Section 3 Children’s nursing interventions

3.1. Interventions

3.2. Maintaining nutrition in children

3.3. Peritoneal dialysis (PD)

3.4. Plasmapheresis

3.5. Transplantation

3.6. Circulatory support

3.7. Intubation and ventilation of a child

3.8. Acid–base balance

3.9. Caring for a child in a variety of settings

3.1 Interventions

Blood transfusion therapy

The cardiovascular system can compensate for blood loss, which is designed to minimize the effects of blood loss. However, compensation for blood loss depends on a child’s age. Blood loss should be treated with blood, especially when blood loss is substantial.

Blood groups

ABO system divides into four main groups:

O – 47% of population compatible with donor O

A – 42% of population compatible with donor A or O

B – 8% of population compatible with donor B or O

AB – 3% of population compatible with donor AB, A, B, or O.

The Rhesus (Rh) system

This blood group system is in addition to the ABO antigen, and expresses a D antigen on red blood cells. This factor is present or absent and termed Rh D positive or negative:

Rh D⁺ comprises approximately 85% of the western population.

Rh D⁻ comprises the rest of the population.

The Rh D factor is significant in both blood transfusions and pregnancy:

Blood transfusions:

– AB blood group with RhD (AB) factor negative is the universal recipient, as they can receive blood from any four blood types, but is rare.

– O blood group with RhD negative (O⁻) is the universal donor and can donate blood to all four blood types.

Pregnancy

– Significant when a woman’s blood is RhD^– but is carrying a fetus that is RhD⁺.

– The mother carrying the infant builds up antibodies against the RhD⁺ red blood cells of the foetus; this does not affect the first pregnancy (this includes a miscarriage), but is stored in the immune system memory.

– In the second pregnancy the antibodies are activated quickly and this can lead to damage to the fetus.

– Following the birth of a first child Anti-D is administered to the mother to prevent reoccurrences in the second pregnancy.

Blood is collected under strict aseptic technique in a plastic vacuum container, from a donor and then mixed with an appropriate anticoagulant solution, such as: citrate-phosphate-dextrose (CPD) or oxalate salts, which prevent clotting by binding with calcium ions. The blood can then be stored under refrigeration for several weeks at a temperature of 1–4 °C.

Changes in blood begin within 24 hours of storage, and continue throughout the entire 21 days, after which blood is considered outdated (Edwards 1998). Box 3.1 show the changes that occur in stored blood.

Box 3.1 Changes that occur in stored blood

Acid-base changes

Because blood is stored in an air-free container, aerobic metabolism cannot take place, but anaerobic metabolism does occur, yet, the end product is lactic and pyruvic acids. Therefore, the longer a unit of blood is stored, the greater will be the amount of acid end products that it contains. The CPD solution used as an anticoagulant adds another acid component to banked blood and reduces the pH of the blood from a normal body pH of 7.4 to about 7.0.

Alterations in electrolyte concentration

When blood is stored the sodium and potassium concentration undergoes alteration. It can be expected that a unit of stored blood will contain approximately 75–80 mEq of sodium and 5–7 mEq of potassium. There is also a progressive loss of red cell viability and the red blood cells tend to take up water, causing a leftward shift in the oxyhaemoglobin dissociation curve and transfused blood cells to be less capable of releasing oxygen to the tissues than would be normal red blood cells.

The microaggregate load in stored blood

An increased aggregation of platelets and leukocytes occurs in stored blood and blood has been filtered through 170 μm filters to remedy it. However, the formation of microemboli are considered smaller than 170 u, have been identified and microfilters with pore sizes ranging from 20 to 90 u are required. However, because those conditions which require massive blood transfusions, are generally an emergency, it is extremely difficult, if not impossible, to prove that the use of microfilters during massive blood transfusions decreases the development of ARDS.

Depletion of clotting factors

Stored blood is deficient in most of the factors necessary for normal coagulation; it is specifically deficient in factors V, VIII, IX and platelets. However, the depletion of platelets and clotting factors vary from patient to patient and it is recommended that patient’s clotting screen and bleeding status be closely monitored during transfusion.

The temperature of stored blood

Blood is stored at a temperature between 1 and 6°C, which is considerably colder than human blood. The normal temperature is generally approximately 37°C. The infusion of large quantities of cold blood can cause patients to become hypothermic. This compromises the patient’s heart rate, blood pressure, cardiac output, and coronary blood flow. The consequent hypothermia impairs the metabolism of citrate and lactate, and increases the patient’s risk of a metabolic acidosis, it increases the affinity of haemoglobin for oxygen, and may impair clotting, and impairs the possibility of detecting a major transfusion reaction.

Blood transfusion reactions (TF)

When mismatched blood is infused, a transfusion reaction occurs and the donor and recipient’s red blood cells are attacked by the recipient’s immune system.

Transfusion reaction can occur with the infusion with as little as 10–15 ml.

The agglutination of the foreign red blood cells blocks small blood vessels throughout the body and is destroyed. This causes a reduction in the capacity of red blood cells to carry oxygen and obstruction to blood flow causing organ damage, both of which are lethal.

TF can also cause

– urticaria, itching, discomfort

– anxiety

– rash

– shortness of breath, nausea, collapse

– tachycardia, hypo/hypertension

– pain: chest, back, abdomen or loin

– generally feeling unwell, complains of a feeling of impending doom.

If any serious adverse reaction or event occurs during or after a blood transfusion it should be reported on the serious adverse blood reactions and events (SABRE) system, accessed by the serious hazards of transfusion (SHOT) website at http://www.shotuk.org.

Complications associated with blood transfusion:

– pulmonary damage

– metabolic acidosis

– blood group incompatibilities

– transfusion reactions

– hyperkalaemia

– hypothermia – with infants or large transfusions a blood warmer should be used.

Nurses have to be vigilant in checking:

The correct blood group and Rh D antigen factor

Confirming with the parent or child the identity

Checking the ID band, e.g. date of birth, hospital number (no wristband – no transfusion)

Donor number matches, CMV negative

Integrity of the bag, e.g. no damage has occurred

Expiratory date of blood

Kell or other antibodies/CMV negative

Blood been autoclaved

Observing for any signs of transfusion reactions. If any of signs occur STOP the transfusion! Report the reaction

Monitoring vital signs:

– temperature

– pulse

– respiratory rate

– blood pressure.

Other blood product derivatives

Packed red cells (whole blood from which most of the plasma has been removed) is generally only used to treat anaemia.

Fresh frozen plasma (FFP) should never be used as a volume expander in this situation. It is better to use FFP for patients with bleeding disorders, whereby there is a deficiency in platelets or clotting factors, e.g. in disseminated intravascular coagulation (DIC), warfarin overdose, trauma or thrombotic thrombocytopenia.

For a more detailed account of blood products see Table 3.1.

Table 3.1 Current blood products

Blood product	Constituents	Uses
Whole blood (510 ± 45 ml)	Use is restricted to circumstances where red blood cells as well as plasma proteins are needed i.e. where large amounts of blood are lost.	Ideal in hypovolaemic shock, since it increases both oxygen carrying capacity and expands circulating volume.
Packed cells (280 ± 60 ml)	This is whole blood, but the majority of the plasma has been removed. It contains half the volume of whole blood, less sodium, potassium, albumin and citrate. Does contain some white blood cells and platelets.	Ideal in chronic anaemia, sickle cell disease, thalassaemia and renal disease. It is not recommended in iron deficiency and vitamin B12 or folate deficiency as these should be treated with the appropriate vitamin e.g. iron tablets.
Washed packed cells	These are packed cells with all the white blood cells, platelets and plasma removed.	Indicated for patients who have a long history of transfusion reactions.
Fresh frozen plasma (FFP) (200–300 ml)	This is blood product, which is nearly always frozen and contains all the coagulation factors.	Used for the treatment of coagulation deficits. It is not recommended as a volume expander, except in certain neonatal conditions.
Cryoprecipitate (20 ± 5 ml)	Prepared from FFP and contains mainly clotting factors (factor VIII and fibrinogen).	Used to treat haemophilia or AIDS patients.
Platelets (50 ± 10 ml)	Produced from the residue left over from the production of plasma and leucocyte-depleted red blood cell concentrates.	Indications for use are thrombocytopenia, when platelet content of blood is reduced due to bleeding or diluted following massive transfusion, in acute leukaemia, aplastic anaemia, DIC or sepsis.

AIDS, acquired immune deficiency syndrome; DIC, disseminated intravascular coagulation.

Despite blood products being essential, they are at times scarce, or difficult to source in emergencies and thus other methods have been introduced, namely: autotransfusion, synthetic blood products, or colloid and crystalloid therapies.

Autotransfusion

Minimizes the need for blood transfusion by a blood donor.

During surgical procedures blood can be salvaged through an autotransfusion device.

Blood can be re-infused back into the patient during surgery if blood loss is great, or saved for transfusion at a later date.

Synthetic blood products

Artificial blood substitutes, or perfluorochemicals, have become available for clinical use.

Used in cases of severe anaemia when transfusion of blood products is not an option.

Use of these products to treat blood loss is still under investigation.

When perfluorochemical microdroplets (which have a high solubility of oxygen) are infused intravenously, oxygen is dissolved in the microdroplets and transported to capillaries for diffusion across capillary walls (Edwards 1998).

Side effects include:

pulmonary oedema

arrhythmias

chest pain

respiratory distress.

Positive effects of perfluorochemicals do not endure beyond 24 hours after infusion due to their short half life.

May reduce blood recipient adverse reactions from donor blood.

Minimizes the use of and improves the cost effectiveness of blood transfusions.

Fluid replacement therapy

Crystalloid therapy

Crystalloid solutions used are 5% dextrose (not a true crystalloid as it contains no electrolytes), 0.9% sodium chloride; dextrose saline and Hartmann’s (see Table 3.2).

Any solution that contains electrolytes will influence fluid movement; the most powerful is sodium.

Sodium added to the extracellular fluid compartment as in intravenous infusion will keep sodium at a normal level and have no effect on fluid movement but the infused solution of 0.9% normal saline/Hartmann’s solution will stay in the circulation and increase/maintain circulating volume.

Table 3.2 Crystalloid infusions

Maintenance fluid

It is extremely important to administer the correct volume.

Devices should be used to administer the fluids and set at the correct rate over a specific period of time, and documented on a fluid balance chart.

Some methods of calculating maintenance fluids:

Body weight and fluid required per day:

first 10 kg = 100 ml/kg

second 10 kg = 50 ml/kg

subsequent 20 kg = 20 ml/kg

Body weight and fluid required per hour:

first 10 kg = 4 ml/kg

second 10 kg = 2 ml/kg

subsequent 20 kg = 1 ml/kg

Resuscitation fluid

If crystalloids are used as the primary resuscitative agents, for example in hypovolaemia, the volumes required to achieve normal haemodynamic values are from two to four times those required with colloids.

Massive crystalloid fluid resuscitation may predispose the patient to adult respiratory distress syndrome (ARDS) or pulmonary oedema, which is thought to be absent with colloid therapy.

Colloid therapy

Colloids work as they contain various amounts of large molecules, which draw fluid into the circulation from the intracellular spaces (the largest fluid compartment of the body), increasing circulating volume (volume expanders).

There are two different types of colloid gelatines and starches (see Table 3.3).

Colloid supplementation, in the presence of normal kidney function, may aid the excretion of excess extracellular fluid.

Using colloids in haemorrhage is to restore plasma volume, and improve or maintain oxygen transport.

Haemodynamic stability is achieved by increasing the blood volume by giving plasma expanders, and thus, providing adequate oxygen and nutrients, which are needed for the maintenance and restoration of cellular function.

Inadequate circulatory blood volume, owing to haemorrhage, causes pooling of blood in the microcirculation, the major effect being a marked decrease in venous return, and a diminished cardiac output.

By administering plasma expanders there is an improvement in oxygen availability, oxygen consumption, circulating volume, haemodynamic status and tissue perfusion.

Colloid is not easily excreted by the kidneys as the renal tubules do not allow protein and other large molecules in the filtrate, thus the effect of can increase, giving rise to fluid overload.

Massive fluid replacement therapy of crystalloid or colloid can lead to the development of pulmonary oedema and haemodilution.

Table 3.3 Colloid infusions: gelatins and starches

The main argument against using crystalloids or colloid to avoid blood transfusions is that it can lead to haemodilution. The blood becomes so dilute that the measured blood haematocrit becomes reduced:

decreases colloid osmotic pressure

reduces haemoglobin content

reduces coagulation factors

reduces electrolytes

reduces white blood cells.

There are less of these elements in relation to fluid contained within blood. This increase in fluid in relation to solutes in the blood will serve to dilute body sodium, increases blood osmolarity and via the renin angiotensin aldosterone system stimulates the release of aldosterone, which will reabsorb more sodium (due to reduced body sodium) and water. The renin–angiotensin–aldosterone mechanism stimulates, via osmoreceptors, the release of antidiuretic hormone (ADH) more water reabsorbed from the renal tubules, causing a net increase in extracellular fluid volume and total body weight. Haemodilution is serious and will require the administration of a blood transfusion to replace the reduction in blood solutes. It is imperative that the cardiopulmonary dynamics be monitored.

Cannulation

A cannula is a vascular device inserted into a peripheral or central vessel to provide:

Diagnostic blood sampling

Therapeutic administration of medications, fluids and or blood products

Invasive pressure monitoring:

– central venous pressure monitoring (CVP)

– pulmonary artery pressure monitoring (PAP)

– arterial pressure monitoring.

The cannula for these is attached to a transducer, which converts the pressure to a waveform display.

An intravenous cannula (for the first two bullet points above) inserted into a peripheral vein is a common procedure increasingly performed by nurses; therefore nurses must be aware of:

relevant anatomy and physiology

criteria for choosing vein and equipment

potential problems

health and safety regulations.

adherence to aseptic technique

comfort of the patient

adequate information regarding the procedure and complications.

Veins used are:

median cubital veins

cephalic vein

basilic vein

metacarpal veins.

Considerations when choosing a vein:

must be best for the child

injury, disease or treatment prevent use of a limb

how the infant/child is positioned

age and weight

if the infant/child is in shock or dehydrated poor superficial peripheral access may be present

temperature will influence venous dilatation e.g. if the child is cold, no veins may be visible.

medications can influence choice e.g. anticoagulants, steroids, risk of bruising.

Insertion:

Consider whether cannula is actually necessary.

Child will be anxious about the procedure and pain. Thus it is essential to use local anaesthetic prior to procedure.

Choose a site away from a joint.

Improve venous access by:

– Ensuring good lighting

– A tourniquet above the cannulation – check local policy

– Opening and closing of the fist, forcing blood into the veins

– Lowering the arm below heart level to increase blood supply

– Light tapping of the vein may be useful, but can be painful and lead to haematoma

– Ointment or patches containing small amounts of glyceryl trinitrate to cause local vasodilatation.

Prevent infection of skin flora contamination from nurse to child:

– appropriate personnel protection equipment should be used

– use aseptic technique and wash hands

– all wipes should be undertaken in one direction, used for at least 30 seconds, allowed to dry (check local hospital policy).

Reduce the number of attempts to cannulate as increased number of puncture sites equates increased entry sites for infection.

Check patency using normal saline.

Cover the cannula with a dressing, which is, transparent and semipermeable, allows the site to be viewed easily.

Change the cannula site every 48–72 hours – this has been shown to reduce infection rates at the cannula site.

Insertion site checked regularly for signs of:

Extravastion/infiltration (see Table 3.4 for infiltration scoring system):

– inadvertent administration of a drug into the surrounding tissues

– clinical symptoms of infiltration are coolness, leakage at the site, swelling and tenderness.

Table 3.4 Infiltration scoring system

Grade	Clinical criteria
0	No symptoms
1	Skin blanched Oedema 2.5 cm in any direction Cool to touch With or without pain
2	Skin blanched Oedema 2.5–15 cm in any direction Cool to touch With or without pain
3	Skin blanched, translucent Gross oedema 15 cm in any direction Cool to touch Mild to moderate pain Possible numbness
4	Skin blanched, translucent Skin tight, leaking Skin discoloured, bruised, swollen Gross oedema 15 cm in any direction Deep pitting tissue oedema Circulatory impairment Moderate to severe pain Infiltration of any amount of blood product, irritant or vesicant

Phlebitis

Acute inflammation of a vein directly linked to the presence of any vascular device.

Infants may cry or children may report pain.

If treated early enough often the symptoms will resolve without further intervention required.

Substances that often cause phlebitis tend to be isotonic solutions, e.g. 0.9% sodium chloride (NaCl) or blood products.

Phlebitis can be further classified into mechanical, chemical and infective, depending on the cause:

– mechanical is predominantly due to cannula problems

– chemical due to the incompatibility of drugs infused

– infective is where infection is at the tip of the cannula (usually confirmed when blood cultures show the same microbiology as the tip which is sent for culture).

Treatment is removal of the line and the application of heat to the site and prescribed analgesia

Flushing of cannula

Flushing guidance is often overlooked, and is an essential component of good care.

Flush volume should be equal to at least twice the volume of the catheter, usually 5–10 ml of 0.9% NaCl (RCN 2003)

An associated hazard is speed shock as a systemic reaction that occurs when a substance foreign to the body is rapidly introduced – occurs most commonly with rapid bolus injection.

Before undertaking cannulation nurses must undergo appropriate training, supervision and assessment by an experienced member of staff and keep updated.

Infections

Fairly minor irritation at the site (local infection)

Bacteraemia, (bacteria are present in the blood)

Septicaemia (systemic infection), which is more serious.

Infections are divided into two groups:

Exogenous – where the microorganisms originate outside the patients’ body (this is usually due to cross infection, e.g. hands of health care professionals and equipment).

Endogenous – this is present due to organisms already present on or in the patients’ body.

Anaphylaxis

Anaphylaxis is a systemic immediate hypersensitivity reaction caused by an immunoglobulin (Ig) E-mediated immunological release of mediators of mast cells and basophils, and with potentially life-threatening consequences.

With increased use of medicines and antibacterials, medicine induced anaphylaxis and anaphylactoid reactions have increased.

Other causative agents include; NSAIDs, anaesthetics, muscle relaxants, latex and radio contrast media.

Anaphylaxis is often unpredictable and so we need to focus on strategies to decrease risks:

Ensure detailed patient history and full physical examination.

Consider the route of the medicine and the rate of the medicine and/or fluid.

Identification of patients with known causes of anaphylaxis.

Sound knowledge of the medicine, as some cross react and also are contraindicated.

Greater number of years since the last administration of the offending agent, the less the chance of a recurrence.

Parenteral route increases the severity and frequency of a reaction, so review the choice of the medicine and route, and if the patient still needs IV route, they remain under medical supervision for 20–30 minutes after medicine administration.

Recommendations for practice

Immediate actions following anaphylaxis depends on the severity of the reaction and these can range from a mild skin reaction to cardiovascular collapse.

Discontinue suspected medicine.

Get help, resuscitation call.

Administer oxygen, epinephrine (adrenaline), IV fluids.

Start ABCDE.

Start CPR if no pulse.

Monitor patient; oxygen saturation, vital signs, ECG.

Provide reassurance and adequate information and communication.

At least 2 hours observation if mild and in severe cases at least 24 hours monitoring of the patient.

Ensure prompt and appropriate reporting and recording in the patient case records and consideration of the Yellow Card Reporting scheme, which advocates the reporting of adverse medicine reactions.

Patient will require advice for the future and this might include: the use of a Medic-Alert (e.g. bracelet) ID system and an Epinephrine kit.

Oxygen therapy

Hypoxia is oxygen deficiency in the body cells caused by:

Deficient oxygenation of the blood – due to respiratory disease or chest injuries.

Inadequate transport of oxygen by haemoglobin – as in anaemia or haemorrhage.

Circulatory inadequacy as in heart disease or emergency situations, e.g. cardiac arrest.

Inability of cells to use oxygen – rare – an example is cyanide poisoning.

Oxygen therapy is a specific medical treatment and is given as prescribed by the medical staff who will write the percentage of oxygen and the method of administration on the prescription sheet. However, the premise of the ‘prescription only’ status of supplemental oxygen is challenged, as delayed oxygen administration because of the need for a medical order may significantly affect an infant or child’s outcome (Wong and Elliott 2009).

The concentration given depends upon the condition being treated and an inappropriate concentration may have lethal effects:

Oxygen toxicity – may follow prolonged periods (over 24 hours) of administration of high (over 50%) concentrations of oxygen.

Atelectasis – alveolar collapse increases with oxygen greater than 50%, as nitrogen is washed out and replaced by oxygen.

Retinopathy or prematurity – high concentrations of oxygen obliterates developing retinal vessels leading to blindness.

Although there are risks associated with oxygen administration to infants and children with acute illness the risks of not providing oxygen are far greater and can ultimately be fatal. High concentrations of oxygen (above 50%) are often prescribed in a severe asthma attack and in pneumonia but may also be seen in shock, haemorrhage, and diabetic ketoacidosis. The British Thoracic Society (2008) recommended that oxygen should be given to patients immediately in most emergency situations without a formal prescription.

The effects of oxygen administered can be monitored using pulse oximetry, which records the oxygen saturation using a non-invasive procedure. The aim is to keep the saturation above 90% if possible.

Oxygen may be given by:

mask

nasal cannulae

oxygen tent

ventilator

endotracheal tube

Ambubag in an emergency.

Nasal cannulae are not suitable for all children because they are not accurate when giving low percentages of oxygen and if a higher percentage is needed there is inadequate humidification. They are useful when a child finds the conventional mask claustrophobic as often happens in children.

If high concentrations of oxygen are used, some form of humidification will be needed or the oxygen will have a very drying effect on the mucosa. If the patient’s own airways have been bypassed as when oxygen is given via an endotracheal tube, humidification is essential.

Humidified oxygen

Oxygen which is delivered in high concentrations and/or over prolonged periods of time can lead to increased secretions and dried mucous membranes. Thus, humidified oxygen therapy is commonly used in the paediatric patient for the treatment of chronic pulmonary conditions, which require very high concentrations of inspired oxygen.

Indications for the use of heated humidification systems:

Patients receiving high concentrations of oxygen (where FiO₂ exceeds 40%) for periods of time exceeding 24 hours.

Patients with conditions causing poor mucociliary transport, sometimes found in patients with severe inflammation of the oropharyngeal mucosa.

Patients with hypothermia. Heated humidified oxygen therapy may help increase a patient’s core body temperature when used in combination with other treatments.

Humidified oxygen therapy is the process of delivering moisture inspired oxygen to patients receiving mechanical ventilation, non-invasive ventilatory support or who are able to breathe independently but require humidified oxygen.

Humidified oxygen can be delivered as a heat and moisture exchanger (HME) or in the form of heated humidification.

Heat and moisture exchanger

HMEs operate by capturing the heat and moisture exhaled by the patient and then circulating it back into the patient’s inhaled gas. Commonly used during transport or when bagging a patient who is using a humidified breathing circuit.

HME filters should be changed every 48 hours.

Be alert to signs of inadequate humidification.

If the use of HME exceeds 96 hours, patients showing signs of inadequate humidification (e.g. mucous plugging) should receive heated humidification.

Heated humidification

Heated humidifiers increase the heat and water vapour content of a gas before delivering it to the patient. Suitable for patients with excessive:

secretions (chronic bronchitis, cystic fibrosis, etc.)

bloody secretions (pulmonary contusion or haemorrhage), very high or very low tidal volumes

spontaneous minute ventilation which exceeds 10 l/min, during hypothermia (body temperature less than 32°C),

patients requiring ventilation exceeding 96 hours.

– Inspired gas temperature should be no greater than 37°C.

– Change the 2-litre irrigation flask just prior to it becoming empty.

– Tubing and chamber should be replaced once weekly.

– Keep the patient’s circuit clear of condensation.

Modes of delivery

Humidified oxygen via Headbox is a means of delivering oxygen therapy to infants and neonates by enclosing the head and neck within a transparent shell of circulating gas.

Humidified oxygen via nasal cannulae that are small plastic tubes inserted into each nostril. The advantage of this method is that the child can continue to feed and play without the mask getting in the way. Nasal mucosa can become very dry so it is essential that the oxygen is humidified.

Humidified oxygen via Thermovent/Hydro Trach T. Children who are able to spontaneously breathe but who require intubation to protect their upper airway may benefit from the Thermovent/Hydro Trach T. This device can be attached onto the Protex connector in order to increase the water vapour content of inspired air. Note that the Thermovent/Hydro Trach T does not provide sufficient humidification to patients with thick or excessive secretions.

Humidified oxygen via Trachy Mask: Tracheostomy is a means of delivering mechanical airway ventilation via a tube inserted into the trachea through an incision in the neck. A Trachy Mask is worn around the neck and attaches to the opening of the tracheostomy tube in order to direct humidified oxygen into the airway.

Oxygen is a flammable gas and thus must be administered safely.

Rewarming procedures

As core temperature drops below 35°C treatment becomes imperative, rewarming of the hypothermic child is only aspect to be considered in the care (Edwards 2003b). This can occur due to exposure, falling into cold water (drowning). The nurse has a broader role in managing and caring for hypothermic children, s/he should: be vigilant during fluid administration; observe blood results and the ECG; document urine output; and ensure that any drugs administered during rewarming are not toxic, and normal prescribed dosages may need to be reduced.

Passive rewarming

Once the patient’s core temperature is less than 35°C, steps should be taken to prevent them losing further heat to the environment. Remove all wet clothing; gently dry the patient, if needed then insulate them with blankets. Patient is allowed to rewarm using just normal metabolic heat production.

Patient may be covered with polythene sheeting, and placed in a warm room. Space blankets prevent radiant heat loss, but not that lost by conduction or convection. As these may cause sparks, they also present a hazard when oxygen is used, so are best avoided. Remember that heat is lost from the head and the back, so insulate these areas.

This method is recommended for both mild (32.2–35°C) and moderate (28–32°C) hypothermias that have an onset of less than 12 hours. Passive rewarming treatment will not rewarm an arrested hypothermic patient, and may have limited value for those who are severely hypothermic e.g. a temperature of less than 28°C.

Close observation, cautious use of fluids and avoidance of vigorous movement to prevent cardiac arrest are essential. Movement contributes to heat loss through convection and may reduce temperature further if not closely monitored. If the temperature fails to rise, and patient become persistently hypotensive, active external rewarming should be commenced.

Active external rewarming

Patient’s skin is warmed, using hot baths, hot air blowers or radiant heat. This method can also be used as an adjunct to internal active rewarming. One of the most effective methods is convective warming therapy which forces heated air directly on to the patient’s skin through a disposable blanket.

Method may be used when the hypothermia has occurred slowly, e.g. over a 12-hour period and is mild or moderate in nature. It is not recommended for use alone in the treatment of patients with severe hypothermia.

Patient’s vital signs and peripheral temperature must be monitored, as rewarming shock may occur in the severely hypothermic patient as a consequence of rewarming the peripheries before the core.

Peripheral rewarming promotes vasodilatation, returning cold, acidotic blood to the heart that has significant effects on myocardial depression. To minimize this effect it is recommended that only truncal rewarming be undertaken. If the patient is persistently hypotensive, or their core temperature continues to fall, active internal rewarming should be started.

Active internal rewarming

This is an invasive procedure, whereby the deep tissues of the body are warmed. It allows the lungs and heart to be rewarmed first. Methods include:

warm fluid for gastric and peritoneal lavage

mediastinal and pleural irrigation

continuous arteriovenous or venovenous rewarming

extra-corporeal rewarming

cardiopulmonary by-pass.

The advantage of active core rewarming is that it avoids the peripheral vasodilatation associated with surface rewarming, and allows correction of any fluid deficits.

The disadvantage is that afterdrop may be observed in patients after internal active rewarming is discontinued. A decrease in temperature of as much as 2°C may occur as blood circulates to the peripheries, recools, and returns to the core. Thus, when more invasive active internal rewarming methods are discontinued, attention is directed to the need for passive and active external rewarming, to prevent afterdrop in temperature.

the method is best incorporated when the hypothermia has occurred very quickly, e.g. in less than 12 hours, and is moderate or severe in nature. The treatment is to reduce the risk of cardiac arrest, by reducing the time the patient’s core temperature is below 32·2°C.

Process of rewarming should proceed at no faster than a few degrees per hour (Edwards 2003). If a patient is rapidly rewarmed oxygen consumption, myocardial demand and vasodilatation increase faster than the heart’s ability to compensate and death can occur.

3.2 Maintaining nutrition in children

Effects of nil by mouth and malnutrition

Absorptive and post-absorptive states:

Absorptive state – process of eating/digestion

Post-absorptive state – fasting should be no more than 12 hours as after this time:

– All glycogen stores in the skeletal and liver is utilized (it is likely this will occur before 12 hours due to stress and to conserve glycogen stores for the brain) eventually the brain has to use fat as a source of energy.

– Lipolysis of adipose tissues is being converted by the liver producing ketones, which can effect acid base balance – body building processes do not take place in an acid environment and reduces wound healing, production of white blood cells, energy

– Finally, catabolism of cellular proteins occurs.

This leads to a:

Anaemia.

Reduction in the production in white blood cells, immunoglobulins – susceptibility to infection.

Reduction in adeno-triphosphate (ATP) in skeletal muscle cells leading to weakness, lethargy, reduced mobility – potential deep vein thrombosis and pulmonary embolism.

Reduction in ATP can also lead to weakened diaphragm and muscles of breathing which can lead to a chest infection or pneumonia.

Some surgeons argue that following bowel or some abdominal surgery the bowel should be rested and fasting is the common practice to allow healing of anastomosis or from handling of the bowel during surgery. However, this practice will lead to a lack of nutrients (utilised due to the stress response) for healing to take place. But the combination of stress and nil by mouth practices can lead the GIT to stop functioning. The GIT lining can be compromised leading to septicaemia from what are normally harmless bacteria living in the bowel, moving into the systemic circulation. Therefore, feeding is essential and should be commenced immediately. The bowel cannot tolerate nil by mouth for very long and even if other forms of feeding are being instigated, e.g. parenteral nutrition, fluid has to be given (minimum 30 ml/hour) to maintain gut integrity, thus if 30 ml can be administered then this can be increased at regular intervals until feeding is resumed.

Enteral feeding (EF)

Enteral feeding (EF) includes any method of delivering nutrients for gastrointestinal tract absorption (Richards and Edwards 2008) and should be initiated at the earliest possible point because:

maintains gut integrity

reduces risk of bacterial translocation

dampens the inflammatory response

reduces complications from sepsis

more cost effective in comparison to parental nutrition.

Early enteral feeding (EF) following any type of surgery is possible (i.e. within 6 hours of insult) and only contraindicated in complete gut failure – which is purported to be very rare. EF includes feeding via:

nasogastric route

nasoenteric route (i.e. placed in the duodenum or jejunum).

Types of tubes

Nasogastric/nasodueodenal are the most commonly used and are suitable for short-term use such as postoperatively or during period of critical care ventilation.

Wide bore tube is used initially to allow easy assessment of gastric contents and aspiration typically occurs every 4 hours to assess gastric content/absorption and pH.

Narrow bore tube should replace the wide bore tube to facilitate long-tem feeding. In addition, the narrow bore tube is more comfortable for the patient and less likely to cause oesophageal irritation or interfere with swallowing.

Gastrostomy if long-term feeding is anticipated due to upper gastrointestinal obstruction. Avoids delays in feeding, less discomfort, and is cosmetically acceptable.

Percutaneous endoscopically gastrostomy (PEG) –made from polyurethane or silicone and held in place by an inflatable balloon. Disadvantage is that it requires local anaesthetic, sedation and radiological support to ensure tube is positioned correctly.

Jejunostomy tube – placed in the jejunum and is the preferable method if the patient has undergone upper gastrointestinal surgery or has severe delayed gastric emptying.

Methods of administration

Bolus feeding: if the patient is restless or confused as the patient may dislodge the tube.

Intermittent continuous feeding: if feeding needs to be interrupted or discontinued to allow gastric emptying, for example for physiotherapy.

Gravity drip –allowed to flow through over a given period of time

Pump assisted feeding – connected to a pump for the majority of the day and typically rested overnight. Most commonly used in the critical care setting, various flow rates per hour from 1 ml to 300 ml.

Complications of enteral feeding (EF)

Complications can be prevented provided the nurse both understands and anticipates the potential problems associated with EF:

Altered gut motility, that is absent bowel sounds can lead to gastric and colonic stasis.

Effects of sedation and analgesia can lead to ileus/pseudo obstruction and distension.

Pulmonary aspiration.

Nausea and vomiting.

Diarrhoea, constipation, large aspirates.

Blockage of tube.

Trauma to the nose.

Incomplete calorific delivery due to the above.

Overfeeding.

Strategies to avoid complications associated with EF:

Large aspirates – give prokinetic agents, e.g. pantoprazole.

Early commencement of EF – day 1 of critical care admission, monitor feeding regime, avoid stopping and starting feed, follow feeding regime.

Care of nasogastric tube to prevent blockages.

Bowel sounds are not required for enteral feeding to commence.

Treat diarrhoea, constipation and vomiting to aid enteral feeding.

Overfeeding

The energy requirements of disease have been overestimated to account for:

high temperature

increase cost of breathing.

This is inappropriate as a child’s resting energy expenditure may represent only 20–30%, rather than 50% as offset by the decrease in physical activity. The energy requirements of patients who are unwell are usually similar to or less than that of healthy subjects. Excess carbohydrate and lipid intake can cause:

Hepatic steatosis.

Abnormal liver function.

Lead to excess carbon dioxide production, which can precipitate respiratory failure.

Lipids may be deposited in the:

– lung and impair diffusion of gases

– produce infusion hyperlipidaemia.

It is recommend that hypocaloric feeding be the current practice in hospital feeding regimes, especially in the early stages of injury (e.g. 1500 kcal/day for up to a week). This would reduce the risk of liver, lung complications and metabolic instability and their consequences. An increase in calorie intake should take place in the recovery phase, when nutrition level is normal and the patient is no longer at risk.

Parenteral nutrition (PN)

Parental nutrition (PN) is the provision of all nutritional requirements intravenously. Instead of food being fed into and absorbed by the gastrointestinal tract, nutrients are infused directly into the venous circulation, thus bypassing the gut. PN contains essential nutrients in quantities to meet the requirements of the individual patient. It is administered via a central venous line. PN is indicated for:

prolonged ileus

uncontrolled vomiting

chronic diarrhoea or malabsorptive states

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