In many childhood illnesses, diagnosis and treatment could be undertaken on the basis of a thorough history and clinical examination. Most children have rather mild illnesses and many of them resolve spontaneously with time, quite often without any major forms of treatment. Most of the time all they need are symptomatic treatment to make them less uncomfortable and nature cures these illnesses quite rapidly. Many common childhood illnesses resolve within a period of 7 to 10 days. Thus, in the vast majority, no further investigations or tests are necessary.
However, in certain situations, some forms of tests may be necessary. This is particularly true when there are unexplained symptoms or when the diagnosis is rather uncertain. Tests may also be necessary to ascertain the severity of a disease, the extent to which complications are present or to determine prognosis. There are a legion of tests and medical investigations available to facilitate these processes. Decisions regarding exactly which tests need to be done should be judiciously done, depending on the circumstances. It is a cardinal principle in the care of children that one does not perform all kinds of investigations haphazardly but decide on essential investigations taking into account the clinical status of the illness. Blanket performance of a multitude of tests is generally specifically avoided in children. Quite a few of the necessary investigations are available through the National Health Service in the government hospitals but some of the more sophisticated tests are available only in the private sector. These are of course likely to be quite expensive.
moreThere are a whole load of blood tests that are available for assisting diagnosis or assessment of the clinical condition and prognosis in children. These may range from the well known blood counts, to estimation of certain chemical substances in the blood and to the more esoteric tests for things like genetic studies. In the commonly performed blood counts several cellular components of the blood are actually counted, either manually by a technician or by a special machine calibrated and programmed to mechanically or electronically count the cells for a given volume of blood. Changes in the blood counts are useful adjuncts to diagnosis. Certain cell types show predictable and well documented responses to certain disease states. Some of the machines are also able to assess the haemoglobin distribution patterns inside the red cells as well and these parameters are useful for sorting out many types of anaemia. Some of the counts also assist in evaluation of how the bone marrow is responding to a given disease state or whether there are indicators of diseases affecting the bone marrow itself and the expected response of the bone marrow to certain treatment modalities. In addition, specific values in certain parameters of the blood counts show specific responses which aid in the treatment of some diseases. A case in point is dengue fever where changes in some of these parameters aid in the diagnosis, prediction of the occurrence of potential complications, assessment of the severity of the complications and the response to treatment. Modern management of complicated dengue fever is to a large extent based on accurate counts and assessments of certain values in the blood count. One may need to perform repeated assessments of certain values to guide treatment.
Certain other blood tests are designed to measure the content of special chemicals and enzymes in the blood. These are quite useful for assessment of the functioning of several organs. Presence of certain abnormal chemicals, increase or decrease in other compounds normally found in the blood and changes in the levels of some of the special enzymes in the blood are very useful indicators of problems arising in, and the functioning of, specific organs and body systems. Acute or chronic damage to these organs are reflected by changing levels of these chemicals and enzymes in the blood. Abnormal functioning of the of the heart, liver, kidney, pancreas and the intestines show up as changes in the amounts of these compounds in the blood. With recovery, these tend to go back to normal levels and thus are useful for assessing recovery as well. In fact, judicious assessments made by these tests are universally used as an adjuvant and sometimes indispensible tool for diagnosis and treatment of quite a few diseases that affect these organs.
Several other blood tests are used to detect the presence of infections. These include blood cultures and other special tests to detect certain substances which act as markers of infections. Blood culture tests detect the actual presence of infecting organisms in the blood and are very valuable when they are positive. However, negative blood cultures do not exclude the presence of infections as organisms may not be present in the small quantities of blood that are taken for the test even though an infection is present. In addition, in some infections restricted to certain organs, the bacteria may not get into the blood stream to be isolated in a blood culture. Prior antibiotic therapy too prevents the blood cultures being positive. In addition to the actual isolation of the organism in blood cultures, it is also possible to test that organism afterwards to ascertain the sensitivity of the organisms to several antibiotics. With that information, the doctors are able to use specific drugs to which the organism is sensitive. They could target the bugs with the most appropriate antibacterial agents to produce the best effect.
Certain blood tests are used for chromosomal analysis and genetic assessments. These are very special and are performed under precise circumstances when such esoteric abnormalities are suspected. They can be performed only in specialised laboratories and some of these facilities are available only through the universities and the private sector. In the vast number of patients these are not required. These tests are indicated only in very special circumstances where there is a real suspicion of a genetic abnormality. Some of these tests are quite expensive to perform as well.
Urine tests too are commonly performed in children. The standard urine full report gives details of several things in urine and is also able to detect the presence of abnormal substances like albumin and sugar in the urine. This test is used to not only detect abnormalities in kidney function but also some other metabolic derangements which are reflected in some abnormalities in the urine. A special test on urine known as the culture test is specifically designed to detect urinary tract infections. It is crucial that urine is collected into a special sterile bottle in a standard way for this test to detect urine infections. Once collected, the urine has to be transported to the laboratory without any delay and the test performed as soon as possible. The best way of performing this test is to collect the urine in the laboratory or the hospital itself so that any possible delay is minimised.
Many types of imaging studies can be performed. The simplest are the x-rays. However, it must be remembered that only certain structures are visible on x-rays and to visualise certain organs and soft tissue structures, other forms of imaging may be necessary. Ultra-Sound Scanning (USS), Computerised Tomography (CT scanning) and Magnetic Resonance Imaging (MRI scanning) are special imaging tests that may be necessary in some cases. All these imaging tests are performed with specific indications as specially the x-rays and CT scanning involves exposure to radiation. There are some long-term undesirable effects of excessive exposure to irradiation and thus unnecessary use of these imaging techniques should be avoided. USS uses sound waves and MRI uses magnetic fields. These are relatively safe as no long-term effects have been consistently described so far. CTs and MRIs are also quite expensive to perform.
There are times at which some other very special investigations may be needed. A case in point is the necessity to perform a lumbar puncture on the spinal column to obtain a small sample of fluid that circulates around the brain and the spinal cord. Analysis of the fluid can provide valuable information regarding many types of abnormalities that occur in the central nervous system. It is really the only sure way to diagnose certain brain infections with a degree of certainty. When indicated, this test has to be performed as soon as possible as delay in the diagnosis of brain disorders could lead to long-term irreversible damage to that organ. Other tests like the Electrocardiogram (ECG), Echocardiogram (ECHO) and Electroencephalogram (EEG) are special tests that detect abnormalities in certain organs. The first two are performed to assess heart function while the EEG detects abnormalities in the electrical activity of the brain. Special investigations on kidney the urinary system involve imaging using dyes which are either injected or instilled through urinary catheters. These are invasive investigations and need to be performed with extreme care. They are selected only on very special indications. In the case of suspected problems arising from the bone marrow, a special test in which aspiration and examination of the contents from the marrow of bones is necessary. This procedure is quite painful and generally all precautions including adequate pain control measures need to be taken. Some other investigations that facilitate direct viewing of certain structures such as the upper and lower airways, urinary bladder, stomach and intestines using specialised telescopic devices are necessary in certain cases. Many of these procedures in children need to be used under general anaesthesia.
In the case of invasive procedures like blood testing and catheter studies, one must always remember that these are distressing to children. Many of them cause a certain amount of pain to children. These tests should be performed only when they are deemed to be essential for proper management decisions to be taken. Many parents request all kinds of tests from doctors and indeed even go to private laboratories and get very many tests performed. Routine testing and "check-up testing" is not necessary in children. In the case of simple viral fevers, many parents get blood counts done repeatedly because of the fear of diseases like dengue fever. Such testing without proper medical guidance is not of much use in many cases.
It is also necessary to keep in the back of one’s mind the undesirable effects that could potentially arise from certain investigations. A case in point is excessive use of x-rays. All types of investigations that involve x-rays pose a radiation hazard to children. There are definite long-term implications of exposure to irradiation. However, these considerations may need to be over-ridden when such procedures are necessary for proper management of certain illnesses.
It is also necessary to consider the cost of some of these investigations. Although the services are provided free of charge from government hospitals, there is a cost that has to be borne by the government and the tax payer. Some of these tests are quite expensive to perform but the patients and parents are totally unaware of what it costs for the government. It is necessary to look at the cost-benefits of such procedures in a given child. In the private sector of course the cost is immediately visible. In the modern world things like health insurance tends to open the flood gates for performance of indiscriminate laboratory testing. Neither insurance nor the social status, which makes it possible to pay for any type of investigation, should be a consideration for performance of a legion of indiscriminate tests in a given case. The key determining factor should be the clinical indications to perform these tests in a given case. Doctors need to use their experience and expertise in selecting appropriate medical testing in children. Performance of all kinds of tests is not a "panacea for all ills" in the care of sick children. Many are the occasions in which doctors are inclined to advise parents that certain tests are not going to contribute further to optimal management of their children. However, in this era of "defensive medicine" which is a direct consequence of increasing litigation against medical professionals, many of them take the path of least resistance to perform a wide array of investigations. This is a situation where everybody is playing safe. Though most unfortunate, such practices are not likely to help the sick children and could be avoided by adequate explanations provided for the parents.
The writer would appreciate feedback from the readers. Please e-mail him at bjcp@ymail.com
KEY POINTS
* Many childhood illnesses do not require the performance of extensive investigations.
* Tests are sometimes required to establish a diagnosis and to assess progress of the disease and recovery from it.
* Several types of blood tests, urine tests, imaging studies and even some very special investigations may be necessary in some cases.
* The tests to be performed are studiously selected depending on the clinical status of the child.
* Some of these procedures are unpleasant for children while others have long-term consequences.
* Haphazard and repeated investigations do not serve any useful purpose.
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