Psience Quest

(2017-10-10, 01:32 PM)chuck Wrote: [ -> ]That's interesting, Tim. Can you post the source of those quotes? Does Parnia say "reflexes don't resume during CPR?" or is that your quote?

Not being argumentative, but I did a quick google search and studies do indicate that pupillary reaction can occur in both cardiac arrest and during CPR.

https://www.ncbi.nlm.nih.gov/pubmed/11373477

Abstract

OBJECTIVE: 
Traditionally, both pupil diameter and reaction to light have been examined to confirm the diagnosis of death. In the present study, we investigated quantitative changes in pupil diameter and light reaction for assessing the efficacy of cardiopulmonary resuscitation (CPR) and as a predictor of outcome.
DESIGN: 
Controlled experimental study.
SETTING: 
Animal research laboratory at a university-affiliated research institute.
SUBJECTS: 
Fifteen domestic male pigs weighing between 33 and 40 kg.
INTERVENTIONS: 
Ventricular fibrillation was induced with an alternating current delivered to the right ventricular endocardium. After 7 mins of untreated ventricular fibrillation, chest compression and mechanical ventilation were initiated and maintained for 6 mins. Restoration of spontaneous circulation then was attempted by electrical defibrillation.
MEASUREMENTS AND MAIN RESULTS: 
Spontaneous circulation was reestablished in 9 of 15 animals. Pupils were fully dilated, and pupillary reaction to light was absent in 7 of the 9 resuscitated animals during untreated cardiac arrest. Progressive decreases in pupil diameter were observed together with restoration of light reaction during CPR, in each animal that was successfully resuscitated. When the pupils remained dilated and unreactive after 6 mins of CPR, resuscitation efforts were uniformly unsuccessful. A highly significant linear correlation between coronary perfusion pressure generated during precordial compression and pupil diameter was documented. Both were predictive of outcome.
CONCLUSIONS: 
Dynamic changes of pupil diameter and reactions to light during cardiac arrest and resuscitation were correlated with coronary perfusion pressure, and both predicted the likelihood that spontaneous circulation and cerebral function would be restored.

Chuck said > "That's interesting, Tim. Can you post the source of those quotes? Does Parnia say "reflexes don't resume during CPR?" or is that your quote?"

I thought you'd placed me on ignore, Chuck...you did say so in the Carne Ross thread....if you remember  

The quote is from Live science but it's a fairly standard piece from Parnia. His is a recognised expert on resuscitation
so unfortunately for some members on here, his statements have to be given their due (over Linda) sorry about that (Arouet, Malf, Steve, Paul...)

This is a clip from one of his many papers.

Immediately following the cardiac arrest, the
mean arterial pressure (MAP) becomes immeasurable,
however, properly performed chest compressions
may raise the systolic values to 60–80 mmHg,
but the diastolic values and hence the mean arterial
pressure still remains inadequate

Concurrent EEG monitoring during a cardiac arrest has shown an
initial slowing of the EEG waves which then progress
to an isoelectric line within approximately 10–20 s
and remain flat during the cardiac arrest until the
resumption of cardiac out put (27, 30) In cases of
prolonged cardiac arrest, however EEG activity
may not return for many tens of minutes after cardiac
output has been returned.

Therefore during cardiac arrest impaired cerebral blood flow
leads to a lack of electrophysiological activity in
the cortex, which is made worse, as the time from
the initial period of ischaemia to adequate resuscitation
is increased. A reduction in cerebral blood
flow in humans is associated with a deterioration
in sustained attention (30)

Immediately after resuscitation there is a period
of multifocal no-reflow, a phenomenon observed
following recovery from cardiac arrest, in which,
despite the restoration of adequate blood pressure
multiple areas of the brain have been shown to develop
perfusion defects that range from a pin hole,
up to 95% of the brain (31) This is thought to occur
due to insufficient restoration of nutritive blood
flow due to a combination of increased blood viscosity
and perivascular oedema and is related to
the initial period of ischaemia. This is followed by
a period of transient global hyperaemia lasting
15–30 min

The papers you've presented are interesting, but nothing more.  I'm not an expert, I've never claimed to be which is why I don't make up my own facts as some of the sceptics on here do). What I do know is that pupillary reaction to light is on a spectrum (mm) and a reaction to light does NOT mean the person is conscious, only that the brain stem is intact/functioning (to some degree). In the onset of cardiac arrest it doesn't function. Denture man's pupils did not react to light for at least half an hour or more and he didn't regain consciousness, he was still in a coma. 

None of the patients in the Aware study on cardiac arrest patients showed any clinical signs of consciousness during
resuscitation

Although no patient demonstrated clinical signs of consciousness during CPR as assessed by the absence of eye opening response, motor response, verbal response whether spontaneously or in response to pain (chest compressions) with a resultant Glasgow Coma Scale Score of 3/15, nonetheless 39% (55/140) (category 2) responded positively to the question "Do you remember any-thing from the time during your unconsciousness". There were no significant differences with respect to age or gender between these two groups.

I suggest you contact Pim Van Lommel if you want further confirmation. He is another expert.

I was really only questioning your statement "which is why reflexes don't resume during CPR" and your attribution of it to Parnia. Obviously that statement is mistaken in light of published scientific studies.

I don't see reflexes mentioned in that quote you have provided.

I'm not making a statement about the pupillary dilation of denture man.

I'm not making a statement that people have or do not have any clinical signs of "consciousness" during CPR.

You stated "which is why reflexes don't resume during CPR" and that is clearly incorrect. Fact. Not opinion.

I think we need to be accurate when discussing these issues.

I notice in the Live Science article the bit about reflexes is not a direct quote. I doubt anyone who had reviewed the literature on reflexes and CPR would state that "reflexes don't resume during CPR."

(2017-10-10, 03:56 PM)chuck Wrote: [ -> ]I was really only questioning your statement "which is why reflexes don't resume during CPR" and your attribution of it to Parnia. Obviously that statement is mistaken in light of published scientific studies.

I don't see reflexes mentioned in that quote you have provided.

I'm not making a statement about the pupillary dilation of denture man.

I'm not making a statement that people have or do not have any clinical signs of "consciousness" during CPR.

You stated "which is why reflexes don't resume during CPR" and that is clearly incorrect. Fact. Not opinion.

I think we need to be accurate when discussing these issues.

I didn't state anything. I quoted Parnia who is a recognised expert in this field and therefore can be relied upon as an accurate source.

(2017-10-10, 04:07 PM)chuck Wrote: [ -> ]I notice in the Live Science article the bit about reflexes is not a direct quote. I doubt anyone who had reviewed the literature on reflexes and CPR would state that "reflexes don't resume during CPR."

Are you trying to suggest that Parnia didn't say that or I'm making up crap ?

(2017-10-10, 04:18 PM)tim Wrote: [ -> ]I didn't state anything. I quoted Parnia who is a recognised expert in this field and therefore can be relied upon as an accurate source.

This quote says nothing about reflexes during CPR.

Quote:Immediately following the cardiac arrest, the
mean arterial pressure (MAP) becomes immeasurable,
however, properly performed chest compressions
may raise the systolic values to 60–80 mmHg,
but the diastolic values and hence the mean arterial
pressure still remains inadequate

Concurrent EEG monitoring during a cardiac arrest has shown an
initial slowing of the EEG waves which then progress
to an isoelectric line within approximately 10–20 s
and remain flat during the cardiac arrest until the
resumption of cardiac out put (27, 30) In cases of
prolonged cardiac arrest, however EEG activity
may not return for many tens of minutes after cardiac
output has been returned.

Therefore during cardiac arrest impaired cerebral blood flow
leads to a lack of electrophysiological activity in
the cortex, which is made worse, as the time from
the initial period of ischaemia to adequate resuscitation
is increased. A reduction in cerebral blood
flow in humans is associated with a deterioration
in sustained attention (30) 

Immediately after resuscitation there is a period
of multifocal no-reflow, a phenomenon observed
following recovery from cardiac arrest, in which,
despite the restoration of adequate blood pressure
multiple areas of the brain have been shown to develop
perfusion defects that range from a pin hole,
up to 95% of the brain (31) This is thought to occur
due to insufficient restoration of nutritive blood
flow due to a combination of increased blood viscosity
and perivascular oedema and is related to
the initial period of ischaemia. This is followed by
a period of transient global hyperaemia lasting
15–30 min

(2017-10-10, 04:23 PM)tim Wrote: [ -> ]Are you trying to suggest that Parnia didn't say that or I'm making up crap ?

The article doesn't directly quote Parnia on reflexes during CPR. It is an indirect quote. Did Parnia actually say "reflexes don't resume during CPR."? We will never know unless we contact the author of the article and request a transcript. I seriously doubt he would say that given the fact that there are a couple of seemingly conclusive studies that state the exact opposite, one of them appearing I believe in Resuscitation Journal, which one could assume Parnia might read.

I don't think you are making up the fact that the article provides an indirect quote of Parnia saying that. I am suggesting that Parnia didn't use those exact words, especially since many actual quotes appear in the article and the bit about reflexes is not a direct quote. 

Why is it such a big deal to you if reflexes occur during some cases of cardiac arrest and CPR? Who cares?

Do you think accuracy isn't important when discussing these topics?

(2017-10-10, 04:43 PM)chuck Wrote: [ -> ]This quote says nothing about reflexes during CPR.

This one does.

Performing cardiopulmonary resuscitation (CPR) does send some blood to the brain — about 15 percent of what it requires to function normally, according to Parnia. This is enough to slow the brain cells' death trajectory, but it isn't enough to kick-start the brain into working again, which is why reflexes don't resume during CPR, he said.

Take it up with Parnia my "friend"

(2017-10-10, 04:59 PM)tim Wrote: [ -> ]This one does.

Performing cardiopulmonary resuscitation (CPR) does send some blood to the brain — about 15 percent of what it requires to function normally, according to Parnia. This is enough to slow the brain cells' death trajectory, but it isn't enough to kick-start the brain into working again, which is why reflexes don't resume during CPR, he said.

Take it up with Parnia my "friend"

You are pointing to the Live Science article!

Do you understand the difference between a direct quote and an indirect quote? A direct quote is enclosed in quote marks. That is something that can be attributed word for word to the speaker. With an indirect quote the author, in this case Mindy, summarizes something that they feel Parnia has said. 

https://www.livescience.com/60593-flatli...ation.html

Even if Parnia did say that, can you see that he would be wrong given the studies I referenced? Showing pupillary response during CPR isn't like trying to find the Higgs Boson. It would seem to be pretty cut and dried.

I don't need Parnia to declare something as fact before I can draw a conclusion from some fairly straightforward published scientific studies.

(2017-10-10, 04:51 PM)chuck Wrote: [ -> ]The article doesn't directly quote Parnia on reflexes during CPR. It is an indirect quote. Did Parnia actually say "reflexes don't resume during CPR."? We will never know unless we contact the author of the article and request a transcript. I seriously doubt he would say that given the fact that there are a couple of seemingly conclusive studies that state the exact opposite, one of them appearing I believe in Resuscitation Journal, which one could assume Parnia might read.

I don't think you are making up the fact that the article provides an indirect quote of Parnia saying that. I am suggesting that Parnia didn't use those exact words, especially since many actual quotes appear in the article and the bit about reflexes is not a direct quote. 

Why is it such a big deal to you if reflexes occur during some cases of cardiac arrest and CPR? Who cares?

Do you think accuracy isn't important when discussing these topics?

"Why is it such a big deal to you if reflexes occur during some cases of cardiac arrest and CPR? Who cares?"

I didn't say it was a big deal. YOU made it out to be for some reason best known to yourself. I simply quoted an expert on the subject.

"Do you think accuracy isn't important when discussing these topics?"

You haven't shown Parnia's statement to be inaccurate. You've presented one paper on pigs and one other paper which doesn't look that impressive to me. I always try to be accurate when posting anything. You however are all the place depending on how you're feeling that day, or at least it seems that way to me with your odd behaviour. I thought I was on ignore ??