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ABSTRACT: Coagulopathy is common after cardiopulmonary bypass (CPB), and platelet dysfunction is frequently considered to be a major contributor to excessive bleeding. Exposure to hypothermia may exacerbate the platelet function defect. We assessed platelet function during and after deep hypothermia with multiple electrode aggregometry (Multiplate(®); Verum Diagnostica GmbH, Munich, Germany).
Twenty adult patients undergoing pulmonary endarterectomy for chronic pulmonary hypertension were cooled on CPB to 20°C and deep hypothermic arrest was used to facilitate surgery. We analyzed platelet aggregation in whole blood samples at 12 measuring points during and after the procedure. Platelet aggregation was stimulated via the thrombin receptor (TRAPtest) at the patient's actual body temperature (AUC-CT) and after rewarming the samples to 37°C (AUC-37). In addition, we tested samples at 2 time points after 2 minutes of in vitro incubation with 20 μg protamine (0.067 μg/μL). Results are expressed as area under the aggregation curve (AUC).
Cooling resulted in a marked decrease of platelet aggregation to a minimum AUC-CT of 20.5 (95% confidence interval [CI] 8.9-32.1) at 20°C body temperature. AUC-CT was significantly different from baseline (92.8, 95% CI 82.5-103.1) for temperatures of ≤28°C (P < 0.001), whereas the change in AUC-37 only became significant at the lowest body temperature (59.4, 95% CI 41.3-77.4). After rewarming to 36°C, AUC-CT and AUC-37 had recovered to 67.6 (95% CI 53.9-81.3) and 71.7 (95% CI 52.5-90.8), respectively. The mean AUC-CT was significantly lower than the mean AUC-37 from cooling at 28°C to warming at 24°C inclusive, and the relationship with temperature during cooling was significantly different between AUC-CT and AUC-37 (regression coefficients 4.7 [95% CI 4.2-5.2] vs 1.3 [95% CI 0.7-1.9]; P < 0.0001). After administration of protamine, mean aggregation decreased significantly for both measurements by 38.2 (95% CI -27.9 to -48.5; P < 0.001) and 44.5 (95% CI -58.5 to -30.5; P < 0.001), respectively. Similarly, adding protamine in vitro resulted in a decrease of mean aggregation by 35.1 (95% CI -71.0 to 0.8; P = 0.055) when measured after administration of heparin, and 56.5 (95% CI -94.5 to -18.5; P = 0.005) at the end of CPB.
Platelet aggregation, assessed by multiple electrode aggregometry (Multiplate), was severely affected during deep, whole-body hypothermia. This effect was partially reversible after rewarming, and was distinct from a general decline of platelet aggregation during CPB. Protamine also caused a significant decrease in platelet aggregation in vivo and in vitro.
Anesthesia and analgesia 03/2013; 116(3):533-40. · 3.08 Impact Factor
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Journal of cardiothoracic and vascular anesthesia 06/2011; 25(3):505-8. · 1.06 Impact Factor
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ABSTRACT: Pulmonary endarterectomy (PEA) is an effective and potentially curative treatment for chronic thrombo-embolic pulmonary hypertension (CTEPH). The postoperative course after PEA is accompanied by a number of complications, which contribute to the high rate of early postoperative mortality. Markers allowing the early detection of infectious complication during the postoperative period may be of major clinical importance. The aim of the prospective study was to analyse a predictive value of five inflammatory markers to recognise inflammatory complications accompanying PEA before the first clinical signs of infection.
Eighty-two patients with CTEPH, who underwent PEA using cardiopulmonary bypass (CPB) and deep hypothermic circulatory arrest (DHCA), were included into the study. Procalcitonin (PCT), tumour necrosis factor-α, interleukin (IL)-6, IL-8 and C-reactive protein arterial concentrations were measured before sternotomy and repeatedly up to 72h after the end of surgery. Haemodynamic parameters, infectious and non-infectious complications were recorded.
Postoperative course was uncomplicated in 59/82 patients (group 1). Fourteen out of 82 patients (group 2) developed an infection in the first 3 days after surgery (bronchopneumonia, n = 9; bacterial sepsis, n = 5). Nine out of 82 patients (group 3) developed non-infectious complications in the same period. PCT and IL-6 were the only significant independent predictors of infection in days 1-3 after PEA. The area under receiver operating characteristic (ROC) curve calculated for PCT to predict postoperative infection was 0.83 (95% confidence interval (CI): 0.74-0.92) compared with 0.74 (95% CI: 0.68-0.81) for IL-6. With the cut-off 2.3 ng ml(-1), the test characteristics of PCT were as follows: sensitivity, 86%; specificity, 83%; negative predictive value, 92%; and positive predictive value, 84%.
The increase in PCT and IL-6 may allow patients at increased risk of infection after PEA to be identified, allowing earlier institution of antibiotic treatment. These changes that occur before infection can be detected clinically. This finding may make the daily monitoring of PCT post-PEA useful.
European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 02/2011; 39(2):195-200. · 2.40 Impact Factor
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ABSTRACT: Cardiopulmonary bypass (CPB) exposes blood to artificial surfaces, which induces a systemic inflammatory activation.This may contribute to hypotension during CPB. A perceived difference between two membrane oxygenators was noted. Data were collected on 222 consecutive patients; four were excluded from the analysis due to having emergency operations. One hundred and twelve (51%) patients received the Apex oxygenator whilst 106 (49%) received the Quadrox. There was no difference between the two groups in the primary outcome; 90/112 patients (80%) in the Apex group and 77/106 (73%) in the Quadrox group (p=0.18, OR: 0.65; 95% CI: 0.34, 1.22) received meteraminol due to marked hypotension during CPB. There was also no difference in the secondary outcomes, length of stay in ICU (22.8 versus 22.7 hours, (OR 0.79, 95% CI: 0.42, 1.48, p=0.16) and length of stay in hospital (8.5 days versus 8.0 days (OR: 0.83, 95% CI: 0.48, 1.45; p=0.52). The choice of oxygenator between the Apex and Quadrox does not have an effect on hypotension in cardiac surgery.
Perfusion 01/2011; 26(3):223-7. · 0.92 Impact Factor
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ABSTRACT: There have been numerous publications on the coagulopathy of cardiopulmonary bypass (CPB). This review provides an introduction to the history and main components of current CPB circuits and summarizes the current knowledge of pathogenesis, prevention, and treatment of the CPB coagulopathy. It encompasses an overview of intra- and postoperative monitoring of coagulation with special emphasis on the near-patient testing, its main complications, and the transfusion support, while taking into account the major changes in the technology used and supportive care provided since its inception.
Critical Reviews in Clinical Laboratory Sciences 12/2010; 47(5-6):197-212. · 5.25 Impact Factor
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ABSTRACT: A diminutive pulmonary artery and right ventricular outflow tract in a 46-year-old woman with a 10-year history of carcinoid syndrome required transannular pulmonary patch enlargement to allow replacement of the pulmonary and tricuspid valves with bioprostheses. The avoidance of anticoagulation permitted further hepatic arterial embolization without an increased risk of bleeding.
Asian cardiovascular & thoracic annals 10/2009; 17(5):510-2.
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ABSTRACT: Previous trials have indicated that cell salvage may reduce allogeneic blood transfusion during cardiac surgery, but these studies have limitations, including inconsistent use of other blood transfusion-sparing strategies. We designed a randomized controlled trial to determine whether routine cell salvage for elective uncomplicated cardiac surgery reduces blood transfusion and is cost effective in the setting of a rigorous transfusion protocol and routine administration of antifibrinolytics.
Two-hundred-thirteen patients presenting for first-time coronary artery bypass grafting and/or cardiac valve surgery were prospectively randomized to control or cell salvage groups. The latter group had blood aspirate during surgery and mediastinal drainage the first 6 h after surgery processed in a cell saver device and autotransfused. All patients received tranexamic acid and were subjected to an algorithm for red blood cell and hemostatic blood factor transfusion.
There was no difference between the two groups in the proportion of patients exposed to allogeneic blood (32% in both groups, relative risk 1.0 P = 0.89). At current blood products and cell saver prices, the use of cell salvage increased the costs per patient by a minimum of $103. When patients who had mediastinal re-exploration for bleeding were excluded (as planned in the protocol), significantly fewer units of allogeneic red blood cells were transfused in the cell salvage compared with the control group (65 vs 100 U, relative risk 0.71 P = 0.04).
In patients undergoing routine first-time cardiac surgery in an institution with a rigorous blood conservation program, the routine use of cell salvage does not further reduce the proportion of patients exposed to allogeneic blood transfusion. However, patients who do not have excessive bleeding after surgery receive significantly fewer units of blood with cell salvage. Although the use of cell savage may reduce the demand for blood products during cardiac surgery, this comes at an increased cost to the institution.
Anesthesia and analgesia 12/2008; 107(5):1487-95. · 3.08 Impact Factor
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Marius Berman,
Steven Tsui,
Alain Vuylsteke,
Andrew Snell,
Simon Colah,
Ray Latimer,
Roger Hall,
Joseph E Arrowsmith,
John Kneeshaw, Andrew A Klein,
David P Jenkins
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ABSTRACT: Pulmonary thromboendarterectomy (PTE) is the treatment of choice for patients with chronic thromboembolic pulmonary hypertension. However, some patients develop severe cardiorespiratory compromise soon after separating from cardiopulmonary bypass, either from early reperfusion pulmonary edema or right ventricular failure secondary to residual pulmonary hypertension. Since 2005 we have used venoarterial extracorporeal membrane oxygenation (ECMO) support in this group that has no other therapeutic option. We review our experience of early ECMO support in the severely compromised patient's post-PTE.
We conducted a retrospective review of all patients undergoing PTE from a single national referral center between August 2005 and August 2007.
One hundred twenty-seven consecutive patients underwent PTE surgery. Seven patients (5.5%) had extreme cardiorespiratory compromise in the immediate postoperative period and required venoarterial ECMO support. Their mean age was 51.3 years with 3 males. When compared with patients not requiring ECMO, these patients had significantly poorer hemodynamic indices before the operation with mean pulmonary artery pressure of 62 mm Hg versus 51 mm Hg (p = 0.02) and pulmonary vascular resistance of 907 dynes/sec/cm(-5) versus 724 dynes/s(-1)/cm(-5) (p < 0.02). Mean duration of support was 119 hours (49 to 359 hours). Five patients were successfully weaned from ECMO support (73%) and 4 left the hospital alive, giving a salvage rate of 57%. For those who did not require ECMO support, hospital mortality was 4.2%.
Early venoarterial ECMO support has a role as rescue therapy post-PTE in patients with severe compromise who would probably otherwise die.
The Annals of thoracic surgery 10/2008; 86(4):1261-7. · 3.74 Impact Factor
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ABSTRACT: The high level of interest in surgical outcomes has led to the publication of mortality rates in the public domain. In cardiac surgery, the availability of quite sophisticated risk assessment has allowed these outcomes to be adjusted for risk. The European System for Cardiac Operative Risk Evaluation is a widely recognized and used risk scoring system and has been used and validated throughout Europe and beyond. The logistic version is now the most commonly applied, but recalibration may be required. The methodology and statistics for measuring risk-adjusted performance are available, and regular audit and performance monitoring should be carried out in all cardiac surgical units. In the United Kingdom, risk-adjusted outcomes are available and regularly updated on the Internet. Presentation of data may be improved by the use of variable life-adjusted display curves. League tables for crude mortality can be misleading and should be avoided. When properly conducted, the measurement of risk-adjusted surgical outcomes should improve quality control and decision making and allow early identification of poor performance. Quality monitoring in medicine is a priority, and similar methods can be employed in other specialties, including anesthesia, by establishing and analyzing risk-stratified outcome data sets.
Seminars in Cardiothoracic and Vascular Anesthesia 10/2008; 12(3):184-90.
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ABSTRACT: Thoracic surgical procedures account for only a small fraction of all surgery undertaken in the NHS. Thoracic surgery is performed in specialist centres as patients often suffer serious co-morbidities and require vigilant care and observation by staff involved in their treatment. Anaesthesia for thoracic surgery challenges the theoretical and practical experience of all involved. This review briefly summarises the anaesthetic skills and knowledge required to deliver a safe and professional service to patients with thoracic pathology.
Journal of perioperative practice 04/2008; 18(3):121-2, 124-9.
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ABSTRACT: To determine whether the application of acupressure bands would lead to a reduction in postoperative nausea and vomiting after cardiac surgery.
Prospective, randomized, double-blind clinical trial.
University-affiliated tertiary care teaching hospital.
Adult patients undergoing cardiac surgery.
One hundred fifty-two patients were enrolled to receive either acupressure treatment (n = 75) or placebo (n = 77). All patients had acupressure bands placed on both wrists before induction of anesthesia; those in the treatment group had a bead placed in contact with the P6 point on the forearm.
Patients were assessed for nausea, vomiting, and pain scores during the first 24 hours of the postoperative period. The incidences of nausea, vomiting, pain scores, and analgesic and antiemetic requirements were similar between the 2 groups. A subgroup analysis by gender implied that acupressure treatment may be effective only in female patients.
Acupressure treatment did not lead to a reduction in nausea, vomiting, or antiemetic requirements in patients after cardiac surgery.
Journal of Cardiothoracic and Vascular Anesthesia 03/2004; 18(1):68-71. · 1.64 Impact Factor
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ABSTRACT: Renal replacement therapy (RRT) is now offered as a routine treatment in most intensive care units (ICU) in the UK for patients suffering from acute kidney injury (AKI). It is important for all ICU staff to understand the underlying principles of the available therapeutic options and the possible complications thereof.
The objective of this review was to provide an accessible theoretical and practical update on the management of RRT. In addition to a detailed discussion of the underlying principles and indications for the various modes of RRT, we will discuss the assessment of kidney function, possible complications and anticoagulation during RRT, following a review of the current literature.
Pubmed, Medline and the Cumulative Index to Nursing and Allied Health Literature were searched using the keywords renal function, RRT, dialysis, renal failure kidney injury, together with intensive care, intensive therapy and critical care. We included only studies published in English from 1998 to 2008 and from these identified and included additional publications. The 12 most relevant publications are referenced in this review.
AKI is associated with increased mortality in ICU, and RRT should be considered early in the disease process. Continuous haemofiltration is the most common modality of treatment in this group of patients, and a detailed knowledge of the management of such patients is required.
Nursing in Critical Care 14(4):207-12. · 1.08 Impact Factor
