The surgeon is regularly exposed to blood, which is the most infective
medium for HIV transmission. The risk must be greater where there are more HIV
particles in the blood and this occurs during the earliest and later stages of
the disease (Fig. 9.2). Thus, patients undergoing surgery who have had a recent
seroconversion illness and who may be unaware that they are HIV positive are
infectious, as well as patients who are known to be HIV positive. The extent of
risk to the surgeon depends on the prevalence of HIV in the patient population,
the number of procedures carried out by the surgeon, and the length of the
period of risk. It is estimated that the risk to a surgeon working in a
high-prevalence American or European inner city area over a 30-year career is
roughly a one in 800 chance of acquiring HIV infection. In Africa, where the
prevalence of HIV disease is thought to be much higher and the risk of HIV
infection in blood products is also higher, a similar career risk has been
estimated to be as high as one in four.
Sources
of infection
The principal route of occupationally acquired HIV infection in
healthcare workers is by skin perforation with a hollow needle containing
HIV-infected blood. Although infection has been reported after solid needle skin
perforation, the risk seems to be about 10-fold less than with hollow needle
perforation where more blood may be injected. Extensive splashing of mucous
membranes and skin, as occurred with spillage of a pack of blood over a nurse,
has also been reported to produce HIV infection.
Precautions
Although screening of all patients for HIV infection before routine
surgery would identify a substantial proportion of patients who might infect the
surgeon, this has not, been accepted because of political and social constraints
in most countries. The risk of contamination to the surgical team can be reduced
by the use of ‘universal precautions’ involving wearing either safety
spectacles or a face mask (Fig. 9.10), and a gown which provides waterproof
protection to the surgeon’s anterior trunk and arms. In addition, boots
rather than open-toed shoes should be worn to improve protection to the feet
should something sharp be dropped. Needle-stick injuries to the hands most
frequently occur on the index finger and palm adjacent to the thumb of the
nondominant hand. This is presumably a result of passing the needle through
tissue with a needle holder held by the dominant hand and attempting to locate
the tip of the needle with the nondominant hand which is also used to retract
tissue. Skin contamination from glove perforation can be reduced approximately
fivefold by wearing two pairs of gloves. It is usually more comfortable if the
larger-sized glove is worn on the inside next to the skin and a half-size,
smaller glove is worn as the outer second layer.
The
most important operative precaution is to carry out the procedure in an orderly
manner. Surgical assistants should be kept to a minimum and should be instructed
not to move while the operation is proceeding. If the assistants’ position is
to be adjusted then the operating surgeon should stop operating while changes
are being made. This should avoid the risk of the operating surgeon injuring an
assistant’s hand while it is being moved across the operative field. The
operation should proceed in a slow and methodical manner with meticulous
attention to haemostasis, taking care to avoid unexpected rapid bleeding which
changes the tempo of the procedure and increases the risk of inadvertent injury
to the operators. No sharp instruments or scalpels should be passed across the
operative field from hand to hand. All instruments are passed from the scrub
nurse to the surgeon and back to the scrub nurse in a dish (Fig.
9.11), thereby
reducing the risk of injury while passing instruments.
• homosexual lifestyle;
• a history of intravenous drug abuse;
• a history of haemophilia treated with factor VIII;
• residents of sub-Saharan Africa;
• the partners of the above, higher risk groups.
Procedure
in the event of contamination with infected blood
A surgeon who has been contaminated with HIV-infected blood should
immediately clean the contaminated area by washing under running water. Where
the source patient comes from a high-risk group and the HIV status is unknown,
it is important that postexposure prophylaxis to HIV should be offered. This
should be started within 1 hour of the injury where possible, so it is
inappropriate to await the result of an HIV antibody test in a high-risk patient
before commencing the prophylaxis. The prophylaxis consists of: zidovudine 250
mg twice daily, lamivudine 150 mg twice daily and indinavir 800 mg three times
daily for I month. The surgeon should then be given hepatitis prophylaxis
since the risk of developing hepatitis after contamination with blood from a
high-risk patient is greater than the risk of HIV infection. A baseline HIV test
should be carried out immediately since seroconversion will not have occurred
immediately after injury. The HIV test should then be repeated approximately
12 weeks after contamination to determine whether seroconversion has occurred.
This is obviously a period of great anxiety, and advice about domestic relations
and procedures at work should be obtained from an HIV counsellor.
Where
a medical practitioner discovers that he or she is HIV positive, the requirement
of the UK General Medical Council is that ‘if their duties involve performing
or assisting in surgical or invasive procedures, they must seek and act upon
occupational advice on any modifications or limitations to their duties which
may be necessary for the protection of patients’.