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The Airway LedgerRespiratory device review

An independent trade magazine on single-use respiratory, anaesthesia and critical care devices

Respiratory, anaesthesia and critical care devices, explained

Respiratory care and anaesthesia devices, explained. Each guide covers how a device is built, where it sits in the circuit and what the clinician checks at the bedside.

Start with breathing circuitsBubble CPAP at the cot side

A clinical engineering bench with coiled clear breathing tubes, a Y-piece, filters and a water trap laid out under a bright lamp
The devices in these guides meet at the bedside: tubes, filters, traps and interfaces that carry and condition the gas a patient breathes.

Start with the sections

Three sections, from the circuit to the airway

Each section opens with an index of its guides. Pick the circuits and their condensate, the filters and humidifiers that condition the gas, or the interfaces that reach the patient.

  1. A clinical engineer's bench with coiled transparent corrugated breathing tubes, a Y-piece and a water trap laid out under a bright lamp.
    01

    Ventilation and Anaesthesia Circuits

    The tubes, connectors and traps that carry gas between the machine and the patient: ventilator and anaesthesia circuits, heated wire tubing and water traps, read against ISO 5367 and the 22 mm connector standard.

    6 guides inside

  2. A row of small cylindrical breathing circuit filters and a humidifier chamber on a clinical supply shelf.
    02

    Filters and Humidification

    The devices that clean and condition inspired gas: heat and moisture exchangers, bacterial and viral filters, and active heated humidification, with the tests and standards behind their stated figures.

    6 guides inside

  3. A neonatal nasal CPAP interface with short prongs and headgear resting on a clean cloth.
    03

    Airway and Oxygen Delivery

    The interfaces that reach the patient: CPAP, BiPAP and NIV masks, bubble CPAP for newborns, nebulizer kits for aerosol delivery, and catheter mounts with closed suction.

    7 guides inside

Section 1 of 3

Ventilation and Anaesthesia Circuits

The tubes, connectors and traps that carry gas between the machine and the patient: ventilator and anaesthesia circuits, heated wire tubing and water traps, read against ISO 5367 and the 22 mm connector standard.

  • A neonatal ventilator circuit with two slim limbs and a small Y-piece connected to a test lung on an ICU trolley.

    Ventilation and Anaesthesia Circuits

    Ventilator Breathing Circuits

    How adult, paediatric and neonatal ventilator breathing circuits differ in tube size, compliance, water traps and connections under ISO 5367.

    Adult, paediatric and neonatal limbs and why the size matters.

  • Close view of a corrugated heated wire breathing tube with water droplets collecting in its dependent loop.

    Ventilation and Anaesthesia Circuits

    Heated Wire Breathing Circuits

    Why heated wire circuits form condensation, how tube and room temperature interact, and the checks that keep rainout out of the airway.

    Warm the tube wall and the water stays in the gas.

  • An anaesthesia machine in an operating theatre with a circle system, soda lime canister and reservoir bag in view.

    Ventilation and Anaesthesia Circuits

    Anaesthesia Breathing Circuits

    How circle and Mapleson anaesthesia breathing systems work, what soda lime does, and how circuits are chosen for adult and paediatric cases.

    The circle system, its valves and the soda lime canister.

  • A transparent water trap on a ventilator circuit partly filled with clear condensate, held in a gloved hand.

    Ventilation and Anaesthesia Circuits

    Water Traps in Breathing Circuits

    What breathing circuit water traps collect, how double traps manage condensate, and how to empty and check them without breaking the circuit.

    Catch the condensate before it reaches the airway.

  • A kitchen table under a warm lamp at night, a printed itemised hospital statement spread flat with a pen resting on the column of CPT codes, a pair of reading glasses and a phone calculator at the edge of the frame, shot from slightly above.

    Ventilation and Anaesthesia Circuits

    Reading a Detailed Hospital Bill: Codes and Dates

    What an itemised hospital statement contains, how CPT codes map to services, and how to check dates of service before paying or disputing a charge.

  • A general practitioner's consulting room in daylight: a desk with a blood pressure cuff, a stethoscope and a printed laboratory report, an empty chair facing the doctor's chair, window light from the left, medium shot at desk height.

    Ventilation and Anaesthesia Circuits

    Symptoms and Prevention: What Patients Read First

    How general medicine information sites frame common symptoms, screening and prevention, and the practical signs that mean a consultation should not wait.

Open the Ventilation and Anaesthesia Circuits index

Section 2 of 3

Filters and Humidification

The devices that clean and condition inspired gas: heat and moisture exchangers, bacterial and viral filters, and active heated humidification, with the tests and standards behind their stated figures.

  • A hygroscopic heat and moisture exchanger filter held beside a ventilator Y-piece in a gloved hand.

    Filters and Humidification

    Heat and Moisture Exchanger Filters

    How HME filters recover heat and moisture, the hygroscopic, hydrophobic and combined types, and how tidal volume changes their efficiency.

    Passive humidification, and its limits at high tidal volume.

  • Two breathing circuit filters on a bench, one straight and one angled, with the pleated filter media visible.

    Filters and Humidification

    Bacteria and Viral Filters

    What bacterial and viral filters capture in a breathing circuit, how electrostatic media work, and where filters sit to protect patient and machine.

    What the filter captures, and where it sits to do it.

  • A heated humidifier base with a water chamber and a temperature probe on a ventilator stand.

    Filters and Humidification

    Humidification in Invasive Ventilation

    Active heated humidification against passive HMEs: target temperature, condensation risk and the checks that keep inspired gas conditioned.

    Active against passive, chosen per patient.

  • A small shop entrance at mid-morning, a laminated notice taped at eye level on the glass door, hand sanitiser bottle on a bracket beside the handle, daylight from the street, shot straight on from the pavement.

    Filters and Humidification

    Infection Control in Shops and Small Premises

    A practical starting point for small shops: written staff rules, a notice customers actually read, and the records that hold up when an inspector asks.

  • A circle of empty chairs in a bright community hall, late afternoon light from tall windows falling across the floor, wide shot from standing height.

    Filters and Humidification

    Family Constellations: Session, Method, Critique

    A plain account of what happens in a family constellation session, how practitioners describe the method and how critics and researchers assess it.

  • Late afternoon light through a tall window in a single care-home bedroom, a wooden bedside table with a framed photograph and a glass of water, bed neatly made, camera at seated eye level.

    Filters and Humidification

    Care Homes Near Aubenas: Daily Life, Admission, Costs

    How a care home near Aubenas works: daily life, the admission file, French fees, APA and social aid, and what families check before signing.

Open the Filters and Humidification index

The bench in pictures

Five views from the guides

Five photographs from the guides below, each with the page that explains the scene in full.

  • A neonatal ventilator circuit with two slim limbs and a small Y-piece connected to a test lung

    Field note 1

    Circuits sized to the patient

    Adult, paediatric and neonatal limbs differ in diameter and compliance, and in small patients that decides whether the set volume reaches the lungs.

  • A row of small cylindrical breathing circuit filters and a humidifier chamber on a clinical supply shelf

    Field note 2

    Filters that condition and clean

    An HME returns heat and moisture from the breath, and the same device often removes particles. Its efficiency falls as tidal volume rises.

  • An oronasal NIV mask and headgear laid on a hospital bed beside a tubing connector

    Field note 3

    The interface is the therapy

    Pressure that leaks around a mask does not reach the airway, so fit and leak are checked as carefully as the machine setting.

  • A transparent water trap on a ventilator circuit partly filled with clear condensate

    Field note 4

    Where the condensate goes

    Warm gas cools in the limb and gives up its water. A trap at the lowest point keeps that liquid out of the airway.

  • A small jet nebulizer chamber fitted into a ventilator circuit near the Y-piece, with mist inside

    Field note 5

    Getting the drug to the lung

    Nebulizer type, circuit position and bias flow decide how much of an aerosol dose actually reaches the patient.

Section 3 of 3

Airway and Oxygen Delivery

The interfaces that reach the patient: CPAP, BiPAP and NIV masks, bubble CPAP for newborns, nebulizer kits for aerosol delivery, and catheter mounts with closed suction.

  • An oronasal NIV mask and headgear laid on a hospital bed beside a tubing connector.

    Airway and Oxygen Delivery

    CPAP, BiPAP and NIV Masks

    How CPAP, BiPAP and NIV interfaces differ, what mask fit and leak mean for therapy, and how to judge an interface at the bedside.

    Seal, leak and skin: how an interface is judged.

  • A neonatal bubble CPAP setup with the expiratory limb submerged in a water bottle and small bubbles rising.

    Airway and Oxygen Delivery

    Bubble CPAP in Neonatal Care

    How bubble CPAP generates pressure through a water column, why the circuit must keep bubbling, and how humidification and prongs are managed.

    Pressure from a water column, and the checks it needs.

  • A small jet nebulizer chamber fitted into a ventilator circuit near the Y-piece, with mist inside.

    Airway and Oxygen Delivery

    Nebulizer Kits and Aerosol Delivery

    Jet, ultrasonic and vibrating mesh nebulizers, where to place a nebulizer in the circuit, and how bias flow and humidity change drug delivery.

    Placement and bias flow decide the dose.

  • A flexible catheter mount with a double swivel elbow attached to an endotracheal tube connector on a training manikin.

    Airway and Oxygen Delivery

    Catheter Mounts and Closed Suction

    What a catheter mount does between the circuit and the airway, how closed suction systems work, and how to keep the assembly light and swivel-free.

    Keep the circuit off the tube and suction in a sleeve.

  • A low wooden stool beside a rolled cotton cushion on a shaded veranda, morning light falling across bare floorboards, a small brass bell and a glass of water at the edge of the frame.

    Airway and Oxygen Delivery

    Breath Meditation for a Complete Beginner

    How to start breath meditation as a complete beginner, keep a daily practice going, and what a first multi-day retreat in Australia involves.

  • A close-up of a Dutch health insurance policy document and a physiotherapy referral letter on a wooden desk, with a pair of reading glasses and a pen, lit by soft daylight from a window.

    Airway and Oxygen Delivery

    Dutch Basic Insurance: Physiotherapy Coverage Explained

    How the Besluit zorgverzekering defines physiotherapy, which conditions are listed in annex 1 of article 2.6, and why the decree sets no amounts.

  • A pharmacy counter in the Netherlands in daylight, a small white box of diclofenac tablets and a tube of gel placed side by side on the counter, a pharmacist's hands in the background sorting a paper bag, shallow depth of field.

    Airway and Oxygen Delivery

    Diclofenac in the Netherlands: forms, dosage, safe use

    How diclofenac and other anti-inflammatory painkillers are used in the Netherlands: gel or tablet, 50 mg dosing, prescriptions and when to ask a pharmacist.

Open the Airway and Oxygen Delivery index

Elsewhere

Other independent publications

For readers who need the practical side of infection control in shops and workplaces, an independent magazine sets out how a small business infection control plan is built, sourced from WHO, ECDC and national health agencies.

For readers who want to follow a UK imaging examination from the clinician's written request through to the returned report, Inside the Scanner explains each step, including how an X-ray image, shadow is formed, what contrast agents do and which rules govern dose and justification.

For readers who want to know what the official labeling actually says, the guide at MedlinePlus drug page main sections walks through MedlinePlus pages, DailyMed label searches and Drug Facts boxes, and explains why patient star ratings carry little weight.

For readers weighing everyday sweating against clinical hyperhidrosis, a Dutch-language reference covers underarm, hand, foot and facial triggers, fabric and pad choices, plus how deodorants differ from antiperspirants: everyday sweating and hyperhidrosis.

A German-language magazine, Sina Vital covers everyday health and vitality through plain explanations of nutrition, sleep, stress regulation and accessible movement, aimed at adults without medical training who want practical markers and a sense of how strong the evidence is.

For readers comparing private addiction treatment in the United States, private drug treatment centers set out treatment by substance, levels of care, sober living, cost and confidentiality questions families ask before deciding.

For breeders and students of canine genetics, coat colour inheritance explains locus by locus how pigment is passed on, from Punnett squares and DNA panels to dilution alopecia and double merle risk.

For the neurological emergency that follows macrocyclic lactone exposure in Collies and related breeds, MDR1 sensitivity in dogs sets out the genetics, the toxicity signs and the emergency protocol.

Sources and standards

The documents behind these guides

The Airway Ledger writes from published material rather than from opinion. These are the standards, reviews and regulator pages the guides rely on, so you can read the originals for yourself.

  • External source

    ISO 5367:2023

    Anaesthetic and respiratory equipment, breathing sets and connectors: leakage, flow resistance and the designation of breathing tubes.

  • External source

    ISO 5367:2014

    The previous edition of the breathing sets standard, still cited by many product documents and regulatory summaries.

  • External source

    Bubble CPAP in Infants

    A clinical review of CPAP in neonates, including the physiology and the evidence for bubble CPAP in low resource settings.

  • External source

    FDA on reprocessed single-use devices

    How the United States regulator treats devices labelled for single use when a hospital or third party reprocesses them.

  • External source

    Humidification of ventilated patients

    A review comparing heated humidifiers with heat and moisture exchangers, their control systems and their limits.

  • External source

    HME humidification properties

    A modelling and measurement study of how much moisture different heat and moisture exchangers return per breath.