Shock (General Overview)... By Shapi.pdf

EMERGENCY MEDICINE
• SHOCK
• Types of shock
Dr. Chongo Shapi (BSc.HB, MBChB).
Medical Doctor
21 March 2024 1
Dr. Chongo Shapi (BSc. HB, MBChB)

INTRODUCTION
• Circulatory failure resulting in inadequate
organ perfusion. Often defined by Reduced
BP— systolic <90mmHg—or mean arterial
pressure (MAP) <65mmHg—with evidence of
tissue hypoperfusion, eg mottled skin, urine
output (UO) of <0.5mL/kg/h, serum lactate
>2mmol/L.
21 March 2024 Dr. Chongo Shapi (BSc. HB, MBChB) 2

CONT’
• Signs: Reduced GCS/agitation, pallor, cool
peripheries, tachycardia, slow capillary refill,
tachypnoea, oliguria.
• MAP = cardiac output (CO) ≈ systemic vascular
resistance (SVR). CO = stroke volume ≈ heart
rate.
• Therefore, shock can result from inadequate
CO or a loss of SVR, or both.

CONT’
Inadequate cardiac output
• Hypovolaemia:
• Bleeding: trauma, ruptured aortic aneurysm, GI bleed.
• Fluid loss: vomiting, burns, ‘third-space’ losses, eg
pancreatitis, heat exhaustion.
• Pump failure:
• Cardiogenic shock, eg ACS, arrhythmias, aortic
dissection, acute valve failure.
• Secondary causes, eg PE, tension pneumothorax,
cardiac tamponade.

CONT’
• Peripheral circulatory failure (loss of SVR)
• Sepsis: Infection with any organism can cause
acute vasodilation from inflammatory cytokines.
Gram –ve’s can produce endotoxin, causing
sudden and severe shock but without signs of
infection (fever, Raised WCC). Classically patients
with sepsis are warm & vasodilated, but may be
cold & shut down.
• Other diseases, eg pancreatitis, can give a similar
picture associated with the inflammatory
cascade.

CONT’
• Anaphylaxis:
• Neurogenic: Eg spinal cord injury, epidural or
spinal anaesthesia.
• Endocrine failure: Addison’s disease, p836 or
hypothyroidism;
• Other: Drugs, eg anaesthetics,
antihypertensives, cyanide poisoning.

APPROACH
• With shock we are dealing primarily with ‘C ’
so get large-bore IV access ≈2 and check ECG
for rate, rhythm (very fast or very slow will
compromise cardiac output), and signs of
ischaemia.

CONT’
• General review: Cold and clammy suggests
cardiogenic shock or fluid loss. Look for signs
of anaemia or dehydration, eg skin turgor,
postural hypotension? Warm and well
perfused, with bounding pulse points to septic
shock.
• Any features suggestive of anaphylaxis—
history, urticaria, angioedema, wheeze?

CONT’
• CVS: Usually tachycardic (unless on B-blocker, or in
spinal shock— and hypotensive.
• But in the young and fit, or pregnant women, the
systolic BP may remain normal, although the pulse
pressure will narrow, with up to 30% blood volume
depletion.
• Difference between arms (>20mmHg)—aortic
dissection?
• JVP or central venous pressure: If raised, cardiogenic
shock likely.
• Check abdomen: Any signs of trauma, or aneurysm?
Any evidence of GI bleed?

MANAGEMENT
• Depends on the type of shock:
a) Septic shock:
b) Anaphylaxis:
c) Cardiogenic shock:
d) Hypovolaemic shock

HYPOVOLEMIC
SHOCK

HYPOVOLEMIC SHOCK
• Identify and treat underlying cause. Raise the
legs.
• Give fluid bolus 10–15mL/kg crystalloid via
large peripheral line, if shock improves,
• repeat, titrate to HR (aim <100), BP (aim SBP
>90) and UO (aim >0.5mL/kg/h).
• If no improvement after 2 boluses, consider
referral to ICU

HAEMORRHAGIC
SHOCK

HAEMORRHAGIC SHOCK
• Stop bleeding if possible. Identification of grade is
significant.
• If still shocked despite 2L crystalloid or present
with class III/IV shock then crossmatch blood
(request O Rh–ve in an emergency).
• Give FFP with red cells (1 : 1 ratio); aim for
platelets >100 and fibrinogen >1 (guided by
results, but eg 1 pool of platelets and 2 pools of
cryoprecipitate per 6–8 units of red cells).
• Consider tranexamic acid 2g IV. Discuss with
haematology early.

SHOCK
SEPSIS

SEPSIS
• Sepsis Life-threatening organ dysfunction caused
by a dysregulated host response to infection.
• Sepsis is a major killer. There are >150 000 cases
of sepsis in the UK each year resulting in >44 000
deaths, and much morbidity.
• Septic shock Sepsis in combination with:
a) EITHER lactate >2mmol/L despite adequate
fluid resuscitation
b) OR the patient is requiring vasopressors to
maintain MAP ≥65mmHg.

CONT’
• Many sepsis-related deaths could be prevented with earlier
treatment. Often, the key failure in sepsis management is not
recognizing sepsis in time.
• Early warning scores help identify inpatients who are becoming
septic.
• Have a low threshold for assessing for sepsis if:
a) The patient has communication difficulties: limited English;
limited verbal communication or cognitive impairment
b) The patient is immunosuppressed, on chemotherapy, or an IV
drug user
c) The patient recently had surgery or is pregnant/recently gave birth
d) The patient has indwelling lines/other foreign material.

ASSESSING RISK IN SEPSIS
MODERATE TO HIGH RISK
CRITERIA
• Reports of altered mental
state or acute deterioration
in functional status
• Respiratory rate (RR) 21–24
• Systolic blood pressure
(SBP) 91–100mmHg
• Heart rate 91–130bpm or
new arrhythmia.
• Urine output: nil for 12–
18h; 0.5–1.0mL/kg/h if
catheterized
HIGH RISK CRITERIA
• Objective evidence of
altered mental state
• RR>24; new requirement
for FiO2 >40% to keep sats
>92% (>88% in COPD)
• SBP <90 or >40mmHg less
than baseline
• Heart rate >130bpm
• Urine output: nil for 18h;
<0.5mL/kg/h if catheterized

CONT’
• Local signs of infection,
incl. redness, swelling, or
discharge around wound
• Rigors, or temperature
<36°C
• Impaired immunity
(illness or drugs)
• Recent
surgery/trauma/invasive
procedure
• Mottled, ashen, or
cyanotic skin. Non-
blanching rash

CONT’
• High risk: At least one high-risk criterion OR at
least two moderate- to high-risk criteria with
AKI or LACTATE >2.
• Moderate to high risk: At least one moderate-
to high-risk criterion.
• Low risk: No moderate- or high-risk criteria.

ACUTE MANAGEMENT IN SEPSIS
• Early recognition and treatment is key.
• Antibiotics: These should be broad spectrum and start
within 1h. Consider covering for non-bacterial
microbes, eg give aciclovir if HSV encephalitis is
suspected.
• Fluids: Give within 1h if high risk with SBP <90, AKI, or
lactate >2 (consider if <2).
❑Give 500mL boluses of crystalloids with 130–
154mmol/L sodium (eg 0.9% saline) over 15mins.
Caution in heart failure.
❑ If no improvement after two boluses, speak with a
senior. (Possible use of inotropes)

CONT’
• Oxygen: Give oxygen as required for target saturations.
These will be 94–98% (or 88–92% if the patient is at
risk of CO2 retention, eg in severe COPD).
• Critical care review: Speak with critical care early if
intensive care support (eg inotropes, ventilation,
haemofiltration, intensive monitoring) may be
required.
• Surgical involvement: Eg emergency wound
debridement.
• Manage acute complications: Shock, AKI, DIC, ARDS,
arrhythmias etc (may spontaneously resolve when
sepsis improves).

SHOCK
ANAPHYLACTIC SHOCK

ANAPHYLACTIC SHOCK
• Type I IgE-mediated hypersensitivity reaction.
Release of histamine and other agents causes:
capillary leak; wheeze; cyanosis; oedema
(larynx, lids, tongue, lips); urticaria.
• More common in atopic individuals. An
anaphylactoid reaction results from direct
release of mediators from inflammatory cells,
without involving antibodies, usually in
response to a drug, eg acetylcysteine.

CONT’
• Examples of precipitants:
a) Drugs, eg penicillin, and contrast media in
radiology.
b) Latex.
c) Stings, eggs, fish, peanuts, strawberries,
semen (rare).

CONT’
• Signs and symptoms
a) Itching, sweating, diarrhoea and vomiting,
erythema, urticaria, oedema.
b) Wheeze, laryngeal obstruction, cyanosis.
Tachycardia, hypotension.

MANAGEMENT
• Secure the airway—give 100% O2 but Intubate if
respiratory obstruction imminent.
• Remove the cause; raising the feet may help
restore the circulation.
• Give adrenaline IM 0.5mg (ie 0.5mL of 1:1000).
Repeat every 5min, if needed as guided by BP,
pulse, and respiratory function, until better
• Give Chlorphenamine 10mg IV and
hydrocortisone 200mg IV

CONT’
• IVI (0.9% saline, eg 500mL over ¼h; up to 2L
may be needed) Titrate against blood
pressure.
• If wheeze, treat for asthma. May require
ventilatory support.
• If still hypotensive, admission to ICU and an
IVI of adrenaline may be needed ±
aminophylline and nebulized salbutamol

CONT’
• When stable, admit to ward. Monitor ECG
• Measure serum tryptase 1–6h after suspected
anaphylaxis
• Continue chlorphenamine 4mg/6h PO if itching
• Suggest a ‘MedicAlert’ bracelet naming the
culprit allergen
• Teach about self-injected adrenaline (eg 0.3mg,
Epipen®) to prevent a fatal attack
• Skin-prick tests showing specific IgE help identify
allergens to avoid

CONT’
• Adrenaline (=epinephrine) is given IM and
NOT IV unless the patient is severely ill, or has
no pulse. The IV dose is different:
100mcg/min—titrating with the response.
• This is 0.5mL of 1 : 10 000 solution IV per
minute. Stop as soon as a response has been
obtained.
• If on a B-blocker, consider salbutamol IV in
place of adrenaline.

THE END!
• Reference as per Oxford Clinical Medicine.

Thanks

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