Everything you need to keep a patient alive and get them to the hospital — nothing else. The Basics is the four decisions, four settings and five numbers. The Protocol tab is the same thing as a flow chart: one box, one decision, read top to bottom.
Ventilation targets, starting settings and drug doses vary between services and are set by your medical director. This page is a general approach, not an order set — follow your own service protocol and online medical control, and where the two disagree, your protocol wins.
In this order. If you are reading nothing else on this page, read this.
If they are not breathing, or not breathing enough, put a bag-valve-mask on their face and squeeze. Two hands, good seal, one breath every 5 to 6 seconds. Nothing you do on the ventilator matters until this is working.
Tube them if they cannot protect their own airway, are not breathing on their own, or are failing BiPAP or CPAP. If they are awake, talking and moving air, try BiPAP first. If you are not sure — keep bagging and ask for help.
Assist-control volume control (A/C-VC). Then tidal volume, rate, PEEP and FiO2. Leave every other knob exactly where the machine put it.
SpO2 is about oxygen: turn FiO2 up or down. EtCO2 is about breathing: turn the rate up or down. Those two cover almost everything you will actually have to fix.
Assist-control volume control, and four numbers. Change nothing else until these are right.
Every breath is the size you set, at the rate you set. The patient can still trigger extra breaths on top of that.
Of predicted body weight — from height and sex, never the stretcher weight. For an average adult that is about 350 to 450 mL. Big breaths tear lungs.
16 to 20 is fine. Do not crank it up to catch up — blowing off too much CO2 drops the blood pressure.
Keeps the small air sacs from collapsing between breaths. Raise it only if the saturation will not hold on oxygen alone.
Start at 100%, then come down to the lowest number that keeps SpO2 at 92 to 96%. Never leave it at 100% just in case.
I:E 1:2, flow around 50 L/min, trigger −2. The defaults are what you want.
| Height | Male | Female |
|---|---|---|
| 5'0" | 300 mL | 270 mL |
| 5'4" | 360 mL | 330 mL |
| 5'8" | 410 mL | 380 mL |
| 6'0" | 470 mL | 440 mL |
| 6'4" | 520 mL | 490 mL |
Predicted body weight from height and sex, then 6 mL/kg. A child is dosed the same way from a weight chart — never from what the patient actually weighs.
Starting settings and tidal volume targets vary by service and by patient. Check them against the protocol you carry before you dial them in.
Five, and only the first two will send you to a knob.
Oxygen in the blood. A COPD patient at risk of retaining CO2 is held at 88 to 92% — enough oxygen, without pushing the CO2 up.
Breathing, measured at the airway. With a head injury keep it 35 to 40 — a high CO2 raises the pressure inside the skull.
The pressure it takes to push each breath in. Above 40, something is blocking the way — go to DOPE.
The pressure actually stretching the air sacs. Over 30 and you are injuring the lung.
Positive pressure squeezes the heart. If the pressure falls as you raise PEEP, that patient needs fluid — not a higher PEEP.
Two variables: oxygen for the saturation, rate for the CO2. Small steps, then look at the patient again.
Turn oxygen up in steps. If 100% still will not hold it, the problem is the tube or the chest, not the oxygen.
Wean in steps to the lowest FiO2 that holds the saturation — 21% if that is what it takes. Oxygen is a drug with a dose, and the wean costs nothing.
Slow or shallow breathing is the usual reason the CO2 is climbing.
You are blowing off more CO2 than the patient is making.
Do not turn anything up. Find out what is blocking the breath first.
Volume first. A dry patient cannot carry the pressure you are giving them.
The first move is always the same: take them off the ventilator and bag. It costs nothing, and it tells you whether the problem is the machine or the patient. Then work DOPE.
Look at the depth marking at the teeth and listen to both sides of the chest. If the tube moved, it is in the wrong place.
Suction the tube. Mucus, blood or a kink is the most common cause of a pressure that suddenly climbs.
One side with no air moving, and the blood pressure falling. Put a needle in that chest.
Take them off the ventilator and bag. If they get better on the bag, the machine was the problem.
Needle decompression, tube troubleshooting and when to escalate are set by your service. Follow the protocol and the procedures you are credentialed for, and call medical control early.
In plain words, and what to do about each one.
Tube, chest, or the patient coughing. Work DOPE.
Follow the circuit from the machine to the face and find the gap.
Turn FiO2 up first, then check the tube — in that order, because oxygen is free and fast.
The patient has stopped triggering. In a spontaneous mode — CPAP or pressure support — the machine will not breathe for them: bag, and switch to a mode with a set rate.
Look for a leak first, then the rate.
None of these are rare. All of them are avoidable.
Run a normal patient on the simulator and turn these four knobs until the numbers land where they should. No score, no case — just the machine and the patient.
Every number on this page is a published one. These are the sources it was checked against.
Four real destinations, not homepages. Start with the ICU OnePager if you only open one.
Every IBCC chapter in one list — the fastest route to the physiology behind any of these cases.
One page that separates a resistance problem from a compliance problem using PIP and Pplat.
Type 1 and type 2 respiratory failure, modes and how to optimise a patient's own breathing before tubing them. The free episode, not the members' course page.
Why lung protection starts on the first breath you deliver, not once the patient reaches a bed upstairs.