Question

Mt. Denali, Alaska elevation 17,660 ft. The climbers slowly ascended the icy cliff in the near darkness of 4 a.m., carefully avoiding the steep crevasses that fell off sharply to either side. Several times each hour, the lead climber Tom would call out "Everyone okay?" They had stopped replying long ago, too exhausted by the supreme effort of simply placing each foot in the proper direction. Three hours into a 12+ hour climbing day, only labored breathing and the crunch of ice under crampons permeated the silence. Emily, a Registered Nurse and the only woman on the six-person expedition team, was third in line, following her friend Mark, the least experienced climber of the group. For the last couple of days, Mark had been coughing heavily, and all morning had been slowing up, causing a backlog behind them and prompting several "everyone okay"'s from Tom. Knowing Mark's competitive spirit, Emily was hesitant to urge him to pick up the pace, and when he pulled up to rest on a protected ledge, Emily motioned to the other climbers to pass on by. Her head was pounding anyway, and she rationalized she could use the break.

"You okay?" Emily asked.

"Yeah....I just....can't seem to....catch my breath," gasped Mark.

"Just rest a minute. There's no rush, Mark. Take your time....slow, deep breaths."

Tom appeared from the upper trail. "What's up?"

"Mark's having a little trouble catching his breath." Emily was getting worried.

Tom looked sharply at her. "How much trouble?"

"Quite a bit, I think." Emily looked over at Mark, whose breathing didn't appear eased by the rest stop, and then back at Tom. "I think we should get him down to a lower altitude. Quickly."

Tom nodded. "I'll get the others."

As they helped guide Mark down the steep trail, Mark's breathing became increasingly labored and was loud enough to worry Emily.

"Geez, do we sound like that?" gasped one of the other climbers. "I mean, I'm out of breath, too, but he sounds horrible!"

"No, we're not that bad. Remember, that's why we spent the prep month at 15,000 feet. Mark was with us, so he experienced the same physiological changes we did. This," Emily nodded at Mark, "is some sort of problem."

Mark deteriorated rapidly and lost consciousness by the time the group reached the lower camp. The urgency of the situation strengthened the tired legs of the climbers as they carried Mark the final yards towards camp. Emily had run ahead to call for support help, and the group was told an airlift was on its way and would be there within the hour. The camp's medical tent had some basic supplies and a resident paramedic, and he and Emily went to work stabilizing Mark with oxygen and a Gammow bag (a pressurization bag).

90 Minutes Later, Denali Valley Hospital

"We have a 28-year-old white male, unresponsive, no prior history of pulmonary disease, who became unconscious around 15,000 feet after hiking to 17,000 feet earlier today. His friends say he was having severe breathing difficulty prior to losing consciousness...." As the paramedic droned on, Emily looked around for the nearest phone so she could locate Mark's family in case this was as serious as it looked.

1. How would the oxygen and Gammow bag help Mark?

2. Are some of the lab normal either below or above normal range as a normal result of the month spent at high elevation? Explain.

3. Which lab values appear to represent the most serious problem Mark is having? Is his situation life-threatening?

4. Compare the results of Alveolar Oxygen Tension to Arterial Oxygen levels. What might cause this type of discrepancy?

5. Come up with a possible diagnosis for Mark’s condition. What data are you using to come to this conclusion?

Here are the results of his blood and pulmonary tests.

The following tables summarize the findings of the Denali Valley Hospital Medical Team:

BLOOD LEVELS

	MARK'S	NORMAL
Arterial Oxygen	52 Torr	80-100 Torr
Arterial Carbon Dioxide	30 Torr	35-45 Torr
Arterial pH	7.23	7.38-7.44
Hematocrit	58%	42-52%
Arterial glucose	102 mg/100ml	60-110 mg/100ml
Urea Nitrogen (BUN)	12 M	7-14 M
Creatinine	1.1 mg/100ml	1-1.5 mg/100ml
Potassium	4.0 meq/L	3.5-5.0 meq/L
Sodium	145 meq/L	136-145 meq/L
Bicarbonate	18 meq/L	20-24 meq/L
Chloride	100 meq/L	98-106 meq/L

No prescription medications or other pharmacological agents were found.

PULMONARY FUNCTION TESTS

Inspired Oxygen Tension	147 Torr	150 Torr
Vapor Pressure	45 Torr	47 Torr
Alveolar Oxygen	110 Torr	98-104 Torr
RQ	0.66	0.78-0.82 Torr
Tidal Volume	0.4 L	0.5 L

HEART RATE: 88 bpm (normal: 60-90 bpm) BLOOD PRESSURE: 105/60 (normal: 110-120/60-80 mm Hg)

Answer 1

1] Use of oxygen and gammow bag helps to increase the level of oxygen in Mark. It increases the atmospheric pressure which is greater than the intra pulmonary pressure. It also increases air entry inside the lungs which in turn decreases strenous breathing for Mark.

2] as mention in the lab values some are normal and few are below and increased. As people started living in high altitudes, the atmospheric pressure is greater than the pulmonary pressures leading to less oxygen binding ability to hemoglobin due to inadequate oxygen in atmosphere and hence increase affinity of RBC for oxygen.

Due to less oxygen, they will easily fatigued

After staying for the days, body will learn to increase the production of erythrocytes which in turn increases oxygen resulting in more RBC's

5] The probable diagnosis which is life threatening in mountain sickness is High Altitude Pulmonary Edema, it may be possible for Mark as he has breathlessness which increases subsequently landed with increased coughing.