METABOLIC Flashcards
What are the main ways in which renal failure can be prevented?
Staying hydrated and avoiding hypovolaemia - talk about the risk of dehydration with d+v
Stopping nephrotoxic drugs
Offer written information to pt
Consider admitting pt to hopsital if they are hypovolaemic and unwell - may benefit from IV drugs
Monitoring Cr and eGFR in those known to have reduced renal functioning and the elderly
Monitoracutely unwell
Regular screening of diabetic and hypertensive patients for renal complications
Prevent childhood UTIs and monitor children who have suffered with them in the past
Outline the impact of haemodialysis on physical and social well-being and psychological health?
requires am AV fistula
4 hours 3x a week in a dialysis centre but 3 days dialysis free
risk of blood infections, thrombosis and internal bleeding
more expensive
Outline the impact of peritoneal dialysis on physical and social well-being and psychological health
less effective than haemodialysis
more flexibility than haemodialysis and better tolerated
complications include peritonitis
have to be trained to work the equipment
cheaper than haemodialysis
if peritoneum becomes fibroses you have to switch to haemodialysis
What governs human transplantation?
The human tissue authority
How is the transplant system organised in the UK?
NHS Blood and Transplant: this is the organization responsible for managing the UK’s organ donation and transplantation system. It works with hospitals, transplant centers, and other organizations to ensure that donated organs are allocated fairly and effectively.
Organ allocation: Organs are allocated based on a number of factors, including the urgency of the transplant, the medical compatibility of the donor and recipient, and the distance between the donor and recipient hospitals.
Waiting lists: Patients who need a transplant are placed on a waiting list, which is maintained by NHSBT. The waiting list is prioritized based on the severity of the patient’s illness and the likelihood of a successful transplant.
Opt-out system: As of May 2020, England operates under an opt-out system for organ donation, which means that individuals are presumed to consent to organ donation unless they have explicitly opted out. Wales, Scotland, and Northern Ireland have similar opt-out systems.
Living donation: The UK also has a system for living donation, in which individuals can donate a kidney or part of their liver to a person in need. Living donors undergo a thorough evaluation process to ensure that they are healthy enough to donate and that the transplant is in the best interest of both the donor and the recipient.
How does the UK’s transplantation system differ from approaches adopted in other countries?
UK is opt out as in Spain, France, Belgium, Croatia, wales etc
Some countries use financial incentives
Cultural and religious beliefs of different communities can impact attitudes towards organ donation e.g. countries with large Muslim populations such as Saudi Arabia and Iran have specific policies to keep donation within the context of Islamic law
How does the transplantation service ration the limited supply of organs for transplant?
Clinical urgency
Tissue type
Waiting time
Geographic location
National transplant list
Discuss the healthcare resource implications of organ transplantation, in particular the cost-effectiveness
- Cost of transplantation: Organ transplantation is a complex and expensive procedure that requires a significant amount of resources. The cost of the procedure itself, as well as the cost of post-operative care and ongoing medical management, can be substantial.
- Availability of organs: The supply of organs is limited, which can create significant resource constraints. Hospitals must maintain facilities for organ storage and transportation, and medical staff must be trained to perform transplantation surgeries.
- Long-term costs: Patients who receive organ transplants often require ongoing medical care and monitoring, which can be expensive. In addition, the cost of immunosuppressant medications, which are necessary to prevent organ rejection, can be a significant financial burden for patients and healthcare systems.
Despite the significant costs involved, organ transplantation is generally considered to be a cost-effective intervention, as it can improve patient outcomes and quality of life. Many studies have demonstrated that the long-term benefits of transplantation outweigh the initial costs, and that transplantation can be a cost-effective alternative to other forms of medical management.
Discuss the healthcare resource implications of blood transplantation, in particular the cost-effectiveness
Cost of blood collection and processing: Blood donation requires a significant amount of resources, including personnel, facilities, and equipment. Blood must be collected and processed in a sterile environment, and must be screened for infectious diseases before it can be used in transfusions.
Availability of blood: Like organs, the supply of blood is limited, which can create significant resource constraints. Hospitals must maintain facilities for blood storage and transportation, and medical staff must be trained to perform transfusions.
Long-term costs: Patients who receive blood transfusions may require ongoing medical care and monitoring, which can be expensive.
Despite the resource implications, blood donation is generally considered to be a cost-effective intervention, as it can save lives and improve patient outcomes. Many studies have demonstrated that the benefits of blood transfusions outweigh the costs, and that blood donation can be a cost-effective alternative to other forms of medical management.
Describe the opt out system for organ donations?
Now that the law has changed, it will be considered that you agree to become an organ donor when you die, if:
you are over 18; you have not opted out;
you are not in an excluded group (people who lack the mental capacity, people who have lived in England for <12 months, visitors to England and those not living here voluntarily)
Outline some ethical dilemmas with the current organ donation system in the uk?
Consent - The opt-out system does not secure people’s actual consent to donation, and so fail to respect their autonomy rights to decide what happens to their organs after they die.
Fairness - Currently, organs are allocated based on medical need and compatibility, which means that some individuals may receive organs ahead of others who are also in need. This raises questions about whether the system is truly fair, and whether other factors such as social or economic status should be taken into account.
Organ trafficking - There have been cases where individuals have been coerced or forced to donate their organs, or where organs have been obtained through illegal means
Death - There is also debate over the definition of death and when it is appropriate to remove organs for donation. Some argue that the current definition of brain death may not be sufficient and that organs are sometimes removed when the donor is not truly dead. This raises questions about the ethics of organ donation and the need for stricter guidelines and oversight.
Cultural and religious beliefs - . Some cultures and religions have beliefs that conflict with organ donation, and individuals may be hesitant to donate their organs because of these beliefs. This raises questions about how to respect individuals’ beliefs while also encouraging organ donation.
What is the NHS Organ Donor Register?
A database maintained by the NHS that records the wishes of individuals regarding organ donation after their death. The register is a confidential and secure electronic database that is accessible only to authorized medical personnel.
By registering with the NHS Organ Donor Register, individuals can indicate whether they would like to donate their organs after their death.
What is the National Transplant Register?
a database maintained by NHS Blood and Transplant (NHSBT) in the United Kingdom that records information about organ donation and transplantation. It is a comprehensive database that contains information on all aspects of the organ donation and transplantation process, including the number of people on the waiting list for organs, the number of organs available for donation, and the outcomes of transplant procedures.
The NTR serves several important functions. It allows medical professionals to track the availability and allocation of organs, and to monitor the outcomes of transplant procedures. It also helps to ensure that organs are allocated fairly and equitably, based on medical need and compatibility.
The NTR also plays an important role in research and development. Researchers can use the data in the NTR to study trends and patterns in organ donation and transplantation, and to identify areas where improvements can be made.
Summarise the current evidence of the effectiveness of PSA screening in the UK
The UK National Screening Committee does not recommend population-wide PSA screening for prostate cancer, as the benefits are uncertain and the risks, including overdiagnosis and overtreatment, may outweigh them.
PSA screening has been associated with overdiagnosis and overtreatment, leading to unnecessary side effects such as impotence and urinary incontinence.
PSA is highly sensitive but very poorly specific!
Following diagnosis the median survival is 15 years so most pt have to live the rest of their life knowing they have cancer
What can raise PSA?
Prostate cancer
BPH
Prostatitis
UTI
Age-normal increase
What are the benefits of PSA testing?
Early detection — PSA testing may lead to prostate cancer being detected before symptoms develop.
Early treatment — detecting prostate cancer early before symptoms develop may extend life or facilitate a complete cure.
What are the limitations of PSA testing?
False negatives
False positives in 75%
Unnecessary invasive investigations with adverse effects
Unnecessary treatment
What is WHOs diagnostic criteria for diabetes?
Fasting venous plasma glucose >=7
2 hour post load venous plasma glucose (OGTT) >=11.1
2 hour post load capillary plasma glucose (OGTT) >=12.2
Random plasma glucose >=11/1
HbA1c 48
If asymptomatic repeat the same test on a subsequent day to confirm diagnosis
Explain sensitivity and specificity’s relevance to diagnostic thresholds
When a diagnostic threshold is set high, the test will identify only those individuals with the disease who have high levels of the marker being measured, leading to high specificity but low sensitivity. Conversely, when the threshold is set low, the test will identify individuals with lower levels of the marker, leading to high sensitivity but low specificity.
Therefore, the choice of diagnostic threshold is a trade-off between sensitivity and specificity. In clinical practice, the choice of diagnostic threshold depends on the specific diagnostic goal and the consequences of false positives and false negatives. For example, in a screening program, a high sensitivity test may be preferred to avoid missing cases of disease, while in a confirmatory test, a high specificity test may be preferred to avoid false positives.
Define ROC curve and its use in evaluating diagnostic thresholds
A receiver operating characteristic curve is a graphical representation of the performance of a diagnostic test across different diagnostic thresholds. ROC curves plot the true positive rate (sensitivity) against the false positive rate (1-specificity) for all possible values of the diagnostic threshold, producing a curve that characterizes the overall diagnostic accuracy of the test.
Explain the different components of an ROC curve and discuss the interpretation of an ROC curve
Axis - x-axis is false positive (1-spec) and y axis is true positive (sens)
Area under the curve (AUR) - overall diagnostic accuracy of the test. 0.5 is useless so you want it to be 0.5-1. AUR of 1 is perfect so the higher the AUC the better it is.
Diagonal line - shows the uninformative test so a test that performs better than chance will have a ROC curve above the diagonal line
Explain the process of determining diagnostic thresholds
Determining diagnostic thresholds involves setting a cutoff value for a diagnostic test that distinguishes between positive and negative test results. The diagnostic threshold is chosen to optimize the trade-off between sensitivity and specificity, taking into account the clinical context and the desired balance between accuracy and cost-effectiveness.
Discuss the different methods used to determine diagnostic thresholds, such as empirical methods, expert opinion, and receiver operating characteristic analysis
Describe the advantages and disadvantages of each method
Empirical methods - sleeecting the diagnostic threshold based on the distribution of test results in a population with and without the condition being diagnosed i.e. setting it to the point where the test result has the highest likelihood ratio. Simple and easy but may not take into account the variability of the test results or clinical context
Expert opinion - involves consulting with clinical experts to determine the appropriate diagnostic threshold based on their clinical experience and judgement. This may be useful for new diagnostic tests or when there is limited empirical data available but may be subject to bias and may not be generalisable to other populations.
Receiver operator characteristic analysis - this involves selecting the threshold that optimises the balance between sens and spec which is most rigorous and takes into account the entire range of possible diagnostic thresholds and allows for direct comparison between tests bit it requires a sufficient sample size and may be computationally complex
Evaluate the evidence for the benefit of blood pressure control in type 2 diabetes?
UK Prospective Diabetes Study - Tight blood pressure control in people with hypertension and type 2 diabetes resulted in reductions in diabetes-related deaths, complications related to diabetes, progression of diabetic retinopathy and deterioration in visual acuity. A target blood pressure of 135/85 mmHg or less was recommended for people with type 2 diabetes
“intensive systolic BP control to less than 130 mmHg was associated with a 10% reduction in all-cause mortality”
“intensive BP reduction has led to a 17% risk reduction of stroke”
Results from the recently published UK Prospective Diabetes Study indicate that the NNT to prevent 1 death related to diabetes is 15 for an average reduction in SBP/DBP of 10/5 mm Hg over 10 years among type 2 diabetic patients with hypertension.
