Learn — Oxygenation, nutrition & elimination

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Lines and tubes — suctioning, ETT, NG, tracheostomy, CVP

Lines and tubes are the invasive devices a ward or intensive care nurse manages every shift: the endotracheal and tracheostomy tube that holds the airway, the suction catheter that clears it, the nasogastric tube that feeds or decompresses the stomach, and the central venous catheter through which drugs, fluid and pressure readings pass. Each one bypasses a natural defence, so the daily nursing of them is what decides whether the patient gets ventilator-associated pneumonia, an aspiration, a bloodstream infection or a blocked airway.

Endotracheal suction is done on clinical indication and not by the clock: visible secretions in the tube, coarse crackles or rhonchi, a rising peak airway pressure, a sawtooth flow-volume loop, a falling oxygen saturation or a patient who cannot clear a cough.
Suction technique is pre-oxygenate with 100% oxygen for 30 to 60 seconds, use a sterile catheter no wider than half the internal diameter of the tube (usually 12 to 14 French in an adult), insert without applying suction, apply suction only while withdrawing, keep each pass to 10 to 15 seconds and limit an episode to about three passes with re-oxygenation between them.
Wall suction pressure is set to 100 to 150 mmHg in an adult, 80 to 100 mmHg in a child and 60 to 80 mmHg in a neonate; higher pressures strip the tracheal mucosa and cause hypoxaemia.
The endotracheal cuff is kept at 20 to 30 cmH2O and checked at least once a shift with a manometer, the tip should sit about 2 to 5 cm above the carina on the chest X-ray, and the centimetre mark at the lip or teeth is recorded every shift so that a tube that has migrated is noticed before it blocks or slips into the right main bronchus.
A nasogastric tube is measured by the nose-to-earlobe-to-xiphisternum method (about 50 to 60 cm in an adult) and its position is confirmed by aspirating gastric contents and testing them on pH indicator paper, with a pH of 5.5 or below accepted as safe to feed; the whoosh or auscultation test is unreliable and is not used, and an X-ray is the arbiter when there is any doubt.
Tracheostomy care needs a spare tube of the same size and one a size smaller plus tracheal dilators kept at the bedside, humidification at all times, the inner cannula cleaned or changed at least eight-hourly and more often with thick secretions, ties tight enough to admit one finger, and the first tube change done by the doctor once the tract is formed at about a week.
Central venous pressure is read with the transducer levelled at the phlebostatic axis, the fourth intercostal space at the mid-axillary line, with the patient supine and the reading taken at end-expiration; a normal value is 2 to 8 mmHg, and a change over time in one patient tells you more than a single number.
Central line care is a bundle: skin preparation with 2% chlorhexidine in 70% alcohol allowed to air dry, a transparent semipermeable dressing changed every 7 days and a gauze dressing every 2 days or sooner if damp, loose or soiled, the hub scrubbed for about 15 seconds before every access, and the line removed the day it is no longer needed.
Clamp a central line before any disconnection and keep the patient flat or head-down while the hub is open, because air entrained through an open catheter causes air embolism; if it is suspected, clamp the line, put the patient head-down on the left side, give high-flow oxygen and call for help.

Oxygen therapy devices and flow rates

Oxygen therapy is the delivery of a higher fraction of inspired oxygen than the 21% of room air, prescribed like any other drug with a dose, a delivery device and a target saturation range. It matters at the bedside because the device chosen decides how much oxygen the patient actually receives: a low-flow device gives a variable concentration that changes with the patient's own breathing pattern, while a fixed-performance device gives a predictable one whatever he does.

Nasal cannula runs at 1 to 6 L/min and gives roughly 24% to 44% oxygen, a useful rule being about 4% added for each litre above room air; it allows the patient to eat and talk but dries the nose above 4 L/min, so humidify beyond that.
A simple face mask runs at 5 to 10 L/min and gives about 40% to 60%; it must never be run below 5 L/min, because a lower flow does not flush the exhaled carbon dioxide out of the mask and the patient rebreathes it.
A partial rebreather mask with a reservoir bag runs at 6 to 10 L/min and gives roughly 60% to 80%; a non-rebreather with a reservoir and one-way valves runs at 10 to 15 L/min and gives up to about 90%, and in both the reservoir bag must stay inflated and must not collapse on inspiration.
The Venturi mask is the only common ward device that delivers a fixed, predictable oxygen concentration regardless of the patient's respiratory pattern, using colour-coded jet adapters, commonly blue 24%, white 28%, yellow 35%, red 40% and green 60%, each with its own flow rate printed on it; colours vary between manufacturers, so read the number on the adapter rather than trusting the colour.
Target ranges are prescribed: 94% to 98% for most acutely ill adults, and 88% to 92% for a patient at risk of hypercapnic respiratory failure such as advanced COPD, obesity hypoventilation or a neuromuscular chest wall disorder.
Humidification is added when the flow is above about 4 L/min, when a mask is used for more than a short period, and always for a tracheostomy or an endotracheal tube, because dry gas thickens secretions and damages the mucosa.
High-flow nasal cannula delivers heated, fully humidified gas at up to 60 L/min with an oxygen fraction that can be set up to 1.0, washes out dead space and generates a small amount of positive pressure, which is why it is tolerated better than a mask at high concentrations.
Complications to watch for are oxygen toxicity with a fraction above 0.6 sustained for more than a day, absorption atelectasis, retinopathy of prematurity in the preterm neonate, drying and bleeding of the nasal mucosa, and pressure injury from the tubing behind the ears and over the bridge of the nose.
Oxygen supports combustion: no smoking or naked flame near the patient, no oil or grease on cylinders and regulators, cylinders kept upright and secured, and equipment checked for leaks.

Airway management

Airway management is the set of manoeuvres, adjuncts and devices used to open and keep open the passage from the mouth and nose to the trachea, and to ventilate the patient when he cannot ventilate himself. It is the first letter of every resuscitation sequence because an obstructed airway kills in minutes, and because in an unconscious patient the commonest cause of obstruction, the tongue falling back against the pharyngeal wall, is relieved by a manoeuvre that costs nothing and takes seconds.

Recognise obstruction by the sound and the movement: snoring means the tongue, gurgling means fluid needing suction, stridor means the larynx, a see-saw or paradoxical chest and abdominal movement with in-drawing means severe obstruction, and silence in a patient who is visibly trying to breathe means it is complete.
Open the airway with a head-tilt and chin-lift in a patient with no suspected cervical spine injury, and with a jaw thrust alone when the neck must be kept still; if a jaw thrust fails to open the airway, opening the airway takes priority over the spine.
An oropharyngeal airway is sized from the corner of the mouth to the angle of the mandible, is inserted upside down and rotated through 180 degrees in an adult or the right way up over a tongue depressor in a child, and is used only in a patient who is unconscious with no gag reflex.
A nasopharyngeal airway is sized from the tip of the nose to the tragus of the ear with a diameter about that of the patient's little finger, is lubricated and passed along the floor of the nose, is tolerated by a semi-conscious patient, and is avoided when a base-of-skull fracture is suspected (periorbital bruising, mastoid bruising or clear fluid from the nose or ear).
Bag-valve-mask ventilation uses the E-C clamp grip, is far more effective with two rescuers (one holding the seal with both hands, one squeezing), and each breath is given over about one second with just enough volume to make the chest visibly rise; over-inflation forces air into the stomach and causes regurgitation.
Ventilation rates without compressions: an adult with a pulse who is not breathing gets 1 breath every 6 seconds, that is 10 a minute, and an infant or child with a pulse gets 1 breath every 2 to 3 seconds, that is 20 to 30 a minute; during CPR with an advanced airway in place, an adult gets 1 breath every 6 seconds with continuous compressions.
Escalation runs from a bag-valve-mask to a supraglottic airway such as a laryngeal mask or i-gel and then to an endotracheal tube; placement is confirmed by waveform capnography as the gold standard, together with visible bilateral chest rise, equal breath sounds in both axillae and no gurgling over the epigastrium.
For choking, a patient who can cough effectively is encouraged to cough and nothing else is done; a conscious adult with severe obstruction gets 5 back blows between the shoulder blades alternating with 5 abdominal thrusts, an infant gets 5 back blows and 5 chest thrusts and never abdominal thrusts, and a pregnant or very obese adult gets chest thrusts instead of abdominal.
If a choking patient becomes unresponsive, lower him to the floor, call for help, start chest compressions immediately, and look inside the mouth before each set of rescue breaths, removing an object only if you can see it; never sweep the mouth blindly.
An unconscious patient who is breathing normally with no suspected trauma is placed in the recovery position on his side with suction available, and is not left alone.

Enema — types and procedure

An enema is the instillation of a solution into the rectum and sigmoid colon, either to empty the bowel by distending it and softening the stool, or to deliver a drug or nutrient that is retained and absorbed. It matters at the bedside because the details that look decorative, the position, the height of the container, the depth of insertion and the temperature of the fluid, are what decide whether the enema works or whether it perforates a bowel or triggers a vagal collapse.

Cleansing enemas act by distension and irritation: normal saline is the safest and the only one used for an infant, tap water is hypotonic and is not repeated because it causes water intoxication, soap suds is irritant and is made with a small amount of castile soap in a litre of water, and a ready-made hypertonic phosphate enema of about 120 to 150 mL works by drawing water into the bowel.
Retention enemas are held in for longer to do their work: an oil retention enema of about 100 to 200 mL softens hard impacted faeces and is retained for 30 to 60 minutes, and medicated, nutrient and sedative enemas are given by the same route.
A return-flow or Harris flush enema alternately runs fluid in and lets it drain out to expel flatus and relieve abdominal distension, and a carminative enema does the same job chemically.
The patient is placed in the left lateral Sims position with the right knee drawn up, because that follows the anatomy of the descending and sigmoid colon and lets the fluid run with gravity rather than against it.
The tube is lubricated and inserted gently towards the umbilicus for about 7.5 to 10 cm in an adult, 5 to 7.5 cm in a child and 2.5 to 3.75 cm in an infant; if there is resistance, stop and do not force it.
The solution is warmed to about 40.5 to 43 degrees Celsius for an adult, and to body temperature for a child; fluid that is too cold causes cramping and fluid that is too hot burns the mucosa.
The container is hung about 30 to 45 cm above the anus for a low enema and about 45 cm for a high enema, and the fluid is run in slowly over 5 to 10 minutes; if the patient cramps, lower the container or clamp the tubing for 30 seconds and then continue.
Adult volumes are commonly 500 to 1000 mL, a child takes about 250 to 500 mL and an infant 150 to 250 mL; the patient is asked to retain a cleansing enema for 5 to 15 minutes and an oil retention enema for 30 to 60 minutes, and a bedpan or a clear route to the toilet is arranged before you start.
Contraindications include suspected intestinal obstruction or perforation, appendicitis or an acute abdomen, recent rectal or bowel surgery, severe neutropenia or thrombocytopenia, and paralytic ileus; check the notes before accepting the order.
Record the type and amount of solution given, the amount and character of the return, the patient's tolerance and any adverse effect.

Care of colostomy patient

A colostomy is a surgically created opening that brings a part of the colon out through the abdominal wall so that faeces leave the body through a stoma into an appliance instead of through the anus. Its nursing is a mixture of observation and teaching: the colour of the stoma tells you whether the bowel is alive, the fit of the appliance decides whether the surrounding skin survives, and the patient's ability to manage it himself decides whether he goes home.

The output tells you the level: an ileostomy drains liquid to porridge-like enzyme-rich effluent in large volumes from the first day or two and excoriates skin quickly, an ascending colostomy drains liquid, a transverse colostomy semi-formed stool, and a descending or sigmoid colostomy formed stool that starts around the third to fifth day and can become predictable.
A healthy stoma is beefy red to pink, moist and shiny, slightly oedematous for the first weeks and shrinking over about six to eight weeks; it has no sensory nerve endings so it does not hurt to touch, and a little bleeding when it is cleaned is normal.
Abnormal appearances are dusky purple or black (ischaemia), pale (anaemia), retraction below skin level, prolapse, stenosis, a parastomal hernia and mucocutaneous separation where the stoma edge parts from the skin.
Empty the pouch when it is one-third to one-half full, because a heavier bag drags the wafer off the skin, and change the whole appliance every three to five days or immediately if there is leakage, itching or burning under it; change it before a meal or first thing in the morning when the output is least.
Measure the stoma with a template at every change for the first six to eight weeks and cut the barrier no more than about 2 to 3 mm larger than the stoma, since exposed skin is what excoriates and a hole that is too tight cuts the stoma.
Clean the peristomal skin with warm water and dry it thoroughly; do not use soaps with oils, alcohol, antiseptics or barrier creams under the wafer, and treat sore skin by correcting the fit and using a paste or ring to fill dips rather than by applying ointment.
Irrigation to regulate the bowel is an option only for a descending or sigmoid colostomy, done at the same time each day with about 500 to 1000 mL of warm water; it is never done for an ileostomy.
Diet advice: eat regular meals, chew thoroughly and drink 8 to 10 glasses of fluid a day; an ileostomy patient needs extra salt and fluid because of the risk of dehydration and hypokalaemia, and must avoid stringy high-residue foods such as popcorn, nuts, coconut, mushrooms, raw celery and corn that block the stoma.
Gas and odour are managed rather than endured: beans, cabbage, onion, carbonated drinks and beer produce gas; fish, eggs, garlic and asparagus produce odour; buttermilk, yoghurt and parsley reduce it, and a filtered or deodorised pouch helps.
Enteric-coated and sustained-release tablets are unreliable in an ileostomy because they may pass through unabsorbed, so the drug chart is reviewed with the doctor or pharmacist.
Psychological care and teaching are part of the treatment: talk about body image, odour, sexual function and return to work, involve the stoma nurse and a patient association, and make sure the patient or a family member has done a complete change unaided before discharge.

Urinary catheter care

An indwelling urinary catheter is a tube passed into the bladder and held there by a balloon, draining urine continuously into a closed collection system. It matters because it is the commonest device-related infection risk in a hospital: every day it stays in adds to the chance of bacteriuria, so the nursing of it is as much about asking whether it is still needed as about how it is cleaned.

Legitimate indications are acute retention or bladder outlet obstruction, accurate hourly output measurement in a critically ill patient, selected perioperative use, healing of an open sacral or perineal wound in an incontinent patient, prolonged immobilisation after trauma, and comfort at the end of life; incontinence alone and staff convenience are not indications.
Sizes: 12 to 14 French for an adult woman, 14 to 16 French for an adult man and 8 to 10 French for a child, with a three-way 20 to 24 French catheter used for irrigation after prostate surgery; the balloon takes 5 to 10 mL in an adult and 3 to 5 mL in a child and is inflated with sterile water, never with saline, which crystallises, or with air, which floats.
Insertion is a strictly aseptic procedure with sterile gloves and drapes, a single-use lubricant or anaesthetic gel, and antiseptic cleaning of the meatus; insert about 5 to 7.5 cm in a woman and 17 to 22.5 cm in a man, or until urine flows and then a further 2.5 to 5 cm, before the balloon is inflated.
In a man the penis is held at about 90 degrees to the abdomen, the foreskin is retracted for cleaning and must be replaced immediately afterwards, because a retracted foreskin left forgotten causes paraphimosis.
Keep the drainage system closed: do not disconnect it to collect a specimen or to move the patient, and take a urine sample by disinfecting the sampling port and aspirating with a sterile syringe, never from the drainage bag.
The bag stays below the level of the bladder at all times, including during transfers, hangs on the bed frame and never touches the floor, and is emptied at least eight-hourly or when two-thirds full using a separate clean container for each patient; the tubing is kept free of kinks and dependent loops.
Secure the catheter to the thigh in a woman and to the thigh or lower abdomen in a man, so that traction does not pull the balloon against the bladder neck and cause ulceration.
Daily meatal care is done with soap and water during the routine bath; antiseptics, powders and creams at the meatus do not reduce infection, and routine bladder irrigation, routine catheter changes by the calendar and prophylactic antibiotics are all unnecessary and harmful.
Review the need for the catheter every single day and remove it as soon as the indication has passed, using a nurse-driven removal protocol where one exists, because early removal is the single most effective infection-prevention measure available.
Asymptomatic bacteriuria in a catheterised patient is not treated except in pregnancy and before a urological procedure; cloudy or strong-smelling urine alone is not an infection, and a urine specimen is sent only when there are symptoms.
For long-term bladder emptying, intermittent clean self-catheterisation is preferred to an indwelling catheter, and a man who is incontinent without retention may be managed with a condom drainage sheath.

Chest tube care

A chest drain is a tube placed into the pleural space and connected to an underwater seal so that air, blood, fluid or pus can leave the chest while nothing is drawn back in, restoring the negative intrapleural pressure that keeps the lung expanded. Its nursing matters because the drainage unit is a one-way valve that only works while it is upright, below the chest and unclamped, and because a clamped or blocked tube in a patient with an air leak becomes a tension pneumothorax within minutes.

The tube is placed in the second intercostal space in the mid-clavicular line to drain air and in the fifth or sixth intercostal space in the mid-axillary line, within the safe triangle, to drain fluid or blood; a mediastinal drain is used after cardiac surgery.
The classical system has three chambers: the collection chamber where drainage is measured, the water-seal chamber filled to the 2 cm mark that acts as the one-way valve, and the suction control chamber, which in a wet system is filled to the ordered level, usually 20 cm of water, and in a dry system is set with a dial.
Normal findings are tidaling in the water-seal chamber, the level rising with inspiration and falling with expiration in a spontaneously breathing patient and moving the opposite way in a ventilated one, intermittent bubbling in the water seal while a pneumothorax is still leaking air, and gentle continuous bubbling in the wet suction chamber only.
Continuous bubbling in the WATER SEAL through the whole respiratory cycle means an air leak: check from the patient outwards, first the dressing and the insertion site, then all the connections, and only then briefly pinch the tube near the chest wall to localise it; report a new or increasing leak.
No tidaling at all means either the lung has fully re-expanded or the tube is kinked, blocked, clamped or displaced; assess the patient's breathing before you decide which, and never assume the good explanation.
Keep the unit upright and always below the level of the patient's chest, keep the tubing free of dependent loops and coiled flat on the bed, and never lift the unit above the chest during a transfer.
Do not strip or milk the tubing as a routine, because it generates dangerously high negative pressure, and do not clamp the tube except very briefly to change the unit, to locate a leak, or when the doctor orders a clamping trial before removal.
Keep a bottle of sterile water and an occlusive dressing and clamp at the bedside: if the tube disconnects from the unit, put the end of the tube into 2 cm of sterile water at once to re-establish a seal, and if the tube comes out of the chest, cover the site immediately with a dressing taped on three sides so trapped air can escape, and call for help.
Measure and mark the drainage level with the date and time each shift, record the volume, colour and character, and report drainage of more than about 100 mL an hour of fresh blood, a sudden gush after a quiet period, or a sudden stop.
Encourage deep breathing, incentive spirometry, coughing and shoulder and arm exercises on the affected side after adequate analgesia, because the lung re-expands with ventilation and the shoulder stiffens without movement.
For removal, give analgesia beforehand, ask the patient to take a deep breath and hold it at the end of inspiration or to bear down while the tube is pulled, apply an airtight occlusive dressing immediately, and arrange the chest X-ray that follows.

Pulmonary artery catheter

A pulmonary artery catheter, still widely called a Swan-Ganz catheter, is a balloon-tipped flow-directed catheter passed through a central vein into the right atrium, right ventricle and pulmonary artery, where it measures right-sided pressures, the pulmonary artery occlusion pressure and the cardiac output. It matters because the numbers it produces separate the causes of shock from one another at the bedside, and because the nursing detail of levelling, zeroing and balloon handling is what makes those numbers true rather than dangerous.

The catheter has several lumens: a proximal port opening in the right atrium for central venous pressure and for the injectate used in thermodilution, a distal port in the pulmonary artery for the pulmonary artery pressure and mixed venous sampling, a balloon inflation port, and a thermistor connection.
The waveform tells you where the tip is as it advances: a low flat trace with a, c and v waves in the right atrium, a tall spiky trace with a near-zero diastolic pressure in the right ventricle, the same systolic pressure but a much higher diastolic with a dicrotic notch in the pulmonary artery, and a small flat trace when it wedges.
Normal values to know: right atrial or central venous pressure 2 to 8 mmHg, right ventricular 15 to 25 over 0 to 8, pulmonary artery 15 to 30 over 8 to 15, pulmonary artery occlusion pressure 6 to 12 mmHg, cardiac output 4 to 8 L/min, cardiac index 2.5 to 4.0 L/min/m2, and mixed venous oxygen saturation 60% to 80%.
The occlusion or wedge pressure reflects left atrial pressure and therefore left ventricular end-diastolic filling, while the central venous pressure reflects right-sided filling; that is why a high wedge with a normal central venous pressure points to the left ventricle and a high central venous pressure with a normal wedge points to the right ventricle or to a pulmonary embolus.
Level the air-fluid interface of the transducer at the phlebostatic axis, the fourth intercostal space at the mid-anteroposterior or mid-axillary line, zero it to atmosphere at the start of every shift and after any change of position, and read every pressure at end-expiration.
Balloon rules: inflate only with air and never with fluid, never beyond the stated volume of about 1.5 mL, never against resistance, for no longer than two respiratory cycles or about 15 seconds, and let it deflate passively rather than pulling back on the syringe.
The haemodynamic patterns are examined directly: hypovolaemic shock gives a low central venous pressure, a low wedge, a low cardiac output and a high systemic vascular resistance; cardiogenic shock gives a high wedge, a low cardiac output and a high resistance; septic or distributive shock gives a low or normal wedge, a high cardiac output and a low resistance.
Complications include ventricular arrhythmias as the catheter crosses the right ventricle, a new right bundle branch block that becomes complete heart block in a patient with existing left bundle branch block, knotting, balloon rupture with air embolism, pulmonary infarction from a catheter left wedged, catheter-related bloodstream infection and pulmonary artery rupture.
A damped or flattened waveform usually means a clot, an air bubble, a kink or the tip against the vessel wall rather than a genuinely low pressure: check the pressure bag at 300 mmHg, the flush system, the connections and the position before acting on the number, and never flush forcefully against resistance.
Routine use has fallen sharply because trials showed no survival benefit and less invasive tools, echocardiography, pulse-contour cardiac output and serial lactate and central venous saturations, give much of the same information, but the values remain a standard examination topic.

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