The kidneys are two bean-shaped organs, each about the size of a fist. They filter blood to maintain the overall health and acid-base balance of the human body. Each kidney consists of one million little filtering units known as nephrons. These are microscopic structures that carry out the cleansing process and produce urine.
Understanding their multifaceted function underscores the need to prioritise their health through a balanced diet, proper hydration and regular exercise.
Filtration and waste removal
The kidneys are responsible for filtering and cleansing the blood of metabolic waste products, excess water and toxins. Approximately 200 litres of blood pass through the kidneys each day. As blood flows through, many substances get filtered into the tubules. These tubules re-absorb substances the body needs – such as nutrients – back into the bloodstream, while excreting waste materials in the form of urine.
Regulation of fluid and electrolyte balance
Maintaining the right balance of fluids and electrolytes in the body is crucial for proper cell function. The kidneys help regulate this balance through various mechanisms. The antidiuretic hormone (ADH), produced by the pituitary gland, signals the kidneys to re-absorb water when the body is dehydrated. Additionally, the kidneys regulate electrolyte levels in the body (e.g., sodium, potassium, calcium) by selectively re-absorbing or excreting them as needed.
Acid-base balance
The kidneys play a vital role in maintaining the body’s acid-base balance. They help remove excess acids and maintain acceptable pH levels in the blood for normal cell function.
Hormone production
The kidneys produce several essential hormones, one of which stimulates the bone marrow to produce red blood cells, ensuring adequate oxygen delivery to tissues. Another hormone the kidney produces helps regulate calcium and phosphate levels in the body, promoting bone health.
Blood pressure regulation
The kidneys also help the body regulate its blood pressure. When your blood pressure drops, special cells in the kidneys release an enzyme called renin that triggers a cascade of events that leads to increased blood volume and blood pressure.
Chronic kidney disease (CKD) is a condition where there is abnormal kidney structure or function for more than three months.
Without the kidneys’ ability to properly function, patients can develop multiple health problems, such as high blood pressure and water retention. If left untreated, the kidneys gradually deteriorate and can stop working completely.
CKD is usually diagnosed through blood and urine tests. The stage of the condition is determined based on its severity. The more advanced the stage of the CKD, the higher the risks of cardiovascular events, such as stroke, heart attack and the need for life-long kidney replacement therapy.
CKD is usually diagnosed through blood and urine tests.
Causes of chronic kidney disease
Diabetes is the most common cause of CKD globally and in Singapore. With an increase in sedentary lifestyles and easy access to hawker food that is often high in salt and fat, it is no wonder that Singapore’s diabetes burden is on an upward trend, which mirrors that of CKD. Other major risk factors for CKD include hypertension, cardiovascular disease and obesity.
Typically, symptoms of CKD do not occur until the more advanced stages. These include breathlessness, leg swelling, loss of appetite, nausea and itch. It is important to screen those at risk so that CKD can be detected early and steps can be taken to slow down its progression. A common misconception among patients is using back pain as an indicator of CKD — but this is not reliable.
SYMPTOMS OF CHRONIC KIDNEY DISEASE
Typically, patients do not develop symptoms of CKD until it becomes more advanced.
Slowing the progression of CKD
The overall management of CKD involves treating its underlying causes, taking measures to slow down its progression, treating complications in the more advanced stages and eventually preparing for kidney replacement therapy.
Dietary and lifestyle modifications play an important role in slowing down CKD progression. These include adhering to a low-salt diet, avoiding high-protein intake and maintaining a healthy body mass index (BMI). To put things into perspective, one plate of char kway teow contains 1.4g of sodium, which is already more than half of the recommended 2g per day. Blood pressure and diabetic control are also crucial, and newer medications have been shown to have an added advantage of slowing down CKD progression.
To protect the kidneys, nephrotoxins — medications that can potentially harm the kidneys — should be avoided. These include non-steroidal anti-inflammatory drugs (NSAIDs). It is not recommended for patients with CKD to take herbal remedies and over-the-counter supplements as their effects on the kidneys are unknown and may be potentially harmful. In addition, some medications, especially antibiotics, need to be adjusted according to kidney function as high drug levels can also affect the kidneys. It is important to inform your general practitioner (GP) if you have been diagnosed with CKD so that they can prescribe and dose medications appropriately.
CKD complications usually develop during the advanced stages. One such complication is anaemia, which occurs when there are insufficient red blood cells in the body. As red blood cells carry oxygen from the lungs to the rest of the body, anaemia can cause patients to be lethargic, look pale and feel breathless. Anaemia can be treated with medications that help the body produce more red blood cells. Iron supplementation will also help make this process more efficient. This can be administered through injections or pills.
Dietary and lifestyle modifications play an important role in slowing down the progression of CKD.
End-stage renal failure
As CKD progressively worsens over time, the kidneys eventually stop working sufficiently to sustain life. Patients will then need to consider kidney replacement therapy (KRT) through dialysis or kidney transplantation. The CGH care team starts preparing for KRT before the patient reaches end-stage renal failure as the preparation process takes time. Kidney transplantation offers the best overall chance of survival and if suitable, should ideally be pursued even before a patient goes on dialysis.
If a kidney transplant is not feasible, dialysis options include haemodialysis or peritoneal dialysis. Both forms of dialysis offer similar outcomes, but one might be more suitable, based on the patient’s preference and concurrent health issues.
In patients who are frail or have other life-limiting conditions such as advanced heart failure, non-dialytic therapy is a reasonable option as dialysis might potentially cause more harm than good. For these patients, the focus would be on optimising medical therapy and palliative care.
Preventing CKD
Can CKD be prevented? Yes! Some measures include ensuring adequate hydration, adopting a low-salt diet, controlling risk factors such as diabetes and hypertension, and avoiding unnecessary nephrotoxins, herbal remedies or over-the-counter supplements. People at risk should undergo regular screening so that any potential CKD can be identified early, and appropriate care management can be optimised.
KIDNEY STONES
Kidney stones (nephrolithiasis) is another common kidney issue, with up to 10 per cent of Singaporeans experiencing a symptomatic kidney stone in their lifetime.
Kidney stones are usually formed when urine becomes concentrated, causing mineral deposits to group together and become crystals that form stones. The kidney stone enlarges over time as more crystals form. Patients with kidney stones may experience an excruciating loin to groin pain and, as well as blood in the urine, nausea and vomiting, fever and chills, and unusually smelly urine.
Persons who have had prior kidney stones are at an increased risk of having a recurrence of the condition. Staying well-hydrated by drinking at least eight glasses of water per day, adding fresh lemon juice to your water, and avoiding salty food can help prevent renal stone formation. Depending on the type of stones a person has, doctors may also advise patients to reduce their intake of certain types of food.
Caring for you at CGH
Approximately 200 patients are initiated on dialysis every year at CGH. The Department of Renal Medicine at CGH provides comprehensive inpatient and outpatient renal services for patients, including acute and chronic haemodialysis, peritoneal dialysis and plasma exchange treatments on top of consultation services to intensive care units and surgical patients.
To empower patients to take control of their health, the CGH renal team encourages and supports patient autonomy in the decision-making of their long-term dialysis decisions. Each option has its pros and cons. For example, peritoneal dialysis is a home-based treatment that offers better quality of life and preservation of residual kidney functions. “CGH is one of the few hospitals in Singapore offering a minimally invasive peritoneal dialysis catheter insertion,” says
Clinical Assistant Professor Sreekanth Koduri, Chief and Senior Consultant, Department of Renal Medicine, CGH. “The team also has close links with the community haemodialysis units and provides medical, nutritional and social support to all the patients under its follow-up care.”
Haemodialysis
A dialysis machine is used to draw blood from the patient. The blood is then circulated through a specialised membrane that serves as an artificial kidney, which removes waste substances before returning the cleaned blood back to the patient. This is usually done at a dialysis centre or the hospital.
Peritoneal dialysis
A cleansing fluid (dialysate) is introduced into the patient’s abdomen. The inner lining of the abdomen, called the peritoneum, acts as a dialysis membrane, removing waste from the blood. This form of dialysis takes place within the body. After a period of time, the used dialysate is drained out of the abdomen. With the proper equipment, this can be done at home.
Enhancing quality of life
In Singapore, the prevalence of CKD among seniors has been steadily increasing over the past decade. In early-2023, CGH established its comprehensive multi-disciplinary CKD clinic for seniors, an initiative designed to enhance the quality of life for this vulnerable population by providing integrated care.
The multi-disciplinary care team of nephrologists, geriatricians, renal nurses, dietitians, pharmacists, physiotherapists and medical social workers provides holistic care that focuses not only on the physical health of patients but also on their mental well-being and social support needs. This integrated approach ensures that patients receive personalised treatment plans that consider their unique circumstances and medical history.
One of the key features of the clinic is its emphasis on the early detection and prevention of CKD. “By detecting the disease early on, the care team can implement appropriate interventions to slow its progression and improve patient outcomes,” says Clinical Assistant Professor Roy Debajyoti Malakar, Senior Consultant, Department of Renal Medicine, CGH. “The clinic also places significant emphasis on educating patients and their caregivers about CKD management, lifestyle modifications, and the importance of adherence to prescribed treatment plans.”
The clinic has also established partnerships with various community organisations and support groups to create a network of resources for patients and their families. This collaborative approach enhances the social support available to patients and fosters a sense of belonging among the senior CKD patients, reducing feelings of isolation and improving their overall well-being.
Mr Tam Hon Yuen was walking to a restaurant one day in Manchester, England, when he felt very breathless and tired, and his colleagues commented that he looked very pale. Suspecting that something was amiss, Mr Tam, in his 50s at that time, decided to see a doctor upon returning to Singapore.
Through a series of blood tests, Mr Tam was diagnosed with chronic kidney disease (CKD). Initially, Mr Tam joined an international clinical trial for a new kidney medicine, which helped regulate his condition, keeping it stable. After the clinical trial, the medicine became one of the options available to patients with CKD. A few years later, Mr Tam’s kidney condition deteriorated further to end-stage kidney disease, and through conversations with Dr Ng Chee Yong, Consultant, Department of Renal Medicine, CGH, it was determined that Mr Tam should commence dialysis as soon as possible.
In what was a pleasant surprise for Mr Tam, now 65, the doctors were able to insert the catheter for him in only four days. While it was initially quite painful and uncomfortable, it was necessary for Mr Tam to receive treatment for his CKD. Mr Tam opted for peritoneal dialysis, which enabled him to carry out his dialysis every night at home with the peritoneal dialysis machine.
With a firm belief that his health is his responsibility, Mr Tam ensures that his peritoneal machine is clean and well-kept, allowing him to carry out the dialysis that takes nine hours every night. While being hooked up to the machine does cause him some difficulty in sleeping, after one year, Mr Tam has started to get used to it and is feeling good. “CKD may be a downhill slope but hopefully, it is a gentle slope for me,” says Mr Tam.
Although dialysis has affected Mr Tam’s lifestyle to a certain degree, he feels that it is a blessing to be able to receive this treatment. “There is no point feeling upset,” says Mr Tam. “I just carry out the dialysis and continue living.” While he is unable to travel to see his grandchildren, who are based overseas, Mr Tam is content with his life and appreciates being able to keep in touch with them through video calls.
Through the years, Mr Tam has had good experiences with the care team at CGH. “Dr Ng has been very understanding and conscientious. I am very grateful to have him as my renal doctor,” he shares. “The renal nurses have also been very dedicated and diligent in their care for me. The renal clinic counter staff have been excellent in providing care for not just me, but the other patients at the clinic as well.”
On his advice for others who might be facing the issue of kidney disease, Mr Tam says, “Go for check-ups, do the full set of bloodwork and find out what the issue is. It would be even better to start these check-ups when you are young, as prevention is better than treatment.”
The renal services in CGH are provided by a multi-disciplinary team, to ensure that patients with kidney conditions receive holistic care in their management of the condition. Members of CGH’s care team share more about their role.
Providing crucial nursing care
CGH’s renal nurses play an important role in supporting patients with end-stage renal failure who require dialysis support. For patients who are beginning haemodialysis, the renal nurses assist the physicians in inserting a catheter (temporary dialysis access) to create an access for the dialysis. The nurses will then commence the dialysis treatment for the patient.
They also educate patients on how to care for the catheter and how to look out for signs of possible access complications.
“As many of our newly-initiated patients express anxiety and fear during the treatment, our nurses often spend time explaining the procedure to the patients so that they can better understand the process,” says Ms Wang Hwee May, Nurse Clinician, CGH. “When a patient’s condition is stabilised and he or she is ready to be discharged, we will then communicate with the renal coordinator to arrange for a step-down dialysis centre in the community for the patients to continue their dialysis there.”
For patients who opt for peritoneal dialysis as their long-term treatment mode, the renal nurses will prepare them for the treatment and educate them on the procedure so that they can continue with the dialysis at home. This involves subsequent follow-ups and arranging for the dialysis consumables to be delivered to patients’ homes.
CGH’s renal nurses are competent in using both the haemodialysis and peritoneal dialysis machines. The nurses are also trained to measure the status of patients’ body fluids using a Body Composition Monitor.
Ms Wang Hwee May, Nurse Clinician, CGH, trains her fellow renal nurses on how to operate a dialysis machine.
Coordinating care
“As renal coordinator, I am responsible for coordinating care for patients with chronic kidney disease,” shares Ms Hirnani Bte Hamid, Renal Coordinator, CGH. “Our role is to help them navigate their treatment journey through education and counselling.” CGH’s renal coordinators, who are allied health professionals, empower patients with the knowledge to make their own decisions regarding dialysis, kidney transplantation and advance care planning. “Working closely with the renal doctors and nurses, we are then able to speak to patients and their family members on their dialysis options and their benefits, so that they can discuss and weigh their choices. We are also involved in patient discharge planning and arranging dialysis placement at centres in the community.”
As renal coordinators also counsel patients who have been recently diagnosed with kidney disease, it can be difficult to break the news to them, and inform them of the need to start dialysis as soon as possible. “We provide a listening ear, address their concerns, and help them overcome their fears,” she says.
Ms Hirnani Bte Hamid, Renal Coordinator, CGH, introduces a patient to a peritoneal dialysis catheter.
Managing CKD through medication
In the inpatient ward setting, renal pharmacists join the doctors for morning rounds and provide individualised pharmacotherapy recommendations based on the patients’ kidney functions. “Renal pharmacists counsel new haemodialysis patients on their new medications and medication changes. This is vital, as these patients often have complex medication regimens and are usually started on new medications when they begin haemodialysis,” says Ms Karmen Quek, Senior Clinical Pharmacist, CGH. “Patients are appreciative of this service, and we equip our patients with knowledge of their medications as they embark on their dialysis journey.”
For outpatient care, the renal doctors refer their patients to the renal pharmacists, who run clinics where they adjust medications to optimise care for patients with hypertension, anaemia, mineral bone disorder and those undergoing haemodialysis. “As pharmacists, we are able to prescribe the appropriate medications until the next doctor’s visit.” The CGH renal pharmacists also work closely with the renal nurses in both inpatient and outpatient settings to address the patients’ medication enquiries.
Ms Karmen Quek, Senior Clinical Pharmacist, CGH, equips patients with knowledge of their medications on their dialysis journey.
Ms Lee Dao Xin, Dietitian, CGH, provides medical nutrition therapy for patients.
Diets to deter the deterioration
“As a dietitian, I provide evidence-based medical nutrition therapy for patients with diabetic kidney disease to assist them in managing their condition,” says Ms Lee Dao Xin, Dietitian, CGH. This is done by gaining a comprehensive understanding of patients’ specific needs based on their lifestyle factors, challenges they encounter while managing their condition, their nutritional requirements based on the stage of their kidney disease and other coexisting conditions.
CGH’s dietitians work together with the other care team members to ensure that patients’ nutrition care plans are in close alignment with their overall medical management. In cases where patients are unable to meet their nutritional requirements solely via food intake, the dietitians prescribe oral nutritional supplements to bridge the gap.
“The flow of knowledge in the patient-therapist relationship is not unidirectional. Sometimes, my patients come up with creative dietary strategies that have proven to be effective for them. These insights can be shared with other patients facing similar challenges.”
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