Chapter 10. Manual Resuscitators

8/11/2019 Chapter 10. Manual Resuscitators

1/32

Chapter 10

Manual ResuscitatorsIntroduction

Breathing systems that use nonrebreathing valves have largely disappeared from

anesthesia pract ice. However, these v alves are st i l l used in small portable manual

resuscitators, which are used primarily for patient transport, suct ioning, and

emergency si tuat ions. They can also be used to administer anesthesia. A manual

resuscitator may be adapted for use during magnetic resonance imaging (MRI) ( 1).

Manual resuscitators are also known as bag venti lators; bag-assist devices; bag-

type resuscitators; bag-valve devices, units, or resuscitators; bag-valve-mask units,

resuscitators, or venti lators; emergency manual venti lators; hand v enti lators; hand-

operated bag resuscitators; manual venti lators; hand-operated emergency

ventilators; hand- or operator-powered resuscitators; handbag resuscitators;

manual bag v enti lators; manually operated resuscitators; manual pulmonary

resuscitators; respiratory bags; resuscitator or resuscitat ion bags; self- inf lat ing

manual resuscitators; self- inf lat ing respirator bags or resuscitators; venti lator bags;

and self- inf lat ing bag-valve devices.

View Figure

Figure 10.1Manual resuscitators. Note the pressure-limiting mechanism near the nonrebreathing valve on the

smaller resuscitators. This can be overridden by placing afinger on top. Note also the air inlet and outflow valves

between the self-refilling bag and the reservoir. (Picturecourtesy of Hudson RCI.)

P.283


2/32

Examples of these devices are shown in Figure 10.1 . Disposable manual

resuscitators that avoid the inconvenience and hazards associated with

reprocessing and steri l izat ion a re commonly used. International and U.S. standards

for resuscitators have been published (2,3).

Components

A typic al man ual resuscita to r is shown diagr amma tic al ly in Figure 10.2. I t has a

compressible self-expanding bag, a bag inlet valve, and a nonrebreathing valve.

The bag inlet and nonrebreathing valves are combined in some units. Optional

components include a pressure-l imit ing device, oxygen-enrichment device, p osit ive

end-expiratory pressure (PEEP) valve, mechanism for scavenging, carbon dioxide

detector, and a port for measuring airway pressure.

Se lf - e x pand i n g B ag

The self-expanding bag (venti lat ing or venti lat ion bag, self- inf lat ing bag, s elf-

ref i l l ing bag, compressible unit , compressible reservoir) is constructed so that it is

inf lated in its rest ing state. Some bags collapse l ike an accordion for storage.

During exhalat ion, the bag expands. I f the volume of oxygen from the delivery

source is i nadequate to f i l l the bag, the dif ference is made up by room air. The rate

at which the bag reinf lates wil l determine the maximum minute volume.

Non r eb r e at h i n g Va l v e

The nonrebreathing valve is sometimes called the direct ional control v alve,

exhalat ion valve, expiratory v alve, inf lat ing valve, inhalat ion-exhalat ion valve,

inf lat ing-exhalat ion valve, inspiratory-expiratory valve, nonreturn valve, patient

valve, routing valve, or one-way inf lat ing valve. I t has a number of parts that

ensure that gas flows out of the bag and into the patient port during inspiration and

from the expiratory port without mixing with fresh gas during exhalat ion.

Body

Most nonrebreathing valves are T-shaped. It is preferable that the housing be

transparent so that the internal mechanism movement can be observed.

The expiratory port is the opening through which exhaled gases pass from the

patient to atmosphere. It may have a means to deflect exhaled gas (Fig. 10.3). A

PEEP valve may be connected at this point. The expiratory port may have a tapered

19- or 30-mm connector for attachment to a scavenging system transfer tube

(Chapter 13). The American Society for Testing and Materials (ASTM) s tandard (2)


3/32

requires that the connector for this port have a ridge (baulk) in its internal lumen so

that it cannot accept a 22-mm male connector.

The patient connector is the part that connects to a tracheal tube, face mask, or

supraglott ic device. I t has 15-mm female and 22-mm male coaxial f i t t ings. I t may be

designed to swivel.

The inspiratory port is the opening through which gas enters the valve from the

bag. It is usually permanently attached to the bag.

Unidirectional Valves

Unidirect ional valves direct the gases from the bag to the patient during inspirat ion

and exhaled gases from the patient to atmosphere. In order to accomplish this,

there are usually two valves. During inspirat ion, gas is directed from the bag to thepatient connection port. At the same t ime, the expiratory port is blocked. During

exhalat ion, the expiratory port is open, and the inspiratory port is blocked so that

the patient exhales to atmosphere. The valve may have a means to prevent air from

entering when the patient is breathing spontaneously so that the patient wil l inhale

gas only from the bag.

View Figure

Figure 10.2Components of a manual resuscitator. The

nonrebreathing valve directs the gas from the bag to the

patient during inspiration. During expiration, thenonrebreathing valve directs exhaled gases from the patientto atmosphere through the expiratory port, and the bag inletvalve opens to allow the bag to fill.

P.284

Sp r i n g - d i s c o r S p r i n g - b a l l V a l v e


4/32

Spring-disc valves are shown in Figures 10.4and 10.5. In Figure 10.4, a spring

holds the disc against the seat. When the pressure on the disc is great enough to

overcome the force of the spring, the v alve opens. As the pressure drops, the

spring causes the disc to close the valve. Some unidirect ional valves have a ball in

place of the disc. The ball or disc may be held in place by gravity rather than a

spring.

Figure 10.5shows a T-shaped valve with a spring disc that alternately blocks the

gas inlet or outlet. When the bag is compressed, the disc is pushed across the

valve, connecting the inspiratory port with the patient port

P.285

while, at the same time occluding the expiratory port. When the bag is released, the

disc moves back toward the bag and allows exhaled gas pass through the

expiratory port. A guide pin keeps the disc centered. I f the patient is b reathing

spontaneously, the disc wil l not close the exhalat ion port, and room air wil l be

inhaled.

View Figure

Figure 10.3The exhalation port may have a means todeflect the exhaled gas away from the operator.


5/32

View Figure

Figure 10.4Spring-disc unidirectional valve. In the closedposition, the spring holds the disc against the seat. When thepressure to the left of the disc increases above the pressureof the spring, the disc is forced away from the seat. Whenthe pressure to the left of the disc drops, the valve closes.

View Figure

Figure 10.5Spring-disc nonrebreathing valve. The disc isheld on the seat by the spring. When the bag is squeezed,the disc moves to the left, closing the expiratory port. At the

end of inspiration, the spring forces the disc to the right sothat the patient exhales to atmosphere and not into the bag.A guide pin keeps the disc in the center. A spontaneously

breathing patient can inhale room air unless a valve isplaced over the expiratory port to prevent air entrainment.


6/32

View Figure

Figure 10.6Edge-mounted flap unidirectional valve.Increased pressure upstream of the flap pushes the flapaway from the seat, opening the valve. When the pressuredownstream of the flap increases above the pressureupstream, the flap is forced back against the seat, blockingthe flow of gas.

F l a p Va l v e

The f lap (leaf) valve has a rigid or f lexible f lap that moves. The f lap may be f ixed to

the housing at the edge (Fig. 10.6) or the center (Fig. 10.7).

Figure 10.8shows a nonrebreathing valve that incorporates two f lap valves. During

inspirat ion, the center-mounted

P.286

flap valve moves to the right. The peripheral f lap v alve covers the exhalat ion port.

During exhalation, the flaps move to the left, preventing exhaled gas from re-

entering the bag, and the exhalat ion ports are uncovered. The peripheral f lap v alve

prevents inhalat ion of room air during spontaneous breathing.


7/32

View Figure

Figure 10.7Center-mounted flap unidirectional valve. Theflap valve is secured by a tab at the center. The tab issecured by a retainer, which is attached to the valve body.

View Figure

Figure 10.8Nonrebreathing valve with two flap valves.During inspiration, the center-mounted flap valve opens,and the peripheral flap closes over the exhalation ports.During exhalation, the central flap valve closes, and the

peripheral flap falls away from the exhalation ports. Thisvalve has an oxygen inlet and two bag inlet valves, which

open if the oxygen flow is not sufficient to prevent anegative pressure from developing in the space to the left.

F is hm o u t h V a lv e

The f ishmouth (duck-bil l) valve (Fig. 10.9) opens and closes l ike a f ish's mouth. As

pressure upstream of the valve increases, it opens at the slit in the center. An

increase in pressure downstream pushes the leaf lets together, closing the valve.

D i a p h r a gm -f l a p Va lv e


8/32

A diaph rag m-f lap valv e is shown in Figure 10.10. The diaphragm is attached at its

periphery. When the bag is squeezed, the diaphragm is pushed to the left and

occludes the expiratory port. Flap valves at the side of the diaphragm open,

allowing gas from the bag to f low to the pa tient. When inspirat ion ends, the

diaphragm returns to its rest ing posit ion and the f lap valves close, allowing the

patient to exhale through the expiratory port. A spontaneously breathing patient

may inhale room air through the exhalation port i f there is no f lap valve to block

ambient air from entering the valve.

View Figure

Figure 10.9Fishmouth unidirectional valve. As pressure tothe left increases, the leaflets open, allowing gas to flow

through the valve. An increase in pressure to the rightpushes the leaflets together, closing the valve and

preventing backflow of gas.


9/32

View Figure

Figure 10.10Diaphragm-flap nonrebreathing valve. Duringinspiration, when the bag is squeezed, the pressure to theright increases and the diaphragm is pushed to the left,closing the exhalation channel. At the same time, the flapsat the edge of the diaphragm open, allowing gas from the

bag to flow to the patient connector. When inspiration ends,

the diaphragm moves away from the exhalation channel andthe flaps close, blocking the inspiratory port.

View Figure

Figure 10.11Mushroom-flap valve. This valve contains amushroom-style diaphragm that is inflated when the

pressure in the pressure channel increases. This occursduring inspiration. When the mushroom is inflated, it blocks

the exhalation channel, allowing the lungs to be inflated.When the pressure inside the mushroom drops at the end ofinspiration, it opens the channel and allows the exhaledgases to pass out of the exhalation channel. The flap valve

prevents backflow of exhaled gases into the bag.

P.287

Mu s h r o o m - f l a p Va l v e

The valve i l lustrated in Figure 10.11combines one mushroom and two flap valves.

The inside of the mushroom is connected to a pressure channel. During inspirat ion,


10/32

the mushroom is inf lated against the seat, preventing f low of gas through the

expiratory port and the inhalat ional f lap opens. During exhalat ion, the inspiratory

flap valve prevents flow back into the bag. The mushroom collapses and opens the

exhalat ion channel. A f lap v alve over the expiratory port prevents room air from

being inhaled during spontaneous breathing.

View Figure

Figure 10.12Fishmouth-flap nonrebreathing valve. Thecircular flap and fishmouth valves are attached, around the

periphery. When the bag is squeezed, the flap valve isseated against the exhalation ports, and the fishmouth

portion of the valve opens. During expiration, the fishmouthcloses and the flap falls away from the exhalation channel.

A second flap valve over the exhalation ports prevents airfrom being inspired during spontaneous respiration.

F i s hm o u t h - f l a p V a lv eThe valve diagrammed in Figure 10.12and pictured disassembled in Figure 10.13

has one f ishmouth and two f lap valves. The f ishmouth and one circular f lap valve

are combined into one piece. The f lap valv es surround the central f ishmouth.

Outside the main valve body is another circular f lap valve. During inspirat ion, the

f ishmouth opens and the circular f lap valve closes the exhalat ion port. The outside

flap valve prevents room air from entering the valve during spontaneous breathing.

During exhalat ion, the f ishmouth section closes. The circular f lap valve attached to

it is l i f ted off the expiratory apertures, allowing exhaled gas to escape to

atmosphere.


11/32

View Figure

Figure 10.13Components of the fishmouth-flapnonrebreathing valve. Left:The patient connection with theexpiratory flap. Center:The fishmouth with its concentricflap. Right:The part of the housing closest to the bag.

P.288

B ag In l e t Va l ve

The bag inlet (ref i l l) v alve is a one-way valve that is opened by negative pressure

inside the bag. When the bag is squeezed, the valve closes. This p revents escape

of gas through the inlet. A simple f lap (Figs. 10.2, 10.7) or spring-disc valve (Fig.

10.4) is most commonly used. This valve is usually located at the opposite end of

the bag from the nonrebreathing valve but may be at the same end and may be

combined with the nonrebreathing valve.

P re s su r e -l im i t i n g Dev i c e

The pressure-l imit ing device (pressure relief device, v alve, or system; overpressure

limit ing system; overpressure valve; pop-off valve; pressure l imit ing s ystem)

protects against barotrauma and may prevent gases from entering the stomach

during manual ventilation (4).

A varie ty of dev ices hav e be en used . One is a spri ng -load ed disc , wi th the tension

on the spring adjusted so that it opens at the desired pressure. Another is a

magnetic device, with the force of the magnet adjusted to open at the desired

pressure. Some systems provide a small hole. The maximum pressure depends on

the size of the hole and how f irmly the bag is compressed. In order to override the


12/32

device, it is usually necessary to place a f inger over the outlet (Fig. 10.1). An

override mechanism may cause confusion (5).

For adult resuscitators, the ASTM standard requires that if there is a device that

l imits the pressure to below 60 cm H2O, there must be an ov erride mechanism (2).

I f the override mechanism can be locked, i t must be designed so that the operating

mode (ON or OFF) is readily apparent to the user. It recommends that if a

resuscitator is equipped with a pressure-l imit ing device, there should be an audible

or visible warning to the operator when the pressure l imit ing device is operat ing. I t

also requires that with a pressure l imit ing device set at a f ixed pressure, that

pressure must be marked on the resuscitator.

The ASTM standard (2) requires a pressure-l imit ing system for infant and child

resuscitators, with an opening pressure of 45 cm H2O and an option for an override.

The means that to c reate a higher inf lat ion pressure is especially important in a

resuscitator designed for infants, because the f irst few breaths may require

pressures as high as 50 to 70 cm H 2O. The pressure needed to overcome flow

resistance in a narrow tracheal tube and to expand the st if f lungs of a premature

infant may exceed 30 to 40 cm H 2O. It is recommended that a manometer be used

with neonatal resuscitat ion devices, because using these resuscitat ion devices can

be associated with extremely high inspiratory pressures (6).

Oxyg en -e n r i c hm en t Dev i c e

Mechanisms to increase the i nspired oxygen concentrat ion above that of room a ir

are present on nearly all resuscitat ion devices.

Oxygen Delivered Near the Bag Inlet Valve

Tubing from an oxygen f lowmeter attached near the bag inlet valve is a simple

means of increasing the concentrat ion of oxygen in the bag. The oxygen does not

enter the bag direct ly. The increase in oxygen concentrat ion is l imited because air

can be drawn into the bag. The delivered oxygen concentrat ion can be increased by

increasing the oxygen f low, but this is of l imited value. The higher the minute

volume and the greater the inspiratory:expiratory (I :E) rat io, the l ower the delivered

oxygen concentration.

Oxygen Delivered Directly into the Bag

Oxygen can be delivered direct ly into the resuscitat ion bag. This method wil l result

in high delivered oxygen concentrat ions without making the resuscitator

cumbersome. However, provision must be made for venting excess oxygen to


13/32

minimize the danger of the nonrebreathing valve locking in the inspiratory posit ion.

I f the oxygen f low is less than the bag f i l l ing rate, the bag inlet valve wil l open and

admit air.

Reservoir

Most units have a reservoir (accumulator) in which oxygen is stored when the bag

is not f i l l ing. I t may be a tube or a bag. When the resuscitat ion bag inlet valve

opens, oxygen from the reservoir enters the bag. In general, resuscitators with

reservoir bags provide a higher fract ion of delivered oxygen than resuscitators with

tubing reservoirs (7). The size of the reservoir may limit the oxygen concentration

delivered. I f the volume of the reservoir is less than that of the bag, the inf lowing

oxygen may not be suff icient to make up the dif ference, and room air wil l b e drawnin. On the other hand, a large reservoir makes a resuscitator more cumbersome.

Op e n Re s e r v o i r

Open reservoirs are shown in Figures 10.14( left ) and 10.15. A piece of corrugated

tubing or other material open to atmosphere is placed l ike a sleeve around the bag

inlet valve. I f the oxygen f low is high, oxygen wil l f low into a tmosphere at the open

end of the reservoir. I f the oxygen f low is low or the reservoir is smaller than the

tidal volume, air wil l be drawn into the bag along with the oxygen. The highest

possible concentrat ion of ox ygen wil l be administered if the reservoir is large andthe oxygen f low is g reater than the minute volume.

View Figure

Figure 10.14Left:A resuscitator with an open reservoir.Right:One with a closed reservoir.

P.289


14/32


15/32

Tidal volume wil l be increased when a two-handed technique is used. Grip strength

is the best predictor of delivered volumes and is more important when the t idal

volume is delivered by a one-hand technique (20). Tidal volume may be increased

by compressing the bag against a solid s urface such as a thigh or the operating

room table. Another method to increase the tidal volume is to compress the bag

between the open palm and body (21 ).

The respiratory rate may be l imited by how fast the bag re-expands, which depends

on the bag construct ion and the size of the bag ref i l l valve inlet. The maximum

compression rate may be reduced at low temperatures (13,22,23 ).

De li v e r ed Oxyg en Conc en t r a t i o n

The ASTM standard (2) requires that a resuscitator for adults be capable of

delivering an inspired oxygen concentrat ion of at least 40% when connected to an

oxygen

P.290

source supplying not more than 15 L/minute and at least 85% with an oxygen-

enrichment device supplied by the manufacturer.

View Figure

Figure 10.15Open reservoir. A:The bag is filling. Oxygenfrom the delivery tubing as well as that in the reservoirflows into the bag. If the volume entering the bag exceedsthat in the reservoir and flowing through the deliverytubing, room air will make up the difference. The size of thereservoir is, therefore, important. B:The bag inlet valve isclosed. Oxygen from the delivery tubing flows into thereservoir. Because the reservoir is open to atmosphere,some oxygen will be lost if the flow is high.


16/32

The delivered oxygen concentrat ion is l imited by reservoir size and the oxygen f low

(7). I f the volume of the reservoir is greater than the volume of the bag and the

oxygen f low is greater than the minute volume, the delivered ox ygen concentration

may approach 100%. If the t idal volume is greater than the reservoir volume plus

the volume of oxygen delivered during inspirat ion, air wil l be drawn into the unit

and reduce the delivered oxygen percentage (24).

Controlled Ventilation

The delivered oxygen concentrat ion wil l be determined by the minute volume, the

size of the reservoir ( i f present), the oxygen f low, and the technique used to

squeeze and release the bag (25 ). I f the bag is allowed to f i l l at i ts most rapid rate,

all of the oxygen in the reservoir may be exhausted and air drawn in. I f bag f i l l ing ismanually retarded, the delivered oxygen concentrat ion wil l be higher (8). This may

be useful when low oxygen flows must be used or when the reservoir is small or not

present, but it l imits the respiratory rate that can be achieved. Furthermore, it may

cause the nonrebreathing valve to jam in the inspiratory posit ion. Activat ing the

pressure-l imit ing device may cause the delive red oxygen concentrat ion to decrease

(26).

Spontaneous Ventilation

With spontaneous venti lat ion, inspired gas may come from the exhalat ion port aswell as the bag. The inspired oxygen concentration can vary f rom 25% to 100%

(24,27). Bags with f ishmouth valves are associated with low inspired oxygen

concentrat ions (24 ,28,29 ).

Reb r ea t h i n g

I f the nonrebreathing valve is competent, inhaled and exhaled gases should not

mix. I f the valve is incompetent, a back leak wil l al lo w exhaled gases to pass back

into the resuscitator.

UseA bag and mask that are the ap pro pri ate s ize fo r the pa ti en t shou ld be sele cte d.

For adults, an oxygen f low of 10 to 15 L/minute is most commonly used. For

children and infants, lower flows are recommended. Higher flows than those

recommended by the manufacturer can result in significant levels of auto-PEEP

(30).

I f anesthetic gases are to be administered, the transfer tube (Chapter 13) from a

scavenging system should be attached to the expiratory port.


17/32

A ma nu al re susc ita tor can be adapted for ma nu al vent i lat ion duri ng MR I by

insert ing an extension tube that is long enough to cover the distance between the

patient and the person squeezing the bag between the nonrebreathing valve and

the bag (1). An extension must not be placed between the patient and the

nonrebreathing valve, as this wil l cause the dead space to be increased.

Hazards

H ig h A i r w a y P r e s s u r e

High airway pressure is a hazard mainly if the patient is intubated. A dangerously

high pressure is less l ikely when a mask or supraglott ic device is used.

View Figure

Figure 10.16Closed reservoir. Top:The reservoir is full,and the pressure increases. Oxygen flows through theoverflow valve. B:The resuscitator bag is filling. Becausethere is insufficient gas in the reservoir, air enters throughthe intake valve.

P.291

Nonrebreathing Valve Sticking in the Inspiratory Position

I f the nonrebreathing valve st icks (locks up, jams) in the inspiratory posit ion, the

patient wil l be at tempting to exhale against a c losed outlet, and continued inf low

wil l quickly cause a continuous and dangerous increase in pressure. A variety of

other condit ions can cause this, including interrupting manual venti lat ion for

observation of spontaneous respiratory efforts, manually restrict ing bag ref i l l , the

valve becoming contaminated with foreign material, a small squeeze or bump on the

bag causing the valve to lock up, coughing, improper assembly, attaching an

oxygen inlet nipple without vent holes direct ly to the resuscitator, fai lure of the


18/32

expiratory f lap valve to open, and a kink in the reservoir tai l

(31,32,33,34 ,35 ,36,37 ,38 ,39,40 ,41 ).

High Oxygen InflowThe ASTM resuscitator standard (2) requires that the valve not jam at an input f low

of up to 30 L/minute. Infant resuscitators are especially prone to obstruct ion with

high f lows because the bag is so small. A case has been reported in which the

pressure monitoring port was connected to an oxygen source (11). This distorted

the inspiratory valve and resulted in excessive pressure.

Asynchrony between Patient Exhalation and the Demand

Valve

Manually act ivat ing a demand valve while the patient is exhaling can cause

dangerously high pressures (8).

Pressure-limiting Device Failure

Pressure-l imiting devices often malfunction, opening well above an acceptable

pressure (26 ,42,43 ).

Excessive Resistance

Resuscitators with high resistance can expose the patient with high expiratory f lows

to acute airway pressure elevations (44 ).

Reb r ea t h i n g

Rebreathing exhaled gases can occur if the valve on the inspiratory l imb from the

bag is not competent or is improperly assembled (45 ,46 ). The f ishmouth valve can

become unseated, allowing rebreathing and/or insufficient pressure during

inspirat ion (47 ). Extension tubing should not be added between the patient and the

valve.

Hypo v e n t i l a t i o n

Studies show that it is more dif f icult to achieve satisfactory venti lation with a

resuscitat ion bag and face mask

P.292

than with a supraglottic airway device or Combitube (48,49 ).

A def ec t ive non reb rea thing valve may hav e forward leak , so durin g ins pirat io n part

of the volume expelled from the bag escapes through the expiratory port (45,50,51 ).

Unrecognized venting through the pressure relief device may result in


19/32


20/32

During spontaneous v enti lat ion, the patient may inhale room air from the expiratory

port as well as oxygen-enriched gas f rom the bag. The inspired oxygen

concentrat ion can vary from 25% to 100% (24,27).

H i gh Res i s t a n ce

Some nonrebreathing valves offer high resistance to f low s o that high negative

pressures must be generated during spontaneous venti lat ion (24 ,27 ,44). The work

of breathing may be quite high.

Con t am i n a t i o n

Because these devices are of ten used on patients who have respiratory infect ions,

they f requently become contaminated (72 ,73 ,74 ). Oxygen f lowing through the valve

may aerosolize bacteria and spread them into the surrounding air. For these

reasons and because these devices are dif f icult to clean, disposable units have

become popular. Bacterial/viral f i l ters (Chapter 7) may be used.

In h a la t io n o f F o r e i g n Bod i es

Part of the inside of the bag or parts of the nonrebreathing valve may break off and

be inhaled (75,76 ).

Checking Manual Resuscitators

Before use, the resuscitat ion bag should be visually inspected for signs of wear

such as c racks or tears. After the bag has been inspected, it should be checked for

leaks. The patient port should be occluded and the bag squeezed. Pressure should

build up rapidly to a point at which the bag can no longer be compressed. I f there is

a pressure l imit ing device, it c an be checked by connecting a pressure manometer

between the patient port and the bag by using a T-f it t ing. I f there is an override

mechanism on the pressure l imit ing device, this should be checked. This check also

determines that the ref i l l valve wil l close when the bag is squeezed.

To check that the bag ref i l l valve opens, the b ag should be squeezed, then thepatient port occluded and the bag released. The bag should expand rapidly.

I f the resuscitator has a closed reservoir, i ts function can be checked by performing

several compression-release cycles with no oxygen flow into the reservoir. The

reservoir should deflate, but the resuscitat ion bag should continue to expand.

A re serv oi r bag f rom a bre athing sys tem is plac ed ov er the patient po rt. Squeezin g

the resuscitat ion bag should cause the reservoir bag to inf late. After the reservoir

bag has become fully inf lated and the resuscitat ion bag has been released, the bag

should deflate easily. This


21/32

P.293

tests the inspirat ion and exhalat ion parts of the v alve and the exhalat ion pathway

for patency. The reservoir bag should deflate easily.

Advantages

The equipment is inexpensive, compact, lightweight, and portable yet rugged.

The equipment is easy to use.

The equipment is simple with a s mall number of parts. Disassembly and

reassembly are usually easily p erformed.

Dead space and rebreathing are minimal if the nonrebreathing valve

functions properly.

With proper attention to the oxygen-enrichment device, oxygen f low, and

venti lat ion technique, it is possible to administer close to 1 00% oxygen with

most resuscitators.

During emergency situat ions in which a connection to a gas source is not

readily available, the resuscitator can be used with room air unti l a s ource of

oxygen becomes available.

The operator has some feel for pressures and v olumes delivered. Barotrauma

may be less l ikely with these devices than with gas-powered resuscitators,

which do not allow the operator to sense when the patient 's lungs are fully

inf lated.

Disadvantages

Some of the valves are noisy and st ick, part icularly when wet.

There may be considerable heat and humidity loss from the patient with

prolonged use. Considerat ion should be given to using a heat and moisture

exchanger with prolonged transport.

feel of the bag is dif ferent from that in other breathing systems. The user's

hand must be re-educated.

The valve must be l ocated at the patient 's head. I ts bulk may be

troublesome, and its weight may cause the tracheal tube to kink or be

displaced downward.


22/32

During infant resuscitat ion, manual resuscitators are unreliable as free-

f lowing oxygen delivery devices (77)

References

1. Taylor W F, Pangburn PD, Paschall A. Manual venti lat ion during magnetic

resonance imaging. Respir Care 1991;36:12071210.

[Medline Link]

2. American Society for Testing and Materials. Standard specif icat ion for minimum

performance and safety requirements for resuscitators intended for use with

humans (ASTM F-920). West Conshohocken, PA: Author, 1993 (Reapproved

1999).3. International Standards Organization. Lung venti latorsPart 4: Part icular

requirements for operator-powered resuscitators (ISO 10651-4). Geneva,

Swi tzer land: Author , 2000.

4. Wenzel V, Idris AH, Banner MJ, et al. Inf luence of t idal volume on the

distr ibut ion of gas b etween the lungs and stomach in the nonintubated patient

receiving posit ive-pressure vent i la tion. Cr i t Care Med 1998;26:364368.

[Fulltext Link]

[CrossRef]

[Medline Link]

5. Anonymous. Ambu/MedicotestInfant/child single-use manual resuscitators: risk

of over pressure. Health Devices Alerts 2002;26(30):2.

6. Hussey SG, Ryan CA, Murphy BP. Comparison of three manual venti lat ion

devices using an intubated mannequin. Arch Dis Chi ld 2004;89:490493.

7. Mazzolini DGJ, Marshall NA. Evaluation of 16 adult d isposable manual

resuscitators. Respir Care 2004;49:15091514.

[Medline Link]

8. Campbell TP, Stewart RD, Kaplan RM, et al. Oxygen enrichment of bag-valve-

mask units during posit ive-pressure venti lat ion: a comparison of v arious

techniques. Ann Emerg Med 1988;17:232235.

[CrossRef]

[Medline Link]

9. Gonzalez del Ray JA, Poirier MP, Digiulio GA. Evaluation of an ambu-bag valve

with a self-contained, colorimetric CO2 system in the detect ion of airway mishaps:

an animal t r ia l . Pediatr Emerg Care 2000;16:121123.


23/32

[Fulltext Link]

[CrossRef]

[Medline Link]

10. Bhende M, Allen WJ. Evaluation of a Capno-Flo resuscitator during transport of

cr i t ica l ly i l l ch i ldren. Pediatr Emerg Care 2002;18:414416.

[Fulltext Link]

[CrossRef]

[Medline Link]

11. Cooper RM, Grgas S. Fatal barotrauma result ing from misuse of a resuscitat ion

bag. Anesthesiology 2000;93:892893.

[Fulltext Link]

[CrossRef]

[Medline Link]

12. Hess D, Goff G. The effects of two-hand versus one-hand venti lat ion on

volumes delivered bag-valve venti lat ion at various resistances and c ompliances.

Resp i r Care 1987;32:10251028.

13. Kissoon N, Nykanen D, Tif f in N, et al. Evaluation of performance characterist ics

of d isposable bag-valve resuscitators. Cr it Care Med 1991;19:102107.

[CrossRef]

[Medline Link]

14. Tif f in NH, Kissoon N, Clarke G, et al. An evaluation of eight disposable and two

nondisposable adult resuscitators. Can J Respir Ther 1989;25:1319.

15. Jesudian MCS, Harrison RR, Keenan RL, et al. Bag-valve-mask ventilation; two

rescuers are better than one: preliminary report. Crit Care Med 1985;13:122123.

[CrossRef]

[Medline Link]

16. Augustine JA, Seidel DR, McCabe JB. Venti lat ion performance using a self-

inf lat ing anesthesia bag: effect of operator characterist ics. Am J Emerg Med

1 987 ;5 :2 672 70 .

[CrossRef]

[Medline Link]

17. Hess D, Goff G, Johnson K. The effect of hand size, resuscitator brand, and

use of two hands on volumes delivered during adult bag-valve v enti lat ion. Respir

Care 1989;34 :805809 .


24/32

18. Hess D, Simmons M, Blaukovitch S, et a l. An evaluation of the effects of

fat igue, impedance, and use of two hands on volumes delivered during bag-valve

venti la t ion. Respir Care 1993;38:271275.

19. Hess D, Spahr C. An evaluation of volumes delivered by selected adult

disposable resuscitators: the effects of hand size, number of hands used, and use

of d isposable medical g loves. Respir Care 1990;35:800805.

[Medline Link]

20. McCabe SM, Smeltzer SC. Comparison of t i dal volumes obtained by one-

handed and two-handed venti lat ion techniques. Am J Crit Care 1993;2:467473.

[Medline Link]

21. Thomas AN, Dang PT, Hyatt J, et al. A new technique for two-hand bag valve

mask vent i lat ion. Br Med J 1993;70:397398.

22. Anonymous. Manual resuscitators. Health Devices 1979;8:133146.

23. LeBouef LL. Assessment of eight adult manual resuscitators. Respir Care

1980;25 :11361142 .

[Medline Link]

24. Mil ls PJ, Baptiste J , Preston J, et al. Manual resuscitators a nd spontaneous

venti la t ionan evaluation. Cr i t Care Med 1991;19:14251431.

[CrossRef]

[Medline Link]

25. Corley M, Ledwidge MK, Glass C, e t al. The myth of 100% oxygen delivery

through manual resuscitat ion bags. J Emerg Nurs 1993;19:4549.

[Medline Link]

26. Finer NN, Barrington KJ, Al-Fadley F, et a l. Limitat ions of self- inf lat ing

resuscitators. Pediatr ics 1986;77:417420.

[Medline Link]

27. Hess D, Hirsch C, Marquis-D'Amico C, et al. Imposed work and oxygen delivery

during spontaneous breathing with adult disposable manual venti lators.

Anesthes iolog y 1994 ;81 :1 25 61263.

[Fulltext Link]

[CrossRef]

[Medline Link]

28. Nimmagadda U, Ramez Salem M, Joseph NJ, et al. Eff icacy of preoxygenation

with t idal volume breathing. Comparison of breathing systems. Anesthesiology

2000;93 :693698 .

[Fulltext Link]


25/32

[CrossRef]

[Medline Link]

29. Tibballs J, Carter B, Whitt ington N. A disadvantage of self- inf lat ing

resuscitation bags. Anaesth Intens Care 2000;28:587.

[Medline Link]

30. Reick CW Jr. Auto-PEEP associated with excessive oxygen f low through f ive

manual resuscitators. Respir Care 1996;41:10091012.

31. Anonymous. Manual reusable pulmonary resuscitators. Technol Anesth 1994;

14,8:56 .

32. Tucker J, Hanson CW, Chen L. Pneumothorax reexacerbated by a self- inf lat ing

bag-valve device. Anesthesiology 1992;76:10671068.

[Fulltext Link]

[CrossRef]

[Medline Link]

33. Hunter WAH, Duthie RA. Malfunction of a Laerdal resuscitat ion valve.

Anaesth es ia 1991;46 :505 506.

[CrossRef]

[Medline Link]

34. Klieck J M, Bushnell LS, Bancroft ML. Barotrauma, a potential hazard of manual

resuscitators. Anesthesiology 1978;49:363365.

[Fulltext Link]

[CrossRef]

[Medline Link]

35. Anonymous. New component designed for resuscitator valve sticking problem.

B iomed Safe Stand 1991;21:123.

36. Ho AM-H, Shragge W, Tit t ley J G, et al. Exhalat ion obstruct ion due to Laerdal

valve misassembly. Cri t Care Med 1996;24:362364.

[Fulltext Link]

[CrossRef]

[Medline Link]

37. Anonymous. Resuscitators, pulmonary manual reusable. Technol Anesth

1991;12:9.

38. Cul len P. Self - inf lat ing vent i la t ion bags. Anaesth Intens Care 2001;29:203.

[Medline Link]

39. Myers DP, de Leon-Casasola OA, Bacon DR, et al. Bilateral pneumothoraces

from a malfunct ioning resuscitat ion valve. J Cl in Anesth 1993;5:433435.


26/32

[CrossRef]

[Medline Link]

40. Anonymous. Improperly cleaned resuscitator valves may s t ick & block airway.

Biomed Safe Stand 1991;21:105107.

41. Jumper A, Desai S, L iu P, et al. Pulmonary barotraumas result ing from a faulty

Hope I I resuscitation bag. Anesthesiology 1983;58:572574.

[Fulltext Link]

[CrossRef]

[Medline Link]

42. Kissoon N, Connors R, Tif f in N, et al. An evaluation of the physical and

functional characterist ics of resuscitators for use in pediatrics. Crit Care Med

1 992 ;2 0: 2 9 22 96 .

[CrossRef]

[Medline Link]

43. Barnes TA, McGarry WP. Evaluation of ten disposable manual resuscitators.

Resp i r Care 1990;35:960968.

[Medline Link]

44. Hess D, Simmons M. An ev aluation of the resistance to f low through the patient

valves of twelve adult manual resuscitators. Respir Care 1992;37:432438.

[Medline Link]

45. Munford BJ, Wishaw KJ. Critical incidents with nonrebreathing valves. Anaesth

In tens Care 1990;18:560563.

[Medline Link]

46. Day CJE, Nolan JP. A rebreathing non-rebreathing valve. Anaesthesia

1 994 ;49 :4 56 .

[Medline Link]

47. Anonymous. Manual resuscitators. Biomed Safe Stand 1998;28:126.

48. Doerges VM, Sauer C, Ocker H, e t al. Airway management during

cardiopulmonary resuscitat iona comparative s tudy of bag-valve-mask, l aryngeal

mask airway and Combitube in a bench model. Resuscitat ion 1999;41:6369.

[CrossRef]

[Medline Link]

P.294


27/32

49. Clayton TJ, Pittman JAL, Gabbott DA. A comparison of two techniques for

manual venti lat ion of the lungs by non-anaesthetists: the bag-valve-facemask and

the cuf fed oropharyngeal a irway (COPA). Anaesthesia 2001;56:756759.

[Fulltext Link]

[CrossRef]

[Medline Link]

50. Anonymous. Valve component on resuscitat ion kits may leak. Biomed Safe

S tand 1989 ;19:3536 .

51. Anonymous. Pulmonary resuscitators. Health Devices 1989;18:333352.

[Medline Link]

52. Hirschman AM, Kravath RE. Venting vs venti lat ing. A danger of manual

resuscitation. Chest 1982;82:369370.

[CrossRef]

[Medline Link]

53. Smith G. Problems with mis-assembly of adult manual resuscitators.

Resusci tat ion 2002;53:109111.

[CrossRef]

[Medline Link]

54. Anonymous. Manual resuscitators subject of safety alert and recall. Biomed

Safe Stand 1998;28:8183.

55. Anonymous. Manual pulmonary resuscitators. Technol Anesth 2002:10.

56. Connors R, Kisson N, Tif f in N, et al . An evaluation of the physical and

functional characterist ics of infant resuscitators. Pediatr Emerg Care 1993;9:104

107.

[CrossRef]

[Medline Link]

57. Doerges V, Sauter C, Ocker H, et al. Smaller t idal volumes during

cardiopulmonary resuscitat ion: comparison of adult and paediatric s elf- inf latable

bags with three dif ferent venti latory devices. Resuscitat ion 1999;43:3137.

[CrossRef]

[Medline Link]

58. Dorges V, Ocker H, Hagelberg S, et al. Smaller t idal volumes with room air are

not suff icient to ensure adequate oxygenation during bag-valve-mask venti lat ion.


[CrossRef]

[Medline Link]


28/32

59. Dorges V, Ocker H, Hagelberg S, et al. Optimization of t idal volumes given with

self- inf latable bags without addit ional oxygen during simulated basic l i fe support.


[CrossRef]

[Medline Link]

60. Devit t JH, Brooks DA, Oakley PA, et al. Mask lung venti lat ion by a mbulance

personnel: a performance assessment. Can J Anaesth 1994;41:111115.

[Medline Link]

61. Barnes TA, Stockwell DL. Evaluation of ten manual resuscitators across an

operational temperature range of -18C to 50C. Respir Care 1991;36:161172.

[Medline Link]

62. Connors R, Kisson N, Tif f in N, et al . An evaluation of the physical and

functional characterist ics of infant resuscitators. Pediatr Emerg Care 1993;9:104

107.

[CrossRef]

[Medline Link]

63. Oliver JJ, Pope R. Potential hazard, with si l icone resuscitators. Anaesthesia

1984;39 :933934 .

[CrossRef]

[Medline Link]

64. Anonymous. Mismating of Laerdal exhalation diverters and Intertech masks.

Techno l Anesth 1988;8 :12.

65. Anonymous. Inspiron disposable adult manual pulmonary resuscitators. Technol

Anesth 1987;8:2 3.

66. Freeman G, Hannallah M. Severe hypoventi lat ion result ing from improper use o f

a d isposable manual resuscitator. J Clin Anesth 1995;7:267.

[CrossRef]

[Medline Link]

67. Kain Z N, Berde CB, Benjamin PK, et al. Performance of pediatric resuscitat ion

bags assessed with an infant lung simulator. Anesth Analg 1993;77:261264.

[Medline Link]

68. Johannigman JA, Branson RD, Davis K , et al. Techniques of emergency

venti lat ion: a model to evaluate t idal volume, airway pressure, and gastric

insuf f la t ion . J Trauma 1991;31:9398.

[CrossRef]

[Medline Link]


29/32

69. Anonymous. Occluded tubing could l imit resuscitator's oxygen f low. Biomed

Safe Stand 1994;24:171172.

70. Anonymous. Damage to oxygen tubing leads to recall of hyperinf lat ion sets,

resuscitator. B iomed Safe Stand 1999;29:77.

71. Anonymous. Resuscitators, pulmonary, manual, disposable. Technol Anesth

1 990 ;1 1:9 10 .

72. Thompson AC, Wilder BJ, Powner DJ. Bedside resuscitat ion bags: a source of

bacter ia l contamination. Infect Contro l 1985;6:231232.

[Medline Link]

73. Hartstein AI, Rashad AL, Liebler JM, et al. Mult iple intensive care unit outbreak

of Acinetobac te r col co ac et ic us subspecies anitratus respiratory infection and

colonization associated with contaminated, reusable venti lator circuits and

resuscitation bags. Am J Med 1988;85:624631.

[CrossRef]

[Medline Link]

74. Weber DJ, Wilson MB, Rutala WA, et al. Manual venti lat ion bags as a s ource

for bacterial colonization of intubated patients. Am Rev R esp Dis 1990;142:892

894.

[Medline Link]

75. Anonymous. Resuscitators, pulmonary manual. Technol Anesth 1985;7:11.

76. Anonymous. Reusable manual pulmonary resuscitators. Technol Anesth

1998;19:6.

77. Martell RJ, Soder CM. Laerdal infant resuscitators are unreliable as free-f low

oxygen del ivery devices. Am J Perinatol 1997;14:347351.

[Medline Link]

P.295

QuestionsFor the following question, select the correct answer.

1. What determines the maximum minute volume delivered from a resuscitation

device?

The rate of oxygen f low into the bag

The rate at which the bag reinf lates

The size of the oxygen reservoir


30/32

The rate at which the bag is squeezed

View AnswerFor the following questions, answer

i f A, B, and C are correct

i f A and C a re correct

i f B and D a re correct

is D is correct

i f A, B, C, and D are correct.

2. Measures that can increase the concentration of oxygen delivered from a

resuscitation bag include

Increasing the oxygen flow

Low minute volume

Addit io n of a reserv oi r to the in le t

A lo wer I :E ra tio

View Answer3. Problems with delivering oxygen directly into the

resuscitation bag include

Diff iculty attaining high oxygen concentrat ions

Nonrebreathing valve locking in the inspiratory posit ion

Excessive pressureInabil i ty to deliver adequate t idal volume because the f lowmeter can only deliver up

to 15 L/minute

View Answer4. Characteristics of an open reservoir include

Oxygen f lows into the reservoir during i nspirat ion

If the t idal v olume is high, air may be added to the gases entering the resuscitat ion

bag

Oxygen enters the bag from the resevoir during exhalat ion

Amb ien t ai r can make up defic ien c ie s in ox ygen volu me duri ng inha lat io n

View Answer5. Characteristics of the closed reservoir include

A val ve to let in amb ien t ai r

A val ve to ven t exces s ga ses from the reservoi r

The presence of a bag

A val ve to prov id e wa rn ing of ex cess ox ygen pressure

View Answer6. What minimum oxygen concentration must a resuscitation

bag be capable of delivering?

Forty percent with up to 15 L/minute oxygen f low


31/32

One hundred percent if the reservoir is smaller than the t idal volume

Eighty-f ive percent with the addit ion of a reservoir

Ninety percent if the reservoir is larger than the t idal volumeView Answer7. Benefits of manually restricting refill of the resuscitation

bag include

A lo wer f low of oxyg en may be us ed

A re serv oi r may no t be needed to deliver hig h oxygen conc en tra t ions

Higher oxygen concentrat ion wil l be d elivered

Higher minute volume can be achieved

View Answer8. Situations that can result in high a irway pressure include

Nonrebreathing valve st icking i n the expiratory posit ion

High oxygen i nf low

Kinking of the reservoir tai l

Use of a demand valve as the patient exhales

View Answer9. Causes of hypoventilation when using a manual

resuscitator include

Incomplete closure of the expiratory port

Low temperature

Venting through the pressure relief device

No auxil iary air intake

View Answer10. The ASTM standard on resuscitators includes the

following provisions concerning pressure limiting devices:

In adults, i f the override mechanism can be locked, i t must be designed so that the

operating mode is readily apparent to the user

For infant and child resuscitators, a device with an opening pressure of 45 cm H 2O

Optional override for infant and child resuscitators

For adults, a device with an opening pressure of 50 cm H2O

View Answer11. Hazards associated with use of a manual resuscitator

include

Barotrauma

Inhalat ion of foreign s ubstances

Delivery of low oxygen concentrat ions

Hyperventi lat ion

View Answer12. What techniques are useful to increase the tidal volume

delivered from a manual resuscitator?

Two-handed technique


32/32

Slowed bag expansion

Compression against a s olid surface

Using the resuscitator at low temperaturesView Answer13. Which of the following are associated with retarding

resuscitating bag expansion?

Increased minute volume

Decreased respiratory rate

Activat io n of th e pressure limit ing de v ic e ma y inc rease th e ins pired ox yg en

concentrat ion

The nonrebreathing valve may jam

View Answer14. Concerning spontaneous respiration through a manual

resuscitator,

A wide vari at ion in ox ygen conc entr at io n ma y oc cur

Fishmouth valves are associated with a higher inspired oxygen concentrat ion

Room air may be inspired through the exhalation port

The bag inlet valve wil l jam

View Answer15. A decreased inspired oxygen concentration may be

caused by

A smal l res erv oi r

Low temperature

A val ve de fec t

Spontaneous venti lat ion

View Answer

Documents

Chapter 10. Manual Resuscitators