Breathing system

Absorbent granules provide heat and moisture, while exhaled gas is saturated with water at body temperature.

The nonrebreathing valve, PEEP valve, and circuit filter.

Cerebral blood flow increases proportionately with arterial CO2.

Poor control of inspired gas concentration, mechanical drawbacks during surgeries, and pollution of the operating room.

The relative location of components in breathing circuits to determine circuit performance.

It closes during bag compression, permitting positive-pressure ventilation and is refilled by flow through the fresh gas inlet.

It serves as a reservoir of anesthetic gas and a method of generating positive-pressure ventilation.

Ethyl violet.

Their simplicity and portability.

Supplemental oxygen.

Ventilation cannot be controlled, and the inspired gas contains unpredictable amounts of atmospheric air.

To prevent kinking or disconnection that could lead to significant rebreathing of exhaled gas.

It changes color to indicate absorbent exhaustion, signaling when to replace it.

It helps when children resist the placement of a face mask or intravenous line.

By the fresh gas flow required to reduce CO2 rebreathing to a negligible value.

A resuscitator contains a nonrebreathing valve.

It opens during controlled or spontaneous inspiration to allow gas flow from the ventilation bag to the patient.

By venting exhaled gas to the atmosphere through exhalation ports in the nonrebreathing valve.

Fresh gas flow forces alveolar air away, maintaining negligible circuit pressure.

A large diameter (22 mm) creates a low-resistance pathway and a potential reservoir for anesthetic gases.

To conserve absorption capacity and minimize the venting of fresh gas.

Amsorb has greater inertness, resulting in less degradation of volatile anesthetics.

It shifts to the right.

9–18 liters of CO2.

Warped disks or irregularities in the valve seat.

By incorporating a CO2 absorber and additional components to manage gas flow.

For example, 160 mL can be lost if the compliance is 8 mL gas/cm H2O at a pressure of 20 cm H2O.

Fresh gas flow forces alveolar air away from the patient and toward the APL valve.

With an absorber, it prevents rebreathing at low fresh gas flows or during closed-system anesthesia.

Rebreathing is minimal, making a CO2 absorber usually unnecessary.

Heat, water, and calcium carbonate.

Adequate fresh gas flow into the circuit and venting exhaled gas through the APL valve before inspiration.

Mapleson A.

Very high fresh gas flows (greater than three times minute ventilation).

Unconsciousness related to a fall in cerebrospinal fluid pH.

CO2 + H2O → H2CO3.

It conserves heat and humidity and has better control of anesthetic depth.

Equal to minute ventilation (≈ 80 mL/kg/min).

Minimal protection of the patient’s lungs against high airway pressures.

They act as check valves, allowing forward flow while preventing reverse flow.

Less than 90%.

Tachycardia and mild hypertension were noted despite high concentrations of sevoflurane.

End-tidal CO2 monitoring, pulse oximetry, or arterial blood gas analysis.

Between 4 and 8 mesh.

Ventilation cannot be controlled, and the inspired gas contains unpredictable amounts of entrained atmospheric air.

They are lightweight, inexpensive, and simple.

The part of tidal volume that does not undergo alveolar ventilation.

To eliminate CO2 from exhaled gas to prevent hypercapnia.

Rebreathing of CO2, which can lead to hypercapnia.

Relatively close to the patient to prevent backflow into the inspiratory limb.

The tube length does not affect dead space due to unidirectional valves.

It helps prevent the entrainment of room air.

Respiratory acidosis.

It avoids direct patient contact and prevents rebreathing of exhaled gases if the flow is high enough.

A by-product of the degradation of sevoflurane by absorbent.

Exhaled moisture.

By dripping a highly volatile anesthetic onto a gauze-covered mask applied to the patient’s face.

It lowers the mask temperature, resulting in moisture condensation.

Ether or chloroform.

2–3 × minute ventilation.

The drier it is, the more likely it will absorb and degrade volatile anesthetics.

They can confuse rather than aid understanding due to the consolidation of functional and physical characteristics.

Greater than 10 L/min.

It allows gases (anesthetics mixed with oxygen or air) to continuously enter the circuit from the anesthesia machine.

Pressure will rise, and gases may exit the circuit through the APL valve to control this pressure buildup.

To vent excess gases and control pressure buildup in the breathing circuit.

Rubber (reusable) or plastic (disposable).

To prevent fresh gas from bypassing the patient during exhalation and being wasted.

A CO2 absorbent consisting of calcium hydroxide and calcium chloride, with additives for increased hardness.

Nonrebreathing circuits that use ambient air as the carrier gas.

It should be at least as great as the patient’s tidal volume.

It allows for the adjustment of pressure within the breathing system.

Higher concentrations of sevoflurane, prolonged exposure, and low-flow anesthetic techniques.

2 × minute ventilation.

2 × minute ventilation.

Hypoxia or hypercapnia.

It may allow rebreathing of carbon dioxide, resulting in hypercapnia.

It is directly proportional to the oxygen concentration and flow rate, and inversely proportional to the minute ventilation delivered to the patient.

It prevents rebreathing of CO2 at reduced fresh gas flows.

Greater size and less portability.

It opens during inhalation to allow the patient to breathe a mixture of fresh and exhaled gas that has passed through the CO2 absorber.

The expiratory valve opens, allowing gas to flow away from the patient, which can be vented through the APL valve or rebreathed after passing through the absorber.

Up to 23 liters.

Calcium hydroxide (80%).

1. CO2 absorber, 2) fresh gas inlet, 3) inspiratory unidirectional valve, 4) Y-connector, 5) expiratory unidirectional valve, 6) expiratory breathing tube, 7) APL valve, and 8) reservoir.

30% to 40%.

Fio2 is the fraction of inspired oxygen, directly proportional to the oxygen concentration and flow rate of the gas mixture supplied.

Due to safety concerns.

To prevent retrograde gas flow from the self-inflating bag.

The enclosed Magill system.

The combination of tachycardia and hypertension.

From white to purple.

It has a fresh gas tube inside the breathing tube.

Rebreathing of CO2 in the presence of low fresh gas flow.

Controlled ventilation and scavenging.

It avoids direct patient contact, preventing rebreathing of exhaled gases if the flow is high enough.

Carbonic acid.

It is crucial for understanding how anesthetic delivery is managed.

To reduce the risk of microorganism retention and potential respiratory infections.

The possibility of kinking or disconnection of the fresh gas inlet tubing.

It incorporates the fresh gas inlet tubing inside the breathing tube, reducing bulk and retaining heat and humidity better.

To assist in ventilation when compressed gases are not available.

In locations or situations where compressed medical gases are unavailable, such as battlefields.

Phase I: nominal capacity, Phase II: rapid pressure rise, Phase III: plateau or slight pressure decrease.

By observing the indicator dye color through the absorber's transparent walls.

1000 mL.

To maintain arterial oxygenation during brief periods of apnea.

A slow reaction.

It should be fully open to keep circuit pressure negligible throughout inspiration and expiration.

14% to 19%.

It allows air to pass through the gauze, vaporizing the liquid anesthetic and delivering it to the patient.

Scavenging is difficult.

Carbon dioxide accumulation under head and neck draping.

The patient should be disconnected from the anesthesia machine and ventilated with a resuscitation bag until repairs are possible.

Ohmeda Universal Portable Anesthesia Complete (U-PAC).

It decreases resistance by being located in the expiratory limb.

Concentrations can vary markedly between fresh gas and inspired gas.

Draw-over anesthesia, which depends on the patient’s inspiratory efforts to draw ambient air through a vaporization chamber.

It usually results in increased cardiac output, elevated arterial blood pressure, and a propensity toward arrhythmias.

High compliance can increase the difference between the volume of gas delivered and the volume actually delivered to the patient.

They result in waste of anesthetic agent, pollution of the operating room environment, and loss of patient heat and humidity.

It is a poor choice due to very high and difficult to predict fresh gas flows.

They increase their minute ventilation by about 2–3 L/min for each mm Hg rise.

They increase the difference between the volume of gas delivered to a circuit and the volume actually delivered to the patient.

Compliance is defined as the change of volume produced by a change in pressure.

Mapleson A design.

It can absorb and degrade them, potentially causing carbon monoxide poisoning.

They may revert to their original color, but no significant recovery of absorptive capacity occurs.

Fentanyl (3 mcg/kg).

3 × minute ventilation (I:E-1:2).