Saline bolus for high HR?

[SimplisticRnx]

I had a patient yesterday who had a regular BP but HR of 180's when standing up. Did orthostatic BP on the patient. Doctor order 1 liter of NS Bolus for 4 hours. Can someone explain the reasoning behind it? I know that NS bolus are common for those with low BP, but I don't get the picture about using it for elevated HR.

[K+MgSO4, BSN]

dehydration?

[sapphire18]

I would agree with dehydration, however I wouldn't be comfortable with a HR that high, esp on an unmonitored patient. Another thing- I wouldn't consider 250cc/hr a "bolus." did it work?

[nightengalegoddess]

We typically bolus for hight heart rate if it is probable dehydration. We bolus 1000 cc within one hour though....Did your paitent also have some CHF? Is that why doc. wanted to give it so slowly?

[nightengalegoddess]

Oh yes, 180 is kind of high......did pt. get a beta-blocker or something too? Yes, 180 is definetly too high for just N.S. bolus therapy! I would think......Why else was the HR high? I would want my pt. on tele as well as make sure there was no pain going on......if he was orthostatic it could certainly be just dehydration but they could also be going into a fib......just wonderin.

[turnforthenurse, MSN, NP]

Tachycardia is one of the first signs of dehydration but a HR in the 180's is kind of high for dehydration to be a cause, imo. Was this a gradual change in HR or did the patient suddenly jump into the 180's? Seems like there would be another cause. Also, a bolus over 4 hours seems too slow....even if the patient had a history of CHF, IMO.

[sapphire18]

Good points made by some previous posters. It does seem too high for simple dehydration, as they are now in SVT territory. Unless it's afib with RVR. I would be expecting some IV cardiac drugs given. I have seen some high sinus tachs in deconditioned patients ambulating or getting OOB for the first time, but not THAT high. Well...maybe 160s/170s...once.

[psu_213, BSN, RN]

Cardiac output (CO) = stroke volume x HR.

Person is dehydrated, therefore less circulating volume. Thus, stroke volume is decreased. To compensate, and maintain CO, HR increases. Therefore, give fluids. Almost anyone who comes in tachycardic to the ER (and/or is orthostatic...and keep increase in HR in mind when standing, not just change in BP) will get a NSS bolus. Although a liter over 4 hours is not a bolus per our standards (although a bolus of 250 cc over an hour is not unheard of for a pt with CHF).

HR of 180, there would probably something in addition to the fluid (Beta blocker, Ca channel blocker...what is sinus or a fib or ??), but they would most likely get the fluid too. I have seen dehydration to the point that HR goes up that high.

[SimplisticRnx]

Thanks for the wonderful answers. The patient wasn't dehydrated, though she was saline lock since she's tolerating her PO. She has a history of hypertension and valve replacement. She isn't taking any hypertensive meds since she has been running low BP's. We hooked her up on tele and she was running some afib. So I don't know if it is dehydration that's causing her high HR. BP is stable though.

[SimplisticRnx]

No CHF history. Considered her age, we didn't want to overdo it.

[Anoetos, BSN, RN]

The bolus was probably to improve volume. When you say orthostatic BP I am assuming this patient was hypotensive, in this case, in addition to possibly lowering heart rate, it would have the effect of improving volume and increasing BP.

That said, beta-blockers are usually first line for high heart rate with hypertension.

This may simply have been a fluid challenge preparatory to removal to critical care and/or possible cardioversion. Was she in afib with RVR by chance?

[Guest343211]

Right. Generally the first line is to treat the cause or possible cause--i.e., dehydration. Of course this is done more carefully in a baby, child, or person with certain cardiac dysfunction or someother issue that could render a problem.

He's following standard protocol. As a surgical recovery ICU nurse of children and adults, over all, I usually prefer colloids; but it really depends on the particulars.

If you dropped a PA catheter into this person (which you won't on the face value of this case), you may well see that the patient's CVP and systematic vascular resistance was very high. This is is indicative of low vascular fluid volume. In an attempt to increase blood flow, the basic calculation noted above, HR * SV = CO, demonstrates the body's response to low volume and thus to increase cardiac output by increasing the HR.