As in Incident command...

IC established!
We'll have several different sections reporting in - recent research, local topics, or highlighting areas of the Sponsor Hospital Council of Greater Bridgeport protocols.

*** Keep in mind - this website does not replace your protocols, and these posts do not reflect SHCGB or Bridgeport Hospital policies. This is a place to discuss research, controversies, or discuss possible future protocols. When in doubt, check your current protocols through the official source.

Friday, March 8, 2013

Nitroglycerin - Old and New: Pt 1

The modern medic gets to use a lot of fancy technology. She interprets capnographic waveforms, reads 12-lead (and 13- and 15-lead) ECGs, places ET tubes, LMAs , and CPAP masks, uses portable lactate analyzers, and even knows how to spell "sphygmomanometer."

Let's face it - compared with all that, nitroglycerin is not a "sexy" EMS tool. 

Unlike this little beauty. You know, I think I've seen this before...
Nitro has been used for angina since 1879, and was also used for "spasms," headaches, and even toothaches. After 133 years of clinical experience, it seems we would have nothing new to say. For example, we take for granted 2 things about NTG:
  • The dose is one tab (or spray), every 5 minutes, to a maximum of 3 doses; and
  • You should to do an ECG to check for an inferior MI before giving it.
I'll talk about using "high-dose" nitro tablets for CHF in Part 1 today, and discuss the evidence-based concerns about using NTG during an inferior or right-sided MI in Part 2.

Increasing the dose - 1, 2, or 3 tabs sublingual
In case you haven't heard, Lasix is old-fashioned, at least for EMS. It's not a good drug for acute hypertensive congestive heart failure, for any number of reasons, and the modern EMS system uses CPAP and nitro instead.

So how do I usually give NTG for CHF? Once the patient gets to the hospital, I'll use a starting dose of IV NTG at 200 - 400 µg/minute.For the first 20 minutes I'll be adjusting the dose up & down pretty frequently, until the patient's breathing gets better, and the BP has come down.

However, the sublingal NTG dosing used by EMS for CHF is usually the same small dose used for angina pectoris, 0.4 mg every 5 minutes. That's about 80 µg/minute, if you assume that it's absorbed over that 5 minutes. 

Let me point out some basic math:


80 µg < 400 µg

As an emergency doctor, I can get around this problem easily: if I don't have IV NTG available, I give several NTG tabs at once. While the nurses are scrambling to get a second IV and program the IV pump, and the respiratory tech is setting up the CPAP, I'm practically dumping the bottle of NTG under their tongue. The higher their blood pressure is, the more I can give. And I don't stop at 3 doses either; I keep giving it every 5 minutes until the IV juice is flowing.

So, this strategy makes sense pharmacokinetically, and some paramedics having been doing this for years, albeit "off-protocol". For one example, read Peter Canning's excellent blog post NTG and The Hero Medic, about a medic who, evidently, felt comfortable with pretty aggressive NTG doses.

So it's good to read about an EMS system that decided to act rationally, and then study it. In an abstract in the most recent Prehospital Emergency Care, EMS researchers in Buffalo discuss their experience with changing the EMS protocol to allow multiple simultaneous doses of nitro for CHF with hypertension, depending on the BP. I copied the entire article below, but the protocol was simply:
        • SBP < 160 mmHg --> 1 tab (0.4 mg)
        • SBP > 160 mmHg --> 2 tabs
        • SBP > 200 mmHg --> 3 tabs
        • Repeat as needed, no maximum # doses
So were patients dropping like flies from this crazy dosing? 

Not so much. Out of 95 patients who got the high-dose NTG, only 3 patients dropped their BP. Which could have been concerning, except that the breathing of those patients was better (which is the whole point), while the hypotension was transient, resolving on the next BP measurement. 

The Bottom Line
Nitroglycerin is an old drug, but we are still learning about how to best use it. Our old habit of "1 q 5', to a max of 3" is perhaps just that, an old habit!

The SHCGB Guidelines, on the other hand, do not set a limit on the maximum number of doses that can be given, and allow the medic to aggressively treat CHF. If the blood pressure is severely elevated during an episode of likely CHF, you can give up to 4 tablets at a time.


Unfortunately, some paramedics may have ingrained patterns of behavior, and there may be doctors who haven't heard about developments in nitro use since 1880. Time to drag them into the 21st century, with all our fancy "new" medications and medical devices!

As for the "sexy" airway tool that looked so familiar above...

Found it!





PREHOSPITAL ADMINISTRATION OF MULTIPLE SIMULTANEOUS NITROGLYCERINE SUBLINGUAL TABS RARELY CAUSES HYPOTENSION
Brian Clemency, Gina Tundo, Jeffrey Thompson, Heather Lindstrom, University at Buffalo, State University of New York
  Background. High-dose intravenous nitroglycerin is a common in-hospital treatment for respiratory distress due to congestive heart failure (CHF) with hypertension. Intravenous nitroglycerin administration is impractical in the prehospital setting. In 2011, a new regional emergency medical services (EMS) protocol was introduced allowing advanced providers to treat CHF with oral nitroglycerin. Patients were treated with two sublingual tabs (0.8 mg) when systolic blood pressure (SBP) was >160 mmHg or three sublingual tabs (1.2 mg) when SBP was >200 mmHg every 5 minutes as needed. To assess the protocol’s safety, we studied the incidence of hypotension following prehospital administration of multiple simultaneous nitroglycerin (MSN) tabs by EMS providers. 
Methods. A retrospective case review of records from a single commercial EMS agency over a six-month period (January–June 2012). Cases with at least one administration of MSN were reviewed. For each administration, the first documented vital signs before and after administration were compared. Administrations were excluded if they were missing pre- or post-administration vital signs. Blood pressure was measured in mmHg.  
 Results. One hundred cases had at least one MSN administration by an advanced provider during the study period. Twenty-five cases were excluded because of incomplete vital signs. Seventy-five cases with 95 individual MSN administrations were included for analysis. There were 65 administrations of two tabs, 29 administrations of three tabs, and one administration of four tabs. The mean change in SBP following MSN was –14.7 (standard deviation 30.7; range +59 to –132). Three administrations had documented systolic hypotension in the post-administration vital signs (97/71, 78/50, and 66/47 mmHg). All three patients were over 65 years old, were administered two tabs, had documented improved respiratory status, and had repeat SBP of at least 100 mmHg. The incidence of hypotension following MSN administration was 3.2%.  
 Conclusion. Hypotension was rare and self-limited in this sample of prehospital patients receiving MSN. 
 

 

14 comments:

  1. I love being asked, "how much nitro did you give?" If only for the simple pleasure of seeing the contortions people's faces make when you give the offhand reply of "probably 30 sprays or so."

    ReplyDelete
    Replies
    1. How long was the transport? Perhaps you were underdosing, and they didn't know how to tell you.

      By the way, thanks for pointing out the Yannopoulos paper - great picture!

      Delete
    2. 12 minutes with the patient if I recall. We had to tell the doc 3 sprays so they wouldn't have a stroke, then I was chided for not using NTG paste after 3 sprays...

      (No prob on the picture, it really did make me think about that Steve Berry comic. Oh, met him last month, great guy in person too.)

      Delete
  2. Nitro tablets? Have I come across a blog from 1988 or so?

    My former system started using NTG spray about then. In 1989 our medical director issued a memo stating that a CHF patient with a systolic BP of 150 or greater was to get NTG spray x 2 every five minutes. After three of those we could call medical control and get an order to continue until the Systolic was at 110.

    Over the years that evolved to NTG sprays x 2 about every 2-3 minutes apart.

    That only ended when we got CPAP because we had no mechanism to give sprays. CPAP seems to work better anyway, but if I were still working in the field, I'd be agitating for either IV NTG or even NTG paste.

    The shocking thing is that any systems think of this as cutting edge in 2013.

    ReplyDelete
    Replies
    1. Nah, it's a blog from 1888!

      Perhaps it isn't cutting-edge, but it's good to see some modest amount of research backing up common sense and clinical experience. Many people are still stuck at the "1 q 5" level, either due to education or mental-framing issues, so these results are helpful.




      Delete
    2. Sadly some people are still stuck in the "Nitro is only for chest pain..." mode as well.

      I don't know how EMS will ever become a profession at this rate.

      Delete
  3. A big thanks to Dr Oselumen i never believe that there still exist a real death spell caster after all this years of disappointment from the enormous spammers on the Internet who go about scamming people, until i was opportune to meet Dr Oselumen a real spell caster, through a close friend called Jennifer who Dr oselumen had helped before, when i contacted him with his email via droselumen@gmail.com i explain how my ex have been giving me problem in my marriage, she never allowed me a moment of peace, and i need to end it by killing her, and i don't want to make use of assassin because it will be risky so i needed to do it in a spiritual way that's why i decided to contact him, he assured me not to worry as i have contacted the right person at the right time, i co-operated with him and in less than a week my ex was dead, she slept and never woke up all thanks to Dr Oselumen indeed he's really a humble man. you can contact dr oselumen for any death spell, such as to kill your superior in the office and take his or her place, death spell to kill your father and inherit his wealth ,death spell to kill anyone who have scammed you in the past ,spell for increase in salaries, spell for promotion at the office, spell to get your ex lover back, if things is not working well in your life then you need to contact him now via Email droselumen@gmail.com call or add him on whatsapp +2348054265852.

    ReplyDelete
  4. get your ex back with a love spell that works fast.
    Dr.Jumba has helped thousands of women get their Ex boyfriends back using his real effective love Spell. After my boyfriend of one year broke up with me, I could barely speak without crying. I felt blindsided and didn't know what to do. I didn't know if I could get him back and the anxiety was unbearable. I needed him back desperately because I loved him so much. So I contacted this great spell caster for help. He helped me cast a return love spell on him and just within 11 hours my boyfriend came back to me crying and begging for my forgiveness. Dr. Jumba released him to know how much I loved and wanted him. And He also opened his eyes to picture how much love we have shared together. As I am writing this testimony right now I am the happiest woman on earth. I want to recommend this great spell caster to anyone that truly needs an urgent solution to a love break up. Email him at wiccalovespelltools@yahoo.com or wiccalovespelltools@gmail.com or Call/WhatsApp him: +19085174108 "I'm so grateful and can say that if you have been broken up with and want to get that person back, Dr.Jumba is the best! I'll never forget how much he helped me
    WEBSITE : drjumbaspellhome.wordpress.com , blog : https://wiccaspelltools.blogspot.com/

    ReplyDelete
  5. i have been suffering from a deadly disease (Hsv) for the past 3 years now, I had spent a lIot of money going from one places to another, from churches to churches, hospitals have been my home every day residence. Constant checks up have been my hobby not until this faithful day, I was searching through the internet, I saw a testimony on how Dr Onokun helped someone in curing his (Hsv) herpes disease, quickly I copied his email which is Dronokunherbalcure@gmail.com just to give him a test I spoke to him, he asked me to do some certain things which I did, he told me that he is going to provide the herbal cure to me, which he did, then he asked me to go for medical checkup after some days after using the herbal cure, behold I was free from the deadly disease, he only asked me to post the testimony through the whole world, faithfully am doing it now, please brothers and sisters, he is great, I owe him in return. if you are having a similar problem just email him on : Dronokunherbalcure@gmail.com

    ReplyDelete
  6. Hi viewers online, I'm Alfonso Vázquez from Mexico. I'm here to share my testimony about how i was helped to get my wife back. I was a cheat and my wife caught me several times. I tried fixing myself and each time i ended up cheating over and over again. I guess i didn't realise what she meant to me until she had left me alone. I began to find a way to get her back but nothing seems to work out perfectly till i came across an article about Lord Zakuza who helped a lot of people globally to get their relationships back. I made contact with him on his WhatsApp number via +1 740-573-9483 and he assured me that my wife will come back to me within 48 hours with his powerful magics and i paid 410 Euros for the materials needed for the work. Surprisingly, my wife came back home after 2 days saying that she still loves me and i swore never to cheat on her anymore. All thanks to Lord Zakuza. Email him via ( lordzakuza7@gmail.com ) or WhatsApp number via +1 740-573-9483.

    ReplyDelete
  7. I completely trusted Dr Paul totally from the time I spoke with him during the period my husband Left me  after11 years of our marriage, He started the spell work on my husband, and gave me so much assurance and guaranteed me that he was going to bring my husband back to my feet in just 48 hours of the spell casting. I was so confident in his work and just as he said in the beginning, my husband is finally back to me again, yes he is back with all his hearts, Love, care, emotions and flowers and things are better now. I would have no hesitation to recommend this powerful spell caster to anybody who is in need of help.. E-mail; astoriashrine @ gmail com

    ReplyDelete
  8. Hello everyone.  I want to share my amazing experience with the great spell caster Dr Mark my husband was cheating on me and when I found out we had a fight which lead him filling for a divorce I cried and fell sick when I was searching about love quotes online I saw people talking about Dr Mark and his great work whose case was similar to mine they left his contact info I contacted Dr Mark and he told me not to worry that after 24 hours he will cancel the divorce and my husband will be back to me after I did everything he asked me to do to my greatest surprise the next day evening it was my husband he knelt down begging me to accept him back, thank you once again Dr Mark you are indeed a blessing to me he can also help you. contact Dr Mark through his email address on: blessedlovetemple@gmail.com

    ReplyDelete
  9. I want to thank of great Dr. Todd he brought my boyfriend back to me. i had seen many people to get him back but nothing, Dr. Todd gave me a consultation and told me all truth, and I trusted Dr. Todd and had him do the spells for me. it took awhile because it was very very messy between us. i had to wait for each spell to do its work. but once the last spell finally was working and the other spells had worked, that is when he called. we met. then it took many more meetings. but now we are back together and i can only thank Dr.Todd, he is the greatest, i will come to Dr. Todd for life. Todd took care of me like family. contact; manifestspellcast @ gmail. com manifestspellcast.wordpress.com
    WhatsApp:+1 604 901 9747

    ReplyDelete
  10. TRUTH BE TOLD!!! There are no perfect relationships. If you truly care and love your partner, don't fight him or her.. instead, fight to keep him/her. This was exactly what I did and with the help of Dr Akhigbe my ex returned back to me and I believe there a lot of people going through heartbreak, Dr Akhigbe can also help you. Email address drakhigbespellhome7@gmail.com

    ReplyDelete