hemodynamic parameters, blood gases, and hemodilution. This model would be valuable for further use in clinically relevant research studies.     

Perioperative fluid and electrolyte management in cardiac surgery: a review

This article can be broken down into three sections. First is a review of extracellular fluid volume management and some of the key physiological principles involved. Second, there is an appraisal of the merits or otherwise of crystalloids and colloids for volume replacement, and finally, a summary of the key points in our appreciation of the behavior of various cations in the perioperative period. In all these areas, there has been much academic endeavor. Sometimes this has generated more heat than light, and the lack of consensus in many areas serves to highlight the need for further work and better understanding.     

Cardiopulmonary bypass recommendations in adults: the northern New England experience

Using a regional cardiopulmonary bypass (CPB) registry, we compared the practice of CPB at eight northern New England institutions to recently published recommendations. We examined CPB practice among 3597 adult patients undergoing isolated coronary artery bypass grafting surgery from January 2004 to June 2005. Registry variables were used to compare regional CPB practice to recommendations on topics of neurologic protection (pH management, avoidance of hyperthermia, minimizing return of pericardial suction blood, aortic assessment, arterial line filtration), maintenance of euglycemia, reduction of hemodilution, and attenuation of the inflammatory response. We report overall regional practice (regional minimum, maximum). All centers used alpha-stat pH management and arterial line filters. Avoidance of hyperthermia (temperature < 37degrees C) was achieved during 23.4% of procedures (regional minimum, 1.5%; maximum, 83.2%). Minimizing return of pericardial suction blood was achieved in 23.7% of cases (0.7%, 93.6%). Aortic assessment was performed during 45.7% of procedures (1.3%, 98.9%). Maintenance of euglycemia (< 200 mg/dL) was accomplished in 82.7% (57.1%, 97.9%) of cases. Hemodilution (hematocrit < 23% on CPB) was lower for men 32.4% (20.6%, 52.3%) than women 77.9% (64.7% 88.9%). Men were less likely to receive red blood cell transfusions in the operating room (11.0%; 1.8%, 20.9%) than women (54.6%; 30.1%, 70.6%). In an effort to attenuate the inflammatory response, surface coated circuits were used in 83.3% of procedures (8.8%, 100%). During this time, gaps existed between regional CPB practice and recently published recommendations. We continue to prospectively measure CPB practice relating to these recommendations to monitor and improve the care provided to our patients.     

Retrograde autologous priming of the cardiopulmonary bypass circuit: safety and impact on postoperative outcomes

OBJECTIVES: Retrograde autologous priming (RAP) is a blood conservation technique used to limit the severity of hemodilution during cardiopulmonary bypass and reduce perioperative transfusions. The aim of this investigation was to examine the safety of RAP and to determine the effect of RAP on adverse outcomes after cardiac surgery. DESIGN: Retrospective cohort study. SETTING: University hospital. PARTICIPANTS: Five hundred fifty-nine undergoing cardiopulmonary bypass. INTERVENTIONS: Data were retrospectively collected on 2 cohorts of adult cardiac surgical patients operated on by a single surgeon. In the RAP group (n = 256), outcome data were analyzed on all subjects over a 2-year period during which RAP was used routinely. This group was compared with a similar cohort of patients undergoing cardiopulmonary bypass over a 2-year period immediately before the introduction of RAP into the clinical practice (no-RAP group, n = 287). MEASUREMENTS AND MAIN RESULTS: In-hospital mortality was not significantly different between the RAP group (2.7%) and the no-RAP group (3.8%, p = 0.636). The incidence of postoperative cardiac arrest was significantly less in the RAP group (1 patient) compared to the no-RAP group (9 patients, p = 0.040). There were no differences between the 2 groups in the incidence of several other postoperative complications, including postoperative delirium (1.6% RAP v 3.1% no RAP), heart block (1.6% RAP v 4.2% no RAP), atrial fibrillation (19.1% RAP v 22.7% no RAP), and requiring postoperative ventilation >24 hours (2.7% RAP v 5.2% no RAP). CONCLUSIONS: The authors observed no evidence of any increase in adverse events in the RAP group of this retrospective cohort study, but they did observe a decrease in the incidence of postoperative cardiac arrest in the RAP group. These findings suggest that RAP is a safe technique and may have a beneficial effect on postoperative outcomes.     

Use of autologous platelet gel in bariatric surgery

Gastric bypass surgery is a common corrective procedure for obesity that is associated with many risks. Recent studies describing the use of autologous platelet gel (APG) have shown promise in preventing certain operative complications and improved healing processes. These improvements have been credited to the concentrated platelets and growth factors present in APG, as well as the native concentrations of fibrinogen. There are numerous applications for the use of APG in surgery, and the list continues to expand. However, little research exists to support the efficacy of APG in bariatric surgery. This case series describes using APG with patients undergoing laparoscopic Roux-en-Y gastric bypass surgery.     

Assessing the effectiveness of retrograde autologous priming of the cardiopulmonary bypass machine in isolated coronary artery bypass grafts

Introduction

Currently, around 35–80% of patients undergoing cardiac surgery in the UK receive a blood transfusion. Retrograde autologous priming (RAP) of the cardiopulmonary bypass circuit has been suggested as a possible strategy to reduce blood transfusion during cardiac surgery.

Methods

Data from 101 consecutive patients undergoing isolated coronary artery bypass grafts (where RAP was used) were collected prospectively and compared with 92 historic patients prior to RAP use in our centre.

Results

Baseline characteristics (ie age, preoperative haemoglobin [Hb] etc) were not significantly different between the RAP and non-RAP groups. The mean pump priming volume of 1,013ml in the RAP group was significantly lower (p<0.001) than that of 2,450ml in the non-RAP group. The mean Hb level at initiation of bypass of 9.1g/dl in patients having RAP was significantly higher (p<0.001) than that of 7.7g/dl in those who did not have RAP. There was no significant difference between the RAP and non-RAP groups in transfusion of red cells, platelets and fresh frozen plasma, 30-day mortality, re-exploration rate and predischarge Hb level. The median durations of cardiac intensive care unit stay and in-hospital stay of 1 day (interquartile range [IQR]: 1–2 days) and 5 days (IQR: 4–6 days) in the RAP group were significantly shorter than those of the non-RAP group (2 days [IQR: 1–3 days] and 6 days [IQR: 5–9 days]).

Conclusions

In the population group studied, RAP did not influence blood transfusion rates but was associated with a reduction in duration of hospital stay.     

A trial of fresh autologous whole blood to treat dilutional coagulopathy following cardiopulmonary bypass in infants

BACKGROUND: Transfusion of fresh whole blood is superior to blood component therapy in correcting coagulopathies in children following cardiopulmonary bypass (CPB); however, a supply of fresh homologous whole blood is difficult to maintain. We hypothesized that transfusion of fresh autologous whole blood obtained prior to heparinization for CPB and infused following CPB would be associated with improved coagulation function when compared with standard therapy. METHODS: A total of 32 infants 5-12 kg undergoing noncomplex open cardiac surgery were randomly assigned to either the treatment or control group. In the treatment group, 15 ml x kg(-1) of autologous whole blood was collected into a CPDA bag prior to heparinization while 15 ml x kg(-1) of 5% albumin was infused intravenously. After reversal of heparin, coagulation tests were drawn in both groups, and the autologous whole blood was infused over 20 min in the treatment group. RESULTS: The treatment group had greater (P < 0.05) improvement in platelet count, prothrombin time, and fibrinogen than the control group. CONCLUSIONS: We conclude that collection of fresh autologous whole blood prior to heparinization and reinfusion following CPB is associated with greater improvement of coagulation status after CPB in infants.