“The only thing necessary for these diseases to the triumph is for good people and governments to do nothing.”
during Cardiopulmonary Resuscitation
Estimating the Risk and
Defining Strategies for Prevention
George C. Mejicano, MD
and Dennis G. Maki, MD
15 November 1998 | Volume 129 Issue 10 | Pages 813-828
To estimate the risk for
acquiring an infectious disease during cardiopulmonary
resuscitation (CPR) or CPR training and to identify strategies to
minimize that risk.
articles published since 1965 were identified through a search of
the MEDLINE database and selected bibliographies.
contained information about transmission of infectious organisms,
particularly HIV and other bloodborne viruses that might be
transmitted through mouth-to-mouth ventilation, contact
exposures, and needlesticks during CPR.
and analytic data from each study.
acquiring infection, especially HIV infection, can delay prompt
initiation of mouth-to-mouth ventilation. Although pathogens can
be isolated from the saliva of infected persons, salivary
transmission of bloodborne viruses is unusual and transmission of
infection has been rare: Only 15 documented cases have been
reported. Most of these cases involved a bacterial pathogen, such
as Neisseria meningitidis. Transmission of hepatitis B virus,
hepatitis C virus, or cytomegalovirus during CPR has not been
reported; all three reported cases of HIV infection acquired
during resuscitation of an infected patient resulted from
high-risk cutaneous exposures. There have been no reports of
infection acquired during CPR training. Simple infection-control
measures, including use of barrier devices, can reduce the risk
for acquisition of an infectious disease during CPR and CPR
training. Postexposure protocols can further protect potential
rescuers and trainees.
The benefit of
initiating lifesaving resuscitation in a patient in
cardiopulmonary arrest greatly outweighs the risk for secondary
infection in the rescuer or the patient. Nevertheless, use of
simple infection-control measures during CPR and CPR training can
reduce a very low level of risk even further.
"And he went up, and lay upon the child, and put his mouth upon
his mouth, and his eyes upon his eyes, and his hands upon his
hands: and he stretched himself upon the child; and the flesh of
the child waxed warm."
II Kings 4:34
From the time of this
first written description of rescue breathing , it was nearly
3000 years before mouth-to-mouth ventilation achieved widespread
medical acceptance . The National Research Council first
recommended mouth-to-mouth ventilation in 1957, and the first
reported out-of-hospital resuscitation took place in 1960 .
Today, mouth-to-mouth ventilation combined with external chest
compressions, termed cardiopulmonary resuscitation (CPR), form
the initial treatment of patients with cardiac arrest. In the
United States, an estimated 100 000 resuscitations are done
annually, and more than 20 million citizens to date have been
formally trained in basic life support .
programs have put CPR at the forefront of public health
initiatives on the basis of the knowledge that prompt action can
save lives, both inside and outside of the hospital [4,5].
Average survival rates for patients with cardiac arrest are low,
even with prompt administration of CPR-10% to 15% [6,7]-and
factors such as age , location of arrest [4,5], and duration
of arrest  profoundly influence the outcome of resuscitation.
However, the strongest predictors of success are whether the
arrest is witnessed [4,6,8], the initial cardiac rhythm [6,8,9],
the time from collapse to initiation of CPR [8,10-12], and the
quality of the CPR administered . The highest rates of
survival and hospital discharge, up to 43%, occur when CPR is
started within 3 to 4 minutes of arrest [7,8,12]. When CPR is
combined with immediate on-site defibrillation, the survival rate
may be as great as 70% . The most recent guidelines from the
American Heart Association  emphasize that prompt
intervention is the key to success: A first responder must be
willing to act without hesitation. Unfortunately, fear of
contracting a communicable disease, especially HIV infection, has
become a major barrier to immediate response [14,15].
of AIDS on Initiation of Cardiopulmonary Resuscitation
Most students in the health professions , nurses [17-19], and
house officers [20,21] have stated in surveys that they would not
perform mouth-to-mouth ventilation on a patient with AIDS. A
recent survey  found that 45% of 433 internists and 80% of
152 nurses would not perform mouth-to-mouth ventilation on a
stranger. The main reason for reluctance was fear of contracting
a serious communicable disease, especially HIV infection.
Even CPR instructors
harbor these fears. A survey of 1794 instructors in Virginia
found that 49% had performed CPR within 3 years. Of these
providers, 40% reported that they had hesitated to provide
mouth-to-mouth ventilation at least once, usually because of fear
of exposure to a contagious disease . Not surprisingly, many
instructors also have concerns about exposure to infectious
diseases during group training done by using mannequins [23-25].
In 1989, the Emergency
Cardiac Care Committee of the American Heart Association 
sought to allay concerns about potential exposure to infectious
agents, particularly HIV and hepatitis B virus (HBV). They
stressed that "delayed ventilation could mean death or
disablement for an otherwise healthy person, while risk to the
rescuer, even with a known HBV/HIV-positive victim, is considered
very low." An editorial and a position paper from the Heart and
Stroke Foundation of Canada [27,28] reaffirmed this position. The
current American Heart Association guidelines  state that
health care workers and public protection professionals have
"moral, ethical, and, in certain situations, legal obligations to
provide CPR." We concur with these statements but believe that it
will take more than reassurances and ethical arguments to
persuade health care workers and the lay public that fear of
infection should not be a deterrent to the initiation of CPR.
Although the absolute
level of risk is low, health care workers have an increased risk
for occupationally acquired infection, particularly infection
with Mycobacterium tuberculosis and HBV [29-31]. Yet recent
reviews of occupationally acquired infection in health care
workers have not addressed the risk for infection as a
consequence of administering CPR. By examining the available data
on the likelihood of transmission of infectious organisms
(particularly HIV and other ubiquitous bloodborne pathogens)
during CPR and the documented cases of infections acquired during
CPR and by summarizing essential infection-control measures that
reduce risk even further, we believe that it is possible to
convince potential CPR providers that the risk for acquiring an
infection during CPR is not zero but is very low and that there
should be no reluctance to begin CPR, including mouth-to-mouth
ventilation, when the procedure is medically and ethically indicated.
Salivary Transmission of Bloodborne Viruses
It is now abundantly
clear that HIV is not transmitted through casual contact [32-35]
(Table 1). Even household members who have shared numerous
personal items with HIV-infected persons, such as eating
utensils, razors, or toothbrushes, have not become infected .
Infection with HIV is acquired through sexual contact; exposure
to unscreened blood products; intravenous drug use; and, among
health care workers, exposure to contaminated sharps. Infants
acquire HIV in utero or during parturition [32,46]. Transmission
by all other routes seems to be very rare [32,39].
Table 1. Risk for
Salivary Transmission of HIV
virus is isolated rarely, and then in very low concentrations,
from the saliva of HIV-infected patients [47,48]. The low
concentration of HIV in saliva is probably the major reason why
dental professionals have a very low risk for occupationally
acquired HIV infection [36,37]. In the United States, no
rigorously documented cases of transmission of HIV from a patient
to a dental worker have been reported, although seven cases may
have derived from dental exposures . In one study of 1309
dental professionals who had no behavioral risk factors for HIV
infection but had cared for multiple patients known to have AIDS
or risk factors for HIV infection , only 1 dentist was
seropositive for HIV.
In a long-term
prospective study of health care workers heavily exposed to
patients with HIV infection , none of the 63 persons exposed
to the saliva of HIV-positive patients on a daily basis developed
antibody to the virus. Even persons who have been bitten by an
HIV-infected person seem to be at low risk: Only four cases of
HIV infection have been ascribed to human bites, and none of
these cases have been confirmed epidemiologically by RNA
subtyping [41-44]. Of 8 HIV-seronegative children bitten by
HIV-infected playmates and 38 health care workers bitten by
patients with AIDS, none have seroconverted despite prolonged
followup [39,40,49]. Moreover, two nurses who performed mouth-to-mouth
ventilation on a patient with AIDS have not developed HIV infection
during prolonged follow-up .
In summary, although
there has been speculation that salivary transmission of HIV may
occur, the evidence does not support this [32,41,50,51] (Table
In contrast to HIV, HBV
poses substantial risks to health care workers [41,52-54].
Hepatitis B surface antigen (HBsAg) was found in the saliva of 31
of 41 patients (76%) with acute hepatitis and was found
intermittently in 75 of 93 patients (81%) with chronic HBV
infection . Thus, salivary exchange may be one mechanism for
nonparenteral transmission of HBV within families [56-58], and
cases of HBV infection acquired through human bites have been
reported [59,60] (Table 2).
Table 2. Risk for
Salivary Transmission of Hepatitis B Virus
However, the sum total
of the evidence suggests that salivary transmission of HBV is
rare (Table 2). Only one case of HBV infection was found after 35
upper gastrointestinal procedures were done with endoscopes that
were presumably contaminated with HBV [61,62]. Moreover, none of
12 students who were exposed to HBsAg-positive saliva through the
sharing of musical instruments with an infected teacher
seroconverted or developed clinical evidence of hepatitis .
Finally, none of 39 persons exposed to HBsAg-positive saliva
during CPR training became infected [63,64], and no cases of HBV
infection acquired as a consequence of giving CPR or
participating in CPR training have been documented. The most
likely reason why salivary transmission is so infrequent is that
the concentration of HBV in saliva is only 1/3000 of that in
serum . The risk for acquiring HBV infection as a result of
performing mouth-to-mouth ventilation is very low and can almost
certainly be mitigated by immunization of the health care workers
and public protection officials most likely to be called on
regularly to perform CPR .
Unlike patients infected
with HIV and HBV, up to one third of persons with antibody to the
hepatitis C virus (HCV) have no identifiable risk factors for
bloodborne infection [67,68]. Hepatitis C virus RNA has been
found by polymerase chain reaction (PCR) in many body fluids,
including sweat , urine [68-70], and saliva [68-76]. The
prevalence of HCV positivity in saliva has ranged widely, from
none of 14 HCV-seropositive patients in one study  to 20% to
62% of HCV-infected patients in others [70,74,75]; this suggests
wide differences in the sensitivity of the assays used to assess
positivity. It seems clear, however, that the concentration of
HCV in blood is several orders of magnitude greater than the
concentration of HCV in saliva .
In one study (Table 3),
none of 62 household contacts of HCV-seropositive family members
showed serologic evidence of infection ; in a prospective
study of the spouses of 11 patients with active HCV infection
, none were positive for HCV RNA by PCR. Similarly, other
investigators have found low rates (1.4%) of HCV seropositivity
in nonsexual household contacts of HCV-positive persons .
Table 3. Risk for Salivary Transmission of Hepatitis C Virus
Despite the frequent
presence of HCV in saliva, only 2 of 305 general dentists (0.7%)
and 7 of 343 oral surgeons (2.0%) had serologic evidence of HCV
infection, although 14.7% of both groups showed one or more
markers for HBV infection . Only a single case of HCV
infection has been attributed to salivary transmission, and this
case was in the recipient of a human bite .
At this time, saliva
does not seem to play a major role in transmission of HCV,
although more work is needed to better elucidate how HCV is
transmitted from person to person (Table 3). It can be concluded
that the risk for acquiring HCV through the performance of CPR is
Cytomegalovirus (CMV) is
a teratogenic virus that has attracted considerable attention as
a potential threat to female health care workers . Outbreaks
of CMV infection in day care centers and the survival of CMV on
fomites, such as paper diapers , suggest that this ubiquitous
virus is more easily transmitted through nonparenteral than
through parenteral routes. Cytomegalovirus can be found in
saliva, both by culture and by PCR, and co-infection with HIV
increases the likelihood of finding CMV in saliva [85-87].
Many cohort studies in
health care workers have assessed the occupational risk for
acquiring CMV (Table 4). Seven studies [88-94] produced
remarkably similar results: a mean annual seroconversion rate
among heavily exposed health care workers of 3%. Despite frequent
exposure to infants and children shedding CMV, the risk of health
care workers for acquisition of CMV was not much higher than the
risk of community controls (mean, 1.6%) [90,93,96] and was much
lower than the risk of day care workers (mean, 14%) [95,96]. A
recent meta-analysis  concluded that pediatric nurses are not
at increased risk for occupationally acquired CMV infection.
Finally, a seronegative pediatric house officer who administered
mouth-to-mouth ventilation to a newborn with congenital CMV
infection did not acquire CMV, despite ingestion of the infant's
CMV-positive secretions .
Table 4. Risk for
Non-Bloodborne Transmission of Cytomegalovirus
Table 4. Risk for Non-Bloodborne Transmission of Cytomegalovirus
Young women who work
with CMV-infected persons must be apprised that they are at some
risk (although this risk is low) for infection with CMV.
Compliance with handwashing can reduce this risk. Pregnant health
care workers and their sexual partners can safely care for CMV-infected
patients if they follow universal precautions [97,99-103].
Data that would pinpoint
the risk for salivary transmission of CMV are, unfortunately, not
available. However, despite the ubiquity of CMV and its frequent
presence in saliva, the information we have indicates that the
risk for acquiring CMV through the administration of
mouth-to-mouth ventilation is probably not great.
disease, which is rare in humans, is one of several devastating
neurologic diseases caused by prions (proteinaceous and
infectious agents) [104-106]. Recently, the emergence of a new
variant of Creutzfeldt-Jakob disease in the United Kingdom,
circumstantially linked to bovine spongiform encephalopathy ("mad
cow disease"), has attracted attention [105,106]. Rare clusters
of Creutzfeldt-Jakob disease have been seen in some ethnic groups
, and cases of suspected iatrogenic transmission have been
linked to corneal transplantation , intracerebral
electroencephalography , dura mater implantation [110-112],
and exposure to cadaveric growth hormone [113,114]. Isolated case
reports have implicated blood transfusion  and solid organ
transplantation . Primates inoculated with tissue from the
spinal cord, eye, lung, liver, kidney, and spleen of persons with
Creutzfeldt-Jakob disease acquired the disease, but they did not
acquire it through exposure to the saliva or blood of infected
persons . Indeed, no cases of Creutzfeld-Jakob disease
resulting from exposure to saliva have been documented. As of
1994, 24 cases of putative acquisition of Creutzfeldt-Jakob
disease by health care workers through occupational exposure had
been described . However, the reported incidence of
Creutzfeldt-Jakob disease is no higher in health care workers
than in the general population .
Given the rarity of
Creutzfeldt-Jakob disease and the lack of clinical or
experimental data showing the plausibility of salivary
transmission, it is unlikely that a rescuer performing mouth-to-mouth
ventilation could contract this disease as a result of efforts
to resuscitate a person in cardiopulmonary arrest.
Transmission of Bloodborne Viruses through Parenteral Exposure
Although the likelihood of acquiring a bloodborne virus, such as
HIV, HBV, or HCV, from exposure to saliva is extremely low (Table
1, Table 2, and Table 3), the risk for acquiring such a virus
through a parenteral biohazardous exposure is substantial (Table
5) [119-127]. In general, the risk for transmission of these
viruses depends on the extent and the circumstances of exposure.
With HIV, deep, penetrating injuries, especially with hollow
needles, greatly increase risk; moreover, the higher the
concentration of HIV in the source patient's blood, the greater
the likelihood of transmission (Table 6) . With HBV, the
presence of detectable e antigen (HBeAg), which is associated
with a much higher concentration of HBV in the blood, greatly
increases risk: The likelihood of transmission of HBV is at least
10-fold greater with parenteral exposure to HBeAg-positive blood
than with exposure to blood from an HBsAg-positive, HBeAg-negative
person (Table 5) [123-125].
Table 5. Risks for Transmission of Bloodborne Viruses by Parenteral
Table 6. Risk Factors for Transmission of HIV after Percutaneous Exposure
to HIV-Infected Blood*
In general (Table 5),
the risk resulting from parenteral exposure is greatest with HBV
(13.1%) [123-125], intermediate with HCV (5.8%) [126,127], and
lowest with HIV (0.32%) [119-122].
Infections That Have Been Acquired through Cardiopulmonary Resuscitation
During the past 30 years, CPR has been given to millions of
persons worldwide . Thus, it is remarkable that only 15 infections
convincingly linked to resuscitation have been reported (almost
all from the United States) (Table 7) [129-139]. With an estimated
100 000 resuscitations performed in the United States each year
, this suggests a risk for infection of less than 1 in 200
000. However, it must be acknowledged that underreporting undoubtedly
occurs and that the actual number of infections is almost certainly
greater. Even if it were 100-fold greater, the absolute level
of risk would still be less than 1 in 2000.
Table 7. Infectious Organisms Transmitted during Cardiopulmonary
No cases of HIV, HBV,
HCV, or CMV infection transmitted by mouth-to-mouth ventilation
have been documented. Bierens and Berden  estimate that the
risk for acquiring HIV infection during mouth-to-mouth
ventilation is between 1 in one million and 1 in one billion,
depending on the population being resuscitated and the circumstances
of the exposure.
The earliest report of a
communicable disease clearly acquired as a consequence of
administering CPR was in 1965: A medical intern developed primary
cutaneous tuberculosis 8 weeks after giving mouth-to-mouth
ventilation to a patient in cardiac arrest who was later found,
at autopsy, to have active pulmonary tuberculosis . Despite
the large number of persons with active tuberculosis worldwide,
no other reported cases are thought to have been acquired during
CPR. Still, a rescuer who has given mouth-to-mouth ventilation to
a patient with pulmonary tuberculosis should have serial
tuberculin skin testing and should be offered chemoprophylaxis if
conversion occurs .
At least four cases of
meningococcal infection in health care workers have been linked
to rescue breathing . The risk for salivary transmission may
be high during mouth-to-mouth ventilation or another intensive
respiratory exposure (such as endotracheal intubation) if a
patient has systemic N. meningitidis infection [143,144].
Providers who have such an exposure should be offered
There have been rare
cases of transmission of gastrointestinal pathogens during rescue
breathing. A physician developed fever and diarrhea 3 days after
performing mouth-to-mouth ventilation on a moribund infant;
cultures from the physician and the child showed Shigella sonnei
. Another report documented transmission of Salmonella
infantis from a 68-year-old woman to the physician who had
attempted to resuscitate her with mouth-to-mouth ventilation
. A recent case report  suggests that Helicobacter
pylori was transmitted, through mouth-to-mouth ventilation, but
definitive evidence of this is lacking.
Herpes Simplex Virus
Herpes simplex virus (HSV)
has been shown to be readily transmitted both from patient to
rescuer and from rescuer to patient [135-137], reflecting the
ubiquity of HSV infection in the general population . Viable
HSV has been obtained from the saliva of 2.5% of asymptomatic
adults , and copious shedding of HSV occurs in persons with
active lesions: One study  reported the isolation of HSV
from 78% of salivary samples and 67% of hand cultures from
persons with active lesions.
Given these statistics,
it is surprising that only two cases of primary herpes labialis
secondary to CPR have been reported; both involved medical
residents who performed mouth-to-mouth ventilation [135,136].
Herpes simplex virus was also transmitted from a physician to a
patient during CPR  (see below).
Other Respiratory Pathogens
In a survey of 27
pediatric house officers, 74% reported ingesting an infant's
secretions during neonatal resuscitation . Eight residents
reported exposure to culture-proven respiratory pathogens during
neonatal suctioning; in one case, cultures from the house officer
matched those from the infant (Neisseria gonorrhoeae). The
authors of this study  estimated that the risk for ingesting
secretions that contain a pathogen during neonatal resuscitation
is 1 in 300.
Group A Streptococci
A firefighter ventilated
a moribund 3-year-old boy with a bag-valve-mask device but
contaminated his hands with the child's secretions during the
resuscitation. While cleaning his equipment afterward, the
firefighter sustained a small abrasion. Within 24 hours, he
became acutely ill with cellulitis emanating from the abrasion,
shock, and acute renal failure. Cultures from the firefighter's
hand wound and from the resuscitated child's blood grew a toxigenic
strain of Streptococcus pyogenes .
In 1986, a nurse
assisted in the resuscitation of a young man with undiagnosed
AIDS, heavily contaminating her ungloved hands with the patient's
blood during insertion of an arterial catheter. Four months
later, the nurse was found to be HIV positive. This is one of
three well-documented cases in which HIV infection seems to have
been transmitted through contamination of skin by blood ; in
each case, the exposure was heavy and prolonged and the exposed
health care worker had chapped hands or other possible skin
breaks. These cases form the basis for the central role of gloves
in universal precautions. It is essential to reemphasize,
however, that only one case of occupationally acquired HIV
infection was seen among 2071 prospectively studied health care
workers who had a mucous membrane or non-intact skin exposure to
HIV-positive blood .
The scene of a
resuscitation is often chaotic, and health care workers engaged
in CPR are therefore at risk for exposure to bloodborne pathogens
from accidental needlesticks and other sharps injuries. Pooled
data from 25 prospective studies of health care workers exposed
to HIV through needlesticks or other parenteral exposures have
quantified the risk for acquiring HIV as 0.32% (95% CI, 0.18% to
0.46%) (21 infections after 6498 exposures) [119-122,151-156].
Two of the cases occurred during CPR and involved deep
needlesticks [138,140]. It is likely that additional cases of
occupationally acquired HIV infection (among the 163 to 177 cases
reported in the United States as of 1996 [151,157]) derived from
sharps exposures during CPR, but the circumstances of the
exposures were not reported. Similarly, it is almost certain that
HBV and HCV infections have originated from parenteral exposures
to these viruses during administration of CPR to infected
patients, but no such cases have been reported to date.
Prevention of sharps
injuries is essential because most exposures to bloodborne
viruses can easily be avoided-fully 37% in the Centers for
Disease Control and Prevention (CDC) HIV Surveillance Study
. This is also true outside of the hospital setting. A study
of occupational exposures in emergency medical service workers
 found that most needlesticks occurred during needle
Eliminating recapping of
needles, making impervious containers for sharps disposal widely
available, achieving maximal compliance with proper sharps
disposal guidelines, and increasing use of needleless systems and
other safety devices form the cornerstone of an institutional
program aimed at reducing the risks of bloodborne pathogens to
health care workers (Table 8) [159-161].
from Rescuer to Patient
Concerns about the
safety of CPR usually focus on risk to the rescuer, but the
potential risk posed to a patient by an infected rescuer also
warrants consideration. However, we know of only one case in
which a patient acquired an infection as a result of contact with
an infected rescuer: A pediatric resident was shown by DNA
subtyping to have transmitted HSV from a crusting cold sore on
his lip to a neonate whom he was resuscitating through an
endotracheal tube .
In clinical practice, if
rescuers have open sores on the hands or the face or lesions in
the mouth, use of a barrier device is strongly recommended .
However, if no barrier devices are immediately available, the
imperative to quickly initiate life-sustaining measures,
including mouth-to-mouth ventilation, must take precedence over
concern about transmission of an infectious agent .
The best evidence
suggests that although the potential exists for acquisition of
infection by a patient during mouth-to-mouth ventilation, the
risk is almost certainly very low (Table 1, Table 2, Table 3, and
Table 4). Because expeditious resuscitation is crucial, it is not
only acceptable but desirable that a qualified rescuer begin
resuscitory efforts, including mouth-to-mouth ventilation, even
if the rescuer is known to be positive for HIV, HBsAg, or HCV
[13,26]. Obviously, if an oral barrier (such as a pocket mask or
bag-valve-mask) is available, it should be used.
mouth-to-mouth ventilation has been given and the recipient
survives, the recipient must be thoroughly evaluated for
infection acquired through CPR (Table 8).
Precautions To Reduce Risk during Cardiopulmonary Resuscitation
The Occupational Safety
and Health Administration mandates that health care institutions
establish programs to protect health care workers from
biohazardous exposures, especially exposures to infectious
diseases [162-164]. These programs must include education of all
employees with respect to risk reduction; a multifaceted strategy
for prevention of sharps injuries and other biohazardous
exposures; and a postexposure protocol to expeditiously determine
the potential risk associated with an individual exposure and,
when indicated, to provide prophylaxis and long-term follow-up.
Training in CPR must address protection from infection during
CPR, with the greatest focus on measures for avoiding sharps
injuries. Table 8 provides model institutional and general
guidelines for prevention and management of the transmission of
infectious agents during CPR.
Health care workers
cannot clinically identify most patients infected with bloodborne
pathogens [165,166]; thus, in 1987, the CDC published
recommendations urging the use of "universal precautions" with
all patients. These recommendations were based on the premise
that every patient must, as a precaution, be considered HIV
positive . An update published in 1988  stressed that
blood and serum pose the greatest risks for transmission of HBV
and HIV and that "general infection control practices already in
existence-including the use of gloves for digital examination of
mucous membranes and endotracheal suctioning, and handwashing
after exposure to saliva-should further minimize the minute risk,
if any, for salivary transmission of HIV and HBV."
Despite the CDC's
exclusion of saliva as a high-risk body fluid with respect to
universal precautions , support for measures to avoid or
minimize contact with saliva during mouth-to-mouth ventilation
and CPR has been almost unanimous. The University of
California-San Francisco, Task Force on the Acquired Immunodeficiency
Syndrome , the American Hospital Association , the
American College of Emergency Physicians , and the U.S.
Public Health Service  have endorsed the use of disposable
devices (Figure 1), pocket masks, and bag-valve-masks to prevent
direct mouth-to-mouth contact between rescuer and patient.
Figure 1. Oral
barrier devices. Top. Adult face mask (Adult Classic Face Mask
with Adjustable Cushion, Vital Signs, Inc., Totowa, New Jersey)
with one-way valve (Vent Easy II Non-rebreathing Valve,
Respironics, Inc., Murrysville, Pennsylvania). Middle. Adult face
mask with one-way valve and extension (Carhill Valve Resuscitation
Device, Bird Life Design, Dallas, Texas). Bottom. Laerdal
bag-valve-mask (Vital Signs, Inc.).
Not all barrier devices
are equally efficacious . When 17 mask and face-shield
resuscitation devices were evaluated in a 60-second simulation of
rescue breathing , most mask devices prevented transmission
of oral organisms but 6 of 8 face shields were contaminated
. All ventilation devices with a one-way valve (with the
exception of one brand) seemed to prevent transmission from the
simulated patient's oral flora to the rescuer's side of the
device. Another device was tested in a simulation model with an
aerosol containing Staphylococcus aureus: At best, only 90% of
organisms were retained . It is unclear how far these data
can be extrapolated to real-life conditions .
Which type of device
optimizes external ventilation? When working with a
bag-valve-mask device, using two hands improves the volume of air
delivered to a patient . Because two hands are needed to
squeeze the bag properly, another rescuer is needed to ensure a
tight fit between the mask and the patient-that is, three
rescuers are better than two [176-178]. Because of this, some
experts have advocated the use of mouth-to-mask devices [179,180].
However, mouth-to-mask methods seem to be second in effectiveness
to mouth-to-mouth methods . One study  evaluated 35
providers to determine how effectively they "ventilated" a mannequin.
After instruction, effective ventilation was achieved by 97%
of the providers who used mouth-to-mouth and mouth-to-mask methods.
Bag-valve-mask ventilation, however, was suboptimal 97% of the
Another problem with
bag-valve-masks and mouth-to-mask devices is that they are not
always readily available, even in hospitals. One study that
reviewed the results of 38 cardiopulmonary arrests in a tertiary
care hospital found substantial delays in the initiation of
rescue breathing. Resuscitation was performed within 1 minute in
only 37% of resuscitations; initiation took longer than 3 minutes
in 18% of resuscitations. Many of the delays occurred because
barrier devices were not immediately available and the rescuers
chose not to give mouth-to-mouth ventilation .
Despite all of these
concerns, the adoption of barrier devices has become de facto
policy in the health care setting, especially in the public
protection sector. New York City requires specified public
places, including bars, theaters, health clubs, and restaurants,
to have infection-control resuscitation equipment available
. A study found that having protective materials readily
available was probably more important than education alone in
improving compliance with the use of barrier precautions .
Management of Exposures to Infectious Diseases during Cardiopulmonary
Indications for Evaluation after Cardiopulmonary Resuscitation
It is essential that
persons performing CPR have access to a postexposure protocol
(Table 8). This protocol will be most consistently and
conveniently administered through an institutional employee
health department .
After CPR, especially if
mouth-to-mouth resuscitation has been given, a formal effort
should be made to ascertain whether the patient could have had a
serious, contagious respiratory infection. This can usually be
done by reviewing the available clinical history and the results
of routine diagnostic studies, such as screening blood tests and
chest radiography. If a biohazardous exposure has occurred (if
blood or open sores were apparent in the patient's mouth and
mouth-to-mouth ventilation was performed or if a member of the
resuscitation team sustained a needlestick or a mucous membrane
or non-intact skin exposure to the patient's blood) the patient
should be tested for infection with bloodborne viruses (Table 8)
. If CPR is unsuccessful, needed cultures and blood
specimens must be obtained before the patient's body is released
for embalming or cremation.
the Source Patient
In the event of a
biohazardous exposure during CPR, the source patient's history
must be ascertained as quickly as possible to determine the
presence of communicable disease and the magnitude of risk (Table
8) . The source patient's blood should be tested for
evidence of infection with HIV, HBV, and HCV [122,151,185]; HIV
testing must be done in compliance with state statutes. With
respiratory contact, especially unprotected mouth-to-mouth
ventilation, an effort should be made to determine whether the
source patient is likely to have active N. meningitidis or M.
tuberculosis infection. If possible, the source patient should be
examined for evidence of active infection, such as labial HSV
infection. If clinical and epidemiologic data from the source
patient are unavailable, the source patient's risk for harboring
a bloodborne virus should be estimated to guide follow-up care of
the exposed health care worker .
the Exposed Rescuer
An exposed rescuer
should immediately and copiously rinse any puncture wound or
exposed mucous membrane with tap water (Table 8) . If the
exposure involves a sharps injury, the area should be squeezed to
induce bleeding and should then undergo surface disinfection with
a virucidal agent, such as an iodophor antiseptic . Baseline
studies in the exposed rescuer should include serologic tests for
infection with HIV, HBV, and HCV [122,185]. The exposed rescuer
should also be counseled about the potential risks for acquiring
an infectious disease.
Agreement on the
management of exposures to N. meningitidis [143-146] and M.
tuberculosis is clear-cut  (Table 9). A rescuer exposed to
N. meningitidis should receive prophylaxis with rifampin,
ciprofloxacin, or (if the rescuer is pregnant) ceftriaxone .
If the source patient is found to have active pulmonary
tuberculosis, baseline and follow-up tuberculin tests at 12 weeks
are indicated. After mouth-to-mouth or other close respiratory
tract exposure, isoniazid chemoprophylaxis should be started
immediately unless the rescuer is immunocompetent and known to be
tuberculin-positive. Chemoprophylaxis should be continued for 6
months if tuberculin conversion is documented; if the rescuer is
immunocompromised, chemoprophylaxis should be continued
regardless of the rescuer's baseline tuberculin status. If the
exposure involves isoniazid-resistant disease, rifampin should be
used in place of isoniazid. For exposure to multidrug-resistant
tuberculosis, pyrazinamide plus a quinolone or ethambutol is
Prophylactic measures to
protect rescuers exposed to blood or body fluids that harbor HBV
are also well defined [66,122]. If the rescuer has not been
immunized against HBV, one dose of HBV hyperimmune globulin (0.06
mL/kg of body weight intramuscularly) should be given immediately
and the three-dose HBV vaccine series should be initiated. If the
exposed rescuer has been immunized, measurement of the rescuer's
level of antibody to HBV will dictate whether HBV hyperimmune
globulin, a booster dose of the vaccine, or both should be given
In contrast, because
donated blood containing detectable antibody to HCV is now
excluded in the preparation of standard immune globulin ,
the Advisory Committee on Immunization Practices has concluded
that there is "no basis for supporting the use of immune globulin
for post-exposure prophylaxis of hepatitis C." Furthermore, the
use of other antiviral agents (such as interferon-alpha) in
postexposure prophylaxis against hepatitis C is not recommended
Until recently ,
the value of postexposure prophylaxis against HIV with
antiretroviral drugs was controversial; in part, it was related
to at least 14 cases of failure of zidovudine prophylaxis to
prevent infection in health care workers after percutaneous HIV
exposure [153,186]. However, a recent international case-control
study (Table 6) found that postexposure use of zidovudine was
associated with a lower risk for HIV transmission (adjusted odds
ratio, 0.2 [CI, 0.1 to 0.6]) [128,189]. Moreover, the combination
of purine analogues and protease inhibitors may be superior to
zidovudine alone [119,190] and seems to be cost-effective .
For these reasons, in May 1998, the U.S. Public Health Service
issued updated guidelines for antiretroviral prophylaxis after
occupational exposure to HIV; in these guidelines, the
antiretroviral regimen recommended is based on a detailed
algorithm for scoring the severity of the exposure and the estimated
magnitude of risk . For high-risk percutaneous exposures
to HIV (such as a deep injury caused by a hollow needle), a
4-week, three-drug regimen with zidovudine, lamivudine, and
indinavir or nelfinavir should be considered (Table 9).
With mucosal contact,
the benefit of postexposure prophylaxis with antiretroviral drugs
remains controversial [122,188], and the new guidelines do not
advocate use of these drugs unless saliva has been contaminated
by HIV-positive blood . Prophylaxis is not recommended for
cases of cutaneous contact unless the exposure involves a high
viral titer, contact is prolonged, the involved area is
extensive, or skin integrity is visibly compromised .
Exposed rescuers must
receive close follow-up  and, if exposed to bloodborne
viruses, must be retested for evidence of infection for at least
6 to 9 months after the exposure [122,186]. The CDC recommends
that health care workers who are seronegative for HIV immediately
after exposure to HIV should be retested 6 weeks, 12 weeks, and 6
months after exposure [186,188,192].
To Reduce Risk during Training for Cardiopulmonary Resuscitation
Although the spread of
infection through the use of training mannequins has more in
common with transmission through fomites or endoscopes than with
transmission through contact with living patients, the use of
precautions has been extended to CPR training since the
possibility that mannequins might harbor infectious agents has
been raised [193-195]. The CDC and the American Heart Association
have issued guidelines on how to clean and disinfect mannequins
[196-198]; following these guidelines can make CPR training safer
and allay the fears of would-be CPR providers [199-202].
It seems prudent to
postpone CPR training if a person is acutely ill with a
potentially contagious disease that can be transmitted through
respiratory secretions (such as a cold, influenza, or herpes
labialis) or has an open lesion or lesions on the face or hands
A potential CPR trainee
with a chronic infection, such as HIV or HBV infection, is
another matter. The American Heart Association addressed this
issue in their most recent Instructor's Manual . Because
speed is of the essence in a cardiopulmonary emergency, exclusion
of a potential rescuer with a known chronic infection might
preclude a patient's chance of survival. Thus, with rare
exceptions, anyone who desires CPR training can receive it,
including those who are positive for HIV, HBsAg, or HCV, provided
that published precautions-use of a separate mannequin and
recommended disinfection at the end of the class-are followed
Every health care provider tacitly accepts that the privilege of
healing and comforting the sick is associated with some risk for
exposure to contagious disease. However, the provider is not
expected to take undue risks, and every effort must be made to
On the basis of the data
reviewed here, we believe that the risk for acquiring an
infectious disease during CPR or CPR training is low: Only 15
well-documented cases have been reported in the past 30 years. In
contrast, the performance of CPR may be associated with a far
higher risk for stress-related illness, such as myocardial
infarction [206,207]. But even with allowance for 100-fold
underreporting, the risk to a potential rescuer is still low,
less than 1 in 2000 resuscitations; moreover, the risk for
acquiring HIV, HBV, or HCV infection is extremely low, about 1 in
one million . In contrast, prompt performance of CPR can
save the life of the person in cardiac arrest 10% to 15% of the
time [6,7]. It seems clear that the societal benefit of
administering CPR to a patient in cardiopulmonary arrest (10 000
to 15 000 lives saved per year in the United States) vastly
outweighs the risks for secondary infection in the rescuer or the
Recent research suggests
that chest compression is more important in achieving adequate
ventilation than mouth-to-mouth ventilation alone [208-211]; in
the future, rescue breathing may not be considered necessary for
basic cardiac life support. For now, it is still considered an
integral feature of CPR .
Despite the very low
risk for acquiring an infectious disease during CPR, efforts must
be made to reduce risk even further (Table 8 and Table 9).
Although more data are needed on the efficacy of oral barrier
devices in preventing infection, these devices should be made
more widely available, both in the hospital and in the community.
Similarly, needleless systems should be used whenever possible,
and procedures for the safe disposal of sharps must be taught and
reemphasized. In addition, all susceptible rescuers and public
protection professionals should be immunized against HBV.
Training programs for CPR must emphasize personal protection and
must follow recommended protocols for decontaminating mannequins
that could harbor infectious agents.
Finally, every hospital
must have a comprehensive protocol (Table 8) to assure
expeditious evaluation and, when indicated, postexposure
prophylaxis, counseling, and long-term follow-up. Public protection
personnel, health care workers, and laypersons who perform CPR
must also have access to such protocols, postexposure evaluation,
Note: A longer version
of this monograph will be published in Weil MH, Tang W, eds. CPR:
Resuscitation of the Arrested Heart. Philadelphia: WB Saunders;
Grant Support: In part
by an unrestricted grant for research in the prevention of
infection from the Oscar Rennebohm Foundation.
Requests for Reprints:
Dennis G. Maki, MD, H4/574 University of Wisconsin Hospital and
Clinics, 600 Highland Avenue, Madison, WI 53792.
Addresses: Dr. Mejicano: J5/210 University of Wisconsin Hospital
and Clinics, 600 Highland Avenue, Madison, WI 53792.
Dr. Maki: H5/574
University of Wisconsin Hospital and Clinics, 600 Highland
Avenue, Madison, WI 53792.
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