Case• 31. Ouch!
You sustain a substantial percutaneous injury to your foot. What should you do?
|Murphy’s law in action. Nice shoes.
You are extracting a difficult tooth and have used a luxator to loosen the tooth prior to elevation. While transferring the luxator to the bracket table, you drop it. The luxator impales itself in your foot.
▪ What diseases of significance may be transferred by the injury?
Most infectious diseases can be transmitted by a sharps injury but the main concerns are hepatitis B, hepatitis C and human immunodeficiency virus (HIV) infection.
▪ What would you do immediately?
Encourage bleeding at the injury site and wash it with soap and water but without scrubbing. Antiseptics should not be used as their effects on the local defence mechanisms are unknown. Free bleeding should be encouraged.
▪ What is the most urgent priority and why?
The most urgent priority is to assess whether there is a significant risk of transmission of HIV infection. Postexposure prophylaxis (PEP) with antiretroviral drugs can significantly reduce the chance of transmission of HIV, but for maximum effectiveness it is recommended that it is administered within 1 hour, and certainly within a few hours. The reduction in risk may be as high as 81%. There is limited evidence that some protection of transmission is still given if the administration of the PEP is delayed, even by as much as 48–72 hours.
▪ How could you obtain postexposure prophylaxis if required?
The Health Act 2006 requires that every NHS employer has a policy on the management of exposure to blood or other bodily fluids. The policy must ensure that advice is available 24 hours a day.
PEP is only available following a formal risk assessment for each individual injury. This involves determining the severity of the injury and the risk that the patient is carrying HIV infection.
The procedure for obtaining a formal risk assessment varies with local circumstances. In hospitals, the infection control consultant(s), hospital casualty or occupational health department will perform the risk assessment and provide the appropriate medication. Those in general practice must contact their local hospital casualty department who will follow their local guidelines. Each dental practitioner should know the contact number and name/position of the appropriate person.
When you phone you will be asked details of the injury and patient. You will then be told whether or not the injury is sufficient to carry a risk of transmission and whether a risk assessment of the patient is required.
▪ What is the risk of developing HIV infection following a sharps injury?
The average risk for transmission of HIV is estimated at 3 infections per 1000 injuries.
▪ What factors affect the risk of transmission?
An increased risk of occupationally acquired HIV infection is associated with:
• A deep injury
• Visible blood on the device that caused the injury
• Injury with a needle that has been in a blood vessel
• A high viral load in the source patient.
The risk from a needlestick injury where the needle has been used to administer a local analgesic is therefore lower as the needle would not be expected to have been placed in a blood vessel if an aspirating syringe was used. PEP is therefore often unnecessary for a needlestick injury from a dental anaesthetic needle.
Splashes of infected blood carry a low risk. Splashes on to broken skin or mucous membranes, including the eye, carry a risk of transmission estimated at being less than 0.1%. It is considered that there is no risk of transmission from a splash of blood on to intact skin.
The viral load is a measure of the virus concentration in the blood. It is higher during the primary infection (the so-called window period), reduces with early infection but then rises with symptomatic and late-stage infection (acquired immunodeficiency syndrome: AIDS). It is reduced with effective treatment.
Your injury is a deep injury by a sharp instrument covered with blood and therefore there is a risk of transmission of HIV.
▪ The patient has returned to the waiting room with your nurse. What will you say and do?
You should explain to the patient exactly what has happened and that there has been an accident involving a surgical instrument and that there is a practice policy, derived from national policy, that should be carried out when this happens. Introducing the HIV assessment of the patient in this way depersonalizes the incident and avoids making difficult judgements, and discriminating against perceived ‘high-risk’ groups for HIV infection. If the policy is written and shown to the patient then this can prevent the patient feeling discriminated against.
The patient should be asked to give informed consent for blood to be taken and tested for HIV, hepatitis B and hepatitis C and for storage of serum. If infection is transmitted, it will be necessary to compare the patient’s sample and the sample of your blood for industrial injury benefit or insurance purposes.
Lengthy pretest counselling is now no longer a requirement prior to testing for HIV. It is only necessary to provide it if the patient requests it or needs it. The benefits of testing to both the dentist and the patient should be stressed. If the patient has an undiagnosed HIV infection then an earlier diagnosis is more likely to lead to effective treatment, and the dentist can have the most effective prophylaxis to prevent transmission. Most patients will be happy to give a sample of their blood under these circumstances. If not, then the reason for the refusal should be explored as sensitively as possible. It may be that patients have an inaccurate idea that they have in some way done something illegal or hold a false belief about the virus itself.
The general population have little knowledge of hepatitis but understand that it is a serious disease and may be aware that it can be transmitted sexually. As a minimum, blood should be obtained to store the serum in case testing is required at a later date.
The dentist will most likely not have the facilities to take the blood and the patient can be asked to go to his or her general medical practitioner with a request or to attend the local Accident and Emergency department. If the dentist does carry out the test then the patient should collect the results from the general medical practitioner.
The possibility that the patient might be HIV-positive will have to be addressed in order to assess the risk of transmission. This must be done in a sensitive manner, preferably in a quiet room and with reassurance about the confidentiality of any answers given. The questions should not be asked by the recipient of the needlestick injury because it is difficult to be objective if you are feeling anxious or distressed. However, in dental practice there may be no other person to handle this issue and you may have to ask the questions yourself. As an alternative you could consider asking the patient to speak on the phone to the local casualty officer responsible for the PEP, sexual health clinic medical staff, a sexual health counsellor or other experienced person.
You should remember that it is not the risk factor that denotes the risk of transmission but how the activity takes place which dictates the relative risk (Table 31.1).