Blood donation & diving

GKAM · 19th November 2006, 23:42

Is there some restriction/contraindication wrt diving within 24h of having donated some blood? If so, then can somebody please explain why and how this would impact a diver?

Thx,
George

Skipbreather · 20th November 2006, 02:47

Quote: (Originally Posted by GKAM)

Is there some restriction/contraindication wrt diving within 24h of having donated some blood? If so, then can somebody please explain why and how this would impact a diver?

Thx,
George

Hi George-

I’m reaching waaaaaay back here, but if memory serves- the US Air Force has a restriction against flight crew flying within 72 hours of losing- including donation- 300 ml of blood. Had to do with not enough hemoglobin to move O2 about. Seeing as it is ‘lights out’ if Rebreather divers suffer from hypemic hypoxia, my guess would be that blood donation- a good and selfless act in and of itself- immediately prior to diving would not be condusive to longevity. Any MDs on the board care to comment?

Best,
Ken

Gene_Hobbs · 20th November 2006, 03:39

Quote: (Originally Posted by GKAM)

Is there some restriction/contraindication wrt diving within 24h of having donated some blood? If so, then can somebody please explain why and how this would impact a diver?

Well...

Quote: (Originally Posted by Ernest Campbell)

The donor’s body replenishes the fluid lost from donation in 24 hours. If not anemic (Hgb<12 Gm/dl) a person can dive in 24 hours after blood donation. It may take up to two months to replace the lost red blood cells. Whole blood can be donated once every eight weeks. The most important part of the blood to the diver is the red blood cell, responsible for the transport of oxygen to the tissues. The fluid part of blood is replenished in about one day. If the diver waits 24 hours and has a normal hematocrit, then diving should be allowed.

Red blood cells are perhaps the most recognizable component of whole blood. Red blood cells contain hemoglobin, a complex iron-containing protein that carries oxygen throughout the body and gives blood its red color. The percentage of blood volume composed of red blood cells is called the “hematocrit.” The average hematocrit in an adult male is 47 percent. There are about one billion red blood cells in two to three drops of blood, and, for every 600 red blood cells, there are about 40 platelets and one white cell. Manufactured in the bone marrow, red blood cells are continuously being produced and broken down. They live for approximately 120 days in the circulatory system and are eventually removed by the spleen.

And the old standby...

Quote: (Originally Posted by Divers Alert Network)

Although blood volume will return to normal shortly following blood donation, a lower red blood cell count may contribute to undesirable signs and symptoms such as fatigue and dehydration. Such conditions are well known to increase one's risk for a dive accident or possible decompression sickness. Medical standards for divers, as defined in a clinical by the Undersea Hyperbaric and Medical Society, states divers should not dive for at least 48 to 72 hours after blood donation. DAN routinely recommends 72 hours.

I have looked for the official UHMS statement with no luck so far, I'll update the thread if I find it.

Take care,
G

Sutty · 20th November 2006, 07:48

I'm not a hyperbaric medic so not qualified to give advice on this - but here's my musings.
On losing a significant volume of blood one of the short-term compensatory mechanisms is the movement of fluid from the tissues into the blood to increase the blood volume back towards normal. Therefore the tissues become relatively dehydrated - we have discussed whether dehydration matters on the forum before but consensus seems to be that it is a good idea to be well hydrated. If I was going to dive shortly after giving blood (eg 48hrs) I would take extra care to ensure good hydration.
The reduction in circulating blood volume per se doesn't really worry me as there is normally a relative fluid overload once immersed as blood moves from peripheral veins back to the central veins due to hydrostatic effects - I would be aware that this effect is reversed on leaving the water, and look for a diver who had lost/donated blood feeling faint after leaving the water.
The reduction in red cells per unit volume (ie relatively anaemic) doesn't worry me much either. The normal haemoglobin/red cell count is higher than required for optimal oxygen delivery to the tissues anyway.
On a personal level only I'd be happy to dive the day after blood donation as long as I was well hydrated, I might hesitate if I had a lot of exertion to do post-dive (like lugging a load of kit up the ramp at Dorothea quarry) - but we shouldn't really be doing that anyway! The only time I have had symptoms after donation was after 15mins on an exercise bike about 3hrs post-donation (yes, I can be a bit dim!), when I stopped and the reduced blood volume pooled in my legs (hot and vasodilated) I felt very faint and had to lie down with legs raised to have a detectable pulse!

Neil

I'd be interested in the diving docs' views on this

Gene_Hobbs · 23rd November 2006, 22:50

Well, this thread bothered me some. Specifically my last post in this thread about the DAN statement (previous wording used for this question). So, I asked for this to be looked at again. It's funny how this one slipped through the cracks. Either way, now there is a better wording from DAN on this topic now.

Quote: (Originally Posted by Divers Alert Network)

Immediately following blood donation, the volume of circulating blood is reduced. Provided the donor eats and drinks normally, blood volume returns to normal within 24 hours. Diving within the first few hours after donating blood is not advisable because of the possibility that reduced blood flow could cause impaired inert gas washout after a dive, and thus an increased risk of decompression sickness. We have no reason to believe that it is necessary to wait more than 24 hours after donation before scuba diving.

There was also an interesting abstract at the 2006 UHMS meeting on hematocrit and DCS. (RRR ID# 3643)

Quote: (Originally Posted by 2006 UHMS Annual Meeting Abstract)

NEUROLOGICAL DECOMPRESSION ILLNESS AND HEMATOCRIT: ANALYSIS OF A CONSECUTIVE SERIES OF 200 RECREATIONAL SCUBA DIVERS.
Newton HB, Burkart J, Pearl D, Padilla W
BACKGROUND: Neurological complications are common in recreational divers diagnosed with decompression illness (DCI). The spinal cord appears to be the region most vulnerable to injury, but the brain, inner ear, and peripheral nerves are also at risk. Prior reports suggest that hemoconcentration, with hematocrit values of 48 or greater, increase the risk for more severe and persistent neurological deficits in divers with DCI. Herein we describe our experience with neurological DCI and hematocrit values in a large series of consecutively treated diver MATERIALS AND METHODS: We performed a retrospective chart review of 200 consecutive recreational divers that received treatment for DCI. Standard statistical analyses were performed to determine if there were any significant relationships between diving-related or demographic parameters, neurological manifestations, and hematocrit RESULTS: In 177 of the 200 divers (88.5percent), at least one severe manifestation of neurological DCI was present. The most common findings were paresthesia, dysesthesia, loss of coordination, and motor weakness. The median hematocrit value was 43, for both male and female divers, with a range of 30 to 61. Hematocrit values did not correlate with diver age (rank correlation = 0.053) or level of diving experience (rank correlation = 0.003). In male divers, the hematocrit did not correlate with the occurrence of severe sensory (p=0.27, Wilcoxon test) or motor (p=0.86, Wilcoxon test) symptoms, including the sub-group with values of 48 or greater. In contrast, female divers with hematocrit values of 48 or greater were significantly more likely to develop motor weakness (p=0.002, Fisher's exact test) and an increased number of severe sensory symptoms (p=0.001, Kendall's tau statistic CONCLUSIONS: Neurological complications are common in recreational divers treated for DCI. Hematocrit values of 48 or higher were correlated with the presence of motor weakness and severity of sensory symptoms in female divers. The hematocrit did not correlate with neurological DCI in male divers.

Dr. Denoble was able to locate one USN diving case report that describes blood donation preceding the dive with DCS. The connection is weak but worth noting.

Quote: (Originally Posted by Divers Alert Network)

This subject stated he first noticed a headache of moderate intensity on surfacing. States it seemed to be behind the eyes. No visual disturbances. Had no difficulty during dive clearing air passages of ears or sinuses. This moderate headache lasted about 24 hours. About 1500 he developed a moderate skin rash over right deltoid and upper arm (anteriorly and laterally) which caused no itching. Was first on oxygen on surface for 30 min and rash disappeared. Went home feeling quite well except for slight headache. About 1800 he noticed mild fleeting pains in various joints on right side involving wrist, elbow, knee and ankle on right side. These pains were mild and transient in character and subject did not report for aid as he thought his symptoms were mild and would subside. Slept well. Following AM had only slight headache. Right triceps area was still sore. Seen 14/18 and he had an ecchymotic area about 3” in diameter with two petechial heads over right triceps area. Some induration present indicative of rather deep extravasation of blood. This patient definitely had some peripheral vascular damage. Trauma as a cause for this bruise could not be accounted for. Intravascular bubbles may be the etiological factor. This case should have been given Rx by recompression. Note: this subject gave 1/2 pint of blood to blood donor service on the afternoon of the day preceding dive. This was not known until after his dive was made. This may have some etiological bearing in this case. Said he felt well after giving blood except for slight nausea following donation. Note RBC is slightly down.

Hope this helps...

Take care

19th November 2006, 23:42	#1 (permalink)
GKAM digital nomad Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: May 2005 Location: Greece Posts: 252	Blood donation & diving Is there some restriction/contraindication wrt diving within 24h of having donated some blood? If so, then can somebody please explain why and how this would impact a diver? Thx, George __________________ Stay #
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20th November 2006, 02:47	#2 (permalink)
Skipbreather Reads the fine print Current Rebreather/s: Megalodon Home Build Other Rebreather/s: Not Bought Yet MK 15.X Home Build Join Date: Mar 2005 Location: Chicago, Illinois, USA Posts: 555	Re: Blood donation & diving Quote: (Originally Posted by GKAM) Is there some restriction/contraindication wrt diving within 24h of having donated some blood? If so, then can somebody please explain why and how this would impact a diver? Thx, George Hi George- I’m reaching waaaaaay back here, but if memory serves- the US Air Force has a restriction against flight crew flying within 72 hours of losing- including donation- 300 ml of blood. Had to do with not enough hemoglobin to move O2 about. Seeing as it is ‘lights out’ if Rebreather divers suffer from hypemic hypoxia, my guess would be that blood donation- a good and selfless act in and of itself- immediately prior to diving would not be condusive to longevity. Any MDs on the board care to comment? Best, Ken Last edited by Skipbreather : 20th November 2006 at 14:25. Reason: fat typing fingers
(Online)

20th November 2006, 03:39	#3 (permalink)
Gene_Hobbs Resident bibliophile Current Rebreather/s: Not Bought Yet Other Rebreather/s: Not Bought Yet Join Date: Sep 2006 Location: Durham, NC, USA Posts: 122	Re: Blood donation & diving Quote: (Originally Posted by GKAM) Is there some restriction/contraindication wrt diving within 24h of having donated some blood? If so, then can somebody please explain why and how this would impact a diver? Well... Quote: (Originally Posted by Ernest Campbell) The donor’s body replenishes the fluid lost from donation in 24 hours. If not anemic (Hgb<12 Gm/dl) a person can dive in 24 hours after blood donation. It may take up to two months to replace the lost red blood cells. Whole blood can be donated once every eight weeks. The most important part of the blood to the diver is the red blood cell, responsible for the transport of oxygen to the tissues. The fluid part of blood is replenished in about one day. If the diver waits 24 hours and has a normal hematocrit, then diving should be allowed. Red blood cells are perhaps the most recognizable component of whole blood. Red blood cells contain hemoglobin, a complex iron-containing protein that carries oxygen throughout the body and gives blood its red color. The percentage of blood volume composed of red blood cells is called the “hematocrit.” The average hematocrit in an adult male is 47 percent. There are about one billion red blood cells in two to three drops of blood, and, for every 600 red blood cells, there are about 40 platelets and one white cell. Manufactured in the bone marrow, red blood cells are continuously being produced and broken down. They live for approximately 120 days in the circulatory system and are eventually removed by the spleen. And the old standby... Quote: (Originally Posted by Divers Alert Network) Although blood volume will return to normal shortly following blood donation, a lower red blood cell count may contribute to undesirable signs and symptoms such as fatigue and dehydration. Such conditions are well known to increase one's risk for a dive accident or possible decompression sickness. Medical standards for divers, as defined in a clinical by the Undersea Hyperbaric and Medical Society, states divers should not dive for at least 48 to 72 hours after blood donation. DAN routinely recommends 72 hours. I have looked for the official UHMS statement with no luck so far, I'll update the thread if I find it. Take care, G __________________ http://rubicon-foundation.org/ Home of the Rubicon Research Repository. For help getting started with the Repository, please visit our FAQ page. PLEASE support our work. "Oxygen is addictive and deadly. Everyone who uses it will eventually die" --RW Hamilton, PhD 1991
(Online)

20th November 2006, 07:48	#4 (permalink)
Sutty Classic Kiss diver Current Rebreather/s: Classic Kiss Other Rebreather/s: Join Date: Jun 2005 Location: Glossop, Derbyshire, UK Posts: 800	Re: Blood donation & diving I'm not a hyperbaric medic so not qualified to give advice on this - but here's my musings. On losing a significant volume of blood one of the short-term compensatory mechanisms is the movement of fluid from the tissues into the blood to increase the blood volume back towards normal. Therefore the tissues become relatively dehydrated - we have discussed whether dehydration matters on the forum before but consensus seems to be that it is a good idea to be well hydrated. If I was going to dive shortly after giving blood (eg 48hrs) I would take extra care to ensure good hydration. The reduction in circulating blood volume per se doesn't really worry me as there is normally a relative fluid overload once immersed as blood moves from peripheral veins back to the central veins due to hydrostatic effects - I would be aware that this effect is reversed on leaving the water, and look for a diver who had lost/donated blood feeling faint after leaving the water. The reduction in red cells per unit volume (ie relatively anaemic) doesn't worry me much either. The normal haemoglobin/red cell count is higher than required for optimal oxygen delivery to the tissues anyway. On a personal level only I'd be happy to dive the day after blood donation as long as I was well hydrated, I might hesitate if I had a lot of exertion to do post-dive (like lugging a load of kit up the ramp at Dorothea quarry) - but we shouldn't really be doing that anyway! The only time I have had symptoms after donation was after 15mins on an exercise bike about 3hrs post-donation (yes, I can be a bit dim!), when I stopped and the reduced blood volume pooled in my legs (hot and vasodilated) I felt very faint and had to lie down with legs raised to have a detectable pulse! Neil I'd be interested in the diving docs' views on this __________________ Never forget that life is a finite resource. Last edited by Sutty : 20th November 2006 at 07:51.
(Online)

23rd November 2006, 22:50	#5 (permalink)
Gene_Hobbs Resident bibliophile Current Rebreather/s: Not Bought Yet Other Rebreather/s: Not Bought Yet Join Date: Sep 2006 Location: Durham, NC, USA Posts: 122	Re: Blood donation & diving Well, this thread bothered me some. Specifically my last post in this thread about the DAN statement (previous wording used for this question). So, I asked for this to be looked at again. It's funny how this one slipped through the cracks. Either way, now there is a better wording from DAN on this topic now. Quote: (Originally Posted by Divers Alert Network) Immediately following blood donation, the volume of circulating blood is reduced. Provided the donor eats and drinks normally, blood volume returns to normal within 24 hours. Diving within the first few hours after donating blood is not advisable because of the possibility that reduced blood flow could cause impaired inert gas washout after a dive, and thus an increased risk of decompression sickness. We have no reason to believe that it is necessary to wait more than 24 hours after donation before scuba diving. There was also an interesting abstract at the 2006 UHMS meeting on hematocrit and DCS. (RRR ID# 3643) Quote: (Originally Posted by 2006 UHMS Annual Meeting Abstract) NEUROLOGICAL DECOMPRESSION ILLNESS AND HEMATOCRIT: ANALYSIS OF A CONSECUTIVE SERIES OF 200 RECREATIONAL SCUBA DIVERS. Newton HB, Burkart J, Pearl D, Padilla W BACKGROUND: Neurological complications are common in recreational divers diagnosed with decompression illness (DCI). The spinal cord appears to be the region most vulnerable to injury, but the brain, inner ear, and peripheral nerves are also at risk. Prior reports suggest that hemoconcentration, with hematocrit values of 48 or greater, increase the risk for more severe and persistent neurological deficits in divers with DCI. Herein we describe our experience with neurological DCI and hematocrit values in a large series of consecutively treated diver MATERIALS AND METHODS: We performed a retrospective chart review of 200 consecutive recreational divers that received treatment for DCI. Standard statistical analyses were performed to determine if there were any significant relationships between diving-related or demographic parameters, neurological manifestations, and hematocrit RESULTS: In 177 of the 200 divers (88.5percent), at least one severe manifestation of neurological DCI was present. The most common findings were paresthesia, dysesthesia, loss of coordination, and motor weakness. The median hematocrit value was 43, for both male and female divers, with a range of 30 to 61. Hematocrit values did not correlate with diver age (rank correlation = 0.053) or level of diving experience (rank correlation = 0.003). In male divers, the hematocrit did not correlate with the occurrence of severe sensory (p=0.27, Wilcoxon test) or motor (p=0.86, Wilcoxon test) symptoms, including the sub-group with values of 48 or greater. In contrast, female divers with hematocrit values of 48 or greater were significantly more likely to develop motor weakness (p=0.002, Fisher's exact test) and an increased number of severe sensory symptoms (p=0.001, Kendall's tau statistic CONCLUSIONS: Neurological complications are common in recreational divers treated for DCI. Hematocrit values of 48 or higher were correlated with the presence of motor weakness and severity of sensory symptoms in female divers. The hematocrit did not correlate with neurological DCI in male divers. Dr. Denoble was able to locate one USN diving case report that describes blood donation preceding the dive with DCS. The connection is weak but worth noting. Quote: (Originally Posted by Divers Alert Network) This subject stated he first noticed a headache of moderate intensity on surfacing. States it seemed to be behind the eyes. No visual disturbances. Had no difficulty during dive clearing air passages of ears or sinuses. This moderate headache lasted about 24 hours. About 1500 he developed a moderate skin rash over right deltoid and upper arm (anteriorly and laterally) which caused no itching. Was first on oxygen on surface for 30 min and rash disappeared. Went home feeling quite well except for slight headache. About 1800 he noticed mild fleeting pains in various joints on right side involving wrist, elbow, knee and ankle on right side. These pains were mild and transient in character and subject did not report for aid as he thought his symptoms were mild and would subside. Slept well. Following AM had only slight headache. Right triceps area was still sore. Seen 14/18 and he had an ecchymotic area about 3” in diameter with two petechial heads over right triceps area. Some induration present indicative of rather deep extravasation of blood. This patient definitely had some peripheral vascular damage. Trauma as a cause for this bruise could not be accounted for. Intravascular bubbles may be the etiological factor. This case should have been given Rx by recompression. Note: this subject gave 1/2 pint of blood to blood donor service on the afternoon of the day preceding dive. This was not known until after his dive was made. This may have some etiological bearing in this case. Said he felt well after giving blood except for slight nausea following donation. Note RBC is slightly down. Hope this helps... Take care __________________ http://rubicon-foundation.org/ Home of the Rubicon Research Repository. For help getting started with the Repository, please visit our FAQ page. PLEASE support our work. "Oxygen is addictive and deadly. Everyone who uses it will eventually die" --RW Hamilton, PhD 1991
(Online)

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