Monitoring Of Organ Function Research Articles

Machine learning enabled multiple illumination quantitative optoacoustic oximetry imaging in humans.

Optoacoustic (OA) imaging is a promising modality for quantifying blood oxygen saturation (sO2) in various biomedical applications - in diagnosis, monitoring of organ function, or even tumor treatment planning. We present an accurate and practically feasible real-time capable method for quantitative imaging of sO2 based on combining multispectral (MS) and multiple illumination (MI) OA imaging with learned spectral decoloring (LSD). For this purpose we developed a hybrid real-time MI MS OA imaging setup with ultrasound (US) imaging capability; we trained gradient boosting machines on MI spectrally colored absorbed energy spectra generated by generic Monte Carlo simulations and used the trained models to estimate sO2 on real OA measurements. We validated MI-LSD in silico and on in vivo image sequences of radial arteries and accompanying veins of five healthy human volunteers. We compared the performance of the method to prior LSD work and conventional linear unmixing. MI-LSD provided highly accurate results in silico and consistently plausible results in vivo. This preliminary study shows a potentially high applicability of quantitative OA oximetry imaging, using our method.

Assessment of tissue biochemical and optical scattering changes due to hypothermic organ preservation: a preliminary study in mouse organs

Clinical transplantation medicine currently faces a significant shortage of organ donors to supply the need of an increasingly aged population. Despite this, organs are still discarded due to graft stress induced by hypoxia or ischemia prior to procurement. Approaches to minimize donor organ discard include appropriate organ preservation and monitoring of organ function. Predominant organ preservation strategies involve hypothermia between 0 °C and 12 °C. In this study, we investigate the effect of temperature alone on tissue microstructural and biochemical parameters during cold preservation of mouse organs. To the best of our knowledge, this is the first study evaluating this cooling effect on multiple tissue parameters such as blood oxygenation, concentrations of blood, methemoglobin, water, lipid, and bile as well as scattering amplitude, Mie scattering power and fraction of Rayleigh scattering. These parameters were extracted by using diffuse reflectance spectroscopy spectral fitting at an extended wavelength range between 450 and 1590 nm and a Monte Carlo look-up table including a wide range of tissue optical properties compared to previous studies. Our findings can be used to understand biological processes undertaking cooling to propose new strategies involving optimized cold storage times and composition of organ preservation solutions for minimized cellular and tissue damage.

Abdominal compartment syndrome among surgical patients.

Abdominal compartment syndrome (ACS) develops when organ failure arises secondary to an increase in intraabdominal pressure. The abdominal pressure is determined by multiple factors such as blood pressure, abdominal compliance, and other factors that exert a constant pressure within the abdominal cavity. Several conditions in the critically ill may increase abdominal pressure compromising organ perfusion that may lead to renal and respiratory dysfunction. Among surgical and trauma patients, aggressive fluid resuscitation is the most commonly reported risk factor to develop ACS. Other conditions that have also been identified as risk factors are ascites, hemoperitoneum, bowel distention, and large tumors. All patients with abdominal trauma possess a higher risk of developing intra-abdominal hypertension (IAH). Certain surgical interventions are reported to have a higher risk to develop IAH such as damage control surgery, abdominal aortic aneurysm repair, and liver transplantation among others. Close monitoring of organ function and intra-abdominal pressure (IAP) allows clinicians to diagnose ACS rapidly and intervene with target-specific management to reduce IAP. Surgical decompression followed by temporary abdominal closure should be considered in all patients with signs of organ dysfunction. There is still a great need for more studies to determine the adequate timing for interventions to improve patient outcomes.

Kidney and liver dysfunction in cardiogenic shock.

Organ dysfunction is a key feature of cardiogenic shock. Active revascularization and contemporary management in intensive care has improved prognosis in cardiogenic shock, but mortality is still unacceptably high. This review will discuss the prevalence, manifestation, management and clinical impact of kidney and liver dysfunction in cardiogenic shock. Patients with cardiogenic shock more frequently have several comorbidities that make them at risk of developing multiorgan failure, including renal and liver dysfunction. Kidney and liver injury and dysfunction will markedly increase mortality of patients with cardiogenic shock. Management requires active monitoring of organ function and knowledge of criteria for detection and classification of organ injury. The SOFA score for prediction of mortality in the critically ill incorporates organ injury and can be used also in cardiogenic shock, but risk prediction models specific for cardiogenic shock exist. Biomarkers reflecting different pathways activated in cardiogenic shock correlate with severity of organ dysfunction and may improve risk prediction in cardiogenic shock. Preliminary data suggest that they can even be future treatment targets. Monitoring renal and hepatic function and identifying injury and dysfunction of these organs is essential for the management and mortality risk assessment of patients in cardiogenic shock.

Analysis of causes and treatment methods of complication of early acute kidney injury in four severely burned patients

Objective: To analyze the causes of complication of early acute kidney injury (AKI) in four severely burned patients, and to explore the related treatment methods. Methods: The clinical data of 4 patients with severe burn complicated with early AKI admitted to Guangzhou Red Cross Hospital Affiliated to Medical College of Jinan University (hereinafter referred to as our hospital) from June 2014 to December 2017 were retrospectively analyzed. All the patients were male, aged 23-33 (30±5) years old, with depth of burns ranged from deep partial-thickness to full-thickness, complicated with myofascial compartment syndrome of extremities and varying degrees of striated muscle injury, and treated in other hospitals before transfer to our hospital. The patients were numbered from small to large according to the total burn area. The total burn area of patients No. 1, 2, 3, and 4 was 10%, 80%, 90%, and 95% total body surface area respectively, their occurrence time of early AKI was 48, 11, 29, and 48 hours after injury respectively, and their time of arriving our hospital was 60, 11, 29, and 144 hours after injury respectively. Hypovolemic shock occurred in patients No. 2 and 3 at admission to our hospital. All the patients received continuous renal replacement therapy (CRRT) after admission to our hospital. Under the support of hemodynamic monitoring and organ function monitoring, the limbs complicated with myofascial compartment syndrome were incised, thorough decompression exploration was performed, and necrotic muscle tissue was removed or amputation was performed. After escharectomy and decompression of limbs, fresh granulation wounds were formed by temporarily covering wounds with Jieya dressing skin or pig skin, multiple debridements, and vacuum sealing drainage. Fresh granulation wounds and other wounds underwent staged eschar excision and shaving were covered with autologous Meek skin graft, particulate skin graft, reticular skin graft and small skin graft respectively. The treatment outcome, CRRT time, operation times, time of recovery of serum creatinine and myoglobin, length of hospital stay, and follow-up were recorded. Results: All the 4 patients were cured after transfer to our hospital. Among them, totally 5 limbs of patients No. 1 and No. 4 underwent amputation because of complication of myofascial compartment syndrome and a large amount of necrotic muscle which could not be preserved. Patients No. 1, 2, 3, and 4 were treated with CRRT for 19, 35, 14, and 25 days respectively and performed with operation for 5, 6, 10, 8 times respectively. Serum creatinine of patients No. 1, 2, 3, and 4 returned to normal on 22, 35, 37, and 48 days after transfer respectively, and their serum myoglobin returned to normal on 18, 28, 25, and 30 days after transfer respectively. Patients No. 1, 2, 3, and 4 were hospitalized for 52, 105, 148, and 156 days and discharged after basic wound healing. Follow-up for 1 to 36 months showed no abnormal renal function in 4 patients. Conclusions: The early AKI in patients No. 1 and 4 was caused by rhabdomyolysis after severe burn complicated with myofascial compartment syndrome, while that of the other 2 cases were also related to hypovolemic shock and poor renal perfusion. The success rate of early AKI treatment in severely burned patients can be effectively improved by removing the causes of diseases at the same time of CRRT and actively treating burn wounds under the support of organ function and hemodynamic monitoring.

Variability in intensive care unit length of stay after liver transplant: Determinants and potential opportunities for improvement

PurposeRecovery after liver transplant (LT) requires extensive resources, including prolonged intensive care unit stays. The objective of this study was to use an assessment tool to determine if LT recipients remain in ICU beyond designated indications. MethodsRecords from 100 consecutive LTs performed in a single institution were retrospectively reviewed. An admission, discharge, and triage screening (ADT) tool was utilized to assess the indications for each ICU day. Data collected included demographics; pre-, intra-, and post-operative course; and complications. Days not meeting ADT criteria were considered additional ICU days. Results100 patients: mean age 55 years (range 24–78 years) and mean MELD score 30 (range 6–47). Three recipients who died within one week were excluded. Forty-eight (49.5%) patients had a total of 75 additional days on initial ICU stay. Univariate analysis revealed no significant differences between patients with and without additional days. 12/97 (12.4%) patients returned to ICU including 5/48 and 7/49 with and without additional days. ConclusionNearly half of the LT recipients remained in ICU an average of 1.6 additional days. Monitoring of organ function appeared to be the most common reason. Opportunities to improve resource utilization could include transfer to an intermediate/progressive care (“step-down”) unit.

Editor's Choice – Current Options and Recommendations for the Treatment of Thoracic Aortic Pathologies Involving the Aortic Arch: An Expert Consensus Document of the European Association for Cardio-Thoracic Surgery (EACTS) & the European Society for Vascular Surgery (ESVS)

Editor's Choice – Current Options and Recommendations for the Treatment of Thoracic Aortic Pathologies Involving the Aortic Arch: An Expert Consensus Document of the European Association for Cardio-Thoracic Surgery (EACTS) & the European Society for Vascular Surgery (ESVS)

Practice and thinking about the establishment and management of burn intensive care unit

The treatment of critically burned patients has benefited from the development of knowledge and technologies that we got in critical care medicine of our country in the past ten years. The close-ended management model of general intensive care unit (ICU) and the idea of general ICU doctors who treat the monitoring of organ function and alternative therapy of organs as their primary tasks would affect the treatments for special critical patients hospitalized in general ICU, especially for those patients who were severely burned. If the burn wounds of patients are not treated timely, properly or in effective manner, the final treatment outcome would be affected. Therefore, the establishment of burn ICU is necessary. The development and close-ended management of burn specialty ICU has significantly improved the success rates, reduced complications, shortened hospitalization time, and increased the quality of wound healing of severe burn patients in the past more than 10 years in our unit. With the reducing of burn, especially severe burn accidents, the construction of regional burn center and burn specialty ICU locating in burn center is necessary. It can not only reduce the waste of medical resource, but also ensure timely and professional treatments for the patients in sudden fire accidents. At present, there is no consensus on the establishment and management model of burn specialty ICU, and further discussion is needed in practice.

The Fundamental Challenges in Organ Transplantation

Organ transplantation is a unique form of therapy for organ failure. The results are overall extremely good, saving the lives of a large cohort of patients that would otherwise die or be left with reduced life expectancy and a poor quality of life. Yet, the success of transplantation creates a problem that is increasingly difficult to manage, - the shortage of organ grafts available for transplantation. Simultaneously, the average age of deceased donors increases in most western countries, and a high prevalence of life-style associated diseases like obesity, diabetes and hypertension impacts organ quality. Various strategies have been applied to cope with the ever-increasing demand for organs. Extended criteria grafts can in many instances be used successfully if transplanted to properly selected recipients, but are associated with an increased risk of short and long-term graft loss due to poor function. Donation after circulatory death as an adjunct to donation after brain death have been successfully introduced in many countries and currently contributes to a significant part of all organs transplanted in Europe and the US (1). Both strategies have raised the need for close monitoring of organ function and therapeutic measures to improve organ quality. Machine perfusion of organs could be a way to both reduce the negative impact of ischemia (2), (3) but moreover as an innovative strategy for reducing the ischemia-reperfusion injury at revascularization (4). Ultimately the concept of using ex-vivo perfusion as a way to achieve reconditioning of organs in order to convert “non-transplantable organs into acceptable grafts has emerged. The approached was pioneered in Lungs by Steen and coworkers in Sweden in 2007 (5). Recently, a similar approach have been reported in liver transplantation (6), (7). The significant progress seen in organ preservation and possible reconditioning over the recent years has even made heart transplantation after circulatory death possible (8). The concerted efforts of the transplant community to find new innovative strategies to alleviate organ shortage is a result of continuous and systematic work, and clearly demonstrates the importance of scientific medicine in improving the treatment and care for our patients.

Consensus Report by the Pediatric Acute Lung Injury and Sepsis Investigators and Pediatric Blood and Marrow Transplantation Consortium Joint Working Committees on Supportive Care Guidelines for Management of Veno-Occlusive Disease in Children and Adolescents, Part 3: Focus on Cardiorespiratory Dysfunction, Infections, Liver Dysfunction, and Delirium

Some patients with veno-occlusive disease (VOD) have multiorgan dysfunction, and multiple teams are involved in their daily care in the pediatric intensive care unit. Cardiorespiratory dysfunction is critical in these patients, requiring immediate action. The decision of whether to use a noninvasive or an invasive ventilation strategy may be difficult in the setting of mucositis or other comorbidities in patients with VOD. Similarly, monitoring of organ functions may be very challenging in these patients, who may have fulminant hepatic failure with or without hepatic encephalopathy complicated by delirium and/or infections. In this final guideline of our series on supportive care in patients with VOD, we address some of these questions and provide evidence-based recommendations on behalf of the Pediatric Acute Lung Injury and Sepsis Investigators and Pediatric Blood and Marrow Transplantation Consortium Joint Working Committees.

Anaesthetic Considerations in the Perioperative Management of Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy.

Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy has emerged as one of the primary modalities of treatment of diffuse peritoneal malignancies. It is a complex surgical procedure with the patients facing major and potentially life threatening alterations of haemodynamic, respiratory, metabolic and thermal balance with significant fluid losses and the perioperative management is challenging for anaesthesiologists and intensive care physicians. Though the alterations are short lived, these patients require advanced organ function monitoring and support perioperatively. The anaesthesiologist is involved in the management of haemodynamics, respiratory function, coagulation, haematologic parameters, fluid balance, thermal variations, and metabolic and nutritional support perioperatively. The chemotherapy instillate used are known to cause nephrotoxicity, cardiotoxicity, dyselectrolytemia and lactic acidosis. The preoperative polypharmacy for pain control, previous surgery and/or chemotherapy, malnourished status secondary to feeding problems and tumour wasting syndrome make the task all the more challenging. The anaesthesiologist also needs to consider the perioperative care from a quality of life perspective and proper preoperative counselling is important. The present overview summarizes the challenges faced by the anaesthesiologist regarding the pathophysiological alterations during the Cytoreductive surgery and Hyperthermic intraperitoneal chemotherapy in the preoperative, intraoperative and postoperative periods.

Efficiency and safety of inhalative sedation with sevoflurane in comparison to an intravenous sedation concept with propofol in intensive care patients: study protocol for a randomized controlled trial

BackgroundState of the art sedation concepts on intensive care units (ICU) favor propofol for a time period of up to 72 h and midazolam for long-term sedation. However, intravenous sedation is associated with complications such as development of tolerance, insufficient sedation quality, gastrointestinal paralysis, and withdrawal symptoms including cognitive deficits. Therefore, we aimed to investigate whether sevoflurane as a volatile anesthetic technically implemented by the anesthetic-conserving device (ACD) may provide advantages regarding ‘weaning time’, efficiency, and patient’s safety when compared to standard intravenous sedation employing propofol.Method/DesignThis currently ongoing trial is designed as a two-armed, monocentric, randomized prospective phase II study including intubated intensive care patients with an expected necessity for sedation exceeding 48 h. Patients are randomly assigned to either receive intravenous sedation with propofol or sevoflurane employing the ACD. Primary endpoint is the comparison of the ‘weaning time’ defined as the time required from discontinuation of the sedating agent until sufficient spontaneous breathing occurs. Moreover, sedation depth evaluated by Richmond Agitation Sedation Scale and parameters of patient’s safety (that is, vital signs, laboratory monitoring of organ function) as well as the duration of mechanical ventilation and overall stay on the ICU are analyzed and compared. An intention-to-treat analysis will be carried out with all patients for whom it will be possible to define a wake-up time. In addition, a per-protocol analysis is envisaged. Completion of patient recruitment is expected by the end of 2012.DiscussionThis clinical study is designed to evaluate the impact of sevoflurane during long-term sedation of critically ill patients on ‘weaning time’, efficiency, and patient’s safety compared to the standard intravenous sedation concept employing propofol.Trial registrationEudraCT2007-006087-30; ISCRTN90609144

A critical care nurse's guide to intra abdominal hypertension and abdominal compartment syndrome

Abdominal compartment syndrome (ACS) is a life-threatening syndrome that is increasing in incidence amongst critically ill patients. A 2005 survey of critical care nurses revealed that there were recognised knowledge deficits of ACS amongst surveyed nurses. The purpose of this review is to inform critical care nurses about ACS and its antecedent, intra abdominal hypertension (IAH). Detection techniques, causes, clinical manifestations and pathophysiology of IAH and ACS will be outlined and medical and nursing management will be reviewed. The incidence of ACS is reported to be up to 35% in the intensive care population with reduced survival when compared to other intensive care patients. Physiological changes that occur with ACS include compromise to the cardiovascular, respiratory, renal and neurological systems and development of metabolic acidosis. Management may incorporate percutaneous drainage of ascitic fluid, use of muscle relaxants, prone positioning and surgical intervention to open, decompress and gradually close the abdomen. Throughout this care the critical care nurse should ensure accurate monitoring of organ function, assessment for recurrence of ACS as well as the amount and type of drainage, appropriate wound management and provision of physical and psychosocial support of the patient. These aspects of care have the potential to impact significantly on patient outcome.

Parameters of multiple organ dysfunction fail to predict secondary amputation following limb salvage in multiply traumatized patients

Objective: the purpose of this retrospective analysis was to evaluate whether systemic parameters that are used to characterize multiple organ dysfunction could also be used to predict the optimal time for amputation in patients failing limb salvage surgery following severe extremity injury. Methods: the principal criterion for the study group was a lower limb amputation following a type IIIb or IIIc open tibial shaft fracture in multiply traumatized patients. This group was then divided into one group of primary amputation (group A) and one group of secondary amputation (group B). Beside these groups a third group of total traumatic lower limb amputation was recruited (group C). Data analysis included demographics, injury severity according to the ISS, evaluation of the limb injury by three different salvage scores (HFS, MESS and NISSSA) and organ function monitoring by the Denver MOD Score over a 14-day period posttrauma or up to 7 days after secondary amputation. Results: within the period 1987–1997 a total of 15 patients were recruited for group A (primary amputation), 10 patients for group B (secondary amputation) and nine patients for group C (traumatic amputation). The MOD score was only positive for pulmonary dysfunction, also reflected by the Horovitz quotient, in those patients that died later in either group. Mortality was higher in group A (three out of 15) compared with group B (one out of 10), which may be due to a higher ISS in group A (mean ISS 28.2 vs. 21.0 of group B). Although the MOD score of all recovered patients revealed no significant difference between group A and B, secondary amputation resulted in significantly longer demand of mechanical ventilation. According to our results secondary amputation may lead to transiently decreased pulmonary function but does not necessarily end in multiple organ dysfunction. The need for amputation in failed limb salvage was not indicated by systemic parameters. Conclusion: the right time for secondary amputation in order to prevent subsequent pulmonary dysfunction cannot be predicted by parameters otherwise indicating organ dysfunction. As the risk of secondary amputation for developing pulmonary dysfunction apparently cannot be estimated the decision for amputation or limb salvage should be made initially after trauma and should be the definite one.

Daily SOFA scoring for ICU patients?

SOFA might be a useful tool for monitoring of organ function in ICU patients [1]. We evaluated optimal frequency of SOFA acquisition in long term ICU patients (i.e. patients staying in the ICU >3 days).

Does SOFA and TISS scores correlate in long term ICU patients?

SOFA score is a useful tool for monitoring of organ function in ICU patients [1]. TISS score is used for measuring of workload in intensive care [2]. We studied if there is any link between SOFA and TISS scores in long term ICU patients (i.e. patients staying in the ICU >3 days).

Nuclear medicine in the monitoring of organ function and the detection of injury related to cancer therapy

This article emphasizes the role of nuclear medicine in the monitoring of function to prevent or limit injury in organs in which toxicity related to cancer therapy may have implications for the survival and/or the quality of life of the patient. After a brief discussion of the advantages of nuclear medicine techniques in detecting organ injury, the effect of radiation therapy and chemotherapy on normal tissue is discussed, underlining the need to characterize adverse effects of cancer therapy in long-term survivors. The use of radionuclides to document organ injury and effects from cancer therapy in heart, digestive tract, kidneys, lungs, major salivary glands, skeleton and brain is then reviewed. In a short section the potential applicability of positron emission tomography in documenting organ toxicity during cancer therapy is discussed. Thanks to the various available radiopharmaceuticals, the ability of the tracers to document specific functional aspects, the improved methods for visualization and quantitation of organ injury and the possibilities of physiological or pharmacological intervention, nuclear medicine gives the clinician potent tools for the monitoring of organ function at risk during cancer therapy. The trend to intensify cancer treatment by combining various treatment modalities and the increasing chances of prolonged survival in a large number of patients call for effective integration of nuclear medicine methods into the recommended guidelines for grading organ injury in clinical oncology.

The clinical significance of prostaglandins and thromboxane as mediators of septic shock.

An evaluation was made of 106 surgical patients with Gram-negative septic shock, both for clinical criteria as well as the biochemical mediators endotoxin, prostaglandin F2 alpha, prostaglandin I2 (prostacyclin), and thromboxane. These data were correlated to various defined shock phases, functional data of vital organs, and clinical outcome. Patients underwent invasive organ function monitoring and the usual laboratory tests of intensive care. Prostaglandins and thromboxane were measured radioimmunologically, endotoxin by the limulus amebocyte lysate test. Endotoxin proved to be a more accurate predictor of severe sepsis than did positive blood cultures. Endotoxin as well as prostaglandins and thromboxane are predominantly released in early shock phases, appearing in plasma concentrations, which correlate with the severity of organ failure. Sepsis-induced respiratory failure coincides with a deterioration of pulmonary prostaglandin inactivation, which contributes to the release mechanism. High systemic prostacyclin activity benefits the patients' organ functions and clinical outcomes, while a predominance of thromboxane seems to effect the opposite. Transpulmonary-thromboxane gradients correlate significantly with pulmonary hypertension in the early phases of septic shock.