The GCS can be used by different observers and still produce a consistent assessment and has been found to be reliable and easy to use (Ciechanowski et al. 2009). However, as with other scoring systems, the GCS should only be used as an aid to patient assessment along with other diagnostic investigations (Zuercher, et al. 2009). Intra-observer differences in measuring the GCS may occur unless training in the use of the tool has been given to prevent inaccurate and inconsistent recordings which could have a detrimental effect on the patient (Mooney and Comerford 2003).

The frequency of GCS monitoring should depend on the severity of the patient’s condition and individual facility guidelines, e.g. after an unwitnessed fall. Instead of stressing the numerical score attached to each response, it is far better to define the responses in descriptive terms.

There are difficulties with using the GCS on an intensive care unit (ICU), particularly in sedated, ventilated, head-injured patients (Ciechanowski et al. 2009). The GCS is not designed to assess sedation levels but how well the brain is functioning (Cree 2003). Differences in scores of two or more have been reported on the same patients by different practitioners (Zuercher et al. 2009), which reiterates the recommendation that clinical decisions should not be based solely on GCS (Holdgate 2006), but that the GCS be used as a component of monitoring neurological function.

Behavioural Responses Assessed

The three behavioural responses assessed are:

• eye opening
  
• verbal response
  
• motor response.

Each is discussed in turn.

Eye Opening

Assessment of eye opening involves the evaluation of the arousal mechanism in the brain stem (Zuercher et al. 2009), the first aspect of consciousness. If the patient’s eyes are closed, the state of arousal is assessed according to the degree of stimulation required to secure eye opening. If a patient is unable to open their eyes because of swelling or surgery, this is not indicative of falling conscious level (Dawes et al. 2007). The scoring is as follows:

• Score 4 – spontaneously: eyes open without the need for speech or touch (Dawes et al. 2007); optimum response.
  
• Score 3 – to speech: eyes open in response to a verbal stimulus (usually the patient’s name) without touching the patient (Dawes et al. 2007). Begin at normal volume and raise your voice if necessary using clear commands (Fairley 2005).
  
• Score 2 – to pain: eyes open in response to central pain only, e.g. trapezium squeeze, suborbital pressure (recommended). Sternal rub (Table 6.2) is no longer recommended. Note that painful stimuli should be employed only if the patient fails to respond to firm and clear commands.

• Score 1 – no response: no eye opening despite verbal and central pain stimulus.

Table 6.2 Central painful stimuli.

Note, record ‘C’ if the patient is unable to open the eyes due to swelling, ptosis or a dressing.

Verbal Response

Assessment of verbal response involves the evaluation of awareness and the integration of the cerebral cortex and the brain stem (Zuercher et al. 2009), the second aspect of consciousness. Comprehension of what the practitioner has said and functioning areas of the higher centres and ability to articulate and express a reply are being evaluated (Waterhouse 2005). Dysphasia or inability to speak can be caused by any damage to the speech centres, e.g. after intracranial surgery or head injury.

It is important to ascertain the patient’s acuity of hearing and understanding of language before assessing this response (Caton-Richards 2010). The lack of speech may not always indicate a falling level of consciousness (Mallett and Dougherty 2000). In addition some patients may require a lot of stimulation to maintain their concentration while answering questions. The scoring is as follows:

• Score 5 – oriented: the patient can tell the practitioner whom they are where they are and the day, the current year and month (avoid using the day of the week or date).
  
• Score 4 – confused: the patient can hold a conversation with the practitioner, but cannot answer the preceding questions accurately (Fairley 2005).
  
• Score 3 – inappropriate words: the patient tends to use single words making little sense and being out of context, typically swearing and shouting (Dawes et al. 2007).
  
• Score 2 – incomprehensible sounds: the patient’s response is made up of incomprehensible sounds such as moans or groans (Dawes et al. 2007) but no discernable words. A verbal stimulus together with a pain stimulus may be needed to get a response from the patient. This type of patient is not aware of his or her surroundings (Mooney and Comerford 2003).
  
• Score 1 – no response: no response from the patient despite both verbal or physical stimuli (Jevon 2008b).

Note, record ‘D’ if the patient is dysphasic and ‘T’ if the patient has a tracheal or tracheostomy tube in situ.

Motor Response

The motor response is designed to ascertain the patient’s ability to obey a command and to localise, withdraw or assume abnormal body positions in response to a painful stimulus, and demonstrates the integrity of the brain stem and spinal cord (Zuercher et al. 2009). If the patient does not respond by obeying commands the response to a painful stimulus should then be assessed.

In the past the application of a peripheral painful stimulus (pressure applied to fingernail bed) has been previously advocated (Teasdale and Jennett 1974). However, this can be traumatic and is no longer recommended. It can cause patients to pull the fingers away from the source of pain; only a central painful stimulus will demonstrate localisation to pain (Waterhouse 2005).

A true localising response involves the patient bringing an arm up to chin level, to pull an oxygen mask off, for instance (Waterhouse 2005). To elicit this response the trapezium squeeze, supraorbital ridge pressure or pressure on the jaw margin is recommended. To avoid soft-tissue injury the stimulus should be applied for no more than 10 seconds and released (Waterhouse 2005).

• Score 6 – obeys commands: ask the patient to stick his or her tongue out; never ask a patient just to squeeze your hand because this could elicit a primitive grasp response; ensure that you ask the patient to let go. As it is important to establish that the response is not just a reflex movement, it is important to ask the patient to carry out two different commands (Dawes et al. 2007).
  
• Score 5 – localises to central pain, if the patient does not respond to verbal stimuli: the patient purposely moves an arm in an attempt to remove the cause of the pain. Supraorbital ridge pressure is considered to be the most reliable technique because this is less likely to be misinterpreted (Fairley 2005).
  
• Score 4 – withdrawing from pain: the patient flexes or bends arm towards the source of the pain but fails to locate the source of the pain (Waterhouse 2005). There is no wrist rotation.
  
• Score 3 – flexion to pain: the patient flexes or bends the arm. It is characterised by internal rotation and adduction of the shoulder and flexion of the elbow, and is much slower than normal flexion (Fairley 2005).
  
• Score 2 – extension to pain: the patient extends the arm by straightening the elbow, sometimes associated with internal shoulder and wrist rotation, sometimes referred to as decerebrate posture (Waterhouse 2005).
  
• Score 1 – no response: no response to central painful stimuli.

PUPILLARY ASSESSMENT

Although pupillary assessment is not part of the GCS, it is an essential component of neurological assessment, especially when consciousness is impaired (Jevon 2008a). Pupillary reaction is an assessment of the third cranial nerve (oculomotor nerve) which controls constriction of the pupil. Compression of this nerve will result in fixed dilated pupils (Jevon 2008a). GCS may be difficult to assess in sedated ventilated patients, and then the pupillary reaction test indicates much about the patient’s neurological status (Dawes et al. 2007). Any changes in pupil reaction, size or shape, together with other neurological signs, are an indication of raised intracranial pressure (ICP) and compression of the optic nerve (Bersten and Soni 2009).

Before undertaking pupillary assessment the following should be noted:

• Any pre-existing irregularity with the pupils, e.g. cataracts, false eye and previous eye injury
  
• Factors that cause pupillary dilatation, e.g. medications, including tricyclic antidepressants, atropine and sympathomimetics, and traumatic mydriasis (Jevon 2008a)
  
• Factors that cause pupillary constriction, e.g. medications including opiates (Fairley 2005) and topical beta blockers.

Pupillary assessment should include the following observations:

• Size (millimetres): before shining light into the eyes, estimate pupil size using the scale printed on the neurological assessment chart as a comparison. The average size is 2–5 mm (Jevon 2008a). Both pupils should be equal in size.
  
• Shape: should be round; abnormal shapes may indicate cerebral damage; oval shape could indicate intracranial hypertension (Fairley 2005).
  
• Reactivity to light: a bright light source (usually a pen torch) should be moved from the outer aspect of the eye towards the pupil – a brisk pupil constriction should ensue. After removal of the light source the pupil should return to its original size. The procedure should be repeated for the other eye. There should also be a consensual reaction to the light source, i.e. both eyes constrict when the light source is applied to one. Unreactive pupils can be caused by an expanding mass, e.g. a blood clot exerting pressure on the third cranial nerve; a fixed and dilated pupil may be due to herniation of the medial temporal lobe (Bersten and Soni 2009). The reaction should be documented (see Fig. 6.1) as + or B for brisk, − or ‘N’ for no reaction and SL or S for some or sluggish reaction (follow local policy). Note that lens implants or cataracts may prevent the pupil from constricting to light (Waterhouse 2005).
  
• Equality: both pupils should be the same shape, size and react equally to light.

Principles of Monitoring the Patient with Seizures

A seizure is an episode of abnormal and excessive discharge of cerebral neurons and varies in severity from being quite mild (partial) to very severe (generalised) (Fitzsimmons and Bohan 2009). During a partial seizure consciousness is impaired and the ability to respond to stimulus is impaired (Considine 2007). A generalised seizure may be non-convulsant (previously referred to as petit mal) or a tonic–clonic seizure characterised by sudden loss of consciousness, stiffening and extension of arms and legs, and forceful clamping of the jaw. This tonic phase usually lasts less than a minute, during which apnoea and cyanosis occur and pupils are dilated and unresponsive (Considine 2007). The tonic phase is followed by the clonic phase in which alternating muscle contraction and relaxation occur along with hyperventilation, eye rolling, excessive salivation, profuse sweating and tachycardia (Considine 2007). Status epilepticus is an emergency situation and requires rapid pharmacological management (Fitzsimmons and Bohan 2009). Psychogenic non-epileptic seizures (pseudo-seizures) may involve asymmetrical motor activity, side-to-side head movements and purposeful movements for many minutes, unlike true epilepsy (Fitzsimmons and Bohan 2009). It is estimated that true epilepsy exists in 20% of cases of pseudo-seizures; however, these patients usually have emotional or psychological disorders and episodes are usually a sign of abnormal coping mechanisms (Fitzsimmons and Bohan 2009). Nursing management of a patient with seizures includes:

• Assessment and thorough history taking are central to accurate diagnosis and management (Fitzsimmons and Bohan 2009)
  
• Airway protection and prevention of aspiration (lateral positioning) (Considine 2007)
  
• ABC preservation – lateral position, high-flow oxygen and intravenous (IV) access (Considine 2007)
  
• Provide support and protection during the seizure activity – remove objects, without applying restraint (Fitzsimmons and Bohan 2009)
  
• Monitor efficacy of drug therapy
  
• Document frequency, duration and presentation of seizures.

PRINCIPLES OF INTRACRANIAL PRESSURE MONITORING

Intracranial pressure (ICP) is the pressure exerted by the normal cerebral components (brain tissue, blood and cerebrospinal fluid [CSF]) within the rigid structure of the skull. The Monroe–Kellie hypothesis contends that to maintain a constant ICP any increase in the volume of these three elements, without a compensatory decrease in the other two elements, will lead to raised ICP (Wolfe and Torbey 2009). CSF is the most commonly displaced component and, if ICP remains high after this is displaced, cerebral blood volume is altered. When the maximal volume shift is reached further increases in intracranial volume will significantly increase ICP (Elliott et al. 2007). This can lead to a fall in cerebral perfusion pressure (CPP) resulting in reduced cerebral perfusion and inadequate oxygen delivery to the brain.

Early detection of a raised ICP is therefore essential in order to prevent increasing cerebral damage and death. There is no absolute recommendation for adequate CPP; however, 70–80 mmHg is considered the critical threshold (Elliott et al. 2007). Normal cerebral blood flow (CBF) is estimated to be 50 ml/100 g per min. When this falls below 12 ml/100 g per min, irreversible ischaemic injury occurs (Wolfe and Torbey 2009). CBF and CPP are directly related to mean arterial pressure (MAP) and ICP (Cree 2003):

MAP is the most crucial factor in maintaining cerebral perfusion (Wolfe and Torbey 2009).

Treatment is aimed at maintaining adequate CPP and oxygenation and the prevention of secondary brain injury (Brain Trauma Foundation 2007).

Vital Signs

It is important to monitor the patient’s vital signs because they can be dramatically affected by a rise in ICP. The centres controlling heart rate, blood pressure, respiration and temperature are located in the brain stem. Of these four vital signs, the monitoring of respirations provides the clearest indication of cerebral function because respirations are controlled by different areas of the brain (Mallett and Dougherty 2000). The rate, character and pattern of respirations must be noted. Abnormal patterns in respirations were discussed in Chapter 3.

A rising blood pressure and falling heart rate and respiratory rate are signs of raised ICP (Cushing’s reflex) (Elliott et al. 2007). A sudden massive rise in ICP, e.g. after a large subarachnoid haemorrhage, can cause a Cheyne–Stokes breathing pattern (Shah 1999). Damage to the hypothalamus can cause changes in temperature.

ICP monitoring Indications

Indications for ICP monitoring include (Wolfe and Torbey 2009):

• All salvageable patients with severe traumatic brain injury (TBI) (GCS 3–8 after resuscitation) and an abnormal CT scan, i.e. haematomas, contusions, swelling, herniation or compressed basal cisterns
  
• Patients with severe TBI with a normal CT scan but with two of the following: >40 years, unilateral or bilateral motor posturing, or systolic BP <90 mmHg.
  
• Patients with non-traumatic intracranial hypertension demonstrating clinical deterioration and imaging consistent with mass effect.

METHODS OF ICP MONITORING

Principles of Intraventricular Catheters

An intraventricular catheter remains the gold standard in ICP monitoring and enables continuous monitoring via a transducer (Padayachy et al. 2010). Intraventricular systems have low infection rates, are considered the most reliable, accurate and inexpensive, and also facilitate drainage of CSF to control ICP (Padayachy et al. 2010). Non-invasive assessment of ICP has been explored but as yet there are no devices accurate enough to be used in clinical practice (Padayachy et al. 2010). ICP is not constant through life and healthy adults and older children have levels of 10–15 mmHg. Evidence suggests that levels persistently >20 mmHg require intervention (Wolfe and Torbey 2009). Non-invasive methods of ICP measurement such as transcranial Doppler sonography and measuring evoked potentials have been explored, but none of these methods has yet reached sufficient accuracy to be used in the clinical setting (Wolfe and Torbey 2009).

Maintaining Accuracy

It is important to:

• check all connections and tubing are secure (Woodward et al. 2002)
  
• maintain the transducer at the same level as the foramen of Monro or at the level of the ear (Littlejohns and Trimble 2005)
  
• record hourly the amount of CSF drained and empty (Woodward et al. 2002)
  
• turn off before repositioning the patient and zero balance and recalibrate whenever the patient’s position is altered (Woodward et al. 2002)
  
• ensure that air bubbles do not enter the transducer or tubing because this could dampen the trace and cause inaccurate ICP measurements (Littlejohns and Trimble 2005).

Suspected blockage of the drain must be reported to the neurosurgeon immediately (Woodward et al. 2002).

ICP monitoring should be continued until the ICP has stabilised and cerebral oedema has resolved, which usually occurs within 7 days (Bersten and Soni 2009).

Principles of Jugular Bulb Oximetry Monitoring

The measurement of ICP and the evaluation of CPP remains the foundation of current intracranial hypertension management, more complex monitoring such as SjO₂, may help to limit secondary injury (Wolfe and Torbey 2009). This advanced form of monitoring involves the insertion of a fibreoptic catheter into the jugular bulb and provides a continuous estimate of cerebral venous oxygen saturation and therefore an indirect assessment of cerebral perfusion (Bersten and Soni 2009; Wolfe and Torbey 2009).

Jugular venous bulb oxygen saturation monitoring (SjO₂) provides an indication of global cerebral oxygen delivery, but not regional ischaemia (Feldman and Robertson 1997). Normal values for SjO₂ range from 50% to 65% with <55% a possible indication of cerebral hypoperfusion and a high saturation >85% may indicate cerebral hyperaemia or inadequate neuronal metabolism (Bersten and Soni 2009). Both extremes are associated with adverse outcomes (Bersten and Soni 2009).

PRINCIPLES OF MONITORING SEDATION

The purpose of sedation in the critically ill patient is to ensure comfort, reduce anxiety, and facilitate treatment and interventions (Jackson et al. 2009). An appropriate level of sedation produces a calm, cooperative patient who is easier to nurse and treat (Gwinnutt 2006). Where possible the patient should still be able to communicate coherently, though in some situations, e.g. raised ICP, deeper sedation and neuromuscular blockade will be required. Benzodiazepines such as midazolam or lorazepam and the short-acting hypnotic drug propofol are the most commonly used sedative drugs (Wunsch and Kress 2009), although sedation regimens most frequently comprise concurrent infusions of opiates and sedatives.

Effects of Over- and Under-Sedation

Historically patients in ICUs were heavily sedated to reduce movement and invoke amnesia of their ICU experience. However, more recently heavy sedation has been associated with an increase in mortality and morbidity such as delirium and prolonged length of stay (Wunsch and Kress 2009). Sedation regimens should be tailored to individual patient’s needs (Aitken et al. 2008) and facilitate comfort, awareness and interaction with their family and carers. Light sedation also enables patients to be assessed for cognitive impairment, i.e. delirium, which is a significant complication of an ICU stay (Wunsch and Kress 2009). Under-sedation may lead to anxiety as well as physical dangers such as accidental extubation and self-harm (Aitken et al. 2008). A relatively new sedative dexemetomidine provides some analgesia and anxiolysis effects and can be used for up to 24 hours in an ICU patient (Wunsch and Kress 2009). Dexemetomidine is predominantly being used for weaning agitated patients from ventilation and is demonstrating potential benefit in the clinical setting.

Assessment of Sedation

There are many different sedation assessment tools currently in use such as Riker Sedation Agitation Scale (SAS), Minnesota Sedation Assessment tool and modified Riker Agitation scale (RAS); the most popular is the Ramsay scale (Jackson et al. 2009). It can be difficult to assess sedation because the needs of patients vary and there are discrepancies between practitioners’ assessment (Jackson et al. 2009). Haemodynamic changes are unreliable because most ICU patients are already labile and these changes may not indicate their sedation status. As corneal reflexes remain until the patient is in a deep coma, gently brushing the tips of the patient’s eyelashes as a method of assessing whether the patient is sufficiently sedated to tolerate traumatic interventions, such as intubation, has been suggested (Woodrow 2008).

Over-Sedation

Problems associated with over sedation include:

• Hypotension
  
• Respiratory depression
  
• Prevention of sleep
  
• Constipation
  
• Impaired enteral motility
  
• Extended weaning times from ventilation
  
• Ventilator-acquired pneumonia (VAP)
  
• Delirium
  
• Amnesia
  
• Muscle wasting
  
• Deep vein thrombosis (DVT).

It is also important to be familiar with the specific side effects of the analgesics or hypnotics used for sedation.

Daily Sedation Interruption

‘Ventilator care bundles’ is a set of key interventions from evidence-based guidelines which when implemented reduce the incidence of VAP and improve patient outcomes (Rello et al. 2010), including:

• No ventilator circuit change unless indicated
  
• Strict hand hygiene with alcohol
  
• Appropriately educated and trained staff
  
• Sedation vacation and weaning protocol
  
• Oral care with chlorhexidine
  
• Cuff pressure control at least every 24 hours
  
• Unit-specific microbiological surveillance with appropriate control measures
  
• Non-invasive ventilation preferred
  
• Follow a restricted transfusion policy
  
• Avoid stress ulcer prophylaxis
  
• Heat moisture exchangers (HMEs) preferred
  
• Use sucralfate where stress ulcer prophylaxis required
  
• Use of special endotracheal (ET) tubes
  
• Semi-recumbant positioning (30° head up)
  
• Selective decontamination of the gut if ventilated >48 hours.

During the process of sedation cessation the patient is allowed to wake up and be assessed for neurological state and readiness for extubation or re-sedated as required (O’Connor et al. 2008). Although some physiological and psychological benefits have been demonstrated, daily sedation interruption requires more investigation to explore the longer-term effects of this practice.

Table 6.3 The Ramsey sedation scale

Source: Ramsey et al. (1974).

MONITORING PAIN AND PAIN RELIEF

For the purpose of this book only some basic principles of monitoring pain and pain relief are discussed. Pain management in the critically ill patient is discussed in more detail in Chapter 14.

Causes of Pain

The patient may have acute pain, e.g. after surgery, or chronic pain, e.g. osteoarthritis, which makes pain management more complex for such patients. Procedures in the ICU that have been identified to exhibit a pain behavioural response include (Puntillo et al. 2004):

• Removal of femoral sheath
  
• Central venous catheter insertion
  
• Tracheal suctioning
  
• Wound care
  
• Wound drain removal
  
• Turning.

Assessing Pain

Self-report is considered the most reliable method of pain assessment and patients should be provided with methods and tools to be able to describe the location and intensity of their pain wherever possible, particularly as many patients are unable to self-report pain (Puntillo et al. 2009; Gelinas et al. 2011). When a patient is unable to self-report pain, valid behavioural scales are frequently utilised; however, often patients may not be able to display behavioural signs and when they do they may not be a reliable indicator of pain (Gelinas et al. 2011)

The use of pain assessment tools improves pain control (Puntillo et al. 2009); available tools are discussed in detail in Chapter 14.

Relieving/Preventing Pain

The pioneering research carried out by Hayward (1975) demonstrated that preparation and honest explanations reduce pain, analgesia requirements and recovery time. Good communication is essential.

Methods of pain relief in the critically ill patient include pharmacological, by a variety of routes: intravenous (e.g. fentanyl, ketamine, morphine), regional (e.g. epidurals), sublingual (e.g. buprenorphine), transdermal (e.g. fentanyl), oral (e.g. oxycodone) and inhaled (e.g. nitrous oxide). Also non-pharmacological therapies can be utilised (e.g. massage). After administration of the chosen pain relief, it is crucial to evaluate the effectiveness of the intervention (Macintyre and Schug 2007). The use of a pain assessment tool appropriate for the patient and type of pain is essential in the assessment and adequate management of pain (Macintyre and Schug 2007). It is also important to be alert to the possible side effects of pain relief, e.g. respiratory depression following opioid administration.

Epidural Analgesia

Epidural analgesia is one of the most effective methods for the management of acute pain (Macintyre and Schug 2007) and is considered to be the gold standard mode of analgesia after major surgery (Chumbley and Thomas 2010). A catheter is inserted into the epidural space and analgesia (e.g. fentanyl) and an anaesthetic (e.g. 0.125% bupivacaine) can be administered either continuously through an infusion in postoperative patients or by bolus injections via nurse or patient-controlled bolus. The insertion site should be checked for leaks, signs of skin irritation and infection (Macintyre and Schug 2007). Close monitoring of the patient is essential to identify any complications which could include:

• respiratory depression
  
• hypotension due to blockage of sympathetic nerves
  
• pruritis due to opiates
  
• urinary retention due to inhibition of the micturition reflex
  
• bradycardia due to local anaesthetic travelling (Chumbley and Thomas 2010) above T4
  
• motor block.

Epidural observations are usually recorded on a separate chart from standard observation charts. The following parameters should be monitored and recorded at intervals dictated by local policy:

• Pain score, sedation score and respiratory rate
  
• BP and heart rate
  
• Sensory block using the Bromage score
  
• Motor block.

Related posts:

Monitoring Hepatic Function Monitoring the Critically Ill, Pregnant Patient Monitoring the Patient with Infection and Related Systemic Inflammatory Response Monitoring the Critically Ill Child Record Keeping Monitoring During Transport

Stay updated, free articles. Join our Telegram channel

Join