Shock, Anaphylaxis & Sepsis Flashcards
What are the etiologies of cardiogenic shock?
Myocardium: Cardiomyopathy, AMI (Can ppt shock if >40% myocardium is involved), Heart failure, Myocarditis
Circuitry: Arrhythmias
Mechanical: Valvular pathology (severe prolapse / regurg / stenosis); Septal Defect
What is the clinical presentation of cardiogenic shock?
- Laboured breathing with audible coarse crackles or wheezing
- Tachycardia
- Delayed Capillary Refill Time
- HypoTN
- Diaphoresis
- Poor peripheral pulses
RHF: ↑ JVP
LHF: Pulmonary oedema
Valvular HF: may present w/ new onset cardiac murmurs.
How is cardiogenic shock managed?
Acute resuscitation
- Airway: ETT w/ Mechanical Ventilation
- Breathing: High Flow O2, maintaining SpO2 >90%
- Circulation: Judicious use of N/S (excessive use will worsen pul edema)
Diagnostics: identify underlying cause
- Cardiac Markers: Trop I
- ECG: for MI and Arrhythmia
- 2DEcho: to identify valvular lesions; TRO Tamponade
Identify +/- reverse underlying aetiology
- Non-Arrhythmic / Obstructive causes: Dobutamine (Alt: Dopamine / NE)
- Arrhythmia: Synchronised Cardioversion (50J for narrow QRS, 100J for wide). Always support circulation w/ fluids +/- dobutamine
- Alternative treatment: IABP (Counter-pulsation reduces left ventricular afterload and improves coronary artery blood flow)
- Treat underlying cause
What are the causes of obstructive shock?
↓ Diastolic filling
- Cardiac tamponade
- Constrictive pericarditis
- Restrictive cardiomyopathy
↓ Venous return
- Tension pneumothorax
- Intrathoracic tumor
↑ Ventricular afterload
- Massive pulmonary embolism (PE)
- Aortic dissection
- Aortic stenosis
- Large systemic emboli
- Severe pulmonary hypertension
What does is the clinical presentation of someone with cardiac tamponade?
Beck’s Triad – Hypotension, Muffled heart sounds, Elevated JVP
Other findings – Sinus Tachycardia, Pulses Paradoxus
What are the ecg findings of someone with cardiac tamponade?
- Sinus tachycardia
- Low voltage QRS complexes: An ECG finding defined by a QRS amplitude < 5 mm in all limb leads or < 10 mm in all chest leads due to attenuation of the electrical signal.
- Electrical alternans: consecutive QRS complexes that alternate in height due to the swinging motion of the heart when surrounded by large amounts of pericardial fluid
What is the management of cardiac tamponade?
Pericardiocentesis
What are the causes of cardiac tamponade?
acute causes
- aortic rupture –> stamford a dissection
- myocardial infarction: weakened muscle rupture
- stabbing punctures blood vessels
- blunt trauma ruptures lots of small vessels
chronic causes
- cancers (from lung or breast)
- uremic pericarditis (irritates serous pericardium)
- hypothyroidism
- chronic inflammation
How does angioedema present?
- Poorly circumscribed swellings of the subcutaneous tissue that tends to be non-pruritic, maybe instead be painful / numb / burning.
- Lasts ~3 days
What is anaphylaxis?
A systemic allergic reaction involving ≥2 systems (not necessarily vascular)
Mucocutaneous: Generalized urticaria /flushing, swollen lips /tongue
Respi System:
- Respi Compromise (dyspnoea, wheeze, stridor)
- May first p/w “lump in throat” due to laryngeal edema
GIT: Crampy abdominal pain, Vomiting, Diarrhoea
Cardiovascular: Hypotension, tachycardia (i.e. Anaphylactic Shock)
How is urticaria managed?
Antihistamines +/- PO Prednisolone (if severe)
How is angioedema managed?
Antihistamines & PO Prednisolone +/- IM Adrenaline (if impending anaphylaxis / Airway angioedema)
How is anaphylaxis managed?
N/S Bolus & Antihistamines (Both H1 and H2 antagonists) & IV Hydrocortisone & IM Adrenaline
Antihistamine:
- Gen1 H1 Blocker: Promethazine, Chlorpheniramine, Diphenhydramine
- Alt: H2 Blocker Cimetidine / Ranitidine if persisting S&S, unresponsive to H1
IV Corticosteroid – IV Hydrocortisone (IV Bolus 100mg Q6H)
- Purpose is to stabilise mast cells and prevent biphasic phenomenon!
- Latter refers to the recurrence of anaphylaxis S&S 12-72 hours post-event
IM Adrenaline:
- For Anaphylaxis = 0.5ml of 1:1,000 = 0.5mg
- For cardiac arrest = 10ml of 1:10,000 = 1mg
Alternative to adrenaline – glucagon (if pt has IHD, Severe HTN, Pregnancy, non-responders)
Requires monitoring
- In resuscitation area
Supplemental high flow O2 +/- Salbutamol
- Electrocardiogram (ECG), pulse oximetry, and viral signs q5 minutes
- Be prepared for intubation / cricothyroidotomy
- Circulatory support w/ N/S or Hartmann’s & above medications
- Observe for at least 24hrs in case of biphasic phenomenon
What is the definition of sepsis?
Life threatening organ dysfunction (confirmed by a SOFA score ≥2) caused by a dysregulated host response to infection
- hypotension: systolic bp < 100mmHg
- altered mental status
- tachypnea: RR> 22/min
What is the definition of septic shock?
A subset of sepsis in which there is profound circulatory, cellular and metabolic abnormalities are associated with a greater risk of mortality than with sepsis alone, defined as sepsis with BOTH
- Persistent Hypotension requiring vasopressors to maintain MAP >65mmHg
- And Serum lactate >2 mmol/L despite adequate volume resuscitation
How should septic shock be managed within the 1st golden hour?
A: Intubate if GCS < 8 or if there reasons to suspect the patient is unable to protect his airway (eg: excessive vomiting)
B: Supplemental oxygen via nasal cannula / partial / non-rebreather mask and aim for SpO2 of 94-98%
C: 2 large bore IV cannulas in the antecubital fossa and provide a fluid challenge of 500ml of normal saline over 30 min to assess for responsiveness
- Responsive / partially responsive – continue fluid resus of at least 30ml/kg
- Monitor adequacy of fluid resus by inserting IDC & aim for urine o/p 0.5ml/kg/hr
- If unresponsive to fluid challenge – consider provision of vasopressor NE
- Aim for a MAP of ≥65mmHg
Investigations
- measure lactate, remeasure if initial lactate is >2mmol/L
- ABG
- obtain blood culture prior to administration of abx: 2 sets of blood culture
Antimicrobial therapy
- administer broad spectrum abx within 1 hour of presentation
I will like to perform vitals monitoring and GCS charting in a HDU / ICU setting
I will like to further monitor the patient’s
- Lactate
- Urine O/P
- MAP +/- Central Venous Pressure
- SpO2 / SCVO2
What are the targets to achieve within 6h of initial resuscitation for septic shock?
CVP 8-12
MAP ≥65mmHg
Urine 0.5ml/kg/hr
ScvO2 70% — or SpO2 94-9
What is the fluid therapy that can be given in patients with septic shock?
Crystalloids
- Either N/S or Hartmann’s is acceptable
- However, if large volume is to be given, N/S can lead to hyperchloremia 🡪 NAGMA. Hence consider Hartmann’s if large volume!
- Do NOT give hydroxyethyl starches
Albumin
30ml/kg crystalloids minimum within first 3h
Continue as long as there is haemodynamic improvement (BPS)
What are the vasopressors that should be given in patient with septic shock?
Vasopressors – if initial 30ml/kg resus is insufficient
- Target MAP 65 [1B]
- Noradrenaline first line [1B]
- Adrenaline or vasopressin 2nd line [2B]
- Dopamine is an alternative [2C] – often given in the wards. Should be started at >5-10mcg/kg, anything lower = vasodilatory effect
- Do NOT give low dose dopamine [1A]
- Dobutamine if myocardial dysfunction[1C]
Other than fluid therapy, vasopressors, how else would you manage a patient with septic shock
Antimicrobial therapy
- IV Abx / Antifungal / Antiviral within 1 hour [Evidence 1B]
- 1 or more broad spectrum abx [1B] for 7-10 days typically [2C]
- Reassess daily for escalation
- Procalcitonin (if no evidence of infection)
Source control
- Anatomical diagnosis
- Intervene within 12 hours [1C] – eg; drainage of abscess
Supportive therapy
- Transfuse if Hb < 7, target 7-9
- Aim for higher Hb if IHD, ACS, Haemorrhage
- No role for EPO
- Venous / arterial blood glucose <10mmol/L w/ insulin
- No bicarbonate is indicated for haemodynamics or lactic acidosis
- No FFP even if abnormal labs
- Platelets if < 10,000 (or 20K if risk of bleeding)
DVT prophylaxis
- LMWH [1B]
- Pneumatic Compression Devices [2C]
Stress Ulcer Prophylaxis
- H2RA / PPI only if there is RF for stress ulcers [1B] – PPI is preferred
- H2RA or PPI can be used (low evidence)
- No need to use if no RF
Nutrition
- Start oral / enteral feeding within 48 hours [2C]
- Avid parenteral nutrition if patient is able to be enterally fed (moderate evidence)
How does one diagnose a central line infection?
When performing blood cultures on patient with suspected line infection – take 1 set of blood c/s from each lumen (central or peripheral) + 1 set from a peripheral vein
If patient has an infected central line (i.e. CVP BSI), CVP will turn positive >120min earlier the peripheral cultures – i.e. a differential time to positivity of >120 mins
This helps us localise the SITE of infection 🡪 if CVP BSI, there will be ↑ bacterial load at CVP 🡪 culture will grow faster = become +ve faster
What is the definition of neurogenic shock?
Caused by a sudden loss of SNS tone to regions distal to the level of injury 🡪 VasoD + prevents reflex tachycardia to the hypotension
SNS supply is from T1-L2/3; Neurogenic Shock occurs at T5 and above (above the level of thoracic splanchnic nerves)
How to manage neurogenic shock?
Exclude other reasons for shock (e.g., other injuries)
N/S Bolus to support the circulation
Inotropic support: Dopamine
How do patients with neurogenic shock present with?
Classic presentation: hypotension, bradycardia, vasodilation
compare and contrast spinal and neurogenic shock in terms of
- definition
- BP
- pulse
- bulbocarvenous reflex
- motor
- time
- mechanism
spinal shock
- definition: immediate temporary loss of total power, sensation and reflexes below the level of injury
- hypotension
- bradycardia
- bulbocavernous reflex absent
- flaccid paralysis
- mechanism: peripheral neurons become temporarily unresponsive to brain stimuli
neurogenic shock
- definition: sudden loss of sympathetic nervous system reflexes
- hypotension
- bradycardia
- bulbocavernous reflex variable
- motor variable
- mechanism: disruption of autonomic pathways –> loss of sympathetic tone and vasodilation
What are the blood cultures that needs to be taken to investigate possible sepsis?
- Do not delay antibiotics for more than 45 min [1C]
- Aerobic + Anaerobic x 2 sets [1C]
- 1 x Vein, 1 x Vascular device [1C]
