How much does Trendelenberg/Shock position actually work??

[Ace844]

Hi All,

I saw this article and thought it provided alittle bit of evidence at least in part to support soemthing which is punded into everyone from the lay-person, to MD...thoughts anyone??

Emergency Medicine Journal 2005;22:867-868; doi:10.1136/emj.2004.019257

© 2005 by BMJ Publishing Group Ltd, and British Association for Accident and Emergency Medicine

This Article

Relationship between Trendelenburg tilt and internal jugular vein diameter

S Clenaghan, R E McLaughlin, C Martyn, S McGovern and J Bowra

Ulster Hospital, Belfast, Northern Ireland

Correspondence to:

S Clenaghan

Ulster Hospital, Upper Newtownards Road, Belfast, Northern Ireland; stepclen@hotmail.com

Objectives: To evaluate the relationship between Trendelenburg tilt and internal jugular vein (IJV) diameter, and to examine any cumulative effects of tilt on the IJV diameter.

Methods: Using a tilt table, healthy volunteers were randomised to Trendelenburg tilts of 10°, 15°, 20°, 25°, and 30°. Ultrasound was used to measure and record the lateral diameter of the right IJV at the level of the cricoid cartilage. Following each reading the table was returned to the supine position. Balanced randomisation was used to assess cumulative tilt effects.

Results: A total of 20 healthy volunteers were recruited (10 men, 10 women). Mean supine IJV diameter was 13.5 mm (95% CI 12.8 to 14.1) and was significantly greater at 10° (15.5 mm, 95% CI 14.9 to 16.1). There was no significant difference between 10° and greater angles of tilt. The effect of the previous angle of tilt did not prove to be statistically significant.

Conclusion: Increasing the degree of Trendelenburg tilt increases the lateral diameter of the IJV. Even a 10° tilt is effective. The cumulative effect of tilt (that is, the effect of the previous angle) is not significant. Ultrasound guided cannulation is ideal, but in its absence Trendelenburg tilt will increase IJV diameter and improve the chance of successful cannulation. While 25° achieved optimum distension, this may not be practical and may be detrimental (for example, risk of raised intracranial pressure).

Out here,

Ace844

[kevkei]

Anecdotally I see this happen when I perform an EJV cannulation. When the only access I have is an EJV (unable to obtain peripheral access), take a quick look. If you see nothing visible, have someone grab the patients ankles while on the floor or stretcher and lift them up to the waist height of the person holding the ankles while standing upright. Whola, engorged EJV's.

Although this isn't a true Trendelenberg position more of a modified Trendelenberg, I think it is probably more effective and practical in most instances in patients without concern for SMR. Unless they are on a LSB, achieving the 10 degree tilt for us is impossible and this is a good alternative that I have found works.

[zippyRN]

another advantage of Uk type stretcher trollies - nearly all have some kind of trendeleburg system built into the top half of the trolley that can used in or out of the trolley mounts

[Ace844]

another advantage of Uk type stretcher trollies - nearly all have some kind of trendeleburg system built into the top half of the trolley that can used in or out of the trolley mounts

We have the same feature on our stretchers in the US as well....It comes as a Standard option if you will!!

[AnthonyM83]

Was there another thread on this same topic? I did a search, but only found this one so far.

I swear there was one with people discussing how shock position doesn't really increase blood pressure except maybe in syncopal episodes. I want to make sure I have it right, because I mentioned it to someone at work and they looked at me like I was crazy.

[VentMedic]

You are correct about that.

Trendelenberg is rarely used in many hospitals except for cannulation of the jugulars. Trendelenberg can lead to aspiration, increased ICP, diaphragmatic restriction and increased anxiety. "Supine is Fine".

The Trendelenburg Position: Another EMS Myth

By Bryan E. Bledsoe, DO, FACEP

December 2004, MERGINET—One of my most-requested conference talks is entitled Myths of Modern EMS. It also corresponds to a series that I wrote for EMS Magazine in 2003. In that lecture, I review numerous EMS practices and the science, or lack thereof, behind them. It stimulates discussion and, as I had hoped, has stimulated some research. Now, I have another EMS myth I can add to my repertoire: the Trendelenburg position improves circulation in cases of shock.

Researchers at the University of Southern California Keck School of Medicine performed a retrospective review of the literature pertaining to use of the Trendelenburg position in shock. They found several studies on the maneuver. One compared six hypotensive patients in clinical shock to five normotensive patients. In nine of the 11 patients, the Trendelenburg position was ineffective, causing reductions in systolic, diastolic and mean arterial pressure. They also found that the abdominal viscera moved up onto the diaphragm, restricting respiratory volumes when patients were placed in the Trendelenburg position. Another study looked at oxygen transport in eight hypovolemic postoperative patients placed into the Trendelenburg position. While the position seemed to increase blood pressure, it did not increase cardiac output. Another researcher studied the effect of the Trendelenburg position on blood distribution and found that only 1.8 percent of the total blood volume was displaced centrally. In a relatively large study of 76 critically ill patients (61 normotensive and 15 hypotensive), they found no change in pre-load or mean arterial pressure for normotensive patients. In normotensive patients, they found a slight increase in cardiac output. However, for hypotensive patients, there was no increase in pre-load or mean arterial pressure. In these patients they found that cardiac output actually diminished—a detrimental effect.

In summary, the Trendelenburg offers no benefit to hypotensive patients. Like the MAST/PASG, another long-held belief can be abandoned as EMS becomes more evidence based.

Reference

Johnson S, Henderson SO. “Myth: The Trendelenburg position improves circulation in cases of shock.” Canadian Journal of Emergency Medicine. 2004;6(1):48-49.

And for the conclusive last word

Use of the Trendelenburg position as the resuscitation position: to T or not to T?

Am J Crit Care. 2005; 14(5):364-8 (ISSN: 1062-3264)

Bridges N ; Jarquin-Valdivia AA

The Neurointensive Care Unit, Vanderbilt University Medical Center, Nashville, TN, USA.

OBJECTIVE: To review the literature on use of the Trendelenburg position as a position for resuscitation of patients who are hypotensive. METHODS: PubMed online, cited bibliographies, critical care textbooks, and Advanced Cardiac Life Support guidelines were searched for information on the position used for resuscitation. Because of the heterogeneity of the data, only pertinent articles and chapters were summarized. RESULTS: Eight peer-reviewed publications on the position used for resuscitation were found. Pertinent information from 2 critical care textbooks and from the Advanced Cardiac Life Support guidelines was included in the review. Literature on the position was scarce, lacked strength, and seemed to be guided by "expert opinion." CONCLUSION: The general "slant" of the available data seems to indicate that the Trendelenburg position is probably not a good position for resuscitation of patients who are hypotensive. Further clinical studies are needed to determine the optimal position for resuscitation.

PreMedline Identifier: 16120887

[Spock]

Trendelenburg position will also decrease functional residual capacity in the lungs which will increase dyspnea in a shock patient. This is from the abdominal contents pushing up on the diaphragm.

That said, we often put the patient into t-burg for central line placement. Also, when we prep the patient for a CABG, both legs are elevated to at least 60 degrees in order to prep the posterior legs. At this point I watch the SBP increase by at least 20 mmHg.

Live long and prosper.

Spock

[AnthonyM83]

Hmmm...that doesn't sound like very convincing evidence. The biggest study had only 15 hypotensive patients (which is who we put in Trendelenberg, no normotensive) and the other study had six hypotensive and they don't say if the two whose BPs did go up were the hypotensive ones (which would matter most to us). PLUS there's the one study where 8 hypotensives' BPs DID go up. Seems more like someone trying to shake things up and come up with a possible myth (which is definitely a good thing and I respect Dr. Bledsoe, but that's not very conclusive).

It's going to take a lot more than those two studies to have people change their beliefs from what's in the textbooks and what they say they've seen work on their own patients. I feel foolish for arguing with someone at work about it, now...

[JPINFV]

^

Ahh, but if trendelenburg doesn't work on normotensive patients than why would it work for hypotensive patients? Also, in the study with 11 patients, 9 patients saw a decrease. At least 2/3rds of the hypotensive patients saw their blood pressure decrease.

Now there's the problem with the study involving 8 patients who saw an increase in BP without an increase in cardiac output. To understand the importance of this we need to understand how trendelenburg is supposed to work. The idea (Starling's effect) is, simply put, that the more blood that reaches the ventricles (venous return), the more blood that will be pumped (stroke volume). If you raise the legs of a patient/subject then more blood should be returning to the heart because of gravity. This increases venous return which increases stroke volume via Starling's. Now how does stroke volume relate to blood pressure.

Cardiac output=(stroke volume)(heart rate).

(Cardiac output)(total peripheral resistance)=Mean arterial pressure=(2/3 diastolic blood pressure)+(1/3 systolic blood pressure) at high heart rates.

(stroke volume)(heart rate)(total peripheral resistance)=(2/3 diastolic blood pressure)+(1/3 systolic blood pressure)

Hence stroke volume is directly proportional to blood pressure.

Now the problem that the study showed was that you do not have this increase in stroke volume with the supposive increase in venous return from the legs. If this is true AND the trendelenburg works, then a different mechanism exists for it to increase the blood pressure besides Starlings.

Now let's throw in the cons. The blood is not going to just increase venous pressure at the heart, but also a the brain. Increase intracranial pressure might be worse for the patient in the long run by causing more damage. Researchers have seen an increase in difficulty breathing because the diaphram now has to lift the abdominal organs while decreasing intrathoracic pressure.

[Richard B the EMT]

OK, I am now going to go completely on memory, and admit this information might not be reliable.

Liquid seeks the lowest levels of it's container due to gravity. Blood is a liquid. Shock is generally when the blood reaching the brain is of insufficient quantity.

Trendelenburg position puts the brain at a lower level than most of the rest of the body. Blood seeks the lowest level of the body, which is it's container, which in trendelenburg position will put more blood to the brain.

When in trendelenburg position, the internal organs below the diaphragm will follow gravity, and press against the diaphragm, which can cause some difficulty breathing.

I do not recall anything on patients in trendelenburg position having any changes in their blood pressure, but, as I indicated at the beginning of this entry, I am writing from memory, without any textbook(s) in front of me. Also, I am due for my EMT refresher classes.