Tips for Anaesthesia Attachments

During your time in anaesthesia, try to spend time on the ITU and with the team that responds to emergencies on the ward and participate in the:

• systematic assessment and treatment of a critically ill patient;
  
• initial management of some common life-threatening emergencies:

airway obstruction;

acute shortness of breath;

shock;

arrhythmia or cardiac arrest;

acute kidney injury;

impaired consciousness.

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Section 1: Recognition and Assessment

Clinical Scoring Systems (Track and Trigger Systems)

All EWS systems are based on the premise that acute physiological deterioration precedes the development of life-threatening acute illness and cardiorespiratory arrest. Simple observations relating to the physiological and clinical status of the patient that can be performed at the bedside on a general ward are recorded and scores are allotted for each observation based on reference to a scoring table (Table 8.1). NICE recommends that the minimum dataset should include:

• heart rate;
  
• respiratory rate;
  
• systolic blood pressure;
  
• level of consciousness;
  
• temperature;
  
• peripheral oxygen saturation.

Table 8.1 An early warning scoring system (from Prytherch DR et al. Resuscitation 2010; 81: 932–7)

Urine output is often also included. Another subjective category is sometimes added to include any patient about whom there are serious concerns, independent of the objective scoring assessment. The importance of this latter point cannot be overemphasized, particularly when the concern is voiced by an experienced nurse who ‘doesn’t like the look of’ a particular patient. Although not a simple bedside observation, measurement of serum lactate concentration can provide valuable additional information (see below). The individual scores derived from each variable are aggregated and trigger thresholds are set that mandate action (for example, the ward nurse must contact the Foundation doctor who must attend the patient within a specified time frame). NICE recommends a graded response dependent on whether the aggregated score is low, medium or high:

• low score – increased frequency of observations and nurse in charge notified;
  
• medium score – urgent call to patient’s primary medical team;
  
• high score – emergency call to medical emergency team/critical care outreach team (see below).

The main advantages of such scoring systems are:

• simplicity, with the need for only the basic monitoring equipment, normally present on any acute hospital ward;
  
• reproducibility between different observers;
  
• staff require a minimum of training;
  
• their applicability to trainee doctors, nurses (both qualified and student) and other health professionals.

Clinical scoring systems are undoubtedly useful but they cannot be relied upon to the exclusion of sound clinical judgment. They fail to identify patients who are at risk (false negatives, low sensitivity) and identify patients as being at risk when they are not (false positives, low specificity).

Critical Care Outreach Teams

Outreach teams have been established in many hospitals to respond either to a patient with a high EWS or to assist the medical team currently managing a patient who is not responding to treatment. Outreach teams are usually multidisciplinary, although their precise makeup will vary from hospital to hospital. The team leader should be trained in the management of critically ill patients and ideally be either an experienced critical care doctor or critical care nurse practitioner. The aims of the outreach team are summarized in Table 8.2.

Table 8.2 Aims of the outreach team

Receiving a Call

The Principles of Assessment

When assessing and managing acutely ill patients, irrespective of the severity of their conditions, the initial aim must be to make the patient safe rather than to determine a precise diagnosis. Many clinical crises can be managed initially by prompt recognition and correction of a modest number of common abnormalities using simple therapies (for example, oxygen and fluids).

It is logical for all members of the healthcare team to use the same systematic approach to assess and treat the ‘at risk’ or acutely ill patient incorporating the following:

• primary assessment and resuscitation using the ‘ABCDE’ approach;
  
• start simple bedside monitoring;
  
• once immediate life-threatening conditions have been treated, secondary assessment of the patient using all available information – history, examination, investigations;
  
• analysis of all the information available and making a diagnosis or a list of differential diagnoses;
  
• a definitive management or care plan including referral to a senior colleague if you have any doubts about your ability to manage the situation safely;
  
• good record keeping.

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Key Points

• The aim of initial interventions is to keep the patient alive and produce some clinical improvement, so that definitive treatment may be initiated.
  
• Always correct life-threatening abnormalities before moving on to the next stage of the assessment.
  
• Resuscitation measures (oxygen, fluids etc.) often take a few minutes to have an effect.
  
• Call for help early. At every stage of the patient assessment, consider ‘do I need help?’

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Once immediately life-threatening conditions have been identified and treated following your primary assessment, undertake a full secondary assessment. Reassess the patient regularly and after every intervention to determine the impact of treatment and to detect any deterioration. Do not try to do everything yourself; use all members of the multidisciplinary team, they are there to help you. To do this you must communicate effectively with everyone: staff, patient, and relatives.

There may be several interventions happening at the same time, particularly if the patient is in a peri-arrest situation; always ensure your own safety and that of the patient:

• take note of environmental hazards such as electricity and fluid spillage;
  
• dispose of needles and other sharps into ‘sharps bins’;
  
• protect yourself by taking universal precautions – aprons, gloves, and masks will reduce the risk of contamination from secretions, blood, and so forth.

Hygiene has an important impact on patient outcome, therefore, despite all the pressures:

• always wash your hands before and after patient contact;
  
• adopt an aseptic no-touch technique (ANTT) for invasive procedures.

Initial Approach to the Patient

Primary Assessment and Resuscitation

The aim is to identify and treat airway obstruction if present. Always treat airway obstruction as a medical emergency and obtain expert help immediately. Untreated, it leads to a lowered PaO₂, risks hypoxic damage to tissues (such as brain, kidneys and heart) and will cause cardiac arrest and death. In a critically ill patient, airway obstruction is frequently due to a depressed conscious level but there are other causes (Table 8.3). The converse is also true; if the patient is talking to you then the airway is likely to be clear.

Table 8.3 Causes of acute upper airway obstruction

Key Points

• Impaired conscious level, for example due to cerebral hypoxia, drugs or acute brain injury, is the commonest cause of airway obstruction on general hospital wards.
  
• Noisy breathing always indicates obstruction; silence may mean apnoea.

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Look, listen and feel for the signs of airway obstruction. This is best accomplished by positioning your ear close to the patient’s nose and mouth whilst looking down across the chest.

Look for Chest Movement:

• Paradoxical chest and abdominal movements (‘see-saw’ respirations).
  
• Use of the accessory muscles of respiration (for example sternomastoid and muscles of the neck, back, and shoulder girdle).

NOTE: central cyanosis is a late sign of airway obstruction.

Listen for Sounds of Air Movement and Any Associated Abnormal Noises:

• Complete airway obstruction is silent.
  
• Partial airway obstruction is noisy.
  
• Silence indicates either complete airway obstruction in the presence of the patient’s obvious efforts to breathe or apnoea (respiratory arrest).

Certain noises assist in localizing the level of the obstruction (Table 8.4).

Table 8.4 The characteristics of airway noises assist in localizing the level of airway obstruction

Feel for Expired Air:

• Place your hand or side of face immediately in front of the patient’s mouth. This will help confirm the presence or absence of airflow and give an indication of the tidal volume.

If there are signs of obstruction, call for expert help immediately and move rapidly to using simple methods of airway clearance: a visual inspection for evidence of obvious upper airway obstruction due to foreign body (for example blood, secretions, food bolus, vomit) and careful airway suction only as far as you can see using a rigid wide bore suction catheter (for example, Yankauer); head tilt and chin lift (Fig. 4.3); insertion of an oropharyngeal or nasopharyngeal airway (see Chapter 2). If these measures fail, tracheal intubation may be required, but should only be attempted by experienced staff. In most situations, intubation will require the use of hypnotic and neuromuscular blocking drugs and an anaesthetist.

Once you are certain that the patient has a satisfactory airway, give oxygen initially at high flow (15 L/min) using a mask with an oxygen reservoir (Fig. 7.4), and move on rapidly to assess breathing. This applies to all patients who are breathless or who exhibit other signs of acute illness, including patients with COPD. Hypoxia kills quickly; hypercapnia kills much more slowly. Reassess the patient and titrate the inspired oxygen to produce an acceptable SpO₂ or PaO₂ (see below).

Assess Breathing (B)

The aim is to assess adequacy of breathing and to diagnose and treat immediately life-threatening conditions such as severe bronchospasm, severe pneumonia, acute exacerbation of COPD, acute pulmonary oedema and tension pneumothorax. If untreated, inadequate breathing will lead to hypoxaemia and may also cause hypercapnia (Figs. 7.1 and 7.2), which can eventually lead to unconsciousness. There are many causes of disordered or inadequate breathing (see Table 8.5). The ‘look, listen and feel’ approach is used again.

Table 8.5 Causes of breathing problems

Look for the Signs of Abnormal Breathing:

• Use of the accessory muscles of respiration, tracheal tug, abdominal breathing, sweating, central cyanosis.
  
• Abnormal respiratory rate; normal is between 12 and 20 breaths/min. A rapid rate is an early sign of severe acute illness and should be regarded as a warning that the patient may suddenly deteriorate. An abnormally low rate suggests a CNS problem.
  
• Depth of each breath.
  
• Pattern (rhythm) of breathing.
  
• Symmetry of movement of the two sides of the chest.

Also Look for:

• Chest deformity, as this may impair the ability to breathe normally.
  
• Raised JVP (which may signify acute severe asthma or a tension pneumothorax).
  
• Chest drains – are they patent, below the level of the chest and swinging/draining?
  
• Abdominal distension, as this may exacerbate respiratory distress by limiting diaphragmatic movement.

Listen for signs of Respiratory Disease:

• Place your ear close to the patient’s face if necessary. Rattling or gurgling airway noises indicate the presence of airway secretions, often due to the inability of the patient to cough sufficiently or to take a deep breath. Inspiratory noisy breathing (stridor) suggests partial, but significant, airway obstruction.
  
• Auscultate the chest, placing the stethoscope in all areas of the chest, both front and back and assess the quality of the breath sounds:

high-pitched expiratory noisy breathing (wheeze) suggests bronchospasm;

bronchial breathing suggests lung conso-lidation;

absent or reduced sounds suggest the presence of a pneumothorax or pleural effusion;

crackles – if fine they suggest pulmonary oedema or pulmonary fibrosis; coarse suggest retained secretions.

Feel the Chest for:

• The position of the trachea in the suprasternal notch. Deviation to one side indicates mediastinal shift (for example, tension pneumothorax or massive pleural effusion).
  
• Equality of expansion – reduced on the side of a pneumothorax or pleural effusion.
  
• Surgical emphysema or crepitus – assume that this indicates a pneumothorax until proven otherwise.
  
• Percussion: hyper-resonance suggests a pneumothorax; dullness suggests consolidation or pleural fluid.

A pulse oximeter should be attached to the patient as soon as possible. This provides invaluable information on the net result of the patient’s respiratory effort in oxygenating blood as it flows through the lungs. In most patients, the target SpO₂ should be 94–98%. Initially high-flow oxygen at 15 L/min using a mask with attached reservoir bag should be given; the inspired oxygen may be reduced later according to the patient’s response. In some patients suffering from severe COPD who are dependent on a hypoxic drive for their breathing (Type II respiratory failure, chronic hypoxaemia and hypercapnia), high concentrations of oxygen may abolish their respiratory drive. Limiting the inspired oxygen concentration may be warranted if there is reasonable suspicion that the patient may have chronic type II respiratory failure. Nevertheless, this latter group of patients remains at risk of end-organ damage, cardiac arrest, or death if their blood oxygen tensions are allowed to fall too low. In this group, titrate oxygen therapy to an initial SpO₂ of 88–92%.

If possible, an arterial blood gas sample should be obtained for urgent analysis provided this does not delay moving rapidly onto assessment of the circulation. This will provide information on:

• Oxygenation, PaO₂: as a ‘rule of thumb’ a numerical difference between the PaO₂ (kPa) and inspired oxygen concentration (%) of more than 10 implies a defect in oxygen uptake.
  
• Ventilation, PaCO₂: hypercapnia (increased PaCO₂) is the result of inadequate alveolar ventilation; hypocapnia, excessive ventilation.
  
• Metabolism, pH, base excess: acutely ill patients usually have a metabolic acidosis (decreased pH, negative base excess) in proportion to the severity of illness. An acidosis may also be seen in diabetic ketoacidosis, or in surgical patients who lose bicarbonate via the gastrointestinal tract (for example, diarrhoea, fistulae).
  
• Many modern blood gas analysers will also measure electrolytes and lactate. An increase in the latter implies significant impairment of tissue oxygenation, even though the PaO₂ may be normal. This signifies a problem with oxygen delivery to the tissues and acute circulatory shock.

Any life-threatening respiratory problem should be treated as soon as it is identified. If the patient’s breathing is dangerously inadequate or if the patient is apnoeic, ventilation must be assisted or controlled using a bag-valve-mask with reservoir attached to high-flow oxygen, 15 L/min, whilst calling urgently for expert help. The addition of a reservoir allows oxygen concentrations close to 100% to be given. For treatment of specific conditions see below.

Key Points

• A pulse oximeter does not measure PaCO₂ and, therefore, gives no indication of the adequacy of a patient’s ventilation.
  
• Hypoxaemic patients tend to hyperventilate, with a resultant low PaCO₂.
  
• If a patient is receiving oxygen therapy, the SpO₂ may be normal, despite inadequate ventilation.
  
• A normal PaO₂ (12–14 kPa) whilst breathing 100% oxygen (FiO₂ ~ 1.0) is not normal.

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Assess the Circulation (C)

The aim is to assess the patient’s haemodynamic status and to recognize and treat circulatory shock, whatever the cause. Shock is inadequate perfusion of the vital organs with oxygenated blood and if untreated will lead to ischaemic damage to the vital organs and organ failure. In many surgical and medical emergencies, the cause of shock is hypovolaemia. Major haemorrhage (overt or hidden) should be assumed until proven otherwise in patients who develop shock in the early postoperative period. Respiratory pathology, such as a tension pneumothorax, can also compromise a patient’s circulatory state, but should have been detected already and treated if the above system has been followed. The ‘look, listen and feel’ approach is used again.

Look for:

• The colour of the hands and digits; are they cyanosed, pale, or mottled, indicating poor peripheral perfusion?
  
• Fullness of the peripheral veins. Are they underfilled or collapsed, signifying hypovolaemia?
  
• The central veins. Are they collapsed, signifying hypovolaemia, or engorged signifying acute left ventricular failure, cardiac tamponade, tension pneumothorax or acute severe asthma?
  
• Other signs of inadequate cardiac output, such as reduced level of consciousness, oliguria (urine volume < 0.5 mL/kg/h).
  
• Obvious signs of blood or ECF loss; bleeding, nasogastric or other drain loss.

NOTE: empty drains do not exclude active bleeding. Haemorrhage may be concealed (for example, intrathoracic, intraperitoneal, pelvic, or into the gut).

Listen for:

• Added heart sounds. Third and fourth heart sounds are heard in diastole and result in a triple rhythm – a gallop rhythm. A third heart sound (early diastole) is indicative of heart failure; a fourth heart sound (late diastole) is also indicative of stiff, poorly functioning left ventricle.
  
• A heart murmur, usually indicative of valvular heart disease.
  
• A pericardial rub, indicative of pericarditis.
  
• Very quiet heart sounds, these may be heard in severe emphysema and pericardial effusion.

Feel for:

• Limb temperature by feeling the patient’s hands and feet. Are they warm, or cool suggesting poor perfusion?
  
• A central pulse (usually the carotid artery) and compare with a peripheral pulse (usually the radial artery). Assess for:

rate;

rhythm/regularity;

volume;

character.

A rapid, weak, low-volume pulse suggests a poor cardiac output. A bounding pulse may indicate sepsis. Measure the patient’s blood pressure. The causes of hypotension are listed in Table 8.6.

Table 8.6 Causes of systemic hypotension

• Absolute hypovolaemia

Dehydration; inadequate input, excessive output

Haemorrhage

Burns

• Relative hypovolaemia

Sepsis

Anaphylaxis

Spinal cord injury

Epidural/spinal anaesthesia

• Cardiogenic

Acute myocardial infarction

Arrhythmia

Severe valvular heart disease

Cardiac tamponade

• Obstructive

Massive pulmonary embolus

Tension pneumothorax

• Drug overdose – e.g. antihypertensives

Finally, measure the capillary refill time (CRT) both centrally and peripherally. Apply firm pressure to a finger tip or toe for 5 s (at heart level or just above) and release: the capillaries should refill (colour returns to the compressed area) in <2 s. Capillary refill time may be affected by the environmental temperature. Repeat the procedure over the sternum.

Heart rate and blood pressure must be placed in context; an elderly patient with poor myocardial reserve may be in extremis with a heart rate of 60/min and blood pressure of 95/60 mmHg, but the same values will be well tolerated or even normal for a fit young adult. Ultimately, definitive treatment of shock will be determined by the cause, the most common being hypovolaemia, sepsis and cardiac failure. These are covered below.

Key Points

• Resting heart rate is normally lower than systolic blood pressure.
  
• In some patients, for example those with gastro-intestinal or intra-abdominal haemorrhage, immediate surgery may be required as the only effective form of resuscitation.
  
• Patients with cardiac failure do just as badly if the heart is underfilled as if it is overfilled and so may benefit from intravenous fluids.

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Assessing Neurological State – Disability (D)

The aim is to assess the patient’s conscious level, identify any impairment and treat the cause if possible. Common causes of unconsciousness are shown in Table 8.7. Hypoxaemia, hypercapnia, or cerebral hypoperfusion should have been detected and treated at an earlier stage of the ABCDE assessment.

Table 8.7 Common causes of a decreased conscious level

Examine the Pupils for Size and Reactivity to Light:

• Pinpoint pupils, reactive: opioids, pontine lesion.
  
• Mid-sized, fixed: lesion in the midbrain.
  
• Dilated, fixed: severe global ischaemia or hypoxia (for example, post-cardiac arrest), hypoglycaemia, brainstem lesion, post-seizure, drug effects (for example, atropine, adrenaline, overdose of tricyclic antidepressant).
  
• Unilateral dilatation, fixed: expanding intracranial haematoma causing uncal herniation, lesion of third (occulomotor) cranial nerve.

Other Important Checks:

• Assess the patient’s conscious level using the GCS (Table 8.8) and record the best response.
  
• Immediately check the patient’s glucose using a rapid bedside Point of Care Testing (POCT) blood analyser to exclude severe hypoglycaemia and send blood urgently for more accurate laboratory estimation.
  
• Check the patient’s drug chart for reversible drug-induced causes of depressed consciousness.
  
• Consider the possibility of acute CNS infection, intracranial haemorrhage or cerebral infarct.
  
• Status epilepticus should be obvious and treated as described below.

Table 8.8 The Glasgow Coma Scale

Key Points

• Patients who are in coma (GCS < 9) are at risk of airway obstruction when supine and airway reflexes may be insufficient to prevent aspiration of secretions, vomit or blood. Nurse in the recovery position and summon expert help to secure their airway.
  
• If there is a risk of co-existing cervical spine pathology, for example a fracture, nurse the patient supine maintaining a patent airway. This mandates the constant presence of a nurse or doctor.
  
• Don’t Ever Forget Glucose (DEFG) in any patient with acute deterioration in conscious level.

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Exposure/Examination (E)

The aim is to allow a full, head-to-toe, back and front examination of the patient. To allow this, full exposure of the body is necessary, carried out in a way that respects the dignity of the patient and prevents heat loss. Initially, the examination should be focused on the area of the body most likely to be causing the patient’s condition; for example, for a patient presenting with shock following a laparotomy, this would be the abdomen. If this step is omitted, vital information regarding the aetiology of the patient’s condition may be missed, such as the presence of a purpuric rash signifying meningococcal septicaemia, or a knife stab wound in the back of the chest.

What to Do Next?

The aim so far has been to assess the patient, treat immediately life-threatening problems, and produce some clinical improvement, to enable a diagnosis to be made and definitive treatment initiated. Even if the patient’s vital signs are still outside the normal range, they should be moving in a direction of improvement. If not, it is essential to summon senior help and, while waiting for this to arrive, reassess the patient using the ABCDE approach to try and identify the cause.

Once things are improving, gather more information about the patient:

• Take a full history from the patient, staff, relatives or the hospital notes. Comorbid conditions (such as ischaemic heart disease, COPD) can have a significant impact upon a patient’s response to critical illness and must not be overlooked.
  
• If not already done, perform a full examination of the patient, using a traditional clinical examination format.
  
• Review the patient’s notes and charts. Assimilate the data on charts by systematic analysis. Study both absolute values of vital signs and their trends.
  
• Check that important routine medications are prescribed and being administered. Look for potential interactions.
  
• Review the results of all laboratory and radiological investigations.

Consider if you have a credible diagnosis that accounts for the patient’s condition and recent deterioration:

• if yes, consider the definitive treatment of the patient’s underlying condition;
  
• if no, reassess the patient in case you have missed something important. Involve senior colleagues.

Consider which level of care is required by the patient (for example, ward, HDU, ITU). This may be dictated by your hospital’s policies. Make complete entries in the patient’s notes of your findings, assessment, and treatment. Record the patient’s response to therapy. Ensure that your entry in the notes is legible, signed, dated, and timed.

Communicating Information About Patient Deterioration

Although the systems outlined above will allow the recognition, initial assessment, and treatment of the acutely ill patient, on the majority of occasions more senior help will be required to manage the problem safely and effectively. The key to achieving this is good communication at all levels:

• Know why you are calling before picking up the phone.
  
• Before making the call, gather all the useful information together.
  
• Do you want a more senior colleague to assess the patient?
  
• Are you calling for advice?
  
• Do you think the patient needs an operation, transfer to a critical care area, CT scan etc?
  
• Be assertive when communicating, avoid aggression, and be honest. ‘I am unsure of what to do next’ or ‘I am worried that I am missing something’ are likely to assist in obtaining help.
  
• Get the message across in the first two sentences: ‘This is Dr . . . I am sorry to disturb you, but Mr Smith is deteriorating and I think that he may need an urgent operation.’

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Key Points

• Always fully expose the patient after ABCD.
  
• Use a system for communicating patient deterioration, e.g. RSVP or SBAR:

R – Reason for calling S – Story V – Vital signs (plus any early warning score) P – Plan

S – Situation B – Background A – Assessment R – Recommendation

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Section 2: Management of Common Emergencies

Acute Shortness of Breath

There are many causes of acute dyspnoea (Table 8.5). However, the differential diagnosis can be narrowed by taking into account the history, examination findings, and the results of blood tests and other investigations such as chest X-ray and 12-lead ECG. Some of the more common causes of shortness of breath are covered in more detail below.

Acute Upper Airway Obstruction

If any patient has signs of airway obstruction expert help should be called for immediately (usually an anaesthetist and depending on the situation, an ENT surgeon). Common causes are shown in Table 8.3. However, while waiting for help to arrive it is possible to quickly and safely start the process of restoring a patent airway and delivering oxygen. Examine the patient for signs of upper airway obstruction.

Look for:

• distress in the patient;
  
• use of accessory muscles, often sat upright, flaring of the alae nasae;
  
• dyspnoea, rapid shallow breaths;
  
• see-saw or paradoxical respiratory pattern;
  
• drooling, not swallowing saliva;
  
• cyanosis.

Listen for:

• abnormal sounds, stridor, wheeze, gurgling;
  
• reduced or absent breath sounds;
  
• inability to vocalize, poor voice strength.

Feel for:

• reduced air movement at the face;
  
• decreased chest expansion;
  
• pulse rate – this is increased due to hypoxia and hypercapnia.

Other features may be apparent with obstruction due to specific causes and are covered below:

• a reduced conscious level (reduced GCS);
  
• swelling of the upper airway or tumour;
  
• external compression of the airway, for example after surgery;
  
• a blocked tracheostomy or laryngectomy stoma.

Reduced Conscious Level (Reduced GCS)

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