Authors: Mark Winstanley, Andy Neill, Dave McCreary, Becky Maxwell, Chris Connolly, Michelle Tipping / Codes: DC5, RP6, SLO1, SLO10 / Published: 02/12/2020
Is lactate lower in septic patients who are prescribed beta blockers?
Title of Paper
Is lactate lower in septic patients who are prescribed beta blockers? Retrospective cohort study of an intensive care population.
Journal and Year
Emergency Medicine Australasia. 2020.
– We like measuring lactate in sepsis – it’s one of the sepsis 6 and the one hour bundle
– High lactate in sepsis is an independent predictor of mortality
– Everyone says lactate comes from ‘anaerobic respiration’ due to tissue hypoperfusion and so prompts haemodynamic resuscitation to improve oxygen delivery.
– This has, however, been questioned (Paul Marik gave a good talk on it at SMACC Chicago, which should be available on their podcast feed) with studies suggesting multiple factors contribute to raised lactate including accelerated aerobic glycolysis stimulated by catecholamines.
– Beta receptor mediated stimulation of Na/K ATPase pump may play a major role in this.
– If this is the case, then patients on beta blockers should have a suppressed response and so lower lactate measurements
– Retrospective cohort study in the ICU of a rural referral hospital in NSW
– Patients from hospital database meeting APACHE III Dx of sepsis and free text search for ‘sepsis’ or ‘septic shock’
– Limited data for SOFA score caused them to revert to older SIRS definition of sepsis
What did they do?
– Compared the first measured lactate of these patients to compare that in patients on regularly prescribed beta blockers to those who weren’t
– First measured in ED or retrieval presentation, or during the episode where sepsis was diagnosed
– Sample size calculation looking for a difference of 1 mmol/L between groups
– Analysed covariates for site of first measured lactate
– Compared mortality between groups
Summary of Results
– 189 patients
– 49 on beta blockers
– 140 not beta blocked
– BB patients were older (71 vs 63.5 years) and more commonly male (76 vs 50%)
– More of the BB groups’ first lactate was on the ward (37 vs 21%)
– NO differences in baseline heart rate (interesting) (111 vs 109), SBP and Sats same
– BB 2.55 (2.05-2.97) mmol/L
– NBB 3.56 (3.07-4.05) mmol/L
– Difference 0.33-1.67 mmol/L
– Lactate higher in ED/Retrieval vs ward (difference 1.65 (0.78-2.52)
– Adjusted for this, lactate still lower in the BB group that NBB, difference 0.87 (0.05-1.69)
– Mortality – no difference 20 (NBB) vs 16% (BB) – though not powered for this at all
– They didn’t assess or adjust for volume of fluid resuscitation
– We don’t know what medication compliance was for the BB group – may explain lack of difference in baseline haemodynamics
In our cohort, pre-existing beta blocker treatment was associated with lower serum lactate measurements in patients presenting with sepsis. Pre-existing beta blocker treatment may reduce serum lactate at presentation in patients with sepsis.
Clinical Bottom Line
Probably more conceptual and hypothesis generating than anything, and adds to evidence that there is more to lactate than anaerobic respiration.
I think clinically it can sit somewhere in the back of your mind for consideration when assessing severity of sepsis in a patient on beta-blockers.
Other #FOAMed Resources / References
This month Chris and Becky turn their eye on the NICE guidelines on bites and stings released in September 2020 and the allied guideline on Lyme disease.
The guideline covers bites and stings including those occurring overseas for all UK patients over 72 hours old!
Most rapid onset reactions are not infection – they are more likely local inflammation or allergic reaction
Most bites DO NOT need antibiotics.
Itching can last up to 10 days.
It is unlikely the bite will become infected.
So first key point: it isn’t Lyme’s disease…….
Comes from tick bites, ticks are in multiple locations in the UK but significant populations in the Scottish Highlands and southern England.
If you need to remove a tick – gently grasp with tweezers near the skin and lift away. Don’t twist.
Look for erythema migrans – this is NOT itchy.
Lyme disease has multiple possible clinical signs and symptoms – have a look at the full guidelines for the full list.
Do not diagnose Lyme disease just because someone has a tick bite.
Do not rule out Lyme disease in people with symptoms but no clear history of a tick bite
You have to be thinking of Lyme to diagnose it……get reading the guideline!!
– does the PPE for COVID-19 work for health care professionals
– Use of personal protective equipment against coronavirus disease 2019 by healthcare professionals in Wuhan, China: cross sectional study
– Liu, 2020, BMJ
– since March 2020 most of our working lives have been dominated by COVID-19. Our departments have been physically and clinically reorientated to deal with this. We spend hours in and out of varying quality of PPE. All of this is based on prior infection control data and somewhat limited understanding of COVID transmission
– But does the PPE work?
– This comes from Wuhan at the beginning of the pandemic and enrolled the healthcare staff who were deployed to help (remember the news showing all those guys in buses showing up in Wuhan)
– It seems that they did almost exclusively COVID work.
– They all had standard PPE and had a buddy system for donning and doffing
– where their experience probably differed was that they all travelled to and from work in a big bus where they all wore masks and then stayed in individual hotel rooms where they had food delivered to the rooms.
– they got tested if they got symptoms and had 3 sequential tests on return and quarantine and serum antibody testing too.
– 420 staff
– 115 doctors, 304 nurses
– there were zero symptomatic staff, zero +ve swabs and zero +ve serology on return
– this is a pretty ringing endorsement for PPE in protecting us from COVID
– however it’s also a big endorsement for strict social distancing and isolation form each other. I can only imagine the carnage if you took all the staff of any ED I’d worked in and put them altogether in work and then let them live together in a hotel with a bar!
– there has been lots of talk about health care workers getting COVID-19 and undoubtedly there have been a decent number of transmissions from patient to carer however lots of us live and commute with other health care workers and lots of our friends are health care workers. Turns out we quite like each other and have a tendency to hang out even when not working and I suspect a lot of transmission is happening in those scenarios (just like it is for all the normal punters).