Ask a doctor on the topic of Anesthesiology

Follow-up question Dr. Berg

February 4, 2015 | 20,00 EUR | answered by Dr. med. Ralf Berg

Hello Dr. Berg,
Thank you for your response, after many days it finally came through. It's strange that my questions always hang in the queue for days.
I would be happy to call you, what was the phone number again? At what time can I call you?
You know, that was the case back then. Unfortunately, something sad happened back then. I don't know if I am right, but isn't a test dose always used before administering a PDA? In my case, no test dose was given back then supposedly due to lack of time, but the entire 15 ml of Naropin was administered.
1. What about the depth of the epidural catheter? Mine was placed at 4 cm back then. I still wonder if that could have been the cause of the high SPA. Is the depth also dependent on weight? I am extremely slender, weighed 49 kg before my pregnancy, and only gained 8 kg during pregnancy, so I weighed only 57 kg. Isn't the depth possibly a bit dependent on this, meaning that one should puncture less deeply in very slim and petite individuals compared to robust, chubby ones?

2. I have another question regarding the ETCO2 value in the monitor readings:
I still don't know how to interpret the ETCO2 value in the monitor readings, maybe you can make an assumption.
In my monitor readings, it says:
21:52 ETCO2 0 mmHg
21:55 ETCO2 0 mmHg
22:00 ETCO2 0 mmHg
22:05 ETCO2 0 mmHg
22:10 ETCO2 0 mmHg
22:15 ETCO2 0 mmHg
22:20 ETCO2 0 mmHg
I don't understand, could this mean that the ETCO2 was not measured? Wouldn't it have been absolutely necessary in my case due to the high SPA? This would mean that I didn't have anesthesia after all, isn't the ETCO2 value automatically measured, or are there cases where it doesn't need to be measured? Then I probably wasn't intubated because during intubation, the ETCO2 value probably must be measured?? But could it also be that the ETCO2 was not measured because I had a manual ventilation bag?
As you may remember, there is a sheet for this: http://www.directupload.net/file/d/3888/4hhuxr5j_jpg.htm
Kind regards, thank you in advance;

Dr. med. Ralf Berg

Good evening, please call me at 015 50990436. Whenever I need more than 30 minutes for your question, the transmission cuts off and my response is lost. Please call me on Sunday from 9.30 onwards. Thank you.

Therefore, the second attempt and very briefly.
Yes, the depth of the puncture to the epidural/spinal space varies depending on size, gender, stature, and of course the thickness of the overlying fat tissue. The depth of the insertion channel to the epidural space at the level of L3/4 is between 3 and 8 cm. A catheter should be inserted 1-2 cm deeper into the epidural space. (so the 4 cm are fine) It is important to note that the additional 1-2 cm should not be advanced further vertically into the spinal canal, but the soft catheter, which is advanced over the steel needle, should deviate downwards, upwards, or laterally into the epidural space. Just by this variation, which is not visible from the outside, anesthesia can be higher or lower with the same injection amount.
Regarding question 2
The table only indicates that no end-expiratory CO2 values were recorded. (A value of 0 does not exist in living humans) This table contradicts the monitor graph which clearly shows a continuous measurement of O2 and EtCO2 from 21.50 to about 22.20, specifically for the EtCO2 of about 5-6 mmHg (which is normal) and the O2 just below 20T. The monitor printout suggests that you were either ventilated through a tube or a mask connected to a CO2 sensor.
In addition to the monitor printout, there must be a handwritten anesthesia protocol. We need that...

With urgent regards,
Dr. R. C. Berg