Assessment and Stabilization



Assessment and Stabilization






/image/image Assessment and immediate management of an emergency

The assessment and immediate management of critically ill patients follows the established ABC approach (Approach/Airway, Breathing, Circulation). What follows is a brief summary of the ABC approach adapted for patients within a critical care environment, further details on each system are considered in individual chapters. Any deterioration during assessment and resuscitation should prompt a return to ‘A’.

Some interventions may need to be performed whilst continuing assessment and emergency treatment, particularly when emergencies are acute and life threatening (e.g. BLS/ALS, see image p.98; needle thoracocentesis of a tension pneumothorax, image p.80).


Approach



  • In all cases it is essential to ensure that those treating the patient are safe to carry out their work.


  • C-spine immobilization is often required where trauma is involved.


  • Give 100% oxygen in acute emergencies, in less acute scenarios titrate the oxygen required to keep SpO2 94-98%.


  • Connect any monitoring available—aim to have SpO2, continuous ECG, and non-invasive BP monitoring as a minimum:



    • Review any information from the monitoring devices (e.g. SpO2, ventilatory parameters, heart rate and rhythm, BP) alongside physical findings when examining the patient


    • Be alert for equipment malfunction (e.g. airway occlusion, ventilator failure, or infusion pump failure); and/or alarms from the monitoring systems which may indicate the cause or extent of problem


  • Obtain a history and detailed information about the patient:



    • From the patient where possible—the minimum history should include the ‘AMPLE’ template advocated in trauma resuscitation


    • From attending staff or from any associated documentation


    • Review notes, observation charts, imaging and blood results—fluid balance, blood gases, electrolytes


    • Physiological scoring systems (e.g. early warning scores, EWS, or ‘track and trigger’ systems) may be used to ‘flag’ up patients at high risk of deterioration (see image p.9)


    • Assess the existing level of support required by the patient (e.g. requirement for inotropes or haemofiltration)



The ‘AMPLE’ history



  • A Allergies


  • M Medication


  • P Past medical history


  • L Last meal


  • E Event (and environment)




Airway

The commonest cause of airway emergencies is airway obstruction. It may be partial or complete.


In the unintubated patient



  • Assess the ability of the patient to breathe, or in conscious patients the ability to speak, listening for:



    • Silence (caused by apnoea or complete obstruction), or abnormally quiet breath sounds


    • Stridor, wheeze, or gurgling


    • A hoarse voice (associated with laryngeal oedema)


  • In unconscious or uncooperative patients feel for breath with your hand or cheek, check for misting on an oxygen mask.


  • Look for evidence of airway obstruction:



    • Bleeding, vomit, secretions, tissue swelling, or foreign bodies


    • Obstruction of the pharynx by the tongue


    • Look for neck swelling or bruising, surgical/subcutaneous emphysema, or crepitus


  • Look/listen for chest and other signs of airway obstruction, including:



    • Paradoxical chest and abdominal movements, tracheal tug


    • Reduced air entry in chest


    • Use of accessory muscles of respiration


    • Hypoxia is a late sign and indicates extreme emergency


  • Exclude obstruction of pharynx by the tongue:



    • Chin lift: useful for infants, edentulous or unconscious patients


    • Jaw thrust: generally more effective than chin lift, and can be done one-handed (skilled) or two-handed (unskilled)


  • Consider airway adjuncts:



    • Oropharyngeal (‘Guedel’) airways are normally only tolerated by unconscious patients


    • Nasopharyngeal airways are tolerated by conscious patients but may cause nasal bleeding on insertion worsening airway problems


    • Laryngeal mask airways (LMAs) require basic training to use, are only tolerated by unconscious patients, and offer limited protection from aspiration


    • Orotracheal intubation is the gold-standard for protecting and maintaining the airway but is only tolerated by anaesthetized or unconscious patients and requires a skilled operator to insert (the nasotracheal route is rarely required outside operating theatres)


  • Using a self-inflating bag and mask to assist ventilation, if possible, may allow time to look for or treat causes of obstruction.


  • Consider endotracheal intubation or an emergency needle cricothyroidotomy/tracheostomy (see image pp.522 and 528):



    • Specialist anaesthetic and/or ENT airway skills will also be required at this point


  • In patients who are unconscious, but maintaining an airway, endotracheal intubation should be considered, or the recovery position should be adopted (or alternatively ‘head-down, left lateral’ if they are lying on a trolley/bed).



In the intubated, mechanically ventilated patient

Work methodically from the ventilator to the patient:



  • Check the ventilator is working (with adequate pressures, tidal volumes, and minute volumes) and that O2 is connected, check that ventilator tubing is still connected and not obstructed.


  • High airway pressure ventilator alarms may indicate obstruction.


  • Low pressure, or low expired volume alarms may indicate a leak.


  • Listen for any air leaks from ventilator tubing or endotracheal cuff.


  • Check the endotracheal tube (ETT):



    • ETT position is normally 20-22cm at lips (compare with any previously noted length), ↑ insertion depth may indicate endobronchial placement. If immediately available, review CXR films to confirm correct placement of tube


    • Check tube patency (by passing a suction catheter through the endotracheal tube to exclude obstruction)


    • Laryngoscopy may be required to confirm correct placement


    • Check end-tidal CO2 to confirm ETT position (provided there is also adequate cardiac output)


  • Disconnect from ventilator and try ventilating with a self-inflating bag (successful ventilation indicates obstruction at the level of ventilator tubing):



    • If unsuccessful then there is an obstruction within or beyond the ETT, consider re-intubating with a fresh ETT and/or passing a fibreoptic scope; also consider causes for failure to expand the lungs (e.g. tension pneumothorax or bronchospasm)


    • Unilateral chest movement may be associated with pneumothorax or endobronchial intubation.



Breathing

Common causes of breathing difficulties include pleural diseases (pneumothorax, haemothorax, or pleural effusion), airway diseases (asthma, secretions, acute exacerbation of COPD), parenchymal disease (collapse, consolidation, ARDS) and cardiogenic disease (cardiogenic pulmonary oedema). Evidence of inadequate breathing should be looked for and corrected, including:



  • Hypoxia—reduced PaO2 or SaO2.


  • Dyspnoea and/or tachypnoea (bradypnoea or Cheyne-Stokes breathing are late/severe signs).


  • Obvious problem, e.g. regurgitation with aspiration, massive bleeding.


  • Absent or abnormal chest movement:



    • Unilateral movements may indicate pneumothorax, pleural effusion, collapse


    • Paradoxical chest-abdominal movement may indicate airway obstruction or flail chest


    • Use of accessory muscles of respiration


  • Raised JVP may be visible.


  • Apex beat or tracheal shift may be seen towards areas of collapse or away from pneumothoraces or pleural effusions.



  • Percussion may reveal effusions or pneumothoraces.


  • Abnormal breath sounds may be heard on auscultation:



    • Silent chest or wheeze may be due to acute severe asthma/bronchospasm (pulmonary oedema may also cause wheeze)


    • Rattling noises suggests secretions


    • Absent unilateral sounds may be due to pleural effusion


    • Bronchial breathing suggests underlying consolidation


  • Patients should be asked to cough to assess their ability to clear secretions which may be limited by neuromuscular problems or pain.


  • Secretions themselves should be examined where possible, and patients encouraged to ‘cough up’ samples


  • Check any intercostal drains—check if drains are still swinging or bubbling, and check the volume of blood or serous discharge


  • Emergency management should be aimed at:



    • Excluding/treating life-threatening conditions (e.g. acute severe asthma, tension pneumothorax, pulmonary oedema, massive haemothorax)


    • Keeping SaO2 94-98%,1 PaO2 >9 kPa, and PaCO2 within the normal limits for the patient with respiratory rate <35 breaths/minute


  • Treatments which can be rapidly commenced include:



    • A trial of bronchodilators if bronchospasm is suspected


    • Chest physiotherapy to clear secretions


    • Non-invasive ventilation in conscious and cooperative patients who do not respond to previous treatment (see image p.53)


    • Endotracheal intubation and mechanical ventilation


In the mechanically ventilated patient



  • Check the degree of any respiratory support:



    • Oxygen, peak pressures, PEEP and minute volume measurements


    • ↑airway pressures or ↓tidal volumes may be due to ↑airway resistance or reduced lung compliance


    • If bronchospasm is present, check the length of the expiratory wheeze (in order to set I:E ratios), and check intrinsic PEEP


  • Tracheal suction may reveal the amount and quality of secretions, and clear mucous plugs (critical care charts also often record the amount and character of secretions).


  • Alveolar recruitment manoeuvres may be helpful in ARDS, atelectasis, or pulmonary oedema.


  • Consider ventilating with a self-inflating bag in order to manually assess compliance.


  • Urgent bronchoscopy may help clear obstructions/secretions

Investigations such as ABGs and CXR will be needed to guide initial management. Where rapidly available, chest US may help diagnose effusions or occult pneumothoraces.




Circulation

Cardiovascular emergencies often present as severe hypotension and shock, heart failure with pulmonary oedema, or cardiac arrest.

Inadequate circulation may be caused by low-output states such as severe hypovolaemia or cardiogenic shock, and high-output states due to peripheral vasodilatation (e.g. sepsis). Non-cardiovascular causes (e.g. endocrine disorders, electrolytes, pneumothorax) should also be considered. In addition, certain interventions such as positive pressure ventilation or epidural analgesia can lead to relative hypovolaemia.

In critical care ECG, arterial BP, and cardiac output monitoring may already be connected to the patient, giving clues to the nature of emergency. Signs of cardiovascular compromise include:



  • Cardiovascular signs:



    • Thready pulse, tachycardia, and hypotension


    • Cold peripheries, prolonged capillary refill (>2 seconds)


    • Alternatively a bounding pulse may occur with hypotension in individuals capable of compensating


    • Bradycardia is a pre-terminal sign, or a sign of vagal stimulation, (e.g. from intraperitoneal blood)


    • JVP may be raised


  • Other signs:



    • Tachypnoea, altered mental state


    • ↓urine output (<0.5 ml/kg/hour)


    • Peripheral oedema


  • Look for obvious or concealed blood/fluid loss.


  • Check any abdominal or wound drains—check they are still in situ and measure the volume of any blood loss.


  • Check the status of any inotropic infusions.


  • Other signs of circulatory insufficiency may include lactataemia or metabolic acidosis.


  • Non-specific signs may be present in ventilated patients, including chest pulsation (indicating a hyperdynamic state), the presence of ETCO2 (indicating both patent endotracheal access and that cardiac output is present), a swinging arterial line trace (a non-specific indicator of hypovolaemia in ventilated patients).


  • Measured variables may also include:

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Jun 13, 2016 | Posted by in CRITICAL CARE | Comments Off on Assessment and Stabilization

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