Thursday, 19 October 2017

Tetanus

In any patient with a wound, first do a risk assessment of the wound, and then their tetanus status:

Tetanus Prone Wound:  >6 hours old and needs surgical treatment
                                      Open compound fracture
                                      Contaminated puncture wound
                                      Clinical evidence of sepsis

High risk tetanus prone wound?   Yes - give immunoglobulin
                                    Heavy contamination with material likely to contain tetanus eg. manure
                                    Extensive devitalized tissue
                                    >24 hours since injury
                                    >10% burns

Tetanus Status Assessment 
Full immunisation - give immunoglobulin if very high risk
Partial immunization - give DTP if next dose due soon, if high risk give immunoglobulin
Not up to date  -give DTP.  Immunoglobulin
Uncertain - give DTP

Immunoglobulin
Give 500iu if it's a high risk tetanus wound
Give 250iu if it's a tetanus prone wound
Need a second dose of Ig if they can't have DTP, or if they have reduced capacity for antibody formation - radiotherapy, hypogammaglobulinaemia

Give both injections in different arms
If have a bleeding disorder, give SC. There is a higher risk of reaction when these are given SC rather than IM.



Tetanus
Tetanus is caused by C. tetani, a gram positive, anaerobic that is commonly found in soil and manure. It produces tetanospasmin, the neurotoxin that causes tetanus. Incubation 10 days. The infection is a  clinical diagnosis, defined as trismus with one or more of the following:
Spasticity
Dysphagia
Respiratory distress
Muscle spasms
Autonomic dysfunction

Treatment
Metronidazole - stop bacterial replication
Diazepam or midazolam - to control muscle spasms
Intravenous tetanus immunoglobulin -5,000 units < 50kg, 10,000 >  50kg. This is the same as the "treatment".
Intubation - may be needed. Sux is safe but there is a very high risk of autonomic instability
Wound cleansing and debridement




SAQ:
A forty eight year old patient attends the emergency department feeling unwell. They have an infected injection site in their anticubital fossa. They have severe trismus, and are writhing around with severe muscle spasms. Sister thinks security needs to escort them out. You suspect that they have a serious and rare infection from their injection site.

a) How would you manage the muscle spasms?
Supportive care with diazepam or midazolam.
b) How would you treat their infection?
You suspect tetanus - or you should because of the spasms. The patient needs supportive care, with monitoring and consideration of early intubation. Give metronidazole to prevent bacterial relocation. Give IM tetanus immunoglobulin 150 units/ kg. IV is no longer available. Monitor their renal function.
Wound debridement.
Watch for autonomic instability, and cardiac collapse. Sedation, and morphine to help reduce the amount of free catecholamine can be helpful.
c) How would you confirm infection?
Tetanus is a a clinical diagnosis.
You can look for serum levels, but these take so long for results to come back - don't delay treatment for serological confirmation.
- Tetanus IgG - If the antibody level is >0.1 IU/ml before IgG, this excludes current tetanus infection. - Detection of toxin in serum is a bio-assay and is only performed if the antibody level is below the protective threshold.
- Absence of toxin does not exclude tetanus.
- Detection of C. tetani in wound material or from a pure isolate

References
http://pedemmorsels.com/tetanus-prevention/
http://stemlynsblog.org/tetanus-in-the-ed/
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/441356/IMW166.02_Tetanus_information_for_health_professionals_v1.4__2_.pdf
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/441355/IMW165.02_Tetanus_Immunoglobulin_Handbook_v1.4.pdf
https://www.gov.uk/government/publications/tetanus-the-green-book-chapter-30
https://www.rcemlearning.co.uk/modules/tetanus/
https://www.rcemlearning.co.uk/foamed/september-2017/#1504201252016-ac52229b-9e50

No comments:

Post a comment