The critically ill patient....

• Background

  • There are no formal criteria of what constitutes 'critically ill'. Broadly speaking, it implies acute organ failure which is potentially life-threatening.
  • Manage patients using the ABCDE approach, outlined below. Address each area before moving on to the next.
  • Get help if repeated fluid boluses are needed, the patient remains unstable despite treatment, or the underlying diagnosis is unclear. Options include seniors, critical care outreach, or the crash team.

• Airway in the critically ill patient

  Assessement

  • Is the airway patent and protected?
  • If the patient is talking, assume the airway is patent.
  • Swallowed tongue is the commonest cause of airway obstruction. Therefore an airway is not protected if the level of consciousness is reduced, especially GCS ≤8, where airway reflexes are reduced. This also carries a risk of aspirating vomit.
  • In trauma, this is also when you would secure the C-spine: initially manually then with a collar and blocks.
  Abnormal sounds:
  • Snoring: pharyngeal obstruction by tongue.
  • Gurgling: fluids in upper away.
  • Stridor: obstruction of upper airway.

  Management

  Management of compromised airway:
  • Simple airway manoeuvres: head tilt and chin lift, or jaw thrust in trauma due to the risk of C-spine injury. May then need to be held in place until further management.
  • Remove obstruction manually or with suction under direct visual inspection.
  • Positioning: sitting up or the recovery position can reduce the risk of swallowing tongue or aspirating vomit.
  Airway adjuncts:
  • Oropharyngeal (Guedel): only appropriate in unconscious patients, as it may trigger gag reflex and vomiting if awake. Rotate as you insert to avoid pushing tongue back into throat.
  • Naso-pharyngeal: can be considered in semi-conscious patients. 7 mm for men and 6 mm for women. Contraindicated in basal skull fracture due to risk of insertion into cranial vault. Caution in those with coagulopathy e.g. on warfarin.
  Intubation and ventilation:
  • Definitive airway management is a cuffed endotracheal tube in the trachea.
  • The cuff is an inflated balloon around the tube which prevents entry of materials down the sides e.g. aspiration.
  • Usually done by an anaesthetist.

• Breathing in the critically ill patient

  Assessement

  Check respiratory rate, respiratory effort, colour, auscultation, percussion, tracheal deviation, O2 sats, and ABG.
  Signs of difficulty:
  • ↑Respiratory rate (RR)
  • ↓O2 sats.
  • Tired, shallow breathing.
  • Asymmetric chest expansion.
  • Accessory muscle use.
  • Abnormalities on chest auscultation.
  • Central cyanosis. Detectable at <85% O2 saturation. Check for blueness on lips or tongue, with the latter more reliable due to consistent blood supply and little inter-ethnic variation in pigmentation. Peripheral cyanosis can be seen on the fingers, toes, and earlobes, but is less specific as can be due to hypoxia or hypoperfusion.
  Specific signs:
  • Cheyne-Stokes breathing: apnoea alternating with deep breaths/tachypnoea. Often a pre-terminal event, and suggests brainstem hypoxia.
  • See-saw breathing (aka paradoxical breathing): abdomen moves outward as chest moves inwards during inspiration, due to downward movement of diaphragm without air entry. Sign of complete airway obstruction.
  • Flail chest: a single rib fractures in two places, leaving a fragment unconnected to the skeleton. As a result, it is pulled in to the low pressure thorax during inspiration, while the rest of the rib cage expands, and protrudes during expiration while the rest of the rib cage contracts. Leads to pain and further local trauma e.g. pneumothorax. Also known as paradoxical breathing.
  O2 saturation:
  • Factors that increase Hb affinity for O2 (left shift of dissociation curve): ↓H+ (alkalosis), ↓CO2, and ↓temperature. Leads to high oxygenation but possible tissue hypoxia due to a failure of the Hb to release O2.
  • Factors that reduce Hb affinity for O2 (right shift of dissociation curve): ↑H+ (acidosis), ↑CO2, and ↑temperature. Leads to hypoxia.
  • In carbon monoxide (CO) poisoning, O2 might be normal as sats monitor can't differentiate between CO and O2 bound to Hb.
  • Accuracy of O2 sats are also reduced by: poor peripheral perfusion, nail varnish and false nails, and bright overhead lights.

  Management

  Basics:
  • Sit patient up or lie on side to maximize V/Q ratio.
  • High flow O2 15 L/min though non-rebreathe mask (i.e. attached to reservoir bag). Delivers around 80% FiO2. Ensure reservoir is inflated before placing. Give to all acutely unwell patients, including those with COPD.
  • Aim for sats of 94-98%, or 88-92% in COPD.
  • Patient should be monitored throughout the time high flow O2 is on. Inappropriate O2 therapy can cause harm in acute MI and COPD.
  • Later downgrade to simple oxygen mask, venturi, or nasal cannulae. See oxygen therapy.
  Further options:
  • Physiotherapy to help clear mucus plugs.
  • Nebulised bronchodilators if there is bronchospasm. Should be driven by oxygen at >6 L/min.
  • Bag-valve mask (BVM) if difficulty ventilating. Critical care support may be needed for intubation and ventilation.
  Monitor response:
  • In general, pO2 should be ~10 kPa below FiO2 (fraction of inspired O2) i.e. atmospheric is 21% = 11 kPa; 30% O2 = 20 kPa etc.
  • Normal pO2 >10.6 kPa. On high-flow O2 it should be higher.
  In patients with tracheostomy:
  • O2 can be given though the mouth and the tracheostomy if needed.
  • Take out inner piece to see if blocked.
  • Use suction around hole, then pass in suction catheter and slowly withdraw.
  • If using BVM on mouth, remember to cover hole while using, or in laryngectomy, BVM the hole directly.

• Circulation in the critically ill patient

  Assessement

  Check cap refill, HR, BP, temperature, and urine output.
  Signs of impairment:
  • Observation: pale or red, capillary refill >2 seconds, ↑JVP. Check central cap refill if peripheral is prolonged.
  • Palpation: may be warm and sweaty or cold and clammy.
  • ↓BP, ↑HR, abnormal heart sounds. Impalpable radial pulse suggests SBP <80. HR may be normal if very fit, β-blocked, or elderly.
  • Reduced urine output.
  More on BP measurement:
  • BP might be normal due to increased peripheral resistance. Only cap refill tells you if the patient is actually perfusing.
  • Hypotension is often a late sign of cardiovascular compromise, especially in the young.
  • All patients with an arrhythmia or SBP <90 should have a manual BP taken.
  In trauma, look for blood 'on the floor and four more':
  • Chest: visible trauma, abnormal movement, dull percussion.
  • Abdomen: visible trauma, tender on palpation.
  • Pelvis: uneven iliac crests, one leg shorter than the other. With even the smallest suspicion, including if there is trauma in the abdomen or legs, stick on a pelvic binder at the level of the greater trochanter.
  • Long-bones: skin colour changes or deformities in the leg. Blood loss results from local trauma and/or from the bone itself, though the latter is generally only significant from the femur.

  Management

  • Obtain peripheral access: large bore cannula (orange/grey) in each antecubital fossa.
  • Take bloods: FBC, U&E, coagulation, glucose, lactate (or done in ABG). Blood cultures and CRP if infection suspected.
  Fluids:
  • Give if SBP <90, SBP 20% below usual in hypertensive patient, MAP <65, or lactate >4 mmol/L.
  • Normal saline is widely available but carries the risk of ↑Cl-. Physiological crystalloids such as Hartmann's may be more appropriate. In major trauma, use blood products.
  • Start with a 500 ml bolus as quickly as possible, or 250 ml in older patients and those at risk of overload.
  • Known as 'fluid challenge' when initially given, as not clear if it is therapeutic. Known as 'fluid filling/loading' if known to be effective.
  • Re-assess once given by going back through ABC. Check BP and HR for response, and chest auscultation and RR for fluid overload.
  • Repeat if needed up to 60 ml/kg, and reduce if fluid overloaded.
  • Aim for MAP >65.
  Further options:
  • If unresponsive to fluids, get critical care help for vasopressors (e.g. norepinephrine) and/or inotropes (e.g. dobutamine).
  • Transfuse if Hb <7 g/dL, aiming for 7-9.

• Disability in the critically ill patient

  Assessement

  Check consciousness, glucose, PERLA, pain, and seizures.
  Level of consciousness:
  • AVPU: Alert, responds to Voice, responds to Pain, Unresponsive
  • Glasgow coma scale (GCS)
  DEFG, Don't Ever Forget Glucose:
  • High or low glucose may cause loss of consciousness and a bedside blood sugar is quick and easy to obtain.
  Pupils:
  • PERLA: are Pupils Equal and Reactive to Light and Accommodation?
  • Unilateral fixed, dilated pupil ('blow pupil') suggests ipsilateral intracranial haemorrhage. Urgent CT is indicated.
  • Bilateral dilated pupils: drug toxicity.
  • Bilateral constricted pupils: opioid OD or pontine stroke.
  Pain and seizures:
  • Are they in pain?
  • Are they on medication which may affect level of consciousness e.g. opioids?
  • Are they seizing?

  Management

  • If they score P on AVPU or ≤8 on GCS, airway is not protected so consider placing in the recovery position, using adjunct, or intubating.
  • Manage glucose (if <4 mmol/L), pain, and seizures as required.

• Exposure in the critically ill patient

  • Unclothe, put on gown, and check for skin changes i.e. trauma or rash.
  • Complete the physical examination, including abdominal exam.

• Adult life support

  Cardiac arrest

  BLS:
  1. Check for danger.
  2. Rouse: shake, call name, pinch trapezius.
  3. If unresponsive, call for help, activate emergency response, and call for AED.
  4. Check for breathing and pulse for 10 seconds (usually carotid).
  5. Start 30 compressions if no pulse – one hand with base on sternum and the other above – then 2 rescue breaths. Continue in 30:2 ratio, with 100-120 compressions/minute, ⅓ depth of chest, allowing full recoil, and minimizing interruptions.
  ALS extras:
  • Pause CPR for rhythm check every 2 minutes, checking pulse if potentially perfusing rhythm seen.
  • ≥150 J shock for shockable rhythms (VF and pulseless VT).
  • LMA or intubation for ventilation, then continuous compressions with 10 breaths/minute.
  • Adrenaline 1 mg IV/IO for asystole/PEA every 3-5 mins (every other 2 minute cycle). Give for shockable rhythms after 2 shocks.
  • Amiodarone for shockable rhythms after 3 shocks.
  Reversible causes of cardiac arrest:
  • 4 H's: Hypoxia, Hypovolaemia, Hypothermia, Hyper/hypo-kalaemia.
  • 4 T's, throw ten toxic tampons: Thrombus (MI, massive PE), Tension pneumothorax, Toxins, cardiac Tamponade.

  Outcomes from CPR

  • In hospital cardiac arrest: 20% survive to hospital discharge; 50% if shockable rhythm, 10% if non-shockable.
  • Out of hospital cardiac arrest: 10% survive to hospital discharge; 30% if shockable rhythm, 5% if non-shockable.
  • By definition, these outcomes relate only to those in whom attempting CPR was considered appropriate. Survival would likely be much lower if CPR was attempted in all cases of cardiac arrest.

  Choking

  1. Encourage to cough if they can.
  2. Look if item can be easily removed with fingers.
  3. Give 5 firm back slaps between the shoulders. Resuscitation Council UK recommend this, while American Heart Association (AHA) doesn't.
  4. 5 abdominal thrusts, by placing fist below sternum and use palm of other hand to push it up and in.
  5. Return to back slaps, and continue alternating cycle (or just continuous abdominal thrusts as per AHA) until dislodged or they stop breathing and need CPR.