➡️ Antimicrobial therapy has been used for millennia
➡️ Treating severe infections can be lifesaving
➡️ However, the widespread use of antimicrobials also has downsides
A 🧵
1/16
➡️ Throughout history, honey, herbs & metals were often used
➡️ One of the earliest known antimicrobial therapies was the topical use of mouldy bread
➡️ This intervention has been recorded in many ancient civilisations, including Egypt, China, Serbia, Greece & Rome
2/16
➡️ Mercury was used for epidemic diseases since the 1300s & especially syphilis
➡️ However, the treatment could be worse than the disease, with mercury poisoning possible
➡️ Treatment could last years, leading to the saying “A night with Venus, a lifetime with mercury”"
3/16
➡️ Paul Erhlich discovered how to identify bacteria by staining them
➡️ He noted some stains were toxic for specific bacteria
➡️ In 1909, he discovered the arsenic-based Salvarsan for syphilis
➡️ This was the first modern antibiotic
4/16
➡️ Alexander Fleming famously discovered penicillin in 1928
➡️ However, it had been used long before
➡️ In 1897, Ernest Duchesne noted Arabian stable boys treating saddle sores with mould from their saddles
➡️ He isolated Penicillium notatum from the mould
5/16
➡️ German scientist Gerhard Domagk explored azo dyes, discovering Prontosil's therapeutic effects in 1932
➡️ French researcher Ernest Fourneau found Prontosil converted into sulfanilamide
➡️ This breakthrough launched the sulfonamide class & the Golden Age of Antibiotics
6/20
➡️ At the beginning of the 20th century, life expectancy was 47 years
➡️ By 2019, in the USA, it was 79 years
➡️ Infections, previously the most common cause of death, had been replaced by non-infectious causes
➡️ Antibiotics, along with other advances, had a huge impact
7/16
➡️ However, it hasn't been plain sailing
➡️ Bacteria naturally develop resistance to toxins
➡️ MRSA was first identified in 1960, a year after methicillin was introduced
➡️ Genes encoding resistance to antibiotics have been identified in 30,000 year old permafrost sediments
8/16
➡️ In 2019, there were an estimated 5 million resistance-associated deaths & 1·3 M attributable deaths
➡️ In the USA, > 2.8 M resistant infections occur yearly, with > 35,000 deaths
➡️ Globally, by 2050, there may be 10M deaths/year, costing the economy $100 trillion
9/16
➡️ There are many drivers of antibiotic resistance
➡️ These include excessive & inappropriate use of broad spectrum antimicrobials
➡️ But, with 50% of critically ill septic patients lacking an identified pathogen, how can use be reduced?
➡️ How do we square the circle?
10/16
➡️ Carbapenems are broad spectrum beta-lactam antibacterials
➡️ Their efficacy is dependent on the duration their serum concentration exceeds the pathogen's MIC
➡️ Continuous infusions can help achieve this
➡️ The aim is ⬆️ antimicrobial efficacy with ⬇️ risk of resistance
11/16
➡️ The BLING II trial compared continuous with intermittent infusions of beta lactams in 432 patients with severe sepsis
➡️ There was no significant difference in
🔴 ICU free days
🔴 90-day survival
🔴 Clinical cure
➡️ However, the trial was not definitive
12/16
12/16
➡️ Enter the MERCY trial!
➡️ An international, multi-center randomised double-blind trial in 600 pts with sepsis
➡️ Meropenem 3g continuous infusion vs 1g 8 hourly bolus
➡️ The primary endpoint is a composite outcome of mortality & emergence of drug-resistant pathogens
➡️ Throughout history, the most mystical substance of all has been blood
➡️ It has been coveted and desired
➡️ Fought for and defended
➡️ Stolen, yet freely given
A 🧵
1/16
➡️ Blood has always been a symbol of power
➡️ In Greek mythology, ichor, the blood of the Gods, was a golden fluid
➡️ It was immortal, pure, & untainted by human weaknesses
➡️ The Gods derived their divine powers & longevity from it
2/16
➡️ Blood has been revered for its restorative properties
➡️ Elizabeth Báthory, a 16th-century Hungarian noblewoman, allegedly killed hundreds of young girls & women
➡️ She bathed in their blood to maintain her youth & beauty
➡️ There are ~ 5.8 million trauma deaths per year globally
➡️ Trauma is the largest cause of death below the age of 50
➡️ One-third of severely injured trauma patients are coagulopathic at hospital arrival
➡️ Fibrinogen is often used, but is it effective?
a short 🧵
1/10
➡️ Trauma-induced coagulopathy is due to inflammation & shock
➡️ It is worsened by hypothermia, acidosis, and hemodilution
➡️ Coagulopathy due to hemorrhage is strongly associated with mortality
➡️ 1/3 of early trauma deaths are due to uncontrolled haemorrhage
2/10
➡️ Fibrinogen is depleted early during major bleeding
➡️ It can be replaced with fresh frozen plasma, cryoprecipitate or fibrinogen concentrate
➡️ Cryoprecipitate includes fibrinogen, factor VIII coagulant, von Willebrand factor, fibronectin & factor XIII
➡️ Death has always fascinated human civilisations
➡️ Not just the ending of a life, but either preparation for the afterlife or attempts to restore an existing life
A 🧵
1/28
➡️ Ancient Egyptians preserved corpses via mummification for an afterlife
➡️ They removed internal organs, used embalming fluids, linen bandages, & intricate coffins
➡️ The wealthy had pyramids
➡️ Relatives, staff & pets were buried alive for the journey to the afterlife
2/28
➡️ In Greek Mythology, the River Styx separated the worlds of the living & dead
➡️ Charon, the Ferryman, required payment from the deceased for passage
➡️ The dead were buried with a coin
➡️ Those unable to pay were left to wander the river bank for 100 years
➡️It's widely used for treatment & prevention of haemorrhage
➡️It's in the WHO's List of Essential Medicines & recommended in the European Traumatic Haemorrhage guideline (2023)
➡️But is it as efficacious as we think?
🧵 1/17
🚩 History
➡️Drs. Utako & Shosuke Okamoto invented TXA in 1962
➡️They identified that the amino acid lysine inhibited the degradation of plasmin, a profibrinolytic enzyme
➡️Lysine was modified to first produce Epsilon- Amino-Caproic Acid and later TXA, x 27 more potent
2/17
🚩 Pharmacology
➡️TXA is a molecular analog of lysine
➡️It inhibits fibrinolysis by preventing the binding of plasminogen to fibrin
➡️This inhibits plasmin formation & displaces plasminogen from the fibrin surface
➡️It also has effects on the immune system & inflammation
➡️ REBOA is an exciting "new" therapy for non-compressible torso haemorrhage
➡️ It's used across the world, but without robust evidence
➡️ Does it work? Is it beneficial?
➡️ A thread...
2/13
🚩 Uncontrollable haemorrhage accounts for
➡️ > 80% of combat deaths
➡️ ~ 40% of civilian trauma-related deaths
🚩 Many have been determined to be preventable deaths
🚩 ~ 67% of fatal bleeding occurs in the torso region
3/13
Emergency thoracotomy (ET) has a long history in resuscitation
🚩 1880 - Paul Niehans first documented ET in human cardiac arrest
🚩 1901 - Kristian Ingelsrud performed the first successful resuscitation
🚩 1953 - Stephenson had 28% survival in 1200 cardiac arrests