Science Tuesday - Public Health, Diagnosis, and Itty Bitty Cups
Guidelines for Epidemics: Who Gets a Ventilator?
By CORNELIA DEAN, The New York Times, March 25, 2008
It may sound unthinkable - the idea of denying life support to some people in a public health disaster like an epidemic. But a new report says doctors, health care workers and the public need to start thinking about it.
The report, by New York State health officials, grows out of the work of a group formed in 2006 to plan for the possibility of an influenza pandemic. The group focused on the breathing machines called ventilators.
Right now, there are enough ventilators to go around. But in an epidemic, there could be a severe shortage of machines and, more important, doctors and nurses to run them. At that point, the new report says, doctors and hospitals would have no choice but to start taking some people off the machines so that others could live.
Removal “is absolutely the crux of the problem,” said a lead author of the study, Dr. Tia Powell, who has spent much of her career studying medical ethics. “There are people who might survive who won’t get a chance at a ventilator if someone who is likely to die even with a vent is using it.”
Before an epidemic strikes, the report says, the public should confront the issue to ensure that any such triage decisions reflect community views, as well as ethical and clinical standards.
“It’s not really a technical solution,” said Dr. Powell, who directs the New York State Task Force on Life and the Law. “It’s values. And the people are the experts on that.”
The report, “Allocation of Ventilators in a Public Health Disaster,” appears in the March issue of Disaster Medicine and Public Health Preparedness, a quarterly journal of the American Medical Association.
The project began in response to outbreaks of bird or avian flu, H5N1 influenza, in Asia. Although just a few hundred people are known to have contracted the disease so far, most of them died of it. So a widespread outbreak would overwhelmingly strain the health care system, not just in machinery, but also in the doctors, nurses and other health care personnel needed to use it.
The report says triage, separating those who will receive treatment from those who will not, should largely depend on the prognosis for recovery, not on factors like underlying health or age.
“We are not interested in quality of life,” Dr. Powell said in an interview. “We are just interested in whether you are able to survive this particular crisis.”
Anyway, she said, age has not been “a particularly sensitive discriminator for survival” in H5N1 flu. Many of its victims have been young.
Though allocating scarce resources is a perennial topic among ethicists and health officials, the authors say their guidelines are the first of their kind in the nation and could be a template for rationing in other catastrophes.
“This kind of thinking, as scary or even horrifying as it may seem, is absolutely critical and is much better done now than on the fly in the middle of a pandemic,” said Dr. Art Kellerman of Emory University, an expert on emergency medicine.
Dr. Kellerman, who was not connected to the study, said that a crisis like a flu pandemic was a matter of when, not if, and that he was “frustrated with people who want to pretend that it won’t be an issue or simply pass the buck to the emergency care physician.”
The guidelines confront that issue explicitly, recommending the appointment of “triage officers” to make ventilator decisions based on information about the number of incoming patients and their conditions, but who will not be involved in caring for them. If doctors and nurses caring for the sick must also make these triage decisions, the report says, the resulting stress can be “corrosive.”
Under the guidelines, “the person who is providing your direct care is not going to be the person who decides whether you stay on the vent or go off,” Dr. Powell said. “You need to know they are advocating for you. They cannot be looking out the door at how many people are waiting for care.”
Dr. Powell noted that rationing - or as she said it is called, “providing alternative standards of care” - was repellent to many Americans. In the early days of kidney dialysis, when dialysis machines were scare, “we were so uncomfortable with that as a nation we essentially made dialysis available to everyone who needs it,” she said. Similarly, she said, much effort has gone into building a fair system for allocating organs for transplant.
But that work “does not really apply to this kind of crisis situation,” she said. “This is a genuine emergency. You are not going to have time to do a careful sorting out, by list.”
So the panel began work by identifying crucial factors for rationing, including these:
¶Recognizing that patients deprived of mechanical breathing assistance should continue to receive care.
¶Using scarce resources like mechanical ventilators to save the greatest number of lives while continuing to care for patients individually. “As the number of affected patients multiplies, accommodating these two goals will require making increasingly difficult decisions,” the report says.
¶Planning, so as not to leave decisions in a pandemic “to exhausted frontline providers.” Public health agencies must accept this obligation, the report says, “despite the difficulties inherent in planning.”
¶Applying any plan broadly and consistently.
¶Publicizing guidelines, seeking public comments and incorporating suggested revisions.
For ventilators, the group established “exclusion criteria,” conditions that would classify people ineligible for ventilators. It includes recurrent cardiac arrest, metastatic cancer with a poor prognosis, severe burns, end-stage organ failure and neurological conditions with high expected mortality.
The report cites “much public comment” about whether it would be better to emphasize ventilator access for children rather than the elderly. And it lists kidney failure as a reason to withhold ventilator support, in part because patients needing dialysis already place increased demand on scarce nursing resources.
When a ventilator is removed from a patient who depends on it, the report says, health workers should follow their institutions’ existing guidelines for withdrawing life support and provide palliative care like sedation, so patients do not experience “air hunger.” In an epidemic, the report adds, “facilities should prepare for a significant increase in demand for palliative care.”
The guidelines are online at http://www.health.state.ny.us/diseases/communicable/influenza/pandemic/ventilators/.
Dr. Powell said she had discussed them at meetings of professional societies and at medical centers around the state and added that she hoped the new report would draw more public attention. One likely step, she said, would be to hold discussions by focus groups.
“The guidelines are intended to reflect the values of New Yorkers,” she said. “And if they don’t, we want advice on how to revise them.”
Dr. Kellerman of Emory said the report should not be allowed to gather dust. “It is important that those guidelines be out there and discussed and struggled with right now,” he said.
Many hospitals already struggle with chronically scarce resources like intensive care beds, he said, and in a pandemic the problem would be far, far worse.
Dr. Kellerman said he was not optimistic. In the first place, he said, the public tends to “tune out” on such disturbing questions. Or, he said, they may accept the guidelines only “until it’s their family member. Then people often feel very differently.”
Cases: When the Disease Eludes a Diagnosis
By BARRON H. LERNER, M.D., The New York Times, March 25, 2008
Lucy, one of my longtime patients, has a neurological ailment she believes I have been unable to adequately diagnose.
Although I hope to make further progress on her case, I have also told her that there may never be a definitive answer. Not surprisingly, she is feeling pretty frustrated with me.
Why do doctors and patients often approach the diagnosis of disease so differently?
Part of the answer lies in the concept of triage - the notion, originated in wartime, of caring for the sickest and most salvageable patients first. Once they were saved, attention could be turned to less drastic cases.
A similar strategy has evolved in emergency rooms, where physicians are trained to “rule in” or “rule out” severe conditions. Thus, doctors immediately consider heart attacks or pulmonary embolisms for patients with chest pain, and intestinal rupture for those with abdominal pain.
But what happens when these conditions are ruled out? In such cases, doctors proceed to search for less dire (and, it must be said, more mundane) diagnoses. The trouble is that at this stage, some physicians, busy with other patients and duties, lose interest.
For example, many patients with chest pain carry a diagnosis of costochondritis (inflammation of the chest wall bones) or gastroesophageal reflux (regurgitation of stomach acid into the esophagus).
These are real conditions. But they tend to generate little interest from many physicians, who may refer to them as “wastebasket diagnoses,” offered when nothing more serious has turned up.
The frustration of patients who believe that the medical profession takes these types of ailments too lightly has led groups of them to form alliances to publicize their illnesses. Foremost among them are fibromyalgia, a syndrome involving muscular and other pains, and chronic fatigue syndrome, which has recently been given increased credibility by the Centers for Disease Control and Prevention.
Part of the problem with these conditions is that existing treatments are not nearly as effective as those for, say, heart attacks and pneumonia. As a result, doctors may grow irritated when patients continually complain of symptoms that cannot be “cured.”
Patients’ frustration may rise even more when their conditions are especially obscure. I once had a patient who complained of persistent drenching sweats that forced her to change her bedclothes several times a night.
Upon learning of this problem, I first went into triage mode, ruling out possible dangerous causes, including tuberculosis, a thyroid abnormality and rare tumors that release hormones. I referred her to a gynecologist on the chance that she was getting hot flashes decades after her menopause.
When all the tests were negative, my patient was understandably upset, even angry. “No doctor that I have spoken to has been able to tell me what it is,” she said, as I remember. She even called a doctor on a local radio show for his opinion.
I recalled this story when I learned recently that my longtime patient Lucy’s new neurologist was questioning whether she had multiple sclerosis, a diagnosis she has carried for more than 25 years. Since I have known her, Lucy has had painful and weak legs that necessitate a walker.
Rather than simply corroborating her existing diagnosis, this doctor had thought outside the box, noting that Lucy’s relatively stable condition - and her lack of brain lesions on an M.R.I., a test not available at the time of her initial diagnosis - warranted a new perspective.
At first, Lucy was excited too. After all, being told you may not have a serious disease like multiple sclerosis is surely good news.
But while the neurologist had correctly questioned the diagnosis, she had a harder time finding a new one. Lucy became discouraged. “I want to know,” she told me. “I point-blank asked the neurologist, ‘What is it?’ And the only answer she can give me is: ‘I don’t know. I’m not sure.’ ”
Eventually, the neurology team decided that Lucy had an atypical form of multiple sclerosis, one that caused unusual neurological symptoms and was present in the spinal cord but not the brain. Yet the doctors admitted that this diagnosis generated more questions than answers about Lucy’s prognosis and her future treatment.
While trying to be as sympathetic as possible, I find myself reminding Lucy of the limits of certainty in medicine. Despite enormous advances in technology, some diagnoses may remain elusive. I also told her that it was highly unlikely her doctors missed diagnosing a disease that could have been successfully treated. But she remains convinced that she deserves to know exactly what she has.
So we will continue to search.
Barron H. Lerner teaches medicine and public health at the Columbia University Medical Center.
SEA SHRINKS FOAM Cups and their messages back from the Arctic Ocean: left, from recent Russian dives; right, from an earlier dive, with a landlubber.
Far Below the Surface of the World’s Oceans, a Tough Place for Foam Cups
By WILLIAM J. BROAD, The New York Times, March 25, 2008
Last August, as a team at the North Pole prepared to plunge more than two miles to the bottom of the Arctic Ocean, some of the dozens of specialists who staged the dive engaged in a time-honored ritual: drawing on foam cups, decorating more than 100 of them.
The cups were then gingerly sent into the deep. During the historic dive, led by Russian scientists, the pressure of the surrounding water crushed the cups to the size of thimbles, also squeezing their whimsies of writing and drawing.
Afterward, the tiny cups became instant mementoes of the polar dive, offering striking proof of the descent into an unfamiliar zone and silent testimony to the crushing power of plain old water.
“The real North Pole,” read one cup’s shrunken writing. “Explore the abyss,” another urged.
Deep explorers have made thousands of such keepsakes over the decades, and more recently, schools have joined the fun as a way to drive home some of the peculiarities of a planet where very deep water covers some 65 percent of the surface.
For example, in 2001, a third-grade class at Harding Elementary School in Corvallis, Ore., decorated 28 foam cups with bright fish, happy faces and American flags. The scientist father of one of the students then sent the cups into the depths of the Indian Ocean, shrinking them into small trophies for a lesson on the crushing weight of deep water.
A comparison to air pressure helps. At sea level, atmospheric pressure is 14.7 pounds per square inch. The deeper the dive, the greater the water pressure. At the resting place of the Titanic, more than two miles down, the pressure is 2.8 tons per square inch. That constantly bears down and tries to obliterate any void.
The pressure on any object in the deep sea, as at sea level, is uniform. It presses from above, below and the sides. That is because the molecules making up fluids (which in physics include both gases and liquids) are free to move about and transmit force in all directions.
Sea creatures are made primarily of water, which is virtually incompressible. So they escape destruction in the abyss.
But the high pressure causes most cavities and hollows, like human lungs, to collapse. So, too, with foam cups. They are almost all void since the foam is 95 percent air, according to the American Chemistry Council. As pressures build during descent, the air slowly compresses and the cups shrink.
Explorers of the deep escape slow torture by descending in small craft known as submersibles. A super-strong personnel sphere protects a pilot and two observers, who peer out through tiny portholes made with extraordinarily thick windows. The air pressure inside is the same as at sea level.
In its early days, Alvin, a pioneering American submersible, often carried outside its crew sphere compressible items like cork bricks and foam balls, cups and wig holders (to make shrunken heads), according to “Water Baby,” a profile of the craft.
“It’s an old trick,” the author, Victoria A. Kaharl, wrote, adding that the pressure of the deep makes “perfect miniatures.”
But the experimentally minded on such expeditions were also tempted to see what might withstand the pressure, and in at least one instance sent down a raw egg.
Filled with incompressible fluid, Ms. Kaharl wrote, the egg returned to the surface “perfectly intact and edible, but salty.”
By CORNELIA DEAN, The New York Times, March 25, 2008
It may sound unthinkable - the idea of denying life support to some people in a public health disaster like an epidemic. But a new report says doctors, health care workers and the public need to start thinking about it.
The report, by New York State health officials, grows out of the work of a group formed in 2006 to plan for the possibility of an influenza pandemic. The group focused on the breathing machines called ventilators.
Right now, there are enough ventilators to go around. But in an epidemic, there could be a severe shortage of machines and, more important, doctors and nurses to run them. At that point, the new report says, doctors and hospitals would have no choice but to start taking some people off the machines so that others could live.
Removal “is absolutely the crux of the problem,” said a lead author of the study, Dr. Tia Powell, who has spent much of her career studying medical ethics. “There are people who might survive who won’t get a chance at a ventilator if someone who is likely to die even with a vent is using it.”
Before an epidemic strikes, the report says, the public should confront the issue to ensure that any such triage decisions reflect community views, as well as ethical and clinical standards.
“It’s not really a technical solution,” said Dr. Powell, who directs the New York State Task Force on Life and the Law. “It’s values. And the people are the experts on that.”
The report, “Allocation of Ventilators in a Public Health Disaster,” appears in the March issue of Disaster Medicine and Public Health Preparedness, a quarterly journal of the American Medical Association.
The project began in response to outbreaks of bird or avian flu, H5N1 influenza, in Asia. Although just a few hundred people are known to have contracted the disease so far, most of them died of it. So a widespread outbreak would overwhelmingly strain the health care system, not just in machinery, but also in the doctors, nurses and other health care personnel needed to use it.
The report says triage, separating those who will receive treatment from those who will not, should largely depend on the prognosis for recovery, not on factors like underlying health or age.
“We are not interested in quality of life,” Dr. Powell said in an interview. “We are just interested in whether you are able to survive this particular crisis.”
Anyway, she said, age has not been “a particularly sensitive discriminator for survival” in H5N1 flu. Many of its victims have been young.
Though allocating scarce resources is a perennial topic among ethicists and health officials, the authors say their guidelines are the first of their kind in the nation and could be a template for rationing in other catastrophes.
“This kind of thinking, as scary or even horrifying as it may seem, is absolutely critical and is much better done now than on the fly in the middle of a pandemic,” said Dr. Art Kellerman of Emory University, an expert on emergency medicine.
Dr. Kellerman, who was not connected to the study, said that a crisis like a flu pandemic was a matter of when, not if, and that he was “frustrated with people who want to pretend that it won’t be an issue or simply pass the buck to the emergency care physician.”
The guidelines confront that issue explicitly, recommending the appointment of “triage officers” to make ventilator decisions based on information about the number of incoming patients and their conditions, but who will not be involved in caring for them. If doctors and nurses caring for the sick must also make these triage decisions, the report says, the resulting stress can be “corrosive.”
Under the guidelines, “the person who is providing your direct care is not going to be the person who decides whether you stay on the vent or go off,” Dr. Powell said. “You need to know they are advocating for you. They cannot be looking out the door at how many people are waiting for care.”
Dr. Powell noted that rationing - or as she said it is called, “providing alternative standards of care” - was repellent to many Americans. In the early days of kidney dialysis, when dialysis machines were scare, “we were so uncomfortable with that as a nation we essentially made dialysis available to everyone who needs it,” she said. Similarly, she said, much effort has gone into building a fair system for allocating organs for transplant.
But that work “does not really apply to this kind of crisis situation,” she said. “This is a genuine emergency. You are not going to have time to do a careful sorting out, by list.”
So the panel began work by identifying crucial factors for rationing, including these:
¶Recognizing that patients deprived of mechanical breathing assistance should continue to receive care.
¶Using scarce resources like mechanical ventilators to save the greatest number of lives while continuing to care for patients individually. “As the number of affected patients multiplies, accommodating these two goals will require making increasingly difficult decisions,” the report says.
¶Planning, so as not to leave decisions in a pandemic “to exhausted frontline providers.” Public health agencies must accept this obligation, the report says, “despite the difficulties inherent in planning.”
¶Applying any plan broadly and consistently.
¶Publicizing guidelines, seeking public comments and incorporating suggested revisions.
For ventilators, the group established “exclusion criteria,” conditions that would classify people ineligible for ventilators. It includes recurrent cardiac arrest, metastatic cancer with a poor prognosis, severe burns, end-stage organ failure and neurological conditions with high expected mortality.
The report cites “much public comment” about whether it would be better to emphasize ventilator access for children rather than the elderly. And it lists kidney failure as a reason to withhold ventilator support, in part because patients needing dialysis already place increased demand on scarce nursing resources.
When a ventilator is removed from a patient who depends on it, the report says, health workers should follow their institutions’ existing guidelines for withdrawing life support and provide palliative care like sedation, so patients do not experience “air hunger.” In an epidemic, the report adds, “facilities should prepare for a significant increase in demand for palliative care.”
The guidelines are online at http://www.health.state.ny.us/diseases/communicable/influenza/pandemic/ventilators/.
Dr. Powell said she had discussed them at meetings of professional societies and at medical centers around the state and added that she hoped the new report would draw more public attention. One likely step, she said, would be to hold discussions by focus groups.
“The guidelines are intended to reflect the values of New Yorkers,” she said. “And if they don’t, we want advice on how to revise them.”
Dr. Kellerman of Emory said the report should not be allowed to gather dust. “It is important that those guidelines be out there and discussed and struggled with right now,” he said.
Many hospitals already struggle with chronically scarce resources like intensive care beds, he said, and in a pandemic the problem would be far, far worse.
Dr. Kellerman said he was not optimistic. In the first place, he said, the public tends to “tune out” on such disturbing questions. Or, he said, they may accept the guidelines only “until it’s their family member. Then people often feel very differently.”
Cases: When the Disease Eludes a Diagnosis
By BARRON H. LERNER, M.D., The New York Times, March 25, 2008
Lucy, one of my longtime patients, has a neurological ailment she believes I have been unable to adequately diagnose.
Although I hope to make further progress on her case, I have also told her that there may never be a definitive answer. Not surprisingly, she is feeling pretty frustrated with me.
Why do doctors and patients often approach the diagnosis of disease so differently?
Part of the answer lies in the concept of triage - the notion, originated in wartime, of caring for the sickest and most salvageable patients first. Once they were saved, attention could be turned to less drastic cases.
A similar strategy has evolved in emergency rooms, where physicians are trained to “rule in” or “rule out” severe conditions. Thus, doctors immediately consider heart attacks or pulmonary embolisms for patients with chest pain, and intestinal rupture for those with abdominal pain.
But what happens when these conditions are ruled out? In such cases, doctors proceed to search for less dire (and, it must be said, more mundane) diagnoses. The trouble is that at this stage, some physicians, busy with other patients and duties, lose interest.
For example, many patients with chest pain carry a diagnosis of costochondritis (inflammation of the chest wall bones) or gastroesophageal reflux (regurgitation of stomach acid into the esophagus).
These are real conditions. But they tend to generate little interest from many physicians, who may refer to them as “wastebasket diagnoses,” offered when nothing more serious has turned up.
The frustration of patients who believe that the medical profession takes these types of ailments too lightly has led groups of them to form alliances to publicize their illnesses. Foremost among them are fibromyalgia, a syndrome involving muscular and other pains, and chronic fatigue syndrome, which has recently been given increased credibility by the Centers for Disease Control and Prevention.
Part of the problem with these conditions is that existing treatments are not nearly as effective as those for, say, heart attacks and pneumonia. As a result, doctors may grow irritated when patients continually complain of symptoms that cannot be “cured.”
Patients’ frustration may rise even more when their conditions are especially obscure. I once had a patient who complained of persistent drenching sweats that forced her to change her bedclothes several times a night.
Upon learning of this problem, I first went into triage mode, ruling out possible dangerous causes, including tuberculosis, a thyroid abnormality and rare tumors that release hormones. I referred her to a gynecologist on the chance that she was getting hot flashes decades after her menopause.
When all the tests were negative, my patient was understandably upset, even angry. “No doctor that I have spoken to has been able to tell me what it is,” she said, as I remember. She even called a doctor on a local radio show for his opinion.
I recalled this story when I learned recently that my longtime patient Lucy’s new neurologist was questioning whether she had multiple sclerosis, a diagnosis she has carried for more than 25 years. Since I have known her, Lucy has had painful and weak legs that necessitate a walker.
Rather than simply corroborating her existing diagnosis, this doctor had thought outside the box, noting that Lucy’s relatively stable condition - and her lack of brain lesions on an M.R.I., a test not available at the time of her initial diagnosis - warranted a new perspective.
At first, Lucy was excited too. After all, being told you may not have a serious disease like multiple sclerosis is surely good news.
But while the neurologist had correctly questioned the diagnosis, she had a harder time finding a new one. Lucy became discouraged. “I want to know,” she told me. “I point-blank asked the neurologist, ‘What is it?’ And the only answer she can give me is: ‘I don’t know. I’m not sure.’ ”
Eventually, the neurology team decided that Lucy had an atypical form of multiple sclerosis, one that caused unusual neurological symptoms and was present in the spinal cord but not the brain. Yet the doctors admitted that this diagnosis generated more questions than answers about Lucy’s prognosis and her future treatment.
While trying to be as sympathetic as possible, I find myself reminding Lucy of the limits of certainty in medicine. Despite enormous advances in technology, some diagnoses may remain elusive. I also told her that it was highly unlikely her doctors missed diagnosing a disease that could have been successfully treated. But she remains convinced that she deserves to know exactly what she has.
So we will continue to search.
Barron H. Lerner teaches medicine and public health at the Columbia University Medical Center.
SEA SHRINKS FOAM Cups and their messages back from the Arctic Ocean: left, from recent Russian dives; right, from an earlier dive, with a landlubber.
Far Below the Surface of the World’s Oceans, a Tough Place for Foam Cups
By WILLIAM J. BROAD, The New York Times, March 25, 2008
Last August, as a team at the North Pole prepared to plunge more than two miles to the bottom of the Arctic Ocean, some of the dozens of specialists who staged the dive engaged in a time-honored ritual: drawing on foam cups, decorating more than 100 of them.
The cups were then gingerly sent into the deep. During the historic dive, led by Russian scientists, the pressure of the surrounding water crushed the cups to the size of thimbles, also squeezing their whimsies of writing and drawing.
Afterward, the tiny cups became instant mementoes of the polar dive, offering striking proof of the descent into an unfamiliar zone and silent testimony to the crushing power of plain old water.
“The real North Pole,” read one cup’s shrunken writing. “Explore the abyss,” another urged.
Deep explorers have made thousands of such keepsakes over the decades, and more recently, schools have joined the fun as a way to drive home some of the peculiarities of a planet where very deep water covers some 65 percent of the surface.
For example, in 2001, a third-grade class at Harding Elementary School in Corvallis, Ore., decorated 28 foam cups with bright fish, happy faces and American flags. The scientist father of one of the students then sent the cups into the depths of the Indian Ocean, shrinking them into small trophies for a lesson on the crushing weight of deep water.
A comparison to air pressure helps. At sea level, atmospheric pressure is 14.7 pounds per square inch. The deeper the dive, the greater the water pressure. At the resting place of the Titanic, more than two miles down, the pressure is 2.8 tons per square inch. That constantly bears down and tries to obliterate any void.
The pressure on any object in the deep sea, as at sea level, is uniform. It presses from above, below and the sides. That is because the molecules making up fluids (which in physics include both gases and liquids) are free to move about and transmit force in all directions.
Sea creatures are made primarily of water, which is virtually incompressible. So they escape destruction in the abyss.
But the high pressure causes most cavities and hollows, like human lungs, to collapse. So, too, with foam cups. They are almost all void since the foam is 95 percent air, according to the American Chemistry Council. As pressures build during descent, the air slowly compresses and the cups shrink.
Explorers of the deep escape slow torture by descending in small craft known as submersibles. A super-strong personnel sphere protects a pilot and two observers, who peer out through tiny portholes made with extraordinarily thick windows. The air pressure inside is the same as at sea level.
In its early days, Alvin, a pioneering American submersible, often carried outside its crew sphere compressible items like cork bricks and foam balls, cups and wig holders (to make shrunken heads), according to “Water Baby,” a profile of the craft.
“It’s an old trick,” the author, Victoria A. Kaharl, wrote, adding that the pressure of the deep makes “perfect miniatures.”
But the experimentally minded on such expeditions were also tempted to see what might withstand the pressure, and in at least one instance sent down a raw egg.
Filled with incompressible fluid, Ms. Kaharl wrote, the egg returned to the surface “perfectly intact and edible, but salty.”