Junior Doctor Notes 🩺

Hypotension

12 min read

  • If considering that the patient is in shock see shock notes: Shock
  • Note that it is not the absolute BP level that dictates the need to intervention but rather the threat to end-organ function; therefore the priority is to assess for tissue hypoperfusion
  • Thin young females often have a SBP of 80-100 mmHg

Phone Call/Presentation Questions

  • Normal blood pressure? and other observations (notably HR and RR)
  • Reason for patient’s admission?
  • Is the patient symptomatic?
    • Mental status?
    • Clammy or pale?
    • Dyspnoea or chest pain?
    • Evidence of bleeding?
    • Temperature?
  • Recent medication (in last hour)?

Instructions Over the Phone

  • If possibility of shock:
    • Administer ≥6L/min by oxygen by mask and attach pulse oximetry to the patient
    • Request an IV trolley at the patient’s bedside with two large-bore 14-16G cannulae ready for insertion (if IV lines not already in place)
    • Give 20 mL/kg normal saline IV as rapidly as possible unless the patient is SOB and may have pulmonary oedema with cardiogenic shock
    • Request ECG immediately and commence continuous cardiac monitoring
    • Organise cross matching of ≥4 units of packed RBCs if the admission diagnosis was GI bleed or if there is evidence of external blood loss
    • Request 1:1000 adrenaline 0.01mg/kg up to 0.5mg (0.5mL) be drawn up ready for IM injection into the upper lateral thigh if you suspect lateral thigh if you suspect anaphylaxis
    • Arrange portable CXR immediately if the patient has dyspnoea or chest pain

Common Causes (Corridor thoughts)

  • Dehydration
  • Medications (often postural hypotension)
    • Antihypertensives, nitrates, sedatives, analgesics
  • Autonomic neuropathy
    • Diabetes, Parkinson’s disease/Parkinson plus syndromes
  • Physiological
  • Iatrogenic
  • Shock
    • Distributive
    • Cardiogenic
    • Hypovolemic
    • Obstructive

Assessment

Bedside

  • Evaluate the patient from the bedside: do they actually look sick or critical
    • The patient may be pale, agitated and sweaty

A → E Assessment

  • Airway clear?
    • If the patient has depressed consciousness, intubation may be required; contact senior urgently as well as duty anaesthetist and ICU
    • Consider intubation and roll patient into the left lateral decubitus position to avoid aspiration; remove loose-fitting dentures
  • Breathing pattern?
    • Tachypnoea is common and may indicate lactic acidosis secondary to tissue hypoperfusion, acute LVF or underlying PE, pneumothorax or cardiac tamponade
  • Cardiovascular:
    • Blood pressure?
      • Measure supine blood pressure in both arms
      • Automated NIBP is notoriously inaccurate at low readings; retake blood pressure manually
      • If the blood pressure is now returned to normal it could have been caused by a vasovagal episode or orthostatic hypotension
      • If hypotension is not severe and the patient appears well, examine for postural vital signs (not needed if hypotensive when supine)
        • Ask for assistance if the patient is unable to stand alone or have the patient sit up over the edge of the bed
        • Repeat HR and BP after they sit or stand for ≥2 minutes and ask the patient if they feel unwell or light-headed
          • HR ↑ >20 beats/min or patient reported light headedness is an indicator of inadequate intravascular volume
    • Pulse Pressure?
      • Narrow pulse pressure means low LV stroke volume and shock
      • Wide pulse pressure means Anaphylaxis or Sepsis (i.e. warm shock)
    • Heart Rate?
      • Low volume or impalpable peripheral pulses indicates hypoperfusion
      • Hypotension usually accompanied by compensatory reflex sinus tachycardia
      • Look at the ECG
        • HR <50 beats/min ⇒ vasovagal episode, autonomic neuropathy, rate-slowing drugs, bradyarrhythmia, or haemorrhagic shock (haemorrhagic shock can have bradycardia sometimes)
        • HR >150 beats/min and evidence of VT, AF with RVR or SVT electrical cardioversion see: Tachyarrhythmia immediate management
        • Other ECG abnormalities can indicate drug toxicity or electrolyte abnormality or 2° to the hypotension
  • Disability:
    • Is the patient orientated?
    • GCS?
    • Pupils?
    • BSL?
  • Environment
    • Febrile/Temperature?
      • Consider sepsis with >38°C or <36°C but be aware of normal temperature sepsis in the elderly and immunosuppressed
      • Hypothermia can also result secondary to shock
    • Abdomen?

Initial Examination: Is the Patient in Shock?

  • This targeted examination aims to identify with the patient is in shock?
ExaminationNotes
VitalsRepeat (esp. HR and BP)
SkinCool, mottled and clammy ⇒ ↓ perfusion
Warm and pink ⇒ adequate perfusion or distributive shock
Poor turgor, lack of sweating ⇒ ↓ perfusion
Purpura (septicaemia) or urticaria/erythema (anaphylaxis)
CVSSmall pulse volume and slow capillary refill >2 sec ⇒ hypoperfusion
Non visible JVP, flat neck veins ⇒ hypovolaemic or distributive shock
Elevated JVP, distended neck veins ⇒ cardiogenic or obstructive shock
Kussmaul’s JVP sign rises on inspiration ⇒ cardiac tamponade or RV failure
RespStridor ⇒ anaphylaxis
Crackles on chest auscultation ⇒ sepsis or cardiogenic shock
Tachypnoea ⇒ acidotic breathing
GITCheck for tenderness or a pulsatile mass (e.g. AAA)
Generalised abdominal tenderness with peritonism ⇒ bowel infarction, intraperitoneal haemorrhage, pancreatitis with third-space fluid loss
CNSAlert, orientated ⇒ maintaining cerebral perfusion
Apprehensive, confused, agitated, delirious ⇒ ↓ cerebral perfusion
UrineUrine output >0.5mL/kg/h or >30mL/h ⇒ adequate renal perfusion
Urine output <0.5mL/kg/h or <30mL/h ⇒ ↓ renal perfusion

Immediate Management

  • Call senior immediately
  • Commence oxygen therapy to maintain saturation >94%
  • Obtain adequate IV access
    • Two large bore 14-16G cannulae in large peripheral veins (antecubital veins preferred)
    • Send bloods for FBC, UEC, coagulation profile and troponin if the ECG is abnormal
    • Check VBG including lactate
    • Request immediate cross match of 2-6 units of packed RBCs if haemorrhage is suspected
  • Resuscitate intravascular depletion
    • Give 20mL/kg normal saline IV over 10 minutes if the patient is hypotensive, JVP is low and there is no crackles on chest auscultation
    • Elevate or squeeze IV bag or use IV pressure cuffs
    • Observe response to fluid challenge by monitoring HR, BP, JVP, peripheral perfusion, basal lung crackles and urine output; repeat 20mL/kg as clinically indicated
      • Titrate fluid resuscitation carefully in a patient with a history of cardiac failure and commence with a smaller fluid bolus of 5mL/kg
      • Ensure all patients who are bleeding maintain a Hb >90-100
  • Treat any immediately apparent cause
    • Give adrenaline 0.3-0.5mg (0.3-0.5mL of 1:1000) IM for anaphylaxis
    • Broad-spectrum antibiotics for septicaemia
  • Insert IDC to monitor urine output (0.5-1 mL/kg/h ⇒ restoration of adequate renal perfusion)
  • 12-lead ECG and review the rhythm strip
    • Give IV atropine bolus (0.5-1.0mg) if HR <50
    • Perform DC cardioversion with appropriate sedation if HR>150 beats/min with hypotension and VT, AF RVR or SVT (see Tachyarrhythmias management)
  • Request portable CXR

Selective History and Chart Review

  • Determine whether a presenting problem or past medical history is a cause of the hypotension and review chart for trends or medication changes
  • Risk factors for hypovolaemic or distributive shock
    • Bleeding, concealed bleeding (e.g. AAA, ectopic pregnancy, pelvic or long-bone fracture)
    • Vomiting/diarrhoea
    • Bowel obstruction, ileus or pancreatitis (third space fluid losses)
    • Burns or generalised erythroderma
    • Fevers, rigors, malaise, recent contact with meningococcal disease
    • Ask female patients about abdominal pain with vaginal bleeding or the use of tampons (⇒ toxic shock syndrome)
  • Risk factors for cardiogenic or obstructive shock
    • Chest pain, dyspnoea, orthopnoea, previous ACS or cardiac interventions ⇒ cardiogenic shock
    • For patients with diabetes or chronic renal impairment consider silent myocardial ischaemia and cardiogenic shock
    • Pleuritic chest pain, whole leg swelling, known malignancy or renal failure ⇒ PE or pericardial tamponade
  • Reason for admission
  • HxPC:
    • Chest pain, SOB
    • Pre-syncope
    • Thirsty?
    • When last void?
  • PMHx
  • Charts
    • Observation chart
      • See whether there has been a slow deterioration or sudden change
      • Check the temperature chart for fever
      • Look for a change in weight as loss of weight can indicate fluid loss
    • Fluid balance chart
      • Look for evidence of hypovolaemia:
        • Reduced PO or IV intake
        • Excessive fluid loss from NG or surgical drains or ileostomies
        • Urine output <30mL/h
      • Check for recent excessive urinary loss from diuretic medications, osmotic diuresis (hyperglycaemia, mannitol administration, hypertonic IV contrast material), post-obstructive renal diuresis, diabetes insipidus, recovery phase of acute tubular necrosis, adrenal insufficiency with vomiting
    • Medication chart
      • Note any recent change in dose or addition of hypotension-inducing medications
        • Antihypertensive medications and alpha-blockers (e.g. antipsychotic medications) lower BP excessively
        • Beta blockers, calcium channel blockers and other antiarrhythmics cause hypotension and counter a reflex tachycardia
        • Diuretics cause hypovolaemia
        • Excessive doses of analgesics or sedatives cause hypotension
        • Recent administration of radiographic contrast may precipitate anaphylaxis
        • NSAIDs and steroids can precipitate GI bleeding and anticoagulants worsen any bleeding

Examination

  • Peripheral CRT, skin turgor
  • Pallor of the palmar creases
  • JVP
  • Heart sounds
  • Calves
ExaminationNotes
Vital signsRecheck HR, BP and peripheral perfusion and assess for improvement
HEENTDry mouth (hypovolaemia)
CVSRecheck JVP to assess for any improvement
Displaced apex beat, S3 gallop ⇒ LVF
Muffled heart sounds, impalpable apex beat ⇒ pericardial effusion
RespCrackles, pleural effusions ⇒ cardiogenic shock
Wheezes ⇒ anaphylaxis, LVF or PE-related bronchospasm
GITTender hepatomegaly ⇒ heart failure
RectalMelaena or haematochezia ⇒ GI bleed
SkinPruritic, urticarial rash with vasodilated peripheries ⇒ anaphylaxis
Pale skin creases and conjunctivae ⇒ occult haemorrhage
ExtSacral or ankle oedema ⇒ pre-existing CCF
UrineReassess urine output

NOTE

Patients with acute cardiogenic shock are note oedematous unless they have previous CCF. Patients with anaphylaxis or sepsis may become oedematous from capillary leakage

Investigations

  • Investigations
    • Note other charts:
      • Fluid charts
      • Medication charts: (e.g. antihypertensives)
    • Bloods
    • Imaging
  • Check recent Hb for trends
  • VBG might show lactic acidosis or hyperkalaemia from low tissue perfusion
  • Urea to creatinine ratio: a ratio >12 is suggestive of volume depletion or a GI bleed
  • Urine sample for MCS if dipstick testing indicates potential urosepsis
  • Review CXR
    • Acute LVF: pulmonary venous congestion, cardiomegaly, Kerley B lines (ABCDE features)
    • Aortic dissection: widened mediastinum (see Aortic Dissection Management for specific CXR fidnings)
    • Pulmonary embolism: plate atelactasis, basal effusion
    • Pneumonia: consolidation, diffuse alveolar changes
  • Echocardiography
    • Will confirm pericardial tamponade or right ventricular strain of PE
    • Hard to organise after hours

Specific Management

  • In most cases IV fluid bolus is the mainstay of management; involve your senior early if hypotension is not fluid responsive
  • Cardiogenic shock
    • Clinically manifested by hypotension, elevated JVP and pulmonary oedema
    • Treat ACS-related causes (see ACS)
      • After giving aspirin, heparin and clopidogrel or prasugrel refer for immediate PCI
      • Fibrinolytic therapy does not substantially improve the outcome in cardiogenic shock1
      • Exclude other causes of hypotension with raised JVP using urgent echocardiogram
      • Also perform urgent echocardiogram in patients with a new murmur as valve repair my be required
    • Inferior STEMI
      • Confirm RV infarction by placing right sided chest leads (usually just V4R but sometimes also with V5R and V6R)
      • STE indicates RV infarction
      • These patients are dependent on preload for their cardiac output so avoid dropping preload with GTN, morphine or diuretics
      • Less likely to develop pulmonary oedema → try small aliquots of normal saline at 2 mL/kg
    • Exclude aortic dissection causing shock from tamponade or severe aortic incompetence
      • Arrange CT scan with IV contrast (CT angiography) or TOE to best distinguish Aortic Dissection from ACS
    • General measures of shock
      • Give maximal oxygenation, careful fluid management and consider inotrope infusions such as noradrenaline with or without dobutamine in the ICU.
      • If these measures are unsuccessful, intra-aortic balloon pump, left ventricular assist device (LVAD) or circulatory bypass are required if a reversible pathological feature is present and it is available

  • Hypovolaemic Shock
    • Control external bleeding: compress or pack any external haemorrhage such as epixstaxis or an open wound
    • Consult surgeon immediately if suspicion of acute blood loss causing hypotension (e.g. GI bleed, ruptured AAA, ectopic pregnancy)
    • Massive bleeding
      • Order uncross-matched blood and consider other blood products such as FFP and platelets
      • notify the blood bank that a massive transfusion is/may be necessary
    • Excess fluid loss via vomiting, diarrhoea, sweating, polyuria, extreme diuretic therapy and third-space losses (e.g. pancreatitis, bowel obstruction, peritonitis) → replace intravascular volume with normal saline
      • Give 20-40mL/kg normal saline
      • Gradually correct the dehydration and include daily maintenance amounts
      • Search for underlying cause
  • Anaphylaxis
    • Treat immediately with adrenaline 0.3-0.5mg (0.3-0.5mL of 1:1000 solution) IM plus normal saline 20mL/kg (see Airway Failure Management)
  • Septic Shock
    • Arrange a CXR and urinalysis/MSU as initial screens; make sure at least two sets of paired blood cultures from two different sites have been sent
    • Examine all areas of the skin looking for a source or entry sites including between the toes, skin folds, perineum, axillae and the ENT for localised infections
    • Consider toxic shock syndrome in any hypotensive premenopausal female particularly with blanching erythema like sunburn; ask about tampon use (now a rare cause)
    • Intravascular fluid resuscitation requires large volumes: up to 50-100mL/kg
    • Ensure Hb is maintained between 70 and 90g/L
    • Patients who are neutropenic (e.g. chemotherapy, diabetes, HIV, immunosuppressed) show few signs of sepsis
      • Give broad-spectrum antibiotics such as piperacillin 4g with tazobactam 0.5g IV plus gentamicin 4-7mg/kg
      • Add vancomycin 1.5 IV 12 hourly if line sepsis is possible
  • Other causes of hypotension
    • Tension pneumothorax
      • Do not wait for X-ray confirmation in an unstable patient
      • Call for senior assistance and get a 14-16G cannula ready to insert into the second intercostal space in the midclavicular line on the affected side
      • Will result in immediate improvement in blood pressure if done properly
      • Follow with insertion of a chest tube
    • Cardiac tamponade
      • Suspect when elevated JVP, hypotension and soft heart sounds (Beck’s triad) with agitation related to intracerebral venous congestion
      • Urgent bedside ultrasound now best confirms the diagnosis
      • Most commonly follows penetrating trauma or is non-traumatic in a patient with chronic renal impairment, malignancy, connective tissue disorders
        • Traumatic → requires immediate surgery
        • Pericardiocentesis with insertion of a catheter into the pericardial sac and aspiration of fluid should result in immediate improvement in non-traumatic cases
    • Massive pulmonary embolism
      • Sudden hypotension, elevated JVP and cyanosis accompanied by additional evidence of acute RV overload such as RV heave, loud P2, right sided S3 or mumur of tricuspid insufficiency
      • See PE management
    • Drug toxicity
      • Common drugs causing hypotension: GTN, vasodilators, opioids, sedatives, antiarrhythmics, beta-blockers, calcium channel blockers and ACE inhibitors
      • Place the patient flat, elevate the legs and give 5-10 mL/kg IV of normal saline to support the BP until the effect of the drug wears off
      • Bradycardia and hypotension from excessive narcotic are reversed by naloxone hydrochloride 0.1-0.2 mg IV, SC or IM every 5 minutes repeated until alert
      • Reduce the dose or alter the schedule of the opioid
    • Vasovagal syncope
      • Usually normotensive by the time you arrive but will still fell nauseated and miserable
      • Warn the patient of continuing to feel faint for several hours afterwards
      • Look for a precipitating stimulus such as pain or exposure to blood with prodromal light-headedness and sweating
      • Ensure no underlying exacerbating factors (e.g. dehydration, infections) as there is no specific treatment

Complications

  • Be wary of post-shock complications over the next few days in hypotensive patients who are successfully resuscitated
    • Multiorgan failure, thrombotic stroke, watershed cortical infarction, diffuse myocardial injury, acute tubular necrosis, hepatic necrosis, bowel ischaemia or infarction

Sources

  1. FRCEM AFTBAFFF, FFSEM MCMMbcF, FACEM ACMMc. Marshall & Ruedy’s On Call: Principles & Protocols. 3rd edition. Elsevier; 2016. 648 p. 157
  2. Common reasons for review lecture Pre-internship teaching 2024

Footnotes

Footnotes

  1. According to On Call ↩

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