ICU Basics

First five minutes

New Hypotension Algorithm

Confirm it, check perfusion, sort the cause, act while you call

Reviewed by Alex G, BSN, RN, CEN, CCRN, CMC, NREMT-P · From the Reference tab of the app

Each step lists what to do, then the choices that lead on. In the app the algorithm is tapped through one decision at a time.

1 Look at the patient: is there a pulse?

  • Feel for a central pulse and look at the patient: awake, breathing, color; do not treat the monitor alone
  • Call for help: the charge nurse and the provider; rapid response team outside the ICU
  • Monitor, SpO₂ and a cuff cycling every 3–5 min; oxygen if SpO₂ is under 92%
  • At least one working large-bore IV; IO if none

No pulse → step 2Pulse present → step 3

2 No pulse: start CPR

  • Call a code; start compressions; pads on
  • Follow the Adult Cardiac Arrest algorithm: an organized rhythm without a pulse is PEA
  • Look hard for the cause: bleeding, tension pneumothorax, tamponade, PE, high potassium, drugs

End of this path.

3 Is the low reading real?

  • Cuff: correct size (too large reads low), arm at heart level; repeat it, or try the other arm
  • Arterial line: level the transducer to the phlebostatic axis (4th intercostal space, mid-chest) and zero it; set too high, it reads low
  • Fast-flush square-wave test: a damped trace (slurred upstroke, no notch) reads systolic falsely low; MAP holds up best
  • A level, zeroed line that passes the square-wave test is usually more accurate than a cuff at low pressures

Real: MAP under 65, SBP under 90, or SBP 40 below the usual → step 4Not real: corrected by the cuff, leveling, zeroing or flushing → step 5

4 Check perfusion and mental status

  • Mental status: new confusion, agitation or drowsiness
  • Skin: cool, mottled, capillary refill over 3 s (low flow), or warm and flushed (vasodilated)
  • HR and rhythm, RR and SpO₂; urine output over the last 1–2 hours
  • Send lactate, CBC, BMP, type and screen; 12-lead ECG; fingerstick glucose if mentation has changed
  • Any sign of poor perfusion is shock: get the provider (or rapid response) to the bedside now

Next: first moves while you call → step 6

5 False low reading: fix the line

  • Overdamped: straighten the wrist and tubing, remove air, aspirate and flush clots, pressure bag at 300 mmHg
  • Re-level after every bed or position change; zero again after any disconnection
  • Line still unreliable: go by the cuff MAP and the patient, and tell the provider (it may need replacing)
  • Recheck BP in 15 minutes and trend it

End of this path.

6 First moves while you call

  • Passive leg raise as a test: from head-up 45°, lay the trunk flat and lift the legs to 45°; not with raised ICP or if breathless
  • Stroke volume or cardiac output up 10% or more within 1–2 min predicts a fluid response; a BP rise is a weaker sign
  • Check every drip and the meds of the last few hours: pressor stopped or line blocked? Sedative, opioid or BP drug started or raised?
  • No crackles, JVD or known overload: fluid bolus per order, 500 mL balanced crystalloid over 10–15 min (250 mL in heart failure)
  • MAP under 50 or falling fast: ask for a push-dose pressor or norepinephrine now, alongside the fluid

A drip or recent drug explains it → step 7No drug cause found: sort the cause → step 8

7 Drug-induced hypotension

  • Stop or turn down the culprit per order or protocol: propofol, dexmedetomidine, opioids, nicardipine, esmolol, nitroglycerin, diltiazem
  • A pressor that stopped (empty bag, paused pump, blocked or infiltrated line): restart it now and check the site
  • Hold the next doses of antihypertensives, diuretics and sedatives until the provider reviews them
  • Opioid with slow breathing or pinpoint pupils: naloxone 0.04–0.4 mg IV, titrated to breathing
  • Rash, wheeze or swelling after a new drug, contrast or blood: stop it; epinephrine 0.3–0.5 mg IM (Anaphylaxis algorithm)

MAP back to target → step 9Still low, or no drug explains it → step 8

8 Which picture fits?

  • Neck veins or CVP: low (empty tank or vasodilated) or high (pump failure or obstruction)
  • Skin: cool and clammy (low flow) or warm and flushed (vasodilated)
  • Lungs: crackles (pump failure), one side silent (pneumothorax), wheeze (anaphylaxis)
  • The last 24 hours: surgery or procedures, drains, anticoagulants, fever, chest pain, new drugs

Fluid or blood loss: flat veins, cool skin, losses or bleeding → step 10Vasodilated: warm, fever, rash or wheeze → step 11Heart: HR under 50 or over 150, chest pain, ECG changes, crackles → step 12Obstruction: JVD with clear lungs, one side silent, sudden hypoxemia, air trapping → step 13

9 Report (SBAR) and keep reassessing

  • S: BP and MAP now and when it fell, HR and rhythm, what you have given and the response
  • B: diagnosis, procedures and new drugs today, usual BP, fluid balance, anticoagulants, code status
  • A: mental status, skin and capillary refill, urine mL/h, SpO₂ and RR, lactate and Hgb; the cause you suspect
  • R: bedside review; orders for fluid, blood, pressor, labs, ECG or imaging; an agreed MAP target
  • Vitals every 5–15 min; escalate if MAP stays under 65, lactate rises, or mentation or urine output worsens

End of this path.

10 Hypovolemia or bleeding

  • Look for blood: dressings, drains, chest tubes, line sites, NG, stool; flank or back pain after femoral access suggests retroperitoneal bleeding
  • Bleeding: firm pressure; CBC, coagulation, fibrinogen, type and crossmatch; call the surgeon or proceduralist
  • Hold anticoagulants and antiplatelets and ask about reversal; ongoing bleeding with shock: blood, not crystalloid, and the massive transfusion protocol
  • No bleeding (diuresis, vomiting, diarrhea, drains): balanced crystalloid in 500 mL boluses, reassessing after each

MAP back to target, perfusion better → step 9Still low → step 14

11 Vasodilated: sepsis, anaphylaxis and others

  • Hives, wheeze, swelling or stridor after a drug, contrast or blood: stop it; epinephrine 0.3–0.5 mg IM, mid-outer thigh (Anaphylaxis algorithm)
  • Infection likely: lactate, blood cultures, then antibiotics within 1 hour; 30 mL/kg balanced crystalloid within 3 hours, reassessing as you go
  • Recent epidural or spinal dose: stop the infusion, check the block level, call anesthesia
  • Steroid-dependent, or shock not responding to fluid and pressors: ask about hydrocortisone 100 mg IV (adrenal crisis)

MAP back to target → step 9Still low → step 14

12 Heart: rhythm, ischemia or pump failure

  • HR under 50 with poor perfusion: atropine 1 mg IV and pacing pads on (Bradycardia algorithm)
  • HR over 150 from the rhythm with poor perfusion: synchronized cardioversion (Tachycardia algorithm); sinus tachycardia is a response, not the cause
  • 12-lead ECG and troponin; ST elevation: activate the cath lab (STEMI algorithm)
  • Crackles (LV failure): no fluid bolus; norepinephrine first, then an inotrope per the team; urgent echo; call cardiology

MAP back to target → step 9Still low → step 14

13 Obstruction: tension, tamponade, PE, air trapping

  • Tension pneumothorax: one side silent, high airway pressures; the provider decompresses now at the 4th–5th intercostal space, anterior to the mid-axillary line
  • Tamponade: muffled heart sounds, JVD, pulsus paradoxus; after heart surgery, chest tube output that suddenly stops; echo now, surgeon or cardiology to drain it
  • Massive PE: sudden hypoxemia, tachycardia, clear lungs, big RV on echo; limit fluid to about 500 mL; ask about lytics or the PE team
  • Ventilated with air trapping (asthma, COPD): disconnect briefly and watch the BP rise, then a lower rate
  • Norepinephrine holds the MAP only while the cause is being fixed

Relieved, MAP back to target → step 9Still low → step 14

14 Still low: vasopressor per order

  • Bridge per order: epinephrine 10–20 mcg or phenylephrine 50–100 mcg IV push every few minutes (no phenylephrine with slow HR or pump failure)
  • Norepinephrine first (epinephrine in anaphylaxis): start 2–12 mcg/min, titrate 1–2 mcg/min every 5 min to the ordered MAP (usually 65)
  • A peripheral start is acceptable short term: large proximal arm vein, site checked often; arterial line next
  • Escalate: intensivist or rapid response to the bedside; ICU bed if outside the ICU

Next: report and reassess → step 9

Drugs in this algorithm

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