Peter Canning writes about a study of high-dose SL (SubLingual) NTG (NiTroGlycerin – GTN GlycerylTriNitrate in Commonwealth countries) by EMS for CHF (Congestive Heart Failure).
I have some problems with the study.
This is just moderate-dose, not high-dose.
I have had protocols that allow for more aggressive dosing (every 3-5 minutes) going back to 2008.
I have probably given more triple-dose NTG than was given to the entire intervention group. I have given over 50 SL NTG to just one patient, while they only managed to give a total of 87 tablets in 29 triple doses in the entire study.
It is good to provide more evidence that multiple dose NTG is safe, but we have had good evidence that prehospital high-dose IV NTG dramatically improves outcomes since the 1990s.
We need more prehospital aggressive IV (IntraVenous) NTG research.
Administration of high-dose nitroglycerin is an effective treatment that has been shown to improve the respiratory symptoms associated with ADHF, and decrease the incidence of death due to myocardial infarction and mechanical ventilation, particularly when initiated early.4 – 6 
I agree with that.
However, EMS is the
best earliest place to start IV NTG.
From 1984 through 1991, new guidelines for the use of intravenous nitrates, based on differential treatment according to blood pressure, were in use.
Overall prehospital mortality rate for APE in all patients was 7.8% (50 of of 640 patients). Mortality after 1984 was significantly lower than before (5.3% versus 13%, P < .01). Nitrates were effective in reducing mortality, even in hypotensive patients. Multivariate analysis showed that outcome was significantly affected by two clinical features (dyspnea and low blood pressure), treatment with nitrates, and calendar period effects (before/after 1984).
Not just hypertensive patients, but also hypotensive patients benefited from EMS IV NTG!
Nitrates were effective in reducing mortality, even in hypotensive patients.
The CHF death rate dropped from 13% all the way down to 5.3%
Am I complaining that the current study is useless?
Not at all.
There is some excellent information that debunks much of the dogma against multiple-dose NTG.
3 cases, but only in the double dose group.
All of the hypotension went away without any treatment.
Zero cases in the triple dose group and the quadruple dose patient did not become hypotensive.
For CHF, more NTG does not produce more of a drop in blood pressure.
Provide evidence, not anecdotes.
Part II will look at the evidence of safety from this study more closely.
Also see –
Is a half a bottle of nitro too much for a single dose?
Sun, 18 Nov 2012
NTG and the Hero Medic
November 7, 2012
 Congestive Heart Failure
5002– ALS – Adult/Peds
2008, 2011, and 2013 Statewide ALS Protocol
Page with link to Full Text Download of Full Protocols in PDF format.
 Prehospital High-dose Sublingual Nitroglycerin Rarely Causes Hypotension.
Clemency BM, Thompson JJ, Tundo GN, Lindstrom HA.
Prehosp Disaster Med. 2013 Aug 21:1-4. [Epub ahead of print]
PMID: 23962769 [PubMed - as supplied by publisher]
 Intravenous nitrates in the prehospital management of acute pulmonary edema.
Bertini G, Giglioli C, Biggeri A, Margheri M, Simonetti I, Sica ML, Russo L, Gensini G.
Ann Emerg Med. 1997 Oct;30(4):493-9.
PMID: 9326864 [PubMed - indexed for MEDLINE]
Clemency BM, Thompson JJ, Tundo GN, & Lindstrom HA (2013). Prehospital High-dose Sublingual Nitroglycerin Rarely Causes Hypotension. Prehospital and disaster medicine, 1-4 PMID: 23962769
Bertini G, Giglioli C, Biggeri A, Margheri M, Simonetti I, Sica ML, Russo L, & Gensini G (1997). Intravenous nitrates in the prehospital management of acute pulmonary edema. Annals of emergency medicine, 30 (4), 493-9 PMID: 9326864