There seems to be some confusion regarding NC use. The IBCC seems to recommend NC and even HFNC, with no real evidence to confirm the idea that HFNC increases aerosol and transmission risks. It might even decrease transmission by avoiding intubation. The IBCC defines HFNC as 30-60Lpm, and compromises with concerns by offering possible treatment at moderate flow 15-30L, for the skeptics. Based on this, it seems normal NC therapy in the ED or pre-hospital should be safe. However, earlier EMcrit discussions advise against O2 NC greater than 6Lpm? Which is it?
Jacob - here’s good info from Hong Kong where transmission to HCW has been very low. Recommend to HFNC/NIV https://www.ncbi.nlm.nih.gov/pubmed/32105633/
This is what we are looking at: https://www.medexsupply.com/respiratory-humidifiers-cpap-and-bipap-systems-systems-accessories-parts-intersurgical-filta-guard-breathing-filters-22-male-22-female-40-cs-x_pid-98510.html?pid=98510&gclid=Cj0KCQjwx7zzBRCcARIsABPRscP09tBOO6Q1oYqtUBC-mNt8TFs6SDOZtlGeFXRNgSuORbukx-reS54aApijEALw_wcB
In some states they are shutting down K-12 schools for up to 2 weeks because of reports (or just for prevention) of a positive test in "someone" that lives within the vicinity. I need some clarification so that my information is correct. The current Covid-19 testing is RT-PCR. It was mentioned on EMRAP that the sensitivity and specificity of this test are around 75%. Am I correct to say first of all that this test is missing 25% of all coronaviruses that this test could capture given the perfect 100% scale (the ideal of course). This would mean that those that test positive do not necessarily have this specific strain. Also if someone tests negative and given that 25% of viruses that could be captured are not this would mean that of the one's captured the indivdual would not have this specific strain. However since not all are captured and the specificity is still low (unless I misheard and it is high) then someone with a negative test could still have this strain. If the specificity is high >90/95% then a negative would be reassuring. I think the actual reliablilty of the testing needs to be publicly clarified. Thank you!
Sensitivity is ~ 75% so a negative test has a significant risk of being a false negative. If the patient's symptoms are consistent with COVID19, if they have high risk exposure (contact w/ COVID19) the recommendation is to get a second test. At this point, we should assume that anyone with respiratory symptoms has COVID19 and a single negative test is not adequate in this setting Specificity is very good though I don't have exact numbers so if the test is positive, the patient has COVID19
Here is the problem Gabriele - it is almost impossible to find published data on sensitivity and specificity of the test. In general we THINK it should be quite specific as the PCR test is looking at 2 genes very specific for this strain. PCR tests done correctly (ie. not contaminated) are usually very specific. Regarding sensitivity we don't know. It certainly is not perfect. There is no as yet accepted Gold-Standard to test against. There are clear reports of patients initially negative with symptoms that later become positive. Is this a test issue or a collection of specimen issue. Not sure. The best ESTIMATE we have (as far as I know currently) is the test appears to be about 75% sensitive. See our Corependium chapter for references: https://www.emrap.org/corependium/chapter/rec906m1mD6SRH9np/Novel-Coronavirus-2019-COVID-19?MainSearch=%22covid%22&SearchType=%22text%22
Hi, There seems to be some confusion regarding which masks we should be wearing. I have heard two options:
N95 - at all times when in close contact vs droplet mask during regular care, with an N95 mask for aerosolized treatments, CPR, intubation, and NP swab collection
The most recent EM-RAP article says use an N95, however the link states only for the above procedures. Can you please clarify this?
For most contact with patient: droplet + contact precautions. Surgical mask and face shield, gloves and disposable gown For aerosolizing procedures (mainly this is intubation for us): airborne + contact - N95, full face shield, gloves and gown.
Just a thought with a recent unstable covid intubation at our shop
-As we don't have vents or NIV masks readily available for crash airway preox, what we have done in a situation where we had a very low pre induction/paralysis sat (50-60%) that was refractory to the non-rebreathers at the bedside is insert an intubating LMA (igel) quickly after the rsi meds were pushed, bag through the LMA with a viral filter attached in line up to a comfortable sat, insert a bougie through the LMA and confirm with tracheal rings + hold up and then insert the ET tube blindly over the bougie after removing the LMA
these are technically intubating LMAs where you could put an ET tube through, but using the bougie and feeling the rings and hold up makes everyone a lot more comfortable with blindly inserting the tube, also added benefit of doing all this after you get your sat up with the LMA alone
this probably assumes relatively normal airway anatomy and the patient being relaxed enough to tolerate the insertion of the LMA well before the 30-45 second mark post RSI meds where we would typically scissor the mouth open to insert the VL blade, another argument is why not just use the BVM alone to get to a safe sat with a viral filter for preox before intubating as usual, but this might involve some leak around the mask seal
I've heard some ER docs are wearing their PPE around the clock until their shift is over. Is any one else doing this? What about the problem with spreading Covid to other work areas. In my ER we have split the department into 2 halves. One for coronavirus and the other for non-coronavirus. Also what do you do for shoe covers? A reference from Emcrit says that removing shoe covers makes things worse. "Shoes Shoe covers aren't recommended, as removing them may increase exposure (ANZICS guidelines). Shoes that are easily cleaned and don't need to be touched might be preferable (e.g. Danskos)." https://emcrit.org/ibcc/covid19/
NIck - In many places including where I work, the COVID19 penetrance is nearly 100% so most of us do wear our N95 mask all day. There are no true "non-COVID" areas. We take them off before we leave the department. I don't use the shoe covers. Most of our docs aren't either. I simply wipe them down with bleach wipes afterwards. I like the idea of easy to clean shoes Good luck!
Aanand- Thanks for your reply. One more thing. Do you wear a surgical mask over your N95 and change that at all during the day? Or do you just simply wear both all day? Or just the N95 by itself?
Jacob R. - March 13, 2020 7:15 PM
There seems to be some confusion regarding NC use. The IBCC seems to recommend NC and even HFNC, with no real evidence to confirm the idea that HFNC increases aerosol and transmission risks. It might even decrease transmission by avoiding intubation. The IBCC defines HFNC as 30-60Lpm, and compromises with concerns by offering possible treatment at moderate flow 15-30L, for the skeptics. Based on this, it seems normal NC therapy in the ED or pre-hospital should be safe.
However, earlier EMcrit discussions advise against O2 NC greater than 6Lpm?
Which is it?
Anand S. - March 13, 2020 7:42 PM
The truth is that no one has the answer. Scott acknowledges these are his opinions and we’ll have to wait and see if better info comes along
Anand S. - March 14, 2020 5:55 AM
Jacob - here’s good info from Hong Kong where transmission to HCW has been very low. Recommend to HFNC/NIV https://www.ncbi.nlm.nih.gov/pubmed/32105633/
Hoda T. - March 14, 2020 12:16 PM
can you give us the name of the viral filter ?
Anand S. - March 16, 2020 8:14 AM
This is what we are looking at: https://www.medexsupply.com/respiratory-humidifiers-cpap-and-bipap-systems-systems-accessories-parts-intersurgical-filta-guard-breathing-filters-22-male-22-female-40-cs-x_pid-98510.html?pid=98510&gclid=Cj0KCQjwx7zzBRCcARIsABPRscP09tBOO6Q1oYqtUBC-mNt8TFs6SDOZtlGeFXRNgSuORbukx-reS54aApijEALw_wcB
Gabriele K., MD - March 16, 2020 7:52 AM
In some states they are shutting down K-12 schools for up to 2 weeks because of reports (or just for prevention) of a positive test in "someone" that lives within the vicinity. I need some clarification so that my information is correct. The current Covid-19 testing is RT-PCR. It was mentioned on EMRAP that the sensitivity and specificity of this test are around 75%. Am I correct to say first of all that this test is missing 25% of all coronaviruses that this test could capture given the perfect 100% scale (the ideal of course). This would mean that those that test positive do not necessarily have this specific strain. Also if someone tests negative and given that 25% of viruses that could be captured are not this would mean that of the one's captured the indivdual would not have this specific strain. However since not all are captured and the specificity is still low (unless I misheard and it is high) then someone with a negative test could still have this strain. If the specificity is high >90/95% then a negative would be reassuring. I think the actual reliablilty of the testing needs to be publicly clarified. Thank you!
Anand S. - March 16, 2020 8:09 AM
Sensitivity is ~ 75% so a negative test has a significant risk of being a false negative. If the patient's symptoms are consistent with COVID19, if they have high risk exposure (contact w/ COVID19) the recommendation is to get a second test. At this point, we should assume that anyone with respiratory symptoms has COVID19 and a single negative test is not adequate in this setting
Specificity is very good though I don't have exact numbers so if the test is positive, the patient has COVID19
Mel H. - March 16, 2020 8:15 AM
Here is the problem Gabriele - it is almost impossible to find published data on sensitivity and specificity of the test. In general we THINK it should be quite specific as the PCR test is looking at 2 genes very specific for this strain. PCR tests done correctly (ie. not contaminated) are usually very specific. Regarding sensitivity we don't know. It certainly is not perfect. There is no as yet accepted Gold-Standard to test against. There are clear reports of patients initially negative with symptoms that later become positive. Is this a test issue or a collection of specimen issue. Not sure. The best ESTIMATE we have (as far as I know currently) is the test appears to be about 75% sensitive. See our Corependium chapter for references: https://www.emrap.org/corependium/chapter/rec906m1mD6SRH9np/Novel-Coronavirus-2019-COVID-19?MainSearch=%22covid%22&SearchType=%22text%22
Sarah M. - March 18, 2020 8:52 AM
Hi, There seems to be some confusion regarding which masks we should be wearing. I have heard two options:
N95 - at all times when in close contact
vs
droplet mask during regular care, with an N95 mask for aerosolized treatments, CPR, intubation, and NP swab collection
The most recent EM-RAP article says use an N95, however the link states only for the above procedures. Can you please clarify this?
Anand S. - March 18, 2020 9:18 AM
For most contact with patient: droplet + contact precautions. Surgical mask and face shield, gloves and disposable gown
For aerosolizing procedures (mainly this is intubation for us): airborne + contact - N95, full face shield, gloves and gown.
Salman A. - March 20, 2020 9:36 AM
Just a thought with a recent unstable covid intubation at our shop
-As we don't have vents or NIV masks readily available for crash airway preox, what we have done in a situation where we had a very low pre induction/paralysis sat (50-60%) that was refractory to the non-rebreathers at the bedside is insert an intubating LMA (igel) quickly after the rsi meds were pushed, bag through the LMA with a viral filter attached in line up to a comfortable sat, insert a bougie through the LMA and confirm with tracheal rings + hold up and then insert the ET tube blindly over the bougie after removing the LMA
these are technically intubating LMAs where you could put an ET tube through, but using the bougie and feeling the rings and hold up makes everyone a lot more comfortable with blindly inserting the tube, also added benefit of doing all this after you get your sat up with the LMA alone
this probably assumes relatively normal airway anatomy and the patient being relaxed enough to tolerate the insertion of the LMA well before the 30-45 second mark post RSI meds where we would typically scissor the mouth open to insert the VL blade, another argument is why not just use the BVM alone to get to a safe sat with a viral filter for preox before intubating as usual, but this might involve some leak around the mask seal
Nick P. - April 5, 2020 3:34 PM
I've heard some ER docs are wearing their PPE around the clock until their shift is over. Is any one else doing this? What about the problem with spreading Covid to other work areas. In my ER we have split the department into 2 halves. One for coronavirus and the other for non-coronavirus.
Also what do you do for shoe covers? A reference from Emcrit says that removing shoe covers makes things worse.
"Shoes
Shoe covers aren't recommended, as removing them may increase exposure (ANZICS guidelines).
Shoes that are easily cleaned and don't need to be touched might be preferable (e.g. Danskos)."
https://emcrit.org/ibcc/covid19/
Anand S. - April 5, 2020 4:05 PM
NIck - In many places including where I work, the COVID19 penetrance is nearly 100% so most of us do wear our N95 mask all day. There are no true "non-COVID" areas. We take them off before we leave the department.
I don't use the shoe covers. Most of our docs aren't either. I simply wipe them down with bleach wipes afterwards.
I like the idea of easy to clean shoes
Good luck!
Nick P. - April 6, 2020 1:54 PM
Aanand- Thanks for your reply. One more thing. Do you wear a surgical mask over your N95 and change that at all during the day? Or do you just simply wear both all day? Or just the N95 by itself?
Anand S. - April 6, 2020 1:58 PM
Wearing surgical mask over to protect n95. If surgical mask gets wet or used in procedure, swap it out