Hypoglycaemia | Acute Management | ABCDE

is a life-threatening condition that you need to be able to recognise and manage in the acute setting. This guide gives an overview of the recognition and immediate management of hypoglycaemia using the ABCDE approach. You can check out our overview of the ABCDE approach here.

This guide has been created to assist students in preparing for emergency simulation sessions as part of their training. It is not intended to be relied upon for patient care.


Clinical features of hypoglycaemia

Hypoglycaemia can present in a variety of different ways. It is a diagnosis that can be easily missed if you don’t consider it as the cause for your patient’s symptoms.

Reference ranges

  • Normal fasting plasma glucose levels: 4.0 – 5.8 mmol/l
  • Hypoglycaemia is defined as plasma glucose levels falling below 4.0 mmol/l
  • Some patients may experience symptoms and display signs of hypoglycaemia at blood glucose levels higher than 4 mmol/L
  • You should always, therefore, interpret the blood glucose reading in the context of the clinical presentation


Symptoms and signs

Diabetes UK developed thorough guidelines for the Hospital Management of Hypoglycaemia in Adults with Diabetes (available online here). They list the following 11 most common clinical features associated with hypoglycaemia.



  • Sweating
  • Palpitations
  • Tremor
  • Hunger



  • Confusion
  • Drowsiness
  • Odd behaviour
  • Speech difficulty
  • Incoordination


General malaise:

  • Nausea
  • Headache


These symptoms can have an insidious onset. It is always possible that the patient is also suffering from another condition (e.g. a UTI), which can present with similar symptoms. Consider hypoglycaemia in anyone presenting with these symptoms but especially those with risk factors.

Any patient with an altered level of consciousness should have hypoglycaemia ruled out.

Risk factors for hypoglycaemia

  • Insulin-dependent diabetes (Type 1 or Type 2)
  • Previous history of hypoglycaemic episodes or reduced hypoglycaemia awareness
  • Impaired renal function
  • Cognitive dysfunction/dementia
  • Alcohol misuse
  • Profound starvation
  • Increased exercise
  • Food malabsorption issues (i.e. coeliac disease, bariatric surgery, gastroenteritis)


Tips before you begin

  • Treat all problems as you find them
  • Re-assess regularly and after every intervention to see if your management is effective
  • Make use of the team around you to delegate tasks where appropriate
  • All critically unwell patients should have continuous monitoring equipment attached for accurate observations including:
    • Blood pressure
    • 3-lead ECG
    • Oxygen saturations
    • Heart rate
    • Respiratory rate
  • Communicate how often you would like these observations to be relayed to you
  • Call for help early using an appropriate SBARR handover structure (check out the guide here)
  • You need to both request investigations and review results as they become available
  • You don’t have to memorise everything off by heart, ask for guidelines and algorithms that are relevant (i.e. hypoglycaemia protocols)
  • If you would like medications or fluids, these will need to be prescribed
  • Don’t forget to document everything you have found and done in the patient notes!

Initial steps

You are likely to be called to see this patient either:

  • On the ward having become more drowsy and unwell OR
  • Presenting to ED with an unknown cause for reduced consciousness



If you are assessing the patient outside of the hospital setting (e.g. pre-hospital care) you need to assess for danger before approaching the patient:

  • A collapsed casualty may be under the influence of drugs or alcohol and could be violent when roused, so be aware of this.
  • If you see that multiple people have collapsed, be aware of the possibility of chemical, biological, radiological and nuclear causes (e.g. carbon monoxide poisoning). The “Rule of Three” is sometimes used to help decide on how to approach in this situation:
    • If there is 1 collapsed casualty, proceed as normal
    • If there are 2 collapsed casualties, with no obvious explanation (e.g. road traffic collision), approach with extreme caution (call 999 before you approach)
    • If there are 3 or more collapsed casualties, with no obvious explanation, do not approach and call 999, requesting specialist support


Once you reach the patient, perform a quick general inspection to get a sense of how unwell they are:

  • If the patient is unconscious, check for a pulse and check that the patient is breathing.


If the patient is unconscious or unresponsive and not breathing start the basic life support (BLS) algorithm as per resuscitation guidelines. Call 2222 for help!

  • Perform AVPU and assess their consciousness level
  • How do they look?
  • What is their breathing like?
  • Are there any clues from around the bedside? (look for drug charts, medication, IV lines, monitoring equipment etc)



  • Introduce yourself to the patient even if they appear unconscious as they may still be able to hear you.
  • If the patient is able to answer questions- ask them how they are feeling.


Ensure you have as much information as possible available to you

  • Patient notes
  • Drug charts including diabetes charts!
  • Observations charts



Assess the patient’s ability to speak, listen to the patient’s breathing for added sounds and inspect the mouth.

  • The presence of stridor (a high pitched inspiratory noise) indicates upper airway obstruction. In post-op bleeding, this might indicate that your patient’s consciousness level is impaired enough to compromise airway patency (the brain is being hypoperfused).



If you think your patient has a compromised airway you need help. Put out a crash call immediately as you require urgent anaesthetic input to secure the airway. You can perform some simple airway manoeuvers in the meantime.

Maintaining the airway whilst awaiting senior support

1.  Perform a head tilt, chin lift manoeuvre.

2.  If noisy breathing persists, try a jaw thrust.

3.  If this is still not enough to open up the airway you can consider the use of an airway adjunct:

  • If your patient is still semi-conscious then consider using a nasopharyngeal (NP) airway.
  • If your patient is able to tolerate an oropharyngeal (OP, or Guedel) airway then you can use one of these. However, this indicates that your patient is seriously unwell as they no longer have a gag reflex.


Re-assess after any intervention

If your patient starts to improve throughout your assessment, they may no longer be able to tolerate the OP airway and you should remove it as soon as possible to prevent gagging/aspiration.




Oxygen saturation: aim for 94-98%.

Respiratory rate:

  • Impaired consciousness may lead to a reduced respiratory rate (bradypnoea).
  • Severe hypoglycaemia may be associated with an irregular breathing pattern- this is a very worrying sign!



Auscultate both lungs:

  • Reduced air entry bilaterally suggests significant airway compromise and the need for critical care input.



Arterial blood gas

An arterial blood gas may be useful to quantify the degree of hypoxia if your patient has very low oxygen saturations, however, it should not delay the treatment of hypoglycaemia.


Chest x-ray

A chest x-ray is not immediately indicated if all your examination findings are normal.




  • Administer oxygen as soon as possible to maximise saturation levels.
    • High-flow oxygen (15 litres) should be administered through a non-rebreathe mask.
  • If the patient is conscious, sit them upright.
  • Maintain oxygen saturations between 94-98%


Assisted ventilation

  • If your patient is unconscious and their respiratory rate is inadequate (too slow or irregular with big pauses), you can provide assisted ventilation through a bag-valve-mask (BVM).
  • Ventilate at a rate of 12-15 breaths per minute (roughly one every 4 seconds).


Re-assess after any intervention





  • Tachycardia is common due to the autonomic effects of hypoglycaemia
  • Bradycardia is a late sign, often preceding cardiac arrest


Blood pressure

  • Blood pressure can be raised during a hypoglycaemic episode due to the stress response.
  • Hypotension might be a sign that your patient is dehydrated.


  • Your patient may appear clammy/pale
  • You may palpate a fast pulse (tachycardia)
  • Capillary refill time may be normal or sluggish due to hypovolaemia


Take blood samples

  • Try if possible to collect blood samples during cannulation
  • Full Blood Count – infection and anaemia
  • CRP – infection/inflammation
  • Urea and Electrolytes – renal function
  • Liver Function Tests
  • Serum Glucose

Record an ECG

  • This should not delay your treatment of hypoglycaemia. However, an ECG should be performed at some point (to rule out arrhythmia as a cause of loss of consciousness).


Secure intravenous access

  • The gold standard is to insert 2 large bore cannulas for acutely unwell patients.

Administer IV fluids

  • Consider fluid resuscitation if your patient has clinical signs of dehydration/hypovolaemia
  • Use NaCl 0.9% or Hartmann’s solution for initial fluid resuscitation
  • Titrate fluids based on the level of haemodynamic instability
  • li>See our guide to prescribing intravenous fluids in adults

Re-assess after any intervention



Blood glucose level

If you know that your patient was at risk of hypoglycaemia and you have an extra person, you can get them to do a finger-prick test while you assess A and B.  However, it is vital to secure the airway and assess breathing as problems with A and B will kill before hypoglycaemia does so if it just you then you will wait until C/D to check the blood glucose level.

For the unconscious John Doe patient who is brought to the Emergency Department without any background information, this might be the first time you realise you are dealing with hypoglycaemia.

Assess pupils

  • What size are they?
  • Are they equal?
  • Are they reactive to light?

Assess level of consciousness- AVPU/GCS

  • The above Airway, Breathing and Circulation problems can all alter the patient’s neurological status because of decreased cerebral perfusion, causing the patient to be confused or drowsy.
  • A formal record of your patient’s consciousness level will be really useful for tracking progress and changes throughout treatment.


Reverse hypoglycaemia

  • Ask for your medical school/hospital’s guideline for the treatment of hypoglycaemia.
  • The method you chose to reverse the hypoglycaemia will depend on:
    • Your patient’s consciousness level
    • Whether they can have enteral feeding or not (i.e. are they nil by mouth)
  • Below is a brief overview of some of the common treatment options available, but these do vary, so check local teaching guidance.
  • Re-test blood glucose 10 minutes after administering treatment


Patient CONSCIOUS (capillary blood glucose <4mmol/L)

GlucoJuice (or other high glucose drink):

  • 1 x 60mL bottle if BM 3-4 mmol/L
  • 2 x 60mL bottle if BM 2-2.9 mmol/L
  • 3 x 60mL bottle if BM <2


Patient CONFUSED (capillary blood glucose <4mmol/L)


  • Apply 2 tubes between the gums and cheeks
  • Rub cheeks to ensure absorption


Patient UNCONSCIOUS or NBM (capillary blood glucose <4mmol/L)

IV access:

  • 50ml of 20% IV glucose


No IV access:

  • 1mg of IM/SC Glucagon (if the patient is malnourished, this treatment is unlikely to be effective, as it requires adequate glycogen stores in the liver)




If symptoms persist once hypoglycaemia has been corrected, consider secondary pathologies (e.g. head injury, alcohol intoxication, drug intoxication, stroke, cerebral oedema)

If hypoglycaemia persists, or hypoglycaemia relapses, consider:

  • Insulin overdose
  • Oral hypoglycaemic (e.g. sulphonylureas) overdose

In the case of overdose, continued monitoring and glucose infusions may be required.





  • We routinely expose all unwell patients to make sure that we aren’t missing anything.
  • In our unconscious patient with an unknown history, we might find sites of self-injection (e.g. areas of lipohypertrohy) which may tell us we are dealing with a patient with diabetes.


  • Someone who has been unconscious for some time might be hypothermic.
  • Hyperthermia might indicate an underlying infection which could contribute to the hypoglycaemia.



Reverse hypothermia

  • Use blankets to re-warm patients who are mild to moderately hypothermic.
  • Consider active re-warming techniques in patients with severe hypothermia.

Re-assess after any intervention


Reassess ABCDE

It is essential to continually reassess ABCDE and treat issues as you encounter them. This allows continual reassessment of the response to treatment and early recognition of deterioration.


Next steps

Well done! Your patient’s blood sugars are rising and they are starting to feel much better. There are just a few more things to do…

Take a history

Now your patient might be able to give you a detailed history of what has happened. If your patient is still confused you might be able to get a collateral history from staff or family members as appropriate. Check out the history taking guides here.



  • Patient notes
  • Observation charts
  • Fluid charts
  • Investigation findings
  • Additionally, make sure to check the medications you have just prescribed and what they are normally taking. It might be that their current regime is inappropriate for them (i.e. insulin requirements might be lower when a patient is acutely unwell if they aren’t eating as much as normal).



It is really important that you document your initial ABCDE findings, any interventions you made and the response the patient had to those interventions. Write down important information you have elicited from the history taking.



You must consider why your patient has had a hypoglycaemic episode and take steps to prevent his from happening again. Discuss the patient with your seniors and the diabetic team. Your patient will likely need a review from the diabetes specialist nurses.

As a junior doctor it would be appropriate to give an SBARR handover outlining your assessment and actions, and to discuss the following:

  • Are there any further assessments or interventions required?
  • Does the patient need a referral to HDU/ICU?
  • Should the patient be referred for a review by a specialist doctor (i.e. endocrinologist)?
  • Should any changes be made to the management of their underlying conditions?




Dr Celestine Weegenaar

ACCS Emergency Medicine Trainee


Will Freake

 Medical Student from the University of Southampton, studying Pre-Hospital Medicine at Barts Medical School



1. Diabetes UK: The hospital management of hypoglycaemia in adults [LINK]

2. Generic core material: prehospital emergency care course/core material. Editorial leads: Andrew Thurgood, Darren Walter; Clinical review team: Andrew Thurgood [et al.]; Contributors, Adrian Noon [et al.]


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