Care of the multiple organ donor

Computed Tomography Angiography (CTA) in Selected Scenarios with Risk of Possible False-Positive or False-Negative Conclusions in Diagnosing Brain Death

It is widely accepted that brain death (BD) is a diagnosis based on clinical examination. However, false-positive and false-negative evaluation results may be serious limitations. Ancillary tests are used when there is uncertainty about the reliability of the neurologic examination. Computed tomography angiography (CTA) is an ancillary test that tends to have the lowest false-positive rates. However, there are various influencing factors that can have an unfavorable effect on the validity of the examination method. There are inconsistent protocols regarding the evaluation criteria such as scoring systems. Among the most widely used different scoring systems the 4-point CTA-scoring system has been accepted as the most reliable method. Appropriate timing and/or Doppler pre-testing could reduce the number of possible premature examinations and increase the sensitivity of CTA in diagnosing cerebral circulatory arrest (CCA). In some cases of inconclusive CTA, the whole brain computed tomography perfusion (CTP) could be a crucial adjunct. Due to the increasing significance of CTA/CTP in determining BD, the methodology (including benefits and limitations) should also be conveyed via innovative electronic training tools, such as the BRAINDEXweb teaching tool based on an expert system.

Donor heparinization is not a contraindication to liver transplantation even in recipients with acute heparin-induced thrombocytopenia type II: a case report and review of the literature

Heparin-induced thrombocytopenia (HIT) type II is caused by an immune-mediated side effect of heparin anticoagulation resulting in a clotting disorder. In the setting of urgent liver transplantation, the question arises whether a graft from a heparinized donor can be safely transplantated in a recipient with even acute heparin-induced thrombocytopenia type II. We report on a patient with end-stage liver disease and acute HIT II waiting for liver transplantation. Despite the risk of life-threatening complications, an organ procured from a heparinized donor was accepted. Assuming heparin residuals within the graft, the donor organ was flushed backtable with increased amounts of Wisconsin solution. The subsequent transplantation and the postoperative course were uneventful; neither thromboses nor graft dysfunction occurred. Even in acute episode of HIT II with circulating antibodies, a patient may receive an organ from a heparin-treated donor, if adequate precautions during organ preparation are observed.

[Organ donation]

For patients with end-stage organ disease transplantation of human organs is a well-established therapy, and in most cases it is the only life-saving one. But the lack of available organs is a big problem. The legal basis in Germany is the transplantation law (TPG). According to this law, every ventilated patient with diagnosed brain death is a potential organ donor. However, brain death may lead to strong reactions in the patient's cardiovascular system as well as disturbances in thermoregulation, water and electrolyte balance, and the endocrine and haemostatic systems. Thus, protecting the organs of the organ donor and, furthermore, caring for his or her relatives are great challenges for every physician and nurse in the intensive care unit.

Intravascular Temperature Control System to Maintain Normothermia in Organ Donors

INTRODUCTION

Temperature regulation in humans is controlled by the hypothalamus. After death by neurological criteria, the hypothalamus ceases to function and poikilothermia ensues. Preservation of normothermia in those patients destined to become organ donors is an important part of maintaining the normal physiology of the organs and organ systems. Typical means of achieving normothermia include increasing the temperature of the ambient air, infrared warming lights, instillation of warmed intravenous fluids, and warm air or water blankets.

METHODS

In this prospective case series of five organ donors, we used an intravascular temperature modulation catheter (Alsius, Irvine, CA) to maintain normothermia in organ donors declared dead by neurological criteria. Data on accuracy of temperature maintenance at 37 degrees C and nursing ease of use were collected.

RESULTS

This intravascular temperature modulation catheter provided an accurate method of temperature regulation in brain death donor and easier to use from a nursing workload perspective.

CONCLUSIONS

Intravascular warming is a viable method for the maintenance of normothermia in organ donors. The experience here provides some insight into the ability of these devices to warm patients in other clinical situations.

Bacterial- and fungal-positive cultures in organ donors: clinical impact in liver transplantation

Infection transmission from donor to recipient is a dreadful complication in transplantation. Although bacteremia was previously detected in 5% of donors without negative impact on recipient outcome, the current expansion of graft pool requires consideration of the infectious risk associated with suboptimal donors. This study aims to evaluate the incidence and risk factors of infection in unselected cadaveric liver donors, the occurrence of microorganism transmission to recipient and its influence on patient survival. Results of microbiologic cultures obtained before harvesting in intensive care unit (ICU) and routinely at harvesting from 610 consecutive liver donors were retrospectively analyzed. Evidence for bacterial and fungal transmission to the recipient was searched for in each culture-positive donor. One or more cultures were positive in 293 donors (48%), while bacteremia was present in 128 (21%). Culture-positive and bacteremic donors were of significantly older age and had longer ICU stays. At multivariate analysis, an ICU stay of 3 or more days was the only significant predictor of donor infection. Although 1-year patient/graft survival rates were not influenced by donor culture positivity, pathogen transmission occurred in 11 cases with high recipient 1-year mortality (45%). In those 11 cases, median donor age was 74 years, significantly much older than that of the other culture-positive donors. In conclusion, donors with a prolonged ICU stay are at increased risk of infection, while older donor age is associated with pathogen transmission to the recipient. Adequate donor maintenance and careful microbiologic surveillance and treatment, especially of elderly donors, may limit transmission of donor infection.

Management of liver transplantation in a patient with a history of heparin-induced thrombocytopenia

Heparin-induced thrombocytopenia (HIT) is an adverse immune-mediated drug reaction in which antibodies are generated usually towards complexes of the soluble platelet protein platelet-factor-4 (PF4) and heparin. The resulting immune complexes activate platelets intravascularly, which increases the generation of thrombin. Therefore, HIT is strongly associated with thrombosis and heparin is thought to be contraindicated. As HIT antibodies decline rapidly in titre, short-term re-exposure to heparin is feasible in special situations. We report an uneventful liver transplantation of a heparinized donor in a patient with a 20-month history of HIT. Before, 2, 5, 12 and 25 days after transplantation, the patient's blood was drawn for analysis of heparin-induced antibodies by a functional assay (HIPA) and by an antigen assay (PF4-heparin/ELISA). Lepirudin was used for postoperative anticoagulation. Apart from hepatic artery bleeding, the clinical course was uncomplicated, neither thrombocytopenia nor thromboembolic complications occurred. Weak heparin-induced platelet activation, caused by pre-existing HIT antibodies was detected before and 12 days after transplantation by the HIPA test; moreover borderline amounts of anti-PF4-heparin antibodies were found. Twenty months after an episode of HIT, a patient may receive an organ from a heparin-treated donor without risk of thrombocytopenia or thromboembolic complications. Avoidance of heparin for postoperative anticoagulation is recommended.

Inhaled nitric oxide in neurogenic cardiopulmonary dysfunction: Implications for organ donation

Many cadaveric organs for transplantation come from patients dying of sudden intracranial catastrophes. Cardiopulmonary dysfunction after such neurogenic insults is a well-recognized entity. The pulmonary dysfunction usually presents as florid pulmonary edema within minutes to hours after the initial intracranial insult and may occur in isolation or co-exist with overt or subclinical myocardial dysfunction. This may result in severe hypoxia, which threatens survival and outcomes in salvageable cases and organ preservation in patients who would be potential organ donors. Thus, rapid initiation of strategies aimed at ameliorating hypoxia after an acute neurogenic insult is paramount. Strategies aimed at improving acute hypoxia include maximizing ventilator support, diuretics, and volume resuscitation. Cardiac dysfunction may require use of ionotropes. We report the case of a 16-year-old female who developed catastrophic acute posterior fossa intracranial bleeding with resulting intractable hypoxia due to neurogenic cardiopulmonary dysfunction that responded dramatically to inhaled nitric oxide (INO). The patient went on to successfully donate organs following a non-heart-beating donor protocol. This therapy, to our knowledge, has never been described previously for use in patients with hypoxia secondary to neurogenic cardiopulmonary dysfunction.

CONCLUSIONS

We document for the first time a dramatic response of hypoxia to INO in neurogenic cardiopulmonary dysfunction. This therapy ameliorates hypoxia, which may have vital implications in minimizing secondary brain injury in salvageable cases and optimizing organ preservation in potential organ donors with catastrophic intracranial insults.

The influence of desmopressin and vasopressors in the donor management on graft function following pancreas transplantation

INTRODUCTION

The use of desmopressin and vasopressors in cadaveric organ donors is considered a risk factor for graft dysfunction following pancreas transplantation by influencing the microcirculation. The aim of this study was to investigate the influence of these substances on early graft function.

PATIENTS AND METHODS

This single-center retrospective trial included 59 patients who underwent simultaneous or solitary pancreas transplantation. The corresponding donor charts were reviewed for the use of vasopressors and desmopressin. Impaired graft function was determined as graft thrombosis or as insulin-dependence for more then 3 days posttransplant. Daily amylase and lipase concentrations from abdominal drains were measured to quantify reperfusion pancreatitis and fistula formation.

RESULTS

Overall, pancreas thrombosis was observed in 4 of 59 (6.8%) recipients. There were no significant differences in thrombosis rate whether the donors received desmopressin (3/38 vs 1/21, P >.1) or the needed vasopressors (3/53 vs 1/9, P >.1). The number of patients who required insulin for more than 3 days posttransplant was comparable whether the donors received desmopressin (9/38 vs 4/21, P >.1), or vasopressors (9/46 vs 3/8, P >.1). At present all recipients with functioning pancreatic grafts (ie, 92.7%) are free of exogenous insulin therapy at 2 to 80 months posttransplant. The amylase/lipase concentrations of peritoneal fluid were independent of the administration of desmopressin or vasopressors in the donors.

CONCLUSION

In this study donor desmopressin and vasopressor administration did not influence graft function after pancreas transplantation.

Desmopressin impairs microcirculation in donor pancreas and early graft function after experimental pancreas transplantation

BACKGROUND

Protective effects of desmopressin in brain dead organ donors oppose reports on a hypercoagulatory potential and an increased leukocyte-endothelial interaction (LEI) after application of the drug. The aim was to evaluate the effect of desmopressin on organ donor's pancreas and early graft function.

METHODS

Donor microcirculation was evaluated via intra-vital microscopy (IVM) in 24 BR (di/di) rats with central diabetes insipidus, randomly assigned to groups I (control without desmopressin application), II (single i.v. application, no pretreatment) or group III (single i.v. desmopressin application, s.c. pretreatment for 3 days). Microcirculation in recipients was evaluated 1 hr and 6 hr after syngenic pancreas transplantation. Groups III and I served as organ donors. After IVM specimens were taken for histology and immunohistochemistry.

RESULTS

Desmopressin in II vs. I led to temporarily (30') increased LEI (Sticker 274.3+/-87.7 vs. 76.5+/-31.1/mm2 endothelial surface; P<0.01) and impaired microcirculation (MCEV 0.43+/-0.07 vs. 0.99+/-0.06 mm/s; P<0.01). Repeated application reduced MCEV and increased LEI for up to 12 hr. Histology in I vs. III showed increased inflammation (n.s.), necrosis (P<0.05) and vacuolization (P<0.01). Immunohistochemistry revealed increased endothelial P-selectin 20' after application. 6 hr after reperfusion organs from III showed reduced MCEV and increased LEI (P<0.01).

CONCLUSION

Repeated application of desmopressin impairs graft microcirculation. Perfusion of the pancreas is significantly reduced at the beginning of organ tissue conservation as well as after reperfusion. These disturbances might partly be due to observed endothelial P-selectin expression. Application of desmopressin up to 12 hr prior to organ explantation may impact graft quality.

Organ donation in children: role of the pediatric intensive care unit

OBJECTIVES

Children waiting for organ transplants continue to die because of the shortage of available organs. Studies of organ donation in children are scarce. The evaluation of the organ donation experience in a pediatric tertiary care hospital may identify factors that influence actual organ donation rates and lead to strategies to improve pediatric organ donation.

DESIGN

Retrospective study.

SETTING

Pediatric intensive care unit in a Canadian pediatric referral center.

PATIENTS

All children with brain death over an 8-yr period (1990-1997).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of 199 children who fulfilled the criteria for brain death, 153 were medically suitable for organ donation. Families were approached for consent to organ donation in 128 (84%) of the 153 suitable cases. Consent was obtained in 63% (81/128) of those asked. Brain death caused by acute neurosurgical lesions was highly correlated to medical suitability and consent. Families identified as ethnic minorities were significantly more likely to refuse. After consent was granted, organs were procured from 63 (78%) of 81 donors, for an average of 3.6 organs transplanted per donor. There was a failure to procure organs in 22% (18/81) of cases after consent had been granted, primarily as a result of cardiocirculatory instability while in the intensive care unit.

CONCLUSIONS

Despite an encouraging 63% consent rate for organ donation when families are approached, only 41% of potential donors proceeded to actual donation. Strategies for a prospective pediatric study should focus on mandatory request, multicultural issues, and aggressive postconsent medical management and procurement. The pivotal role of the pediatric intensive care unit practitioner should be emphasized.

The potential benefits of the pediatric nonheartbeating organ donor

OBJECTIVE

To examine the population of the pediatric intensive care unit in a large children's hospital to determine the potential importance of pediatric nonheartbeating organ donors (NHBDs).

STUDY DESIGN

We analyzed retrospectively the 6307 admissions to the pediatric intensive care unit at the Children's Hospital of Philadelphia from January 1992 to July 1996 to identify all deaths. The hospital records of the children who had died were then reviewed to determine the mode of death, organ donation rate of heartbeating donors, and the number of potential NHBDs. Criteria for the NHBD included the decision to forgo life-sustaining therapy, death occurring within 2 hours of withdrawal of life support, and the absence of sepsis, HIV, hepatitis, or extracranial malignancy.

RESULTS

Of 319 deaths, 102 (32.0%) died with resuscitation, 84 (26.3%) were brain-dead, 111 (34.8%) had withdrawal of life support, and 22 (6.9%) were on do-not-resuscitate orders. Of the 84 brain-dead children, 74 (88.1%) were medically suitable heartbeating donors, and 43 (58.1%) donated organs. Of the 111 patients who had life support withdrawn, 31 (27.9%) qualified for NHBDs.

CONCLUSIONS

The routine use of the NHBD has the potential to increase organ donation at our institution by 42%. We discuss the ethical issues relating to NHBDs required to properly include these patients as potential organ donors.

Effect of hydroxyethylstarch in brain-dead kidney donors on renal function in kidney-transplant recipients

BACKGROUND

Hydroxyethylstarch used as a plasma-volume expander in brain-dead kidney donors has been suggested to induce osmotic-nephrosis-like lesions. We have studied its effect on kidney-transplant function.

METHODS

52 patients who had received hydroxyethylstarch of iodinated contrast-media before brain death were excluded. 69 other brain-dead patients were prospectively included over 18 months and randomised into two groups. In the hydroxyethylstarch-gelatin group, patients received hydroxyethylstarch up to 33 mL/kg for colloid plasma-volume expansion, and afterwards received modified fluid gelatin. In the gelatin-only group, patients received only modified fluid gelatin as colloid plasma-volume expander. Multiple organs were procured in 29 cases, which included the kidneys in 27 cases (hydroxyethylstarch-gelatin 15, gelatin-only 12).

FINDINGS

There were no significant differences in the characteristics of patients between the two groups of kidney donors or of recipients (except for a small imbalance in sex in the recipients). During the first 8 days after transplantation, nine of 27 (33%) patients required extrarenal haemodialysis or haemodiafiltration in the hydroxyethylstarch-gelatin group compared with one of 20 (5%) in the gelatin-only group (p = 0.029). Serum creatinine concentrations were significantly lower in the gelatin-only group than in the other group (p = 0.009). 10 days after transplantation, mean (SD) serum creatinine was, respectively, 145 (70) and 312 (259) mumol/L.

INTERPRETATION

These data suggest that hydroxyethylstarch used as a plasma-volume expander in brain-dead donors impairs immediate renal function in kidney-transplant recipients.

Intensive care management of paediatric organ donors and its effect on post-transplant organ function

OBJECTIVES

1. To document the clinical course of paediatric beating heart organ donors. 2. To evaluate the effect of the ICU management of pediatric donors on the immediate function of transplanted organs. 3. To examine the validity of current donor selection criteria.

DESIGN

Retrospective chart review and case series study.

SETTING

Multidisciplinary ICU of tertiary referral paediatric hospital.

PATIENTS

All patients who became solid organ donors between January 1980 and July 1990.

OUTCOME MEASURES

1. Incidence of major physiological abnormalities of the cardiovascular, pulmonary, renal and metabolic systems. 2. Number of organs retrieved and transplanted, reasons for non-transplantation of donated organs. 3. Immediate post-transplant function of transplanted organs.

RESULTS

Seventy-seven organ donors were identified from whom 134 kidneys, 31 livers and 12 hearts were transplanted. Sixty (78%) patients developed diabetes insipidus. Sustained hypotension occurred in 41 (53.2%) and was commoner in patients treated with inotropic agents in the presence of a low central venous pressure and in patients with diabetes insipidus who did not receive anti-diuretic hormone replacement. Twenty-seven patients suffered at least one cardiac arrest. The data on post-transplant function were obtained for 129 kidneys (from 70 donors) 30 livers and 9 hearts. Fifty-two kidneys, 10 livers and 2 hearts were transplanted from donors who had suffered at least one cardiac arrest without apparent adverse effect on post-transplant organ function. Thirty-six kidneys from 31 donors suffered either acute tubular necrosis (ATN) or primary non-function. The donors of these organs spent longer in ICU (60.6 +/- 45.7 h versus 41.8 +/- 30.1 h p = 0.045) and had a higher mean maximum serum sodium concentration (163.4 +/- 10.9 versus 158.5 +/- 9.5 mmol/l p = 0.05) than those without these complications. The serum creatinine concentration and degree of inotropic support did not predict post-transplant function. Standard biochemical tests for hepatic function, the dose of inotropic agent received, time in ICU and incidence of hypotension did not predict post-transplant liver function.

CONCLUSIONS

Aggressive fluid resuscitation and management of diabetes insipidus may promote stability in paediatric organ donors. Donor cardiac arrest does not alter the ICU course or compromise post-transplant organ function. The current criteria used for donor selection failed to predict post-transplant organ function and their use may increase organ wastage.

Hemorrheological changes associated with brain death and their implications for potential organ donors

Successful transplantation of donor organs from brain-dead patients requires adequate maintenance of hemodynamic parameters. Blood flow and tissue perfusion are highly dependent upon hemorrheology. The aim of the present study was to evaluate hemorrheological parameters in potential organ donors compared to healthy volunteers. Whole blood-, plasma- and corrected blood viscosity, hematocrit, erythrocyte deformability, and erythrocyte aggregation were obtained in ten consecutive brain-dead patients and ten matched volunteers. Compared to controls, hematocrit and whole blood viscosity at high and medium shear rates and erythrocyte deformability were significantly decreased. Plasma viscosity was significantly increased in all patients. In the same group, a highly significant increase was observed at all shear rates when viscosity was corrected for hematocrit. Definite rheological abnormalities were found in the blood of brain-dead patients, something which might lead to impaired organ function after transplantation. Therefore, optimizing such parameters by special fluid management may be of importance in potential organ donors.

Nurses' responses to organ procurement from nonheartbeating cadaver donors

Brain-dead donors (ie, heartbeating cadaver donors) have been an accepted source of transplantable organs for many years. Clinicians in some medical centers are considering nonheartbeating cadaver donors (ie, patients who decide to discontinue life-support measures and become organ donors) as another source of transplantable organs. This study explored registered nurses' responses to caring for nonheartbeating cadaver donors and described their intentions to care for such donors, their reactions to caring for them, and the meaning of these reactions and intentions. The nurses interviewed expressed resentment at the intrusion of technology; they preferred brain-dead status in organ donors; they feared legal repercussions from families; they speculated about nonheartbeating cadaver donors' ability to feel pain, and they expressed concern about withdrawing life-support measures, honoring patients' wishes, allocating nursing care as a scare resource, and witnessing family members' pain.

[Can hydroxyethylamidon be used during intensive care of brain-dead organ donors?]

In France, most of the kidney grafts are obtained from brain dead organ donors. Brain death induces numerous changes, especially in haemodynamic status, requiring the infusion of large volumes of fluid. The aim of this study was to evaluate the effect of hydroxyethyl starch (HES) on the organ donors and the kidney graft function in recipients. We compared two groups of brain dead organ donors and the kidney grafts, differing by the infused solutions: either a combination of HES (Elohes, Biosedra) and 4% human albumin solutions (HES group), or albumin alone in the control group (Albumin group). In the two groups, sex-ratio, age, cause of brain death and duration of therapy were similar. Fluid requirements were identical in the two groups: respectively 2,211 +/- 1,512 mL in the Albumin group vs 2,452 +/- 1,094 mL in the HES group (p = 0.17). However, the volume of albumin was significantly decreased in the HES group: 711 +/- 822 mL (p = 0.0001). Therefore the cost was lower in the latter: 638 +/- 633 vs 1766 +/- 788 FF. The coagulation status was not significantly different between the two groups. Amylasemia was higher in the HES group, but the difference was not significant. In the Albumin group, urinary output increased, but not significantly and creatinemia was decreased: 113.9 +/- 62 vs 131.5 +/- 44 mumol.L-1 (p < 0.05). The two groups of recipients were also similar for sex-ratio, age, kind of graft, cause of the chronic renal failure and ischaemia times.(ABSTRACT TRUNCATED AT 250 WORDS)

[Anesthesia and intensive care for heart-lung transplantation]

Since Shumway carried out the first successful heart-lung transplant (HLT) in Stanford in 1981, HLT has become a new therapeutic means for patients with end-stage pulmonary disease or arterial hypertension. However, it is still rarely carried out because of a lack of donors and the complexity of the surgery and postoperative course. This review described the criteria for proper donor and recipient selection, as well as the anaesthetic and postoperative management of HLT patients at Marie Lannelongue Hospital. The lack of suitable organ grafts results, at least in part, from improper donor management. Pulmonary oedema by fluid overloading and excessive haemodilution should be carefully prevented. Low doses of catecholamines and vasopressin maintain circulatory stability and convenient organ function. The indications for HLT (primary pulmonary hypertension, Eisenmenger's complex, and end-stage bronchopulmonary disease) are all characterized by severe pulmonary hypertension, hypoxaemia and cardiac failure. Careful anaesthetic induction is required to avoid circulatory collapse. Cardiopulmonary bypass (CPB) should be started early, so that mediastinal dissection may be carried out in satisfactory haemodynamic conditions. After unclamping the aorta, circulatory support with fluid and catecholamine infusion is often required. High inspired oxygen fraction and end-expiratory positive pressure may be required because of reperfusion pulmonary oedema. Blood transfusion is often needed as there are major blood losses due to dissection of the posterior mediastinum during CPB. Postoperative catecholamine administration is prolonged over several days. Negative fluid balance is often necessary to reduce pulmonary oedema. Improvement in surgical technique, early extubation, and late prescription of steroids have reduced the incidence of tracheal complications. Acute renal failure often occurs as a result of prolonged CPB, hypovolaemia, drug nephrotoxicity and sepsis. Bacterial complications (pneumonia, mediastinitis) are the main causes of early death. After the 15th postoperative day, opportunistic infections and allograft rejection are the main complications. Since 1981, major advances in HLT recipient management resulted in improved survival rates (70-80% at 1 year, and 60-70% at 2 years for the best teams). Despite the complexity of management, and the longterm threat of obliterative bronchiolitis, HLT is, at present time, the only possibility for these young patients to recover a normal quality of life.

Mortality during intensive care after orthotopic liver transplantation

The postoperative course of 335 adult patients who underwent orthotopic liver transplantation from 1968-1987 was reviewed retrospectively to identify patients who died in the intensive care unit and the causes of death. Forty-four percent of all deaths occurred in the intensive care unit. The mortality rate in the intensive care unit peaked in 1984 (48%), but decreased to 11% in 1987. The main causes for death in the intensive care unit were infection (55%) and haemorrhage (19%). The patients who died spent more time in the intensive care unit, had a longer period of tracheal intubation and received a larger intra-operative blood transfusion than patients who died in other locations.