SGEM#522: Va-so-Pressors – Can You Run Them Peripherally?

0:00[♪ INTRO MUSIC PLAYING [♪ Welcome to the Skeptics Guide to Emergency Medicine. Meet him, greet him, treat him and treat him. Today's date is September 30th, 2026, and I'm your Skeptaglost, Ken Millm. The title of today's podcast is... Vesopressors! Can you run them peripherally? And our guest Skeptic is Dr. Aaron Skolnick. He's an assistant professor of emergency medicine at the Mayo Clinic, Alex School of Medicine, and Vice Chair of Critical Care Medicine at the Mayo Clinic in Arizona. Aaron is a full-time, multi-disciplinary, intensivist, and is the medical student clerkship director for Critical Care. Welcome back to the SGM, Aaron. Thanks, Ken. It's great to be back. You know, last time we got together, it was in Alaska, and we were talking about Magnum P.I. That was a fun course. We were at a course that we were teaching.

1:02Yeah, it was amazing. I'm not going to lie. It was maybe a little bit more epic than the small non-air conditioned room that I'm doing this podcast with you from right now. But you know what, I'll take any chance to do one of these with you, Ken, no matter where the timer plays. You know, it's funny, the things you remember from trips and things like that, and obviously, I got to hang out with your wife, Jess, and your three wonderful kids, and all of that stuff. But I still remember one of your kids expressing the fact that he couldn't believe that water came out of the tap cold in Alaska, because that never happens in Arizona. Yep, mind-blowing. But kids recognize, right? Yeah, I just actually we were up in Prescott last weekend, where the nighttime temperature just hit a bone-chilling 55 Fahrenheit, and the kids all had the puffy's on, and they were ready to look for snow. Yeah, in Canada, we just call that pool weather.

2:07Why don't you give us a case to start today's episode? Sure. 72-year-old woman presents by EMS with fever, productive cough, confusion, and progressive weakness. Her temperature is 39.2 Celsius, heart rate of 118, respiratory rate 28, oxygen saturation 91% on rumour, and a blood pressure of 78 over 44 millimeters in mercury. That's abnormal, right? Yeah, that's a little low. She has course crackles over the right lower lung field and cool extremities. Jess radiography demonstrates a right lower low of infiltrate. Her lactate is 4.1 millimeters per liter. You establish two ultrasound guided 18 gauge peripheral IVs, administer appropriate antibiotics, and begin judicious crystalline resuscitation. Her blood pressure remains 82 over 46 with a map of 58. And the nurse asks you, do you want me to start the north of an effin through the peripheral? Well, you put in the central line. I love it when nurses ask the question. It's not really a question. It's like, hey, I've got the norwrap you already set up here while you're fiddling around,

3:08getting the central line going. That's right. It's not a question. The line is primed, right? Yeah, yeah, yeah. It's not a question. Well, shock is one of those diagnoses where time actually matters. And at its core, shock is inadequate oxygenation and cellular utilization of that oxygen. It results in tissue hypo perfusion. And that's why your lactate goes up. And if it goes uncheck, this process can lead to organ dysfunction, cardiovascular collapse, and even death. And for many of our patients, fluids alone will not restore adequate perfusion. And that's where vasopressors come in. They increase vascular tone and blood pressure with norwraping effort generally being our first line vasopressors, at least where I work, for a distributive or septic shock. Yeah, that's our first line vasopressor where I work too. And traditionally, we're taught that the vasopressors must be in a central penis catheter, CBC, right? The rationale makes sense. These are potent vasoconstrictors. So we worry that if they extravise into the surrounding tissue,

4:11they could theoretically produce local schemia, tissue necrosis, or even a limb-threatening injury. And a catheter sitting at a big central vein provides rapid dilution of the medication and avoids some of those small peripheral vessels where infiltration might, emphasis on might, cause trouble. Yeah, but here's the problem. Is that central lines are not benign. And certainly it's not like, boom, I got a central line. It's not instantaneous like you see on TV. Placement takes time. You got to get the equipment ready. You've got to have somebody who has the expertise to start a central line. And often you need ultrasound guidance. Complications also can accompany a central line placement. And you could puncture the artery, therefore bleeding. You could hit a lung and drop a lung, cause an arrhythmia, a venous necrosis. Or of course, you could also get an infection. Meanwhile, this patient's mean arterial pressure or map is still circling the drain. Right. And you know, I think Ken was the first person I heard say,

5:15anytime you say might, right, you have to say might not. Right. So they might cause trouble or they might not. And in fact, the alternative is sitting right there in the patient's arm. Right. You've got this great looking peripheral IV. It's probably already functioning. You're probably already giving drugs or fluids through it. And starting to open effort through that line allows us to treat the shock sooner, sort of long-term vasculine access later, and sort of protect the map. And the 2021 surviving sepsis campaign reflected this shift by recommending initiation of vasopressives peripherally, rather than delaying therapy until central access is obtained. Yeah, and that brings us to the tension at the bedside. We don't want to delay potentially life-saving drug while we're waiting for the perfect vascular access. Or in other words, perfect is the enemy of good. However, we also want Norreppy to infiltrate into somebody's arm. And the relevant question isn't whether peripheral vasopressors are perfectly safe, because you know, as well as I do, nothing we do in the emergency department

6:19or in the ICU is, quote, perfectly safe. It's about how often clinically important adverse events occur under what circumstances and whether peripheral administration can spare the patient the need for an invasive central line. You could say that we were under a lot of pressure to make the right decision. That was my, that's going to be the dead joke for the episode. I see what you did there. You did there. Previous systematic reviews suggested that complications from peripheral vasopressors were uncommon and predominantly minor. However, those reviews had some important gaps, including limited agent-specific information, relatively little information about midline catheters, and limited data addressing whether or not peripheral administration avoids central venous catheter placement. So what's the question we're going to try to answer on today's episode? The question for today is, in critically ill adults requiring vasopressors, what is the incidence of adverse events associated with peripheral

7:20intravenous vasopressor administration, and how often does this strategy avoid placement of a central venous catheter? And what reference do we have to try to address this question? Yeah, the reference is Zhang Zhang at all, incidence of adverse events in peripheral intravenous vasopressor use, a systematic review and meta-analysis, and this comes from Jammah Network Open, 2026. Okay, let's run through the peacock. What was the population? So the population included adults greater than or equal to 18 years with hypotension, shock, critical illness, or risk of shock requiring vasopressor therapy. Eligible designs were RCTs, prospective or retrospective observational cohort studies, and case series that contained at least 10 patients. And they excluded a number of different studies and all this, those in the show notes. What was the intervention? The intervention was vasopressor administration through a peripheral intravenous catheter.

8:22And what did they compare it to? There was no conventional control group for the principal analysis. Okay, and so what was the outcome they were looking for? And in particular, what was their primary outcome? So the primary outcome was the pooled incidence of localized adverse events associated with peripheral vasopressor administration, expressed per catheter, and divided into minor and major adverse events. All right, and did they have any secondary outcomes? The secondary outcome was the pooled proportion of peripheral catheters for which a central venous catheter placement was avoided. And what type of study was this? This was a systematic review and meta-analysis of predominantly observational incidents and prevalent studies. So the authors' conclusions were, quote, in this systematic review and meta-analysis of adult patients, adverse events incidents was low after short-term vasopressor administration through peripheral IV catheters, particularly short catheters.

9:23These findings suggest that peripheral IV administration might reduce the need for central venous catheter placement with appropriate monitoring, end of quote. All right, let's go through a quality checklist for systematic reviews. The first question is, do you think the main question was clearly stated? Yes. Do you think the search for studies was detailed? Who had exhaustive I think it was. Do you think the criteria used to select the articles for inclusion was appropriate? Yes. Do you think that the studies that they ended up including were sufficiently valid for the type of question they asked? Well, we're going to we're going to say unsure for this one, right? So it's a systematic review and meta-analysis of 49 studies. 31 were retrospective observational studies, 14 prospective observational studies, and only four were randomized control trials. So you got four RCTs and then 45 other observational studies. I'm sensing some giggle coming.

10:31All right, were there results similar from study to study? No, there was actually substantial heterogeneity. So for all vasopressors combined, minor adverse events had an i-squared of 95.2 percent. And central venous catheter avoidance had i-squared of 98.6 percent. Even nor up in effort specific minor adverse events had an i-squared of 93.9 percent. So the wide variation most likely reflects differences in the populations, the catheter type and location, vasopressor dose and duration, monitoring protocols, and of course study design. Yeah, and this is this is a problem when you have such high heterogeneity, you wonder whether or not they should try to meta-analyze these data, like combine them, because it is a lot of apples and oranges going on in there when you have heterogeneity north of 90 percent. Absolutely. Final question, though, were any financial conflicts of interest reported? No apparent major financial conflict.

11:35All right, so let's go through the results. Like you said, they included 49 studies. And these were studies published from 1997 to 2025. And they got over 33,000 peripheral IV catheters used for vasopressor administration and critically ill adults, so 33,000. Now patients mean or median age across study really had a wide range. It was from 36 all the way up to 81 years, so there's some heterogeneity. Most studies were conducted in the ICU. That's where you work mainly. With others coming from the emergency department, the ORs, the operating room, the wards, intermediate care units, or some mixed settings. Most patients received vasopressors through a short peripheral IV catheter, and four studies used at midline and one used both. And when you looked at what type of vasopressor that was used, nor epinephrine was by far the most popular with 70 percent getting nor epi.

12:39Aaron, what was the key result? In this study, short term peripheral vasopressor administration was associated with the low pooled incidence of adverse events, with major events being extremely rare, while central venous catheter placement was avoided in about 60 percent of cases. All right, so let's talk about they divided them into minor adverse events and major adverse events. What were the minor adverse events? Among 31,212 catheters, well that's a lot of catheters, there were 735 minor adverse events. The pooled incidence across all vasopressors was 2.3 percent, with the 95 percent confidence interval ranging from 1.5 to 3.7 percent, but again, an i-squared value of 95.2 percent. And so I'll put a table in the show notes that details the different vasopressors and the minor adverse events and you'll get your pooled adverse events incidence there with the 95 percent confidence intervals. Let's switch to major

13:42adverse events. Well, there were only 31 major adverse events in total, 30 venous thromboembolic events, and one case of tissue necrosis requiring a fasciotomy. So they had one case of tissue necrosis requiring surgery there out of 33,000 catheters. All right, importantly, the results differed substantially according to the catheter type. All 30 of those VTEs that you talked about, all 30 of those venous thromboembolisms occurred in the four studies using midline catheters, giving a pooled incidence of 1.4 percent. Yeah, and you know, even though that number in absolute is still pretty small, I think that goes with some of the existing data about thromboembolic complications in midline catheters, which you know from where I sit, I'm not 100 percent sure of what their role will be in our in our future practice, you know, there's especially if we don't need a central venous catheter to give phasorpressors. Among 43 studies using short peripheral IV catheters, which was 29,596

14:49catheters, there was only one major adverse event, the tissue necrosis event corresponding to a pooled incidence of 0.0 percent, 95 percent confidence interval in i squared, all 0 percent. When both catheter types were considered together, the pooled incidence of major adverse events was again a nice round number, 0 percent. How about the secondary outcomes? They had pooled proportions of cases in which central venous catheter placement was avoided while phasorpressors were administered peripherally. So how many times or what percentage of catheters did they think that they could avoid putting in a CVC? Yeah, and this was reported in 38 studies involving 15,371 catheters with a pooled central venous catheter avoidance proportion of 59.7 percent and a 95 percent confidence interval ranging from 46.4 to 71.7 percent. Wow, so 60 percent of the time

15:50they felt they could avoid putting in a CVC. Okay, those were the results. Let's talk a little nerdy and I already alluded to this earlier in your quality checklist answers and this was about the garbage in or garbage out or gigo. This was a big meta analysis. I mean, that's like we've all said it. This is 33,000 plus catheters. It's a big denominator, but that doesn't necessarily mean you've got high quality evidence. 31 of the 49 studies were retrospective observational studies and only four were randomized control trials and on top of that 61 percent were rated as unclear or high risk of bias and that matters when you're looking for adverse events. If an infiltration or minor extravacation wasn't recognized or documented in the chart, you're not going to pick that up in a retrospective study. In fact, retrospective studies reported fewer minor adverse events than

16:51the prospective observational studies and the RCTs. Meta analyses can improve the precision, right? So you can get those confidence intervals around that point estimate down, but it can't make bias disappear. Number two, apples and oranges. There was a lot of heterogeneity. The i squared was 95 percent for minor adverse events and almost 99 percent for central-venous catheter avoidance. And these studies included OR, ED and ICU patients receiving different phasorpressors, different doses and concentrations through different catheter sizes and locations for very different lengths of time. So that 2.3 percent number is an average of some really different clinical situations. Don't assume it represents the risk for the patient that's sitting in front of you. Yeah, it's a population, it's an average, it's not the end of one that you're treating. The nerdy point number three is what exactly are we measuring? Only about 1-3rd of the studies reported

17:52catheter gauge and a similar proportion reported catheter location. Infusion duration ranged from a few minutes to days. Even the outcome definitions were broad. Quote minor adverse events, quote, included everything from pain and swelling to extravization, cellulitis and thromboflabitis. Those aren't necessarily equivalent events, ooh, I have a little pain, to I got cellulitis and thromboflabitis. Pulling them gives us a number, but we need to be careful about what that number means clinically. Nerti point number four, rare doesn't mean zero. So there was only one major tissue injury amongst almost 30,000 short peripheral IV catheters, and that is reassuring. But a pooled estimate of 0.0 percent doesn't mean the risk is zero. Rare events are exactly the events that are most likely to be missed by retrospective chart review or incomplete follow-up. And there's another wrinkle, the denominator here was the catheters,

18:56and not necessarily individual patients. And that's not quite the same question our patient is asking when they want to know what are the chances that this will hurt me. Yeah, and you may not know, but I have favorite numbers, and you probably know my favorite number five. I think most people know five is my favorite number. My second favorite number is 11, because of this is spinal tap and this goes to 11. But my third favorite number is that nice round number zero. But just because they got zero and a pooled estimate doesn't mean the risk is zero. All right, the fifth and final nerdy point, incidence is not safety. This may be the most important point. There wasn't a central line control group for the main analysis. So this review tells us how often complications were observed with peripheral vasopressors. It does not tell us that peripheral vasopressors are safer as safe, like equivalent, or superior, are better than central venous catheterization. Likewise, the 60% CBC avoidance number

20:04doesn't prove that the peripheral strategy caused those central lines to be avoided. This is reassuring descriptive evidence, but not comparative evidence. All right, that's enough nerdyness, Aaron. How about you comment on the authors' conclusions and compare them to the SGM's conclusions? Absolutely. And I, you could argue, Ken, that this is also a little bit nerdy. But we, the collective we at the SGM, would be a little more cautious. This systematic review and metanalysis provides reassuring, but low certainty evidence that major complications are uncommon with short-term vasopressors through short peripheral IVs. It supports starting a clinically indicated vasopressor through a well-functioning PIV rather than delaying treatment for central access. It doesn't establish that peripheral administration is universally safe, or that it should always replace central access. All right, how about you give us an SGM bottom line? The bottom line here, don't let the perfect line be the enemy of the good line. If a patient needs

21:05vasopressors now, starting them through an appropriate, closely monitored short peripheral IV appears reasonable, well, you decide whether or not they need a central line. So how are you going to resolve that case that we presented at the beginning of the show? Well, you don't wait for a central line. Norapinephrine has started through the 18 gauge peripheral IV. The site's checked on frequently. And the dose is titrated to her blood pressure into peripheral profusion. Over the next several hours, her blood pressure and mental status improve. Her vasopressor requirement falls. And the Norapinephrine has stopped without infiltration or extravization. She never needs a central line, and she's admitted to the ICU. So how do you think we should take this systematic review and meta-analysis on the issue and apply it clinically? These data support starting a vasopressor through an appropriate short peripheral IV, rather than delaying treatments solely to obtain central access. They shouldn't be interpreted as permission to run concentrated vasopressors through any peripheral line indefinitely.

22:05For us, this supports a pressors first central line if needed approach rather than a rigid central line before pressors always approach. Yeah, and I like what you put in there. This isn't a run-a-pressor through the peripheral line and forget about it. Like, this is not an indefinite thing. This needs to be monitored to see if it's working, see if the patient's improving, or see if they need a central line. All right, so what are you going to tell the patient at the bedside? I think you tell the patient your blood pressure is dangerously low, and we need to give you some medicine to bring it up. We can start it right away through the IV in your arm. Serious problems from doing this for a short time would appear to be very uncommon, but the medicine can leak out of the IV and damage the surrounding tissue. We'll check the IV often, and if you need the medicine for longer, we might need to put an IV into a much larger vein. I like how that is sort of really patient centered, and at a level that a patient could understand. Short sentences, your blood pressure is low, we've got this thing in your arm, and we might have to go to a bigger thing, you know, into a larger vein. So I really like

23:10that part of the SGM process about translating. I mean, here you have a systematic review and meta-analysis of over 33,000 peripheral IVs with 70% getting nori-epinephrine, and now we're supposed to translate that into English at the bedside. That's a real challenge, and so I like that part of the show. All right, it's time for the keener contest, and... There was no winner last week. A double dummy trial is when each participant receives both treatment routes, but only one contains the act of medication. Aaron, what's the question this week? Oh man, I could have gotten that keener contestant. I got to make sure I enter every time. The question this week is, why is norepinephrine called norepinephrine?

24:10And it has nothing to do with a nori-ester or something like that, which they're currently having some bad weather up along the east coast. It's not a nori-ester, it's a norepinephrine thing. And if you know the answer, then send an email to the sjm at gmail.com with keener in the subject line, and the first correct answer will receive a cool skeptical prize. Well, Aaron, thanks again for coming on and being my guest skeptic as our ICU expert. Ken, the pleasure was mine as always, and this is a favorite topic, and I think any time we can bust up even in part some dogma and help people to practice good to solid medicine with the patient at its center, I'm happy to help. The only way this could be better, the only way is if we are at some exotic locale at a course for Rick Buchada teaching and doing this poolside or mountainside on a slope or in Alaska or Hawaii

25:10or something like that, that's the only way this could be better. Talking nerdy in an exotic locale. I love talking nerdy best when I am watching the bald eagle's sore outside the window. All right, well, can you give the sjm tagline? Remember to be skeptical of anything you learn, even if you heard on the skeptic's guide to emergency medicine. Talk to everyone next week.