Intensive care medicine and organ donation: exploring the last frontiers?

The main, universal problem for transplantation is organ scarcity. The gap between offer and demand grows wider every year and causes many patients in waiting list to die. In Spain, 90% of transplants are done with organs taken from patients deceased in brain death but this has a limited potential. In order to diminish organ shortage, alternative strategies such as donations from living donors, expanded criteria donors or donation after circulatory death, have been developed. Nevertheless, these types of donors also have their limitations and so are not able to satisfy current organ demand. It is necessary to reduce family denial and to raise donation in brain death thus generalizing, among other strategies, non-therapeutic elective ventilation. As intensive care doctors, cornerstone to the national donation programme, we must consolidate our commitment with society and organ transplantation. We must contribute with the values proper to our specialization and try to reach self-sufficiency by rising organ obtainment.

A new technique for avoiding barotrauma-induced complications in apnea testing for brain death

Prompted by our experience with complications occurring with apnea testing (AT), we discuss complications reported in the literature. AT is an integral part of brain death assessment. Many complications of AT have been described, including hypoxemia, arterial hypotension, tension pneumothorax and cardiac arrest. We conclude that a commonly used technique in conducting AT can create auto-positive end expiratory pressure (PEEP) and contributes to many complications. The mechanism of occult auto-PEEP in AT is discussed. Intensive care unit patients may have a compensated and asymptomatic relative hypovolemia that can be decompensated by a small amount of auto-PEEP produced by air trapping during insufflating oxygen (O2) through a 7.0 endotracheal tube (ETT). It could then lead to decreased preload, decreased stroke volume, decreased cardiac output and thus, to hypotension and a compensatory tachycardia. The placement of the standard O2 tubing (6mm outside diameter [OD]) inside the 7.0 ETT (7mm inside diameter [ID]) greatly decreased the ETT lumen (73%). We changed our practice to instead use readily available small pressure tubing to insufflate O2 for AT to avoid excessive reduction in the ETT lumen. The change from standard O2 tubing (6mm OD) to pressure tubing (3mm OD) will greatly decrease the reduction in cross-sectional area of 7.0 ETT lumen from 73 to 18% and avoid potential complications of air trapping, auto-PEEP and barotrauma. We have successfully used this new simple technique with readily available equipment to eliminate auto-PEEP in AT while preserving oxygenation.

Mortality patterns among critically ill children in a Pediatric Intensive Care Unit of a developing country

BACKGROUND AND AIM

Advances in biomedical technology have made medical treatment to be continued beyond a point, at which it does not confer an advantage but may increase the suffering of patients. In such cases, continuation of care may not always be useful, and this has given rise to the concept of limitation of life-sustaining treatment. Our aim was to study mortality patterns over a 6-year period in a Pediatric Intensive Care Unit (PICU) in a developing country and to compare the results with published data from other countries.

MATERIALS AND METHODS

Retrospective cohort study was conducted in a PICU of a tertiary care hospital in Pakistan. Data were drawn from the medical records of children aged 1-month - 16 years of age who died in PICU, from January 2007 to December 2012.

RESULTS

A total of 248 (from an admitted number of 1919) patients died over a period of 6 years with a mortality rate 12.9%. The median age of children who died was 2.8 years, of which 60.5% (n = 150) were males. The most common source of admission was from the emergency room (57.5%, n = 143). The most common cause of death was limitation of life-sustaining treatment (63.7%, n = 158) followed by failed cardiopulmonary resuscitation (28.2%, n = 70) and brain death (8.1%, n = 20). We also found an increasing trend of limitation of life-sustaining treatment do-not-resuscitate (DNR) over the 6-year reporting period.

CONCLUSION

We found limitation of life support treatment (DNR + Withdrawal of Life support Treatment) to be the most common cause of death, and parents were always involved in the end-of-life care decision-making.

Analysis of RNA from Alzheimer's Disease Post-mortem Brain Tissues

Alzheimer's disease (AD) is a uniquely human, age-related central nervous system (CNS) disorder for which there is no adequate experimental model. While well over 100 transgenic murine models of AD (TgAD) have been developed that recapitulate many of the neuropathological features of AD, key pathological features of AD such as progressive neuronal atrophy, neuron cell loss, and neurofibrillary tangle (NFT) formation have not been observed in any TgAD model to date. To more completely analyze and understand the neuropathology, altered neuro-inflammatory and innate-immune signaling pathways, and the complex molecular-genetics and epigenetics of AD, it is therefore necessary to rigorously examine short post-mortem interval (PMI) human brain tissues to gain a deeper and more thorough insight into the neuropathological mechanisms that characterize the AD process. This perspective-methods paper will highlight some important recent findings on the utilization of short PMI tissues in sporadic (idiopathic; of unknown origin) AD research with focus on the extraction and quantification of RNA, and in particular microRNA (miRNA) and messenger RNA (mRNA) and analytical strategies, drawing on the authors' combined 125 years of laboratory experience into this investigative research area. We sincerely hope that new investigators in the field of "gene expression analysis in neurological disease" will benefit from the observations presented here and incorporate these recent findings and observations into their future experimental planning and design.

Attitudes towards organ donor advocacy among Swedish intensive care nurses

OBJECTIVES

To explore the attitudes of Swedish intensive care nurses towards organ donor advocacy.

BACKGROUND

The concept of organ donor advocacy is critical to nurses who care for potential donors in order to facilitate organ donation (OD).

DESIGN

A retrospective cross-sectional study was employed.

METHODS

Inclusion criteria in this survey were to be a registered nurse and to work in a Swedish intensive care unit (ICU). Participants were identified by the Swedish association of health professionals. A number of 502 Swedish ICU nurses answered the 32-item questionnaire Attitudes Towards Organ Donor Advocacy Scale (ATODAS), covering the five dimensions of organ donor advocacy: attitudes towards championing organ donation at a structural hospital level, or at a political and research level, attitudes towards actively and personally safeguarding the will and wishes of the potential organ donor, or by using a more professional approach and finally to safeguard the will and wishes of the relatives. Data were analysed with the SPSS version 18·0 and the results were assessed by using Student's t-test and post hoc test, analysis of variance (ANOVA), χ(2) , Pearson's correlation and regression analysis.

RESULTS

The most favoured advocacy action was safeguarding the POD's will and wishes by a professional approach, closely followed by actively and personally safeguarding the POD's will and wishes. Nurses at local hospitals reported a more positive attitude towards organ donor advocacy overall compared with nurses at larger regional or university hospitals. Important factors leading to positive attitudes were seniority, working experience, participating in conversations with relatives, caring for brain-dead persons and private experiences from OD or organ transplantation.

CONCLUSIONS

Intensive and critical care nurses with short working experience in university hospitals showed the least positive attitude towards organ donor advocacy. This is problematic because many ODs and all transplantations are performed in university hospitals.

RELEVANCE TO CLINICAL PRACTICE

This study emphasizes the importance of organizing the care of PODs and their relatives in a way that promotes advocacy.

EEG guidelines in the diagnosis of brain death

In France, for the determination and diagnostic validation of brain death the law requires either two EEG recordings separated by a 4-hour observation period, both showing electrocerebral inactivity; or cerebral angiography examination. Since EEG is available in most hospitals and clinics, it is often used in this indication, at the patient's bedside, especially in the context of organ donation. However, very precise methodology must be followed. The last French guidelines date back to 1989, before the development of digital EEG recording. We present the new guidelines from the Société de Neurophysiologie Clinique de Langue Française. Electrocerebral inactivity may be confirmed when a 30-minute good quality EEG recording shows complete electrocerebral silence, defined as no cerebral activity greater than 2 uV, having first ruled out the possible influence of sedative drugs, metabolic disorders or hypothermia. In the presence of sedative drugs, CT brain angiography will be the gold standard test for this diagnosis. In the newborn, the utmost caution is indicated since electrocerebral inactivity can be observed in the absence of cerebral death. In the infant, the criterion for the observation period to be respected between both EEG recordings needs to be more clearly refined.

ICU Nurses' Knowledge, Attitude, and Practice Towards their Role in the Organ Donation Process from Brain-Dead Patients and Factors Influencing it in Iran

BACKGROUND

Nowadays, ICU nurses play a significant role in the care of brain-dead patients and their families. Therefore, their knowledge, attitude and practice towards this issue are extremely important to the success of organ donation.

OBJECTIVE

To assess ICU nurses' knowledge, attitude and practice towards their role in the organ donation process from brain-dead patients and factors influencing it in Iran.

METHODS

In a cross-sectional analytical study, 90 ICU nurses working in Ghaem and Emam Reza Hospitals affiliated to Mashhad University of Medical Sciences were selected through a stratified random sampling. Data were collected from the participants by a questionnaire included demographic information, and factors influencing the nurses knowledge, attitude, and practice towards their roles in the organ donation process.

RESULTS

90 nurses participated in this study. 70% of the research subjects had spoken with their own families about organ donation; 20% had organ donation cards. The mean±SD score of nurses' knowledge was 49.13±9.6, attitude 21.49±14.32, and practice was 3.66±6.04. 80% of nurses had a mean knowledge about their roles in the organ donation process; 82% agreed with their roles in this process, and 97% showed weak practice in this regard.

CONCLUSION

Nurses did not have adequate knowledge, attitude, and practice towards their role in organ donation process. It is suggested to include nursing courses on the organ donation process and organ transplantation as well as educational programs to acquaint nurses with their roles in the organ donation process.

Brain Death after Liver Transplantation for Fulminant Hepatic Failure: A Report of Two Cases

Cerebral injury may persist and brain death may occur following an emergency liver transplantation (LT) for fulminant hepatic failure (FHF) even if the graft functions well. We herein present two patients developing brain death following emergency LT for FHF.

The effect of brain death in rat steatotic and non-steatotic liver transplantation with previous ischemic preconditioning

BACKGROUND & AIMS

Most liver grafts undergoing transplantation derive from brain dead donors, which may also show hepatic steatosis, being both characteristic risk factors in liver transplantation. Ischemic preconditioning shows benefits when applied in non-brain dead clinical situations like hepatectomies, whereas it has been less promising in the transplantation from brain dead patients. This study examined how brain death affects preconditioned steatotic and non-steatotic liver grafts undergoing transplantation.

METHODS

Steatotic and non-steatotic grafts from non-brain dead and brain dead-donors were cold stored for 6h and then transplanted. After 2, 4, and 16 h of reperfusion, hepatic damage was analysed. In addition, two therapeutic strategies, ischemic preconditioning and/or acetylcholine pre-treatment, and their underlying mechanisms were characterized.

RESULTS

Preconditioning benefits in non-brain dead donors were associated with nitric oxide and acetylcholine generation. In brain dead donors, preconditioning generated nitric oxide but did not promote acetylcholine upregulation, and this resulted in inflammation and damage. Acetylcholine treatment in brain dead donors, through PKC, increased antioxidants and reduced lipid peroxidation, nitrotyrosines and neutrophil accumulation, altogether protecting against damage. The combination of acetylcholine and preconditioning conferred stronger protection against damage, oxidative stress and neutrophil accumulation than acetylcholine treatment alone. These superior beneficial effects were due to a selective preconditioning-mediated generation of nitric oxide and regulation of PPAR and TLR4 pathways, which were not observed when acetylcholine was administered alone.

CONCLUSIONS

Our findings propose the combination of acetylcholine+preconditioning as a feasible and highly protective strategy to reduce the adverse effects of brain death and to ultimately improve liver graft quality.

Healthy baby delivered vaginally from a brain-dead mother

Case

A pregnant (20 gestational weeks) 32-year-old woman was found in cardiac arrest. Spontaneous circulation returned after 15 min. She became brain dead on the 13th hospital day. The patient was in stable circulatory condition under nasal desmopressin and 20-30 mg/day of hydrocortisone. On the 92nd hospital day at gestational week 33 + 3 days, natural labor began and a healthy 2,130-g girl (Apgar 6/8) was delivered vaginally with minimum assistance.

Outcome

The baby was discharged 40 days after birth and followed up regularly.

Conclusion

Brain death remains a hopeless condition for patients, but a brain-dead woman may still be able to naturally deliver a healthy baby.

Short- and long-term effects of brain death on post-transplant graft function in a rodent model

OBJECTIVES

Heart transplantation has become the most effective treatment for end-stage heart failure. Donors after brain death (BD) are currently the only reliable source for cardiac transplants. However, haemodynamic instability and cardiac dysfunction have been demonstrated in brain-dead donors and this could therefore also affect post-transplant graft function. We studied the effects of BD on cardiac function and its short-term (1 h) or long-term (5 h) impacts on graft function.

METHODS

In Lewis rats, BD was induced by inflation of a subdurally placed balloon catheter (n = 7). Sham-operated rats served as controls (n = 9). We continuously assessed cardiac function by left ventricular (LV) pressure-volume analysis. Then, 1 or 5 h after BD or sham operation, hearts were perfused with a cold preservation solution (Custodiol), then explanted, stored at 4°C in Custodiol and heterotopically transplanted. We evaluated graft function 1.5 h after transplantation.

RESULTS

BD was associated with decreased left ventricular contractility (ejection fraction: 37 ± 6 vs 57 ± 5%; maximum rate of rise of LV pressure dP/dtmax: 4770 ± 197 vs 7604 ± 348 mmHg/s; dP/dtmax-end-diastolic volume: 60 ± 7 vs 74 ± 2 mmHg/s; slope Emax of the end-systolic pressure-volume relationship: 2.4 ± 0.1 vs 4.4 ± 0.3 mmHg/µl; preload recruitable stroke work: 47 ± 9 vs 78 ± 3 mmHg; P <0.05) and relaxation (maximum rate of fall of left ventricular pressure dP/dtmin: -6638 ± 722 vs -11 285 ± 539 mmHg/s; time constant of left ventricular pressure decay Tau: 12.6 ± 0.7 vs 10.5 ± 0.4 ms; end-diastolic pressure-volume relationship: 0.22 ± 0.05 vs 0.09 ± 0.03 mmHg/µl, P <0.05) 45 min after its initiation and for the rest of 5 h compared with controls. Moreover, after transplantation, graft systolic and diastolic functions were impaired in the 5-h brain-dead group, while they were identical in the 1-h brain-dead group compared with the corresponding controls.

CONCLUSIONS

We established a well-characterized in vivo rat model to examine the influence of BD on cardiac function using a miniaturized technology for pressure-volume analysis. These results demonstrate that impaired donor cardiac function after short-term BD is reversible after transplantation and long-term BD renders hearts more susceptible to ischaemia/reperfusion injury.

[French guidelines on electroencephalogram]

Electroencephalography allows the functional analysis of electrical brain cortical activity and is the gold standard for analyzing electrophysiological processes involved in epilepsy but also in several other dysfunctions of the central nervous system. Morphological imaging yields complementary data, yet it cannot replace the essential functional analysis tool that is EEG. Furthermore, EEG has the great advantage of being non-invasive, easy to perform and allows control tests when follow-up is necessary, even at the patient's bedside. Faced with the advances in knowledge, techniques and indications, the Société de Neurophysiologie Clinique de Langue Française (SNCLF) and the Ligue Française Contre l'Épilepsie (LFCE) found it necessary to provide an update on EEG recommendations. This article will review the methodology applied to this work, refine the various topics detailed in the following chapters. It will go over the summary of recommendations for each of these chapters and underline proposals for writing an EEG report. Some questions could not be answered by the review of the literature; in those cases, an expert advice was given by the working and reading groups in addition to the guidelines.

The usefulness of end-tidal carbon dioxide monitoring during apnea test in brain-dead patients

Background

The apnea test (AT) is essential to confirming the diagnosis of brain death, but critical complications can occur if the AT is maintained over a long period. To minimize the AT period, we used end-tidal carbon dioxide (ETCO₂) monitoring because ETCO₂ is closely correlated with partial pressure of arterial carbon dioxide (PaCO₂). The aim of the present study is to evaluate the usefulness of ETCO₂ monitoring during apnea testing.

Methods

We reviewed 61 patients who were pronounced brain dead at our hospital from July 2009 to December 2012. The subjects were divided into two groups: the N-group, in which capnography was not used, and the C-group, in which capnography was used to monitor ETCO₂. In the C-group, whenever arterial blood was sampled, the PaCO₂ - ETCO₂ gradients were calculated and the ventilator setting adjusted to maintain normocapnia prior to apnea testing.

Results

Twenty-eight subjects in the N-group and twenty-nine subjects in the C-group were included. The gender ratio, age, and cause of brain death were not different between the two groups. Prior to the AT, the normocapnia ratio was higher in the C-group than in the N-group. During the AT, the total test period was shorter in the C-group. Moreover, systolic blood pressure increased in the C-group and decreased in the N-group during apnea testing.

Conclusions

ETCO₂ monitoring during AT allows the PaCO₂ level to be predicted, which reduces the duration of the test and stabilizes systolic blood pressure. Thus, with ETCO₂ monitoring, the AT can be fast and safe.

Brainstem death: A comprehensive review in Indian perspective

With the advent of cardiopulmonary resuscitation techniques, the cardiopulmonary definition of death lost its significance in favor of brain death. Brain death is a permanent cessation of all functions of the brain in which though individual organs may function but lack of integrating function of the brain, lack of respiratory drive, consciousness, and cognition confirms to the definition that death is an irreversible cessation of functioning of the organism as a whole. In spite of medical and legal acceptance globally, the concept of brain death and brain-stem death is still unclear to many. Brain death is not promptly declared due to lack of awareness and doubts about the legal procedure of certification. Many brain dead patients are kept on life supporting systems needlessly. In this comprehensive review, an attempt has been made to highlight the history and concept of brain death and brain-stem death; the anatomical and physiological basis of brain-stem death, and criteria to diagnose brain-stem death in India.

Inhaled nitric oxide for the brain dead donor with neurogenic pulmonary edema during anesthesia for organ donation: a case report

Neurogenic pulmonary edema (NPE) in brain dead organ donors occurring after an acute central nervous system insult threatens organ preservation of potential organ donors and the outcome of organ donation. Hence the active and immediate management of NPE is critical. In this case, a 50-year-old male was admitted to the intensive care unit (ICU) for organ donation. He was hypoxic due to NPE induced by spontaneous intracerebral hemorrhage and intraventricular hemorrhage. Protective ventilatory management, intermittent recruitment maneuvers, and supportive treatment were maintained in the ICU and the operating room (OR). Despite this management, the hypoxemia worsened after the OR admission. So inhaled nitric oxide (NO) therapy was performed during the operation, and the hypoxic phenomena showed remarkable improvement. The organ retrieval was successfully completed. Therefore, NO inhalation can be helpful in the improvement of hypoxemia caused by NPE in brain dead organ donors during anesthesia for the organ donation.

Maternal organ donation and acute injuries in surviving children

PURPOSE

The purpose of this study is to test whether maternal deceased organ donation is associated with rates of subsequent acute injuries among surviving children after their mother's death.

METHODS

This is a longitudinal cohort analysis of children linked to mothers who died of a catastrophic brain event in Ontario, Canada, between April 1988 and March 2012. Surviving children were distinguished by whether their mother was an organ donor after death. The primary outcome was an acute injury event in surviving children during the year after their mother's death.

RESULTS

Surviving children (n=454) had a total of 293 injury events during the year after their mother's death, equivalent to an average of 65 events per 100 children per year and a significant difference comparing children of mothers who were organ donors to children of mothers who were not organ donors (21 vs 82, P<.001). This difference in subsequent injury rates between groups was equal to a 76% relative reduction in risk (95% confidence interval, 62%-85%).

CONCLUSIONS

Deceased organ donation was associated with a reduction in excess acute injuries among surviving children after their mother's death. An awareness of this positive association provides some reassurance about deceased organ donation programs.

The core of after death care in relation to organ donation - a grounded theory study

OBJECTIVES

The aim of this study was to investigate how intensive and critical care nurses experience and deal with after death care i.e. the period from notification of a possible brain dead person, and thereby a possible organ donor, to the time of post-mortem farewell.

RESEARCH METHODOLOGY

Grounded theory, based on Charmaz' framework, was used to explore what characterises the ICU-nurses concerns during the process of after death and how they handle it. Data was collected from open-ended interviews.

FINDINGS

The core category: achieving a basis for organ donation through dignified and respectful care of the deceased person and the close relatives highlights the main concern of the 29 informants. This concern is categorised into four main areas: safeguarding the dignity of the deceased person, respecting the relatives, dignified and respectful care, enabling a dignified farewell.

CONCLUSION

After death care requires the provision of intense, technical, medical and nursing interventions to enable organ donation from a deceased person. It is achieved by extensive nursing efforts to preserve and safeguard the dignity of and respect for the deceased person and the close relatives, within an atmosphere of peace and tranquillity.

Confirming the brain death diagnosis using brain CT angiography: experience in Tokat State Hospital

OBJECTIVE

Fourteen brain death cases diagnosed in Mart 2012-May 2013 period in Tokat State Hospital were studied retrospectively. CT angiography experience about those cases was shared, and use of CT angiography in confirmation of brain death was discussed.

MATERIAL AND METHODS

All 14 cases were patients on mechanical ventilator, who did not respond to medical and surgical treatments at intensive care unit and were diagnosed clinically with brain death. All of these patients had CT angiography as a confirmatory test using a 4-slice CT scanner in Radiology department in Tokat State Hospital.

FINDINGS

Six of the patients were female and eight were male. All of them were referred from intensive care unit and had clinical brain death diagnosis before CT angiography. In the evaluation of CTA, four-point scoring involving opacification loss in both ICVs and cortical segments of MCA was used. CTA examinations confirmed brain death diagnoses in all patients who had clinical brain death diagnoses, and no confliction between CTA findings and clinical diagnoses was observed.

CONCLUSION

Demonstrating the lack of cerebral circulation is a necessity for confirmation of brain death diagnosis. While conventional angiography remains the standard method, CTA emerged as an alternative method. In parallel to increase in prevalence of organ implants, CTA, a fast and efficient method, has been increasingly used in confirmation of brain death diagnoses.

Reuse of liver grafts following the brain death of the initial recipient

AIM: To determine if there is a reasonable prospect of success of a re-use liver transplantation.

METHODS: We systematically searched for reports of liver graft re-use using electronic searches of PubMed and Web of Knowledge. We performed hand searches of references lists of articles reporting re-use of grafts.

RESULTS: A systematic review of the literature reveals 28 liver transplantations using previously transplanted grafts. First and second recipients ranged in age from 4 to 72 years and 29 to 62 years respectively. Liver disease in the first recipient was varied including 5 (18%) patients with fulminant liver failure who died subsequently of cerebral edema. The second transplantation was performed after a median interval of 5 d (one day-13 years). Viral hepatitis was present in 3 (11%) of the initial recipients and in 8 (29%) of final recipients. Hepatocellular carcinoma was present in 6 (21%) of the final recipients. Early survival after the final transplantation was 93%, whereas long-term survival was 78% with a mean follow-up of 23.3 (3-120) mo.

CONCLUSION: Outcomes of transplantation using previously transplanted grafts in this select population are similar to those seen with conventional grafts.

Experiences of donor families after consenting to organ donation: a qualitative study

AIM

The aim of this study was to investigate the experience of Norwegian donor families during organ donation after brain death.

METHODS

This was a qualitative study using personal interviews. Twenty donor-family members from thirteen different situations were interviewed about their experience of being a close relative in an organ donation situation. The principles of qualitative content analysis were used.

FINDINGS

An experience of strain caused by the organ donation situation was identified. Lack of comprehension and awareness of the process of organ donation contributed to this, and continuing information after the consent was given appeared to be necessary. Reconciliation with the decision of organ donation and the subsequent situation was gained through understanding the organ donation process, through recognition of the increased strain and through satisfaction resulting from the contribution made by organ donation. Healthcare personnel were key persons in contributing to such understanding and recognition.

CONCLUSION

When attending to families in an organ donation situation, the focus must be on ensuring comprehension of the situation both through information provided in the hospital and during follow-up. It seems essential to arrange for a period of parting that can contribute to reconciliation, and to offer follow-up according to individual needs.

History of brain death as death: 1968 to the present

The concept of brain death was formulated in 1968 in the landmark report A Definition of Irreversible Coma. While brain death has been widely accepted as a determination of death throughout the world, many of the controversies that surround it have not been settled. Some may be rooted in a misconstruction about the history of brain death. The concept evolved as a result of the convergence of several parallel developments in the second half of the 20th century including advances in resuscitation and critical care, research into the underlying physiology of consciousness, and growing concerns about technology, medical futility, and the ethics of end of life care. Organ transplantation also developed in parallel, and though it clearly benefited from a new definition of death, it was not a principal driving force in its creation. Since 1968, the concept of brain death has been extensively analyzed, debated, and reworked. Still there remains much misunderstanding and confusion, especially in the general public. In this comprehensive review, I will trace the evolution of the definition of brain death as death from 1968 to the present, providing background, history and context.

Modifying the vessel walls in porcine kidneys during machine perfusion

BACKGROUND

Endothelial glycocalyx regulates the endothelial function and plays an active role in maintaining vascular homeostasis. During ischema and reperfusion, the glycocalyx is rapidly shed into the blood stream. A Corline heparin conjugate (CHC; Corline systems AB, Uppsala, Sweden) consists of 70 heparin molecules that have the capacity to adhere strongly to biological tissues expressing heparin affinity. We hypothesized that CHC could be used to restore disrupted glycocalyx in vivo in kidneys from brain-dead pigs.

MATERIALS AND METHODS

Brain death was induced in male landrace pigs (n = 6) by inflating a balloon catheter in the epidural space until obtaining negative cerebral perfusion. The recovered kidneys (n = 5 + 5) were perfused by hypothermic machine perfusion using two Lifeport kidney transporters (Organ Recovery Systems, Chicago, IL). CHC (50 mg) (including 25 mg biotinylated CHC) or 50 mg unfractionated heparin (control) was added to the perfusion fluid in the respective machines. In one case, the kidneys were used only for dose escalation of CHC with the same procedure.

RESULTS

CHC was detected by immunofluorescence and confocal microscopy in the inner surface of the vessel walls. The binding of CHC in the kidney was confirmed indirectly by consumption of CHC from the perfusion fluid.

CONCLUSIONS

In this first attempt, we show that CHC maybe used to coat the vessel walls of perfused kidneys during hypothermic machine perfusion, an approach that could become useful in restoring endothelial glycocalyx of kidneys recovered from deceased donors to protect vascular endothelium and possibly ameliorate ischemia and reperfusion injuries.

Pulse pressure variations to guide fluid therapy in donors: a multicentric echocardiographic observational study

PURPOSE

Preload responsiveness parameters could be useful in the hemodynamic management of septic shock.

METHODS

A multicentric prospective echocardiographic observational study was conducted from March 2009 to August 2011. Clinically brain-dead subjects were included. Pulse pressure variations (ΔPPs) were recorded. Cardiac index, variation of the maximum flow velocity of aortic systolic blood flow, and right ventricular function parameters were evaluated via transthoracic echocardiography. Fluid responsiveness was defined by at least 15% cardiac index increase, 30 minutes after a 500-mL colloid solution infusion. The number of organs harvested was recorded.

RESULTS

Twenty-five subjects were included. Pulse pressure variation could not discriminate responders (n=15) from nonresponders (n=10). The best ΔPP threshold (20%) could discriminate responders with a sensitivity of 100% and a specificity of 40%. Variation of the maximum flow velocity of aortic systolic blood flow, tricuspid annular plane systolic excursion, and right ventricle dilation could not discriminate responders from nonresponders. Eighteen subjects underwent organ harvesting. The number of organs harvested was higher in responders (3.5 [3-5]) than in nonresponders (2.5 [2-3]; P=.03).

CONCLUSIONS

A ΔPP threshold of 13% is insufficient to guide volume expansion in donors. The best threshold is 20%. Fluid responsiveness monitoring could enhance organ harvesting.

Brain death in ICU patients: Clinical significance of endocrine changes

Numerous studies have been carried out among patients admitted in intensive care unit (ICU) having primary endocrine pathology, endocrine manifestations of systemic diseases or post-endocrine tissue surgery. However, minimal literary evidence is available highlighting the endocrine changes occurring during brain death in critically ill patients. A precise and timely diagnosis of brain death is required to convey the relatives about the prognosis and also to possibly plan for organ retrieval for transplantation purposes. The diagnosis of this condition as of today remains largely a clinical one. Brain death is associated with a multitude of endocrinological alterations which are yet to be completely unraveled and understood. Evaluating these endocrinological modifications lends us an added vista to add to the existing clinical parameters which might help us to confirm the diagnosis of brain death with a higher degree of precision. Moreover, since the efficacy of hormone replacement therapy to benefit in organ retrieval remains yet unproven, newer diagnostic modalities and research studies are definitely called for to strategize the optimal dosage and duration of such therapies.