During the regular ward duty, the nurse has to record various clinical observations in respect of the patient. Hence a conscientious recording of the findings on temperature, pulse, blood pressure, respiration, pallor, jaundice, cyanosis, cough and sputum, urine, stool, fluid intake and output with fluid balances becomes very important.
Temperature
The temperature chart is an important document for the physician as a rise of temperature indicates the possibility of an unexpected bacterial infection and a fall in temperature indicates that infection is under control. Different terms are used for the different ranges of temperature as under in Centigrade and Fahrenheit scale:
Body temperature | Centigrade | Fahrenheit |
|---|---|---|
Normal | 36.6–37.2°C | 98–99°F |
Subnormal | Below 36.6°C | Below 98°F |
Febrile | Above 37.2°C | Above 99°F |
Hyperpyrexia | Above 41.6°C | Above 107°F |
Hypotheremia | below 35°C | Below 95°F |
There are three classical types of fever:
Continued: When fever does not fluctuate more than 1°C (1.5°F) during the 24 hours and at no time touches the normal.
Remittent: When the daily fluctuation exceeds 2°C.
When a paroxysm of intermittent fever occurs daily the type is called “quotidian,” when on alternate days “tertian,” when two days intervene between consecutive attacks it is called “quartan.”
While taking temperature, the nurse must remember following points:
- The thermometer must be accurate, the mercury must have gone inside the bulb.
- A falsely elevated temperature will be obtained if the patient has just taken a hot drink.
- The temperature is usually slightly higher in the evening than in the morning.
- In women the temperature is elevated after ovulation in the latter part of the menstrual cycle.
- The thermometer must be kept in position long enough (usually two minutes) to allow the mercury to reach the body temperature.
- In conscious adults the temperature is taken in the mouth (under the tongue) or in the axilla. In young children the thermometer is placed in the fold of the groin and the thigh flexed on the abdomen or it may be placed in the rectum. The temperature of the mouth and rectum is generally half a degree higher than that of the groin or axilla. In unconscious or uncooperative patient, the thermometer is placed in the axilla and patient's arm is closed against the side. When hypothermia is suspected a special low reading thermometer is inserted into the rectum.
- Sometimes neurotic patients may draw attention of the nurse or physician by surreptitiously warming the thermometer in a cup of warm water or tea.
- In fever there is associated tachycardia (increased pulse rate). Fever without tachycardia suggests a false reading.
In specticemia, urinary tract infections or malaria, patient feels intense cold and shivers violently. This is called rigor. When temperature rises shivering or rigor disappears and after the peak of temperature the patient sweats profusely. The typical cold, hot and sweating (effervescent) phase is sometimes seen in malaria.
PULSE
The heart pumps blood into arteries by contraction about 72 times per minute. Each contraction of heart is called a heart beat and can be 3heard by a stethoscope. The pressure in the arteries increases with each beat of the heart and this pressure or distension in the artery can be felt by the nurse in any large artery: ‘radial’ at the wrist, ‘brachial’ at the curve of elbow, ‘carotid’ on either side of neck, ‘temporal’ just in front of the ear, ‘femoral’ in the groin, ‘dorsalis pedis' in the front of foot and ‘posterior tibial’ behind the medial malleolus.
As a routine the radial pulse at the wrist is generally used. It is best felt with the tips of fingers, the patient's forearm being pronated and the wrist is slightly flexed. While examining the carotid pulse, the nurse should palpate one at a time, patient's left carotid by nurses's right thumb and patient's right carotid by nurses's left thumb. Simultaneous compression of both carotid arteries will lead to synope or unconciousness of the patient due to sudden snapping of blood supply to the brain.
The following five features must be observed while recording the pulse:
- Rate of pulse per minute.
- Rhythm.
- Character.
- Volume: Normal, low or high.
- Presence or absence of delay of the femoral pulses compared with radials (radiofemoral delay).
1. Rate
In most healthy people the mean pulse rate (heart rate) is between 70 to 80 per minute. The resting heart rate varies between 50 to 100 per minute. During sleep, in athletes and in diseases like hypothyroidism and complete heart block the rate falls below 50 per minute and is called “bradycardia”. After excercise and due to anxiety, excitement, shock (e.g. bleeding), fever, thyrotoxicosis the rate increases above 100 per minute. This is called “tachycardia.” The heart is under the control of the nervous system and responds to the needs of the body, slowing at rest and quickening when there is need for greater effort.
Pulse is better felt by putting the fingers on the radial artery while talking to the patients so that patient is not conscious. Pulse rate is counted for at least half a minute.
The nurse should remember that in cases of “atrial fibrillation” when atria or upper chambers of heart contract very fast the weak 4heart beats will not be able to pump blood into arteries, only strong ventricular contractions will be felt as pulse. The rate of heart beat should be counted by simultaneously hearing by a stethoscope and this rate is more than pulse rate.
This should be recorded as pulse “deficit.”
2. Rhythm
The nurse should record the rhythm of the pulse, whether it is:
Regular → Normal pulse
Completely irregular → Atrial fibrillation
Irregularity has a recurring pattern → Due to extra-systole or premature low volume beat followed by a pause.
3. Character of Pulse
It varies in different cardiovascular disorders as under:
- Slow rising pulse: A small volume with a gradually rising peak (e.g. aortic stenosis).
- Collapsing pulse: A rapid upstroke and rapid descent of pulse wave (e.g: aortic regurgitation).
- Pulsus paradoxus: In this the heart sounds may still be heard by stethoscope on the chest, at a time when no pulse is palpable at radial artery. This occurs during inspiration in a case of pericardial “effusion.”
- Pulsus alternans: When a strong heart beat alternates with a weak heart beat as in premature beat or when the contractility of left ventricle has severely declined.
4. Volume
This describes the strength of the pulse, whether it is full and bounding, or weak and thready. Following a heart attack (myocardial infarction or after excessive blood loss the pulse volume becomes thready (scarcely palpable).
5. Radiofemoral Delay
In coarctation of aorta, a disease where there is a constriction in descending aorta, the radial pulse is felt while the femoral pulse is not felt.5
The typical arterial pulse should be described as: Rate is 70/minute, beats are regular in rhythm, equal in volume, normal in character (or collapsing in character) and are symmetrically present.
BLOOD PRESSURE
It is a very important clinical observation as repeated blood pressure recording can either forewarn an impending collapse or a hypertensive crisis. Every nurse must know how to record blood pressure and practise till competence is attained.
The blood pressure is measured by an instrument called sphygmomanometer. This consists of (i) an inflatable cuff to be wrapped around any upper arm or thigh. The normal width of the cuff in an adult is 12.5 cm, for obese persons 16 cm, for thigh 18 cm, for children under 8 years 8–9 cm, under 4 years 5–6 cm, under 1 year 2.5 cm (ii) a mercury manometer attached to a tube to the cuff, which measures the pressure in the cuff.
The nurse should learn certain important tips how to record blood pressure correctly. The patient should be sitting or lying at ease. The arm should be bared completely, the cuff is wrapped around the arm closely with the lower border about an inch (2.5 cm) above the cubital fossa. The nurse should be able to palpate the brachial artery. Now the cuff is inflated to a pressure of 30 mmHg above the level at which the radial pulsation can no longer be felt. The stethoscope is then placed lightly over the brachial artery. The pressure in the cuff is lowered slowly 5 mm Hg at a time until the thumping of the artery can be heard through the stethoscope. The pressure in the manometer at which the first sound is heard is the systolic blood pressure (SBP). The pressure in the cuff is further reduced until the sound disappears. The pressure in the manometer at which the sound disappears is the diastolic blood pressure (DBP). The sounds which are heard through the stethoscope are called ‘Korotkoff's sounds.’ The systolic pressure's denotes the maximum pressure of blood in the artery as the ventricle contracts, the diastolic pressure is the lowest pressure when the ventricle relaxes between beats.
Normal Blood Pressure
The average systolic pressure in healthy adult is 100 to 140 mm Hg. The average diastolic pressure is 60–90 mm Hg. Thus, a healthy young 6adult may have a mean systolic pressure of 120 mm Hg and a diastolic pressure of 70 mm Hg. The nurse should record this as BP 120/70 mm Hg. Elderly persons may have a blood pressure of 170/90 mmHg due to hardening of the arteries. In children it may be closer to the lower end of the scale.
Pulse Pressure
The difference between systolic and diastolic pressure is called pulse pressure and ranges between 30 to 60 mm Hg. A wide pulse pressure indicates a heart disease called aortic valve regurgitation.
Abnormal Blood Pressure
Abnormal blood pressure must be considered in relation to patient's age. A blood pressure of 140/90 would indicate abnormal and severe in a child, while much higher systolic pressure in an elderly patient is inevitable due to loss of elasticity in the peripheral arterial system.
Postural Blood Pressure
Normally the blood pressure in a person is lowest when he is relaxed in body and mind and is in a recumbent position. It rises some what on sitting up or standing. But in patients receiving antihypertensive drugs the blood pressure falls when the patient stands up and rises when he lies down. Hence the nurse must mention the position in which BP is recorded, lying down, sitting or standing. Sudden fall in BP while sitting up or standing up from lying position is called “postural hypotension.” It is advisable to record BP in patients taking treatment for high blood pressure in both recumbent and standing position.
The BP is also raised after exercise, anxiety and excitement. In nervous patients the first reading is often high, a second reading when the patient has become accustomed to the procedure and is more relaxed, may be more accurate. The nurse should also record the pulse rate at the same time, as in excitement or anxiety hormones called catecholamines (adrenaline and noradrenaline) are circulating in the blood which temporarily increase both pulse and blood pressure.
If the nurse wants to take a second reading of BP for accuracy, then air pressure in the cuff should always be allowed to fall to zero after the first reading.7
Jugular Venous Pressure
In certain patients taking intravenous fluids specially in presence of congestive heart failure, the venous pressure is also to be monitored to prevent a fluid overload in heart. The simple bedside method is to observe the jugular veins in the neck. The patient should be allowed to rest in 45° above horizontal, over the nurses left hand and the pulsation in the jugular vein is observed in the neck. The height of the distended jugular vein above the collar bone is measured which indicates increased venous pressure or increased right atrial pressure in heart. In congestive heart failure, when the heart is unable to pump blood into the circulation effectively and the right atrium is not emptied at each beat, the pressure in the neck veins rises accordingly. So, the jugular veins in the neck are distended above the collar bone.
Central Venous Pressure
In patients whose heart is weak and they need intravenous fluids, their venous pressure is measured by placing a catheter into the internal jugular vein and catheter is attached to a water manometer reading up to 10 cm of water. The reading in the manometer is called the central venous pressure (CVP) which helps in monitoring the rate and volume of intravenous fluid to prevent fluid overload in the heart.
RESPIRATION
The nurse should count the respiration of the patient quietly while recording the pulse without the knowledge of the patient. The normal respiration rate in an adult is about 14 to 18 per minute. The main causes of fast breathing (tachypnoea) are exercise, fever, nervousness, diseases of lungs and pleura, metabolic acidosis, diseases of brain and hysterical overbreathing.
Characters of Respiration
Due to obstruction in various parts of respiratory tract, the character of breathing changes which should be known to the nurse.
- Bubbling sounds are produced due to obstruction in nasal passage
- Snoring sound is produced due to paralyses of soft palate
- Rattling sound is produced due to obstruction in the trachea (e.g., death rattle in terminal stage of patient due to mucus)
- Audible expiratory wheezing or whistling sound is produced due to obstruction in bronchi (e.g., bronchial asthma).
Type of Breathing
- Cheyne-stokes breathing: This is rapid breathing (hyperventilation) alternating with stoppage of respiration (apnoea) in left heart failure and various brain diseases.
- Stertorous breathing: This occurs in apoplexy.
- Hissing respiration: This occurs in uremia.
- Air hunger: The patient opens the mouth to suck in air as in diabetic ketoacidotic coma.
Odors or Smell in Breath
The odors or smell in patient's breath can be easily recognised by the nurse to indicate substances consumed or the disease process.
- Alcohol and paraldehyde
- Sweet and sickly in diabetic ketoacidosis
- Ammoniacal or fishy in uremia
- Mousy in hepatic failure.
COUGH AND SPUTUM
Cough is a reflex mechanism either caused to expel irritants like sputum, foreign body, etc. or as a simple irritation of mucus membrane of the upper respiratory passage. Accordingly there may be a productive cough or a nonproductive dry cough. A cough expectorant may be required to expel the sputum in productive cough where as a cough suppressant medicine may be required to control a dry cough. Elderly or debilitated patients with bronchopneumonia may be too weak to cough out the thick tenacious sputum and may require physiotherapy and suction by a suction machine.
In order to collect sputum for laboratory examination, waxed cartons with screw tops or spitoons are issued to patients by the nurse. The patient is advised to collect 24 hours sputum inside the carton/spitoon. The cartons are easily destroyed by burning. The sputum so collected is sent to the laboratory when its examination 9provides valuable information as to the nature of the respiratory illness. The nature, amount and color of sputum gives valuable information about the type of respiratory illness. Sputum may be mucoid, purulent or frothy. Any of these varieties may contain blood or the sputum may consist of only blood (hemoptysis).
Mucoid sputum indicates chronic bronchitis without secondary infection. It is clear, tenacious and sticky. In asthma, the sputum is tenacious and contains casts of the bronchial tree.
Mucopurulent sputum indicates chronic bronchitis with secondary bacterial infection.
Purulent sputum is thick and yellow (or green) and not sticky. It is commonly coughed out by patients of bronchiectasis, and in lung abscess it may be copious in quantity if the affected part of lungs is drained by proper posture. The nurse should learn the chest physiotherapy to drain such sputum out of patient's lungs.
Frothy sputum is seen in pulmonary edema, may be white or pink.
Rusty sputum is characteristics of pneumonia. Blood tinged sputum or haemoptysis may be due to tuberculosis, bronchiectasis, pulmonary embolus, carcinoma and heart disease (narrowing of mitral valve or mitral stenosis). The nurse should also remember that while in haemoptysis or coughing of blood, it is bright color, frothy and continuous for a day or two; in hematemesis or blood vomiting there is always consequent black and tarry stools (malena).
Sputum is bright yellow or green when a bacterial lung abscess ruptures into the bronchus. Sputum is anchovy sauce when an amoebic hepatic abscess has discharged into the lungs.
The odor (smell) of the sputum is putrid (foul smelling) in bronchiectasis and lung abscess.
Microscopical Examination of Sputum
Sputum is sent to laboratory for two reasons (i) to see it under the microscope for detecting bacteria like Mycobacterium tuberculosis and other pathology (ii) to culture for bacteria which has caused the infection and its susceptibility to antibiotics. Eosinophils may be found in the sputum in allergic conditions, e.g. asthma, aspergillosis and pneumonia due to parasitic worms. Malignant cells may be seen in sputum in bronchogenic carcinoma.10
Fungi, yeasts and golden yellow asbestos bodies are rarely seen in sputum.
URINE
There is a saying that the ghosts of dead patients do not ask why we did not employ advanced clinical investigations but they ask why we did not test their urine. So examination of urine is a basic investigation and is a must for each new patient. It is easy to do and gives valuable tips for diagnosis.
Volume
The normal quantity of urine passed daily varies from 700 to 2500 ml depending on amount of fluid drunk and the amount lost in perspiration, in the breath, and from the bowel. A normal adult passes on an average 1200 ml urine per day. An excretion of urine occurs physiologically after food or drink, and after exposure to cold. Conversely diminished excretion occurs when little food or drink has been taken and after sweating in hot climate, in diarrhoea, vomiting, fever, extensive burns and sudden lowering of BP.
A pathological increase (polyurea) occurs in diabetes mellitus and insipidus, during elimination of oedema fluid by diuretics and sometimes in renal failure. Excessive passage of urine at night (nocturia) is often the first symptom of chronic renal failure.
A pathological decrease (oliguria) occurs in acute glomerulonephritis and chronic renal failure. Complete stoppage of urine output (anuria) is uncommon and most often results from an obstruction in the urinary tract.
In severely ill patients and in patients receiving intravenous fluids, the nurse should maintain an intake output chart, i.e. records of all fluid taken by month or by IV route and all the fluid lost by urine, vomit or bowel over 24 hours. The balance should be drawn. Normally fluid intake will exceed output by about 500 ml because no record is possible of fluid loss by perspiration and breath amounting to about 500 ml.
Colour and Transparency
The normal colour of urine is straw colour. Small amount of blood gives urine a smoky appearance, while larger quantities make it 11brownish or red. In blackwater fever (a complication of antimalarial drugs) haemoglobin in large amounts gives urine a brownish black or almost black colour.
In jaundice, bile pigment causes urine dark yellow colour with a yellow froth on shaking. An abnormally pale urine may be seen in renal failure.
Drugs can also lead to discolouration of urine as under:
- Tetracycline (yellow)
- Anthracene purgative (orange)
- Nitrofurantoin(brown)
- Furazolidone (brown)
- Rifampicin and pyridium (red)
- Methylene blue (green)
- Methyldopa and iron sorbitol (grey or black)
- Desferioxamine (reddish brown).
Normal urine is transparent to look at but various substances in it may make it opalescent, e.g. pus, bacteria, phosphate, protein and urates. Phosphate dissolves on adding acid.
Specific Gravity
Specific gravity of urine depends upon the weight of substances dissolved in it compared with water. The specific gravity of water is 1000 and that of urine usually varies from 1012 to 1024. It is more practicable to measure the specific gravity with a ‘Urinometer’. While recording specific gravity of urine it should be ensured that the glass container used should be clean and free from detergents, and the urinometer should float freely in the measuring cylinder. The depth to which it sinks is calibrated to give the reading. The reading at the bottom of the meniscus is the relevant, one. As the instrument is calibrated at 16°C, a falsely low reading will be obtained if urine is tested while warm, so it should be allowed to cool to room temperature. If there is insufficient quantity of urine in container, the urine should be diluted witn an equal volume of distilled water and the last two figures of the urinometer reading doubled. Recently, specific gravity is more accurately obtained even from a small quantity of urine using a commercial test strip (Multistix SG).
If the person drinks a larger quantity of water, the urine is dilute with a low specific gravity. If the person's fluid intake is restricted, then the urine becomes concentrated with a high specific gravity if 12the kidneys are healthy. In diabetes, although a lot of urine is passed, the presence of sugar in the urine leads to a high specific gravity.
As renal failure develops, the kidneys progressively lose their ability to concentrate and dilute urine, whose specific gravity approximates more and more to 1010 (the specific gravity of the glomerular filtrate) until the concentration of urine is same as plasma. The morning urine which is the most concentrated is the best specimen for test. If the specific gravity of morning urine or any other specimen of urine exceeds 1.018, it indicates normal concentrating power of kidney.
Reaction or pH
Normal urine is nearly always acid and turns blue litmus paper red. If the patient is taking excess alkalis, or if the urine is infected or has been allowed to stand, the reaction becomes alkaline and red litmus paper turns blue on being dipped in the urine.
DEPOSITS IN URINE
Protein (Albumin)
Normally less than 150 mg (50 to 150 mg) protein is excreted in the urine over a 24-hour period and random samples contain less than 20 mg/litre. When excretion of protein exceeds 150 mg in 24 hours it is called pathological proteinuria. One-third of protein in normal urine is albumin and two-thirds consists of globulin.
Occasionally protein (albumin) appears in urine in healthy young adults after exercise or prolonged standing and this is known as ‘Orthostatic proteinuria. Fever may transiently increase urinary protein excretion in healthy people. The glomerular filter in kidneys is too fine to allow molecules of protein to pass through into the urine. Therefore presence of protein (albumin) constantly in the urine indicates the presence of kidney disease. Proteinuria may also be due to diseases out side the kidneys, e.g. congestive heart failure. Diseases affecting the lower urinary tract usually cause only slight proteinuria.
The protein in the urine is tested by following methods:
- Boiling test: This is the commonest method which can be used by the nurse. Fill two-thirds of the test tube with urine and boil the top layer over a flame. If urine becomes cloudy, forming a precipitate it indicates the presence of either of protein or of 13phosphates; then add 10 per cent acetic acid. If the precipitate disappears it was due to phosphates, if it persists protein is present,
- Eshach's albuminometer: Protein in the urine can be measured more accurately but in a simple manner.
- Albustix test: This is a simple method in which the test end of the strip is dipped in the urine and the colour compared with the colour strip provided; the deep green colour indicates greater amount of protein.
Sugars
Several reducing sugars like glucose, lactose, pentose, fructose, galactose may be found in the urine. Glucose is by far the most important of these. The presence of any appreciable amount of glucose in the urine indicates either ‘diabetes mellitus' or renal glycosuria. If presence of glucose in urine (glycosuria) is accompanied by symptoms like excessive urination, thirst and appetite then diagnosis of diabetes mellitus is not in doubt. It can only then has to be confirmed by recording a high blood sugar level (fasting and postprandial). Sometimes in older people diabetes mellitus is detected only by a routine urine test without any symptoms.
Sugar in the urine can be detected by following methods:
- Benedict's test: Take 5 ml of Benedict's reagent in a test tube, add 8 drops of urine, boil for 2 minutes and allow to cool. If sugar is present, then a precipitate will appear, colour varying from light green to brick red. Approximate quantitative results can be recorded for sugar in urine from the colour of the precipitate.Light green turbidity0.1–0.5 gm/dl sugarGreen precipitate0.5–1.0 gm/dl sugarYellow precipitate1.0–2.0 gm/dl sugarRed precipitate2.0 gm/dl sugar or over
- Reagent strips (multistix, diastix): These tests are also easy to perform. The reagent strip is dipped for few seconds in the urine and the colour of the test end of the strip is compared with the colour chart on the bottle. A change from brown or blue through green indicates that the urine contains an abnormal amount of glucose.
- Clinitest: Five drops of urine are placed in the test tube and 10 drops of water are added. One clinitest tablet is dropped into the 14tube, when a boiling reaction takes place. Fifteen seconds after the boiling has ceased, the tube should be shaken gently and the colour of the contents compared with the colour scale provided. If sugar is present, the colour of fluid changes through green (0.5 per cent) to orange (2 per cent). The test is very useful for diabetics needing insulin, because it tells not only whether sugar is present but also to what degree. Clinitest tablets should be kept in a bottle tightly screwed and should be used only if they are white with speckled blue.
Ketone Bodies
Acetone, acetoacetic acid may appear in the urine of patients with severe diabetes mellitus, after starvation and prolonged vomiting. The ketone bodies are detected by following tests:
- Rothera's test: 10 ml urine is saturated with ammonium sulphate by adding an excess of the crystals. 3 drops of strong freshly prepared solution of sodium nitroprusside and 2 ml of strong ammonia solution are then added. A deep permanganate colour is produced. A positive test indicates presence of acetone and aceto-acetic acid, a negative test excludes ketone bodies in urine.
- Ferric Chloride test (Gerhardt's test): 10 per cent ferric chloride is added drop by drop to 5 ml of urine in a test tube. A precipitate usually forms but disappears again when more ferric chloride is added. The solution becomes brownish-red if aceto-acetic acid is present. A positive ferric chloride reaction is obtained only if aceto-acetic acid is present in considerable amount. If with the same specimen of urine the Rothera's test is positive but the ferric chloride test is negative, that indicates only presence of small quantities of ketone bodies. If both tests are positive, the patient has enough ketone bodies in the urine and he needs urgent treatment.
- Reagent Strips: To test ketone bodies are also available. A mauve colour of the test end of the strip, 15 seconds after dipping in urine indicates presence of ketone bodies.
Bile Pigments
Bile pigments are present in the urine of patients suffering from jaundice. If such a urine is shaken in a test tube, there will be formation of a stable yellow froth due to presence of bile salts and bile pigments.15
- ICTO test: Five drops of urine are placed on the test mats provided. One ictotest tablet is placed in the centre of the moistured area. Two drops of water are placed on the tablet and allowed to flow on to the mat and the colour change in the mat is observed 30 seconds afterwards. If bile pigment (bilirubin) is present, the mat turns purple.
- Reagent strips: It also available to test the presence of bilirubin in urine.
Blood
Whole blood may appear in the urine (haematuria), in certain conditions like stones, cancers etc. Very large numbers of red blood cells in the urine may lead to a smoky appearance of the urine and still more number can produce a brown or red colour.
Menstrual contamination is the most common cause of blood in the urine. Otherwise diseases of kidney, ureter, bladder or urethra and sometimes heavy excercise usually causes haematuria. Red cell casts in urine suggest bleeding into the renal tubules inside kidney. Blood in the urine is usually tested by following method.
Reagent strip: A strip of multistix is dipped into the urine and examined 25 seconds later. The colour in the test end of the strip changes from cream to green or blue.
THE FAECES (STOOL)
Inspection of the stools of patient provides valuable information. Examination of a patient with bowel disturbance is not complete without a stool examination. The nurse should direct the patient to evacuate in a bed pan and preserve it as the white surface of the bedpan provides an ideal background for the detection of blood, pus and mucus. In constipation, there is reduction in frequency of defecation or a constant sensation of rectal fullness with incomplete evacuation of stools or sometimes painful defecation with passage of small hard balls of faeces known as ‘Scybalae’. Sometimes impaction of ‘scybalae’ in the rectum occurs in elderly dehydrated patients which requires mannual evacuation by doctor or nurse. The patient of constipation is given either a bulking agent (Ispaghula) or faecal softener (liquid paraffin, Docusate sodium) or stimulant laxative (casteroil, bisacodyl).16
Diarrhoea means frequent or loose stools. Physiologically diarrhoea is defined as a faecal output exceeding 200 gm/day when dietary fibre content is low. If the patient presents with a history of frequent small volume stools, associated with urgency and gripping pain (tenesmus), the site of underlying disorder is most likely the distal colon. If the patient presents with a history of large volume, the underlying disease is usually in small intestine (especially if the stools are greesy or show other signs of malabsorption). In the malabsorption syndrome, the motions are large, bulky and pale. In thyrotoxicosis (thyroid gland enlargement with toxic features) although the motions are very frequent they are usually small but normally formed.
Black stools may be produced by the ingestion of iron or bismuth. “Malena” is the term applied to black and tarry stools due to bleeding from the oesophagus, stomach or duodenum when blood is altered in its passage through the bowel. Approximately 60 ml blood is required to produce a single black stool. Pallor of the stools may be due to lack of entrance of bile into the intestine, (as in obstructive jaundice) to dilution and rapid passage through the intestine (as in diarrhoea) or an abnormal high fat content (as in malabsorption).
When bleeding occurs in the lower bowel, as in carcinoma of rectum or haemorrhoids the blood is bright red and often appears as streaks of blood in the stool. In intussusception they may look like red currant jelly.
Purulent or pus containing stools are found in severe dysentery or ulcerative colitis, or in cases where an abscess has found its way into the intestine. In ulcerative colitis stools may contain blood and mucus in later stages. In bacillary dysentery the stools at first consist of faecal material mixed with blood and pus, later of blood and pus without faecal material. In amoebic dysentery stools characteristically consist of fluid faecal material, mucus and small amounts of blood. The stools of steatorrhoea are very large, pale and putty-like or porridge-like and sometimes frothy. They stick to the sides of the lavatory pan and are difficult to flush away and float in water, being colourless, almost odourless, alkaline in reaction and contains a number of small flocculi consisting of sheds of epithelium and particles of mucus.
Orthotolidine Test for Occult Blood
A small portion of stool (the size of a pea) is suspended in 5 ml of distilled water and boiled for 5 minutes. A 4 per cent stock solution of 17Orthotolidine in 95 per cent ethyl alcohol is prepared. A 1 in 5 solution is made in glacial acetic acid. 1 ml of this reagent, 0.25 ml of the faecal suspension and 0.25 ml of hydrogen peroxide are mixed in a test tube; after 3 minutes, a dark green colour indicates a strongly positive test, and a pale green colour indicates weak positive test.
The stools are then examined under the microscope for ova or cysts of worms. Adult thread worms, round worms or tape worms may pass in the stools.
CAUSES OF DISEASE
Though diseases affect different parts of body like diseases that affect heart, diseases that affect respiratory system and others affecting the brain, we can also classify or group diseases as per the cause or ‘aetiology’. Aetiology of a disease may be environmental and induced by factors outside the body. For example, intense cold can lead to frost bite, infected food can cause food poisoning or enteritis. Diseases can also be caused by microbes which enter the body from the environment. Similarly some diseases can be inherited which either manifest at birth (e.g. mongolism) or may manifest at a later age (e.g. diabetes). Nutrition has also a role to play in causation of disease. Nutritional deficiency is the cause of many disorders like night blindness, scurvy, pellagra etc. An elderly man in a state of poor nutrition is more prone to invasion by bacteria than an young healthy man. Furthermore the human body is endowed with a complex system to defend against the noxious agents which invade and threaten it. This is called the ‘immunity system’. When this immunity system becomes prone to invasion by noxious agents (e.g. microbes) one suffers from disease.
Classification of Diseases
Depending upon the various aetiological factors described above, diseases can be classified as under:
- Genetical (heredity) diseases
- Immunological diseases
- Diseases due to physical and chemical agents:
- Drugs including smoking and alcohol
- Excess of heat and cold
- Poisoning
- Occupational health hazards
- Traumatic (injury)
- Infective disorders due to:
- Bacteria
- Viruses
- Fungi
- Rickettsiae
- Parasites
- Neoplastic or cancer-diseases due to unknown causes; cancers affecting various organ systems, e.g. cancer of stomach, breast cancer, blood cancer (leukemia), lymph node cancer (Hodgkin's and non Hodgkin's lymphoma), Bone cancer (osteogenic sarcoma) etc.
- Allergic diseases: Caused by allergic reaction to external or internal allergens, e.g. bronchial asthma, eczema.
- Degenerative diseases: Caused by degenerative changes in an organ, e.g. atherosclerosis of blood vessels, osteoarthritis of joints.
- Metabolic and endocrine diseases: These occur due to disturbances in metabolic process or abnormal secretion of hormones by endocrine glands, e.g. diabetes mellitus, thyrotoxicosis.
- Diseases due to deficiency of nutritional factors, e.g., kwashiorkor, marasmus, pellagra.
GENETIC FACTORS IN DISEASE
Chromosome
Each human being bears within the nucleus of its cell a set of chromosomes which is characteristic both in number and in morphology of that human being. These chromosomes are threads of basic material known as DNA (deoxy ribonucleic acid). DNA stores the genetic information. DNA is composed of two polypeptide chains, twisted together to form a double helix. In simpler way it can be said that DNA is responsible for determining the character of a person. Sited along the length of each chromosome are a series of genes which are responsible for reproducing all the different characteristics of the child-to-be. If the gene is faulty, the result is termed “genetic disorder”.19
Genes are of two types:
- Structural genes: Responsible for the synthesis of specific proteins, e.g. haemoglobin, colllagen and enzymes.
- Control genes: It thought to modify the action of structural genes.
The fertilised ovum contains a net of 46 chromosomes, i.e. two sets of 23 chromosomes, one set from the sperm and one set already in the ovum. This fertilized ovum, containing chromosomes and genes from both parents, is the blue print from which all cells in the growing fetus will be patterned. Of this 23 chromosomes each in ovum and sperm, one is a sex chromosome and remaining 22 are autosomes. Of the 23 chromosomes in ovum (female) the sex chromosome is called ‘X’. Similarly the sperm has a sex chromosome which may be either ‘X’ or a smaller one ‘Y’. The baby's sex will be inherited as under.
Abnormalities in Sex Chromosome
Occasionally abnormalities in sex chromosomes may occur. Thus the ovum may contain an extra sex chromosome ‘XX’. If it unites with a sperm containing sex chromosome ‘Y’ then the baby will be a male with XXY. This abnormal baby will not develop properly, will be sterile with small genitalia and may be mentally retarded. Some examples of sex chromosome abnormalities are:
47XXY: A boy with Klinefelter's syndrome has an extra X chromosome in male sperm resulting in XXY sex chromosome constitution. The main features include the man is enunuch, sterile (due to absent sperm production), mentally retarded, has small genitalia and gynaecomastia. There may be XXXY sex chromosome constitution.
45XO: A girl with XO sex chromosome constitution (sex chromosome from sperm is absent). The main clinical features in these females are 20short height, primary amenorrhoea, lack of secondary sexual characters, webbing of the neck, deformity of forearm (cubitus valgus) coarctation of aorta, low intelligence.
Abnormalities in Autosomes
There are a number of abnormalities in men with autosomes. In Down's syndrome (mongolism) there is an extra autosome. At the time of conception the ovum has 47 chromosomes instead of 46. The addition takes place at chromosome 21. As a result every cell produced in the growing foetus carries the abnormalities and a mentally subnormal child is born with characteristic physical defects. This defect occurs in about 1 in 700 live births and the baby is born with a flat face, widely spaced and upward slanting eyes, epicanthic folds, brachycephaly, malformed ears, broad and/ or short neck, a single transverse palmar crease, mental retardation. These patients have a pleasant quiet personality and show a great fondness for music. These patients also have congenital heart disease and acute leukemia. They usually die within first year of life but some survive into adulthood.
Philadelphia Chromosome (Ph)
This is an acquired chromosomal abnormality associated with chronic myeloid leukemia (blood cancer). The abnormality takes place at the chromosome 22, where a part of chromosome (autosome) 22 is detached and gets attached to another autosome, usually chromosome 9. The leukemia patient without Philadelphia chromosome (Ph’) has a poor survival rate.
Dominant and Recessive Chromosomal Disorders
There are many genetic disorders which are inherited’ from parents. An abnormal gene may be passed on from generation to generation. These hereditary disorders are more likely to be seen when marriages take place among near relatives. There is then inbreeding of the defective gene. Many of the defective genes passed on to the future generation are “recessive” (dormant or quiscent). Such a gene may only cause disease if it links up with a similar recessive gene. The mating of two defective recessive genes is much more likely to occur in marriages between near relatives or cousins in same family. Other 21hereditary genes are known as “dominant” because they give rise to defect in future generations without having to linkup with other similar genes. Depending on whether the affected gene is an autosome or sex-chrosome (X chromosome is commonly affected), the disorders can be classified into “Autosomal dominant”, “Autosomal recessive” and “X-linked dominant” and “X-linked recessive” disorders. Some common examples are given below:
Autosomal dominant disorders: | Achondroplasia Fascioscapulo humeral muscular dystrophy. Marfan's syndrome Polycystic kidney disease (adult form) |
Autosomal recessive disorder: | Albinism Limb-girdle muscular dystrophy cystic fibrosis |
X-linked dominant disorder: | Vitamin-D resistant ricket |
X-linked recessive disorder: | Duchenne muscular dystrophy. Haemophilia |
Haemophilia is the best known example of X-linked recessive disorder. Antehaemophilic globulin (AHG) a blood clotting factor required for normal blood clotting is missing in these patients due to an inherited genetic defect. Consequently these patients bleed profusely from a minor injury leading to death sometimes, unless he is transfused the globulin (AHG). In this disorder if an affected man marries a normal woman, then all his daughters will be carriers but none of his sons will be affected. An X-linked disorder is never transmitted from father to son, that is because his affected X chromosome pass on to daughters and Y chromosome (healthy) pass on to his sons.
If a woman carrying a X-linked recessive disorder marries a normal man, then half of her sons will be affected and half of her daughters wiil be carriers because each of her children has an equal chance of inheriting from her either the normal X chromosome or the one bearing the defective gene.
Some common diseases appear to have a genetic factor as part of the aetiology. These diseases include diabetes mellitus where heredity plays a major role. So also is the case of essential hypertension, coronary artery disease, peptic ulceration, where familial incidences 22can be traced. When both parents are diabetics, their children are more prone to diabetes than children of healthy parents.
Mitochondrial Inheritance
Mutations in the genes encoded by the mitochondrial chromosome cause a number of diseases that affect organs highy dependent upon oxidative metabolism like brain, retina, kidneys, and heart. Since mitochondria is derived entirely from ovum, the inheritance is purely maternal; the affected female passing defective mitochondrial chromosome to all her offsprings. Many myopathics and cardiac chanelopathies are due to mitochondrial inheritance.
The human genome has nearly one lakh genes of which 20,000 are functional.
Cytogenetics
Cytogenetics is the study of chromosome by light microscopy. Chromosomal analysis is done by growing human cells in tissue culture, stopping mitosis by additing cochicine, then photographing and matching.
Indications for Cytogenetic Analysis
- Patients with malformations suggestive of one recognized chromosomal syndrome
- Physical or mental retardation
- Ambiguous genitalia/hermaphroditism
- Delayed puberty or primary amenorrhoea
- Certain malignant or premalignant diseases like meningioma neuroblastoma, renal cell carcinoma, Wilm's tumor, retinoblastoma leukemia and lymphoma
- Prenatal diagnosis
- Inborn errors of metabolism.
It is possible to diagnose in utero, before the middle of second trimester several mendelian disorders, all chromosome aberrations and a number of non-mendelian congenital malformations. All women conceiving after age of 35 be offered prenatal diagnosis. Amniotic fluid cells and chorionic villous sampling for trophoblastic cells are done for the purpose. The chromosomes of the cell can be studied by FISH or the genes by PCR. The fetal cells circulating in maternal blood can also 23be studied for the purpose. Ultrasound, fetoscopy, fetography and amniography can diagnose fetal malformations. Raised maternal alfa fetoprotein indicates neural tube defect in the fetus or renal agenesis. Its low level may point so fetal trisomy, i.e. Down's syndrome.
Clinical Significance of Genetics
Advancement in genetics have brought lot of improvement in prevention of genetic disorders. For example, the risk of Down's syndrome (mongolism) can be known now. The risk of having a child with Down's syndrome is about 1 in 100 in women who have previously had an affected child. So that the disorder can be prevented in such high risk mothers. Similarly healthy female carriers of Duchenne muscular dystrophy and haemophilia can be detected before their marriage.
By examining the cells in amniotic fluid or examining the fluid itself, serious genetic disorders in the baby can be detected and such foetuses can be aborted. Similarly by determining the sex of the foetus, an undesirable foetus can be aborted. For example, a male foetus in the womb of carrier mother of Duchenne muscular dystrophy is most likely to be a Duchenne baby and hence undesirable. Diseases like Down's syndrome, anencephaly and spina bifida can be now detected in foetus by antenatal diagnosis (from aminotic fluid).
Genetic Advice
Nowadays many genetic disorders can be prevented by educating the parents about nature and cause of the genetic disorder and how to avoid pregnancy and when to terminate a pregnancy with a foetus having possible genetic disorder.
Recombinant DNA Technology
By this method nowadays fragments of DNA containing specific genes of interest can be incorporated into the DNA of a plasmid and then grown in culture inside a microbial host Escherichia coli.
By this technique, human insulins, growth hormone, interferon can be synthesized in large quantity for clinical use. By this method, preclinical and antenatal diagnosis of some genetic disorder is also now possible. In future the genetic diseases can be treated by recombinant DNA technique by direct replacement of defective gene (as in diabetes, haemophilia etc.).