Sleeping at altitude

Most people will agree they do not sleep as well at high altitude, especially over 9000 ft/2500 m. In sleep, the drive to breathe is blunted, which may lower the oxygen and raise carbon dioxide in the blood. This  causes high blood pressure in some adults and children but what else does it cause? Pediatric pulmonologist and sleep specialist Ann Halbower wonders if it effects growth and development in children. Family practice physician Lisa Zwerdlinger has many years of experience treating patients in Leadville and sometimes has babies that need oxygen for a year to gain weight.

A study published in the Archives of Diseases of Children in February this year analyzed previously published studies of oxygen levels in awake children at altitudes between sea level and 4000 meters, including Summit County.  We are in the early phase of formulating a study on night time oxygen levels at various ages. since it takes years for research to be completed we recommend anyone with health issues that may be related to altitude to have a sleep study. this is very simple: a finger clip connected to a wrist band where data is collected.

when to stop using oxygen after an illness

Several parents returned to the clinic this week with their children on oxygen after respiratory illness. Our protocol has been to discontinue the oxygen when their saturation is above 89 in clinic. Now that many parents have a home pulse oximeter, children are using oxygen for longer periods. Measurements at home may be fine during the day, and the child attends school, then decreases at night so parents continue oxygen. since most oxygen equipment is rented by the month, this is not more expensive. I think it helps the lungs to heal, possibly reducing future problems such as pulmonary hypertension.

New information comes from one of the students rotating here at Ebert Family Clinic: Justin Lockwood, a pediatric resident. He reports that even in Denver some children require oxygen during respiratory illnesses that do not get a diagnoses of asthma or pneumonia.

Kilimanjaro

Overflow crowd tonight at St. John’s church where Katherine Jeter shared her story of climbing Mt Kilimanjaro with others from the county, celebrating her 75th birthday that year. I am so inspired by the people older than I am who are challenging themselves like this. This peak is a mile higher than our 14er’s! The average age in this group was 65. Using acetazolamide/Diamox helped many of the climbers.

When Should Oxygen Be Given To Children At High Altitude?

This article was published in the Archives of Disease in Childhood in 2009.

The authors reviewed 14 studies in the scientific literature for normal oxygen values for children ages 1 week to 12 years.

Hypoxemia (low oxygen) was defined as oxygen saturation at or below the 2.5th% for healthy children at a given altitude.

At 8,200 feet (2,500 meters) elevation 97.5 % of children had oxygen concentrations above 90%

At 10,498 feet (3,200 meters) elevation this decreased to 85%, with  2.5 % of children were below this.

Should children living in Leadville, Alma and Fairplay be allowed to go untreated when their oxygen levels are 85-89%?

Now that many families have a pulse oximeter parents are measuring their children’s oxygen levels when they are sick, and presumably when they are well.

Therefore deciding when a child has a low oxygen that needs treatment can be based on the child’s levels when healthy. Unfortunately, these oximeters are not accurate in infants.

Increased Risk of Breast Cancer at High Altitude?

Stacy has lived in the high country for a long time. She knows I am interested in research to understand our risks and benefits. So she asked me again when I passed her on the trail,  “is breast cancer more common in women who live at high elevations? ” She knows so many women who have been affected.
Public health stats show that people live longer up here and there is a lower incidence of cancer. I assume this corrects for people who move away for treatment or health conditions. Since cancer patients are treated in many different clinics outside the area, there hasn’t been any reports that we’ve seen. But we do have many friends affected. It’s a good question.

Adaptation v.s. Aclimatization

Why don’t babies in Nepal and La Paz need oxygen? IMG_2996Dr. Chris in La Paz with 20 year old Maria and her mother

Research comparing ethnic groups that have lived at high altitude for centuries, such as native Tibetans, and more recent immigrants such as the Han Chinese in Tibet, showed changes in adaptation. People living in the Andes, Himalayas and mountains of Ethiopia have higher lung volumes, more nitric oxide in the blood, high oxygen carrying hemoglobin levels and increased respiratory rates which are genetic.

Those of us living in the mountains of Colorado have been here at the most 150 years, not long enough to establish gene-based adaptation. We do acclimatize over weeks and months with changes in hemoglobin levels, respiratory rates and lung volumes but not to the extent of the above populations.

During my travels to La Paz Bolivia and Cuzco, Peru I noticed the people were smaller. At Ebert Family Clinic we analyzed over 10,000 pieces of growth data on children up to four years old from our electronic medical record. A high per cent are below the standard growth chart: seven percent compared to three percent. Most catch up by age two years.

 

How to keep oxygen on your young child

Both tourist and local children may need supplemental oxygen during illnesses at high altitude. There are excellent providers available 24 hours a day to set up tanks and concentrators so most don’t have to stay in the hospital, but can be comfortable at home with the family. It is a mistake to admit these children to the hospital just because they won’t keep the nasal cannula in their nose. Hospital guidelines make it difficult for nurses to implement adequate control measures over these fiesty little ones.

At Ebert Family Clinic we have found a very effective method: magazines. Tape a magazine around both child’s arms so that they cannot bend their elbows to pull off the cannula. After 30 minutes of not being able to use their arms, most children will accept the oxygen.

Mountain resident high altitude pulmonary edema (MR-HAPE)

For five years I have been writing about children who live above 2500 feet with no history of travel who present with a respiratory illness and hypoxia. Because they do not appear very sick (toxic is the word we use in medical terms), repond to oxygen only, and have inconsistent or poor response to asthma medications, I have decided this is a form of HAPE. Observations by other clinicians support this:

  • Anthony Durmowicz and Ed Noordeweir et al. in Journal of Pediatrics May 1997:
  • “Although no data exists to support or refute the speculation that the presence of an ongoing pulmonary inflammatory process at the time of ascent to high altitude may predispose for the development of HAPE, I have observed that many children visiting high altitude who had HAPE at presentation had evidence of a preexisting inflammation-producing illness, such as a viral URI, OM, or GAS pharyngitis, that had begun before their ascent to high altitude.”
  • “Also noteworthy, the theory of increased endothelial cell permeability in response to hypoxia along with an increase in epithelial cell permeability may result in clinical pulmonary edema and the development of spontaneous HAPE in high altitude residents who acquire relatively mild respiratory tract illnesses seem to support this speculation.”

Careful review of the clinical records for these patients has not shown any factor that can reliably differentiate HAPE from other respiratory diagnoses such as asthma or pneumonia. Physical findings, symptoms, x-ray changes all overlap. The distinguishing feature to me is the clinical picture of a nontoxic patient with a low oxygen at altitude. HAPE is associated with increased pressures in the lungs, which can be diagnosed on an echocardiogram.  I am trying to organize a study to help us understand the causes of hypoxia which will include measuring pulonary pressures during acute episodes.

Asthma and Altitude

She died on the Breckenridge bike path clutching her inhaler, I heard. For years I was reminded by a memorial along the path. Then another man called last week say he is selling his house located at 10,500 feet because his trouble breathing interferes with skiing and rock climbing. “I use my inhaler 50 times a day,” he told me. “The doctor said I have asthma.”  Recently two doctors in Summit County have started to question whether some people living at high altitude may have another cause of their breathing problems such at high altitude pulmonary edema or pulmonary hypertension.

I frequently see children in my office with a respiratory illness and low oxygen, with readings in the 80’s or below. They are not leaning forward, gasping for air, using their rib muscles to breathe, like a person with an asthma attack severe enough to cause low oxygen. They do not have wheezes heard with the stethoscope. We usually give a trial of albuterol, since the medicine has minimal side effects and asthma is a common condition, but it rarely makes a big difference. We also test peak flows on patients over 5 to try and measure airway resistance seen in asthmatics. Then we send them home on oxygen, the treatment for high altitude pulmonary edema, and they get better.

Many of the families whose children need oxygen during illnesses are evaluated by lung specialists at Colorado Children’s Hospital or National Jewish Hospital. They are all told they have asthma and treated with inhaled steroids and albuterol. Pulmonary testing in the older children suggests reversible airway disease in about half. Recently the pulmonologist told us he does not believe the child had HAPE and requested a chest x-ray at the time of any future episode.

“Fulminant cases of HAPE do show dramatic changes in the x-rays, such as a recent case of a six year old who returned from sea level and overnight his oxygen dropped into the 40’s. But when we see patients with milder illness they often have clear lungs and the chest x-ray will not be abnormal until a day or two later. I rarely orders x-rays to make the diagnoses.

Since the pulmonologists are skeptical about the occurrence of HAPE in residents at high altitude, Dr. Ebert-Santos is proposing the syndrome be called “Acute Hypoxia of High Altitude Residents” or AHHAR. We need to figure out what is going on with our lungs at altitude. I’m trying to organize research concerning these issues.