Need advice on stethoscopes

[Guest leviathan]

Hey everyone,

 

Does anyone know whether there are differences in amplitude between a bad and a good stethoscope? The one I have now is a cheap $20 'scope which I use for basic blood pressure measurement and breath sounds, but it's REALLY quiet. I'm wondering if shelling out for a more expensive cardio will be worth it to serve my purposes of basic brachial pulse auscultation, because I have had several instances where I coudln't even hear the pulse on a patient and had to palpate the BP....Alternatively, could this be an issue not of amplitude, but of quality?

 

Thanks for any advice.

[Guest aneliz]

The general rule, you get what you pay for also applies to stethoscopes... you will notice a definite difference in sound quality between a cardio II (or III) and the $20 deals.

[Guest leviathan]

I know there is an obvious difference in sound quality, but I was asking about sound *amplitude*.

[Guest Elaine I]

Hi Leviathan,

 

I'm assuming from your questions that you are looking for a stethoscope for your St. John Ambulance volunteer work, and possible entry into the primary care paramedic program. If that is the case, you don't need as good of scope as a medical student/resident/physician. Most of the paramedics I work with have a Littman Classic II. Avoid those scopes with two tubes, as the tubes will often bang together, which makes it difficult to auscultate a BP.

 

Personally, I have some difficulty in hearing, and as such, have a Master Cardiology stethoscope. My reason for that one over the Cardiology III was rather simple - it weighed less. Since I wear my stethoscope around my neck, weight was an issue. There are times, though, when I wish I had the small side of the Master Cardiology scope for the assessment of pediatric patients. I was also fortunate - my stethoscope was bought for me by my employer, which meant that the extra cost wasn't an issue.

 

Elaine

[Guest leviathan]

Hi Elaine,

 

You are correct in your assumption. I don't need a better sounding one though, I just need a louder sounding stethoscope. I find it really hard to hear the pulse on some patients, although maybe it's not the stethoscope and it's just me not having good technique or the patient has a quiet pulse.

 

I've been at an airshow with F18s flying overhead and had no troubles hearing on some people, other times I've had to take vitals on someone in a quiet first aid room and just can't find it.

 

Do you have any experience with this?

[Guest Elaine I]

Hi Leviathan,

 

Difficulty hearing in noisy environments - absolutely! Two weeks ago, I was attempting to auscultate a patient's lungs to determine if the stab in the chest he'd received had caused a tension pneumothorax, to determine if I needed to put in chest needle(s). The patient was initially talking, and then arrested, so my level of suspician was high - however, not enough to indicate the need for the procedure. Between the diesel engine, the siren, and instructing the high school co-op student how to do CPR (oops - I thought he was a college paramedic student - he was riding out with the primary care crew also on scene, so we took him with us for the experience - guess I should have checked his credentials first...), it was rather noisy!

 

Lots of other factors affect how well you can hear. For example, it is sometimes difficulty to hear through thick adipose tissue. If someone's BP is lower, that can make it harder to hear. If your stethoscope isn't directly over top of the brachial artery, you will have more trouble. Try locating the brachial pulse before taking BPs, to see if that will help.

 

To further increase your ability to hear, definately upgrade your $20 stethoscope. You should be able to pick up a Classic II for about $80. Also, make sure you have properly fitting ear pieces. Personally, I find that the soft, comfortable type don't fit my ears well, and I can't ear as well with them. Therefore, I use the harder, more uncomfortable but better fitting type. I also adjust my stethoscope so that it is sitting well in my ears before attempting to listen.

 

No matter what you do, there will be times when you can't hear. You will learn the "tricks of the trade" to determine a BP in those cases. Most times, you can palpate it - pre-hospital or out-of-hospital, the systolic pressure is typically more important. Also, you can try putting the SpO2 monitor on the hand of the same arm that you are taking a BP on. Pump up slowly. When you loose the sat reading, you have an approximate systolic BP.

 

Hope that helps!

Elaine

[Guest leviathan]

Hi Elaine,

 

Thanks! You're always so helpful. Usually what I do is just take the systolic BP via palpation in those cases, and you're right, it is more important. I never considered using a pulse ox to check BP, that's a smart idea and I'll have to try it in the future.

 

PS - Wish I was the one with you on that transport and not the high-school co-op student. Was the patient in PEA, or why didn't you shock? Would it have hurt to try poking a needle in to see if any air came out, or is it too risky of a procedure? Mid-clavicular line, second intercostal space, right?

[Guest Elaine I]

Hi Leviathan,

 

The patient started out talking but combative. The report from the PCP on scene before me was that they could not get a BP. At that time, the patient had full air entry bilaterally (and was able to take deep breaths on command). I asked the PCP and firefighter to package the patient, and went to check on my partner who was treating the second patient.

 

I asked my partner whether his patient was ALS or BLS. He told me BLS, so I instructed my partner to come in the back with me (and the high school co-op student), while a police officer drove. The patient was loaded into our ambulance, and we were off (4 minutes total on scene time). About 1 minute out, the patient arrested. I intubated. I instructed the co-op student how to do CPR, which he did (took a bit of coaxing!). Once I intubated, I still heard good air entry bilaterally, so there was no need for chest needles. My partner started two large bore IVs, and we began running fluid. If memory serves correctly, the patient was in a PEA wide complex at a rate of about 40.

 

Upon arrival at the hospital (about 6 minutes later), the Trauma Team Leader directed that the chest be opened immediately. There was about a 1/2 cm laceration to the right lung, which had caused an accumulation of about 1 litre of blood in the chest cavity. The knife had not caused any further damage. The aorta was clamped, and intraventricular epinephrine was given. The heart was defibrillated several times. Eventually, the heart did start beating; however, by that time it was about 30 minutes post-arrest. The patient made it through the OR, but died shortly thereafter.

 

Unfortunately, I don't know the specific cause of death. I went up to the ICU the next day to inquire, but was told to check at the PR office (???). That was a new one for me, since my name was on the chart... Oh well - I'll find out through other means; it will just take longer.

 

(The call made for an interesting read in the newspaper - according to the Sun, the patient didn't have a pulse upon our arrival, we resuscitated successfully on scene, and then he died again at the hospital...)

 

Regarding chest needles - we use two different sites - 2nd intercostal space, midclavicular line or 4th intercostal space, midaxillary line.

 

Elaine