Sickle Cell Trait

Cramping Syndromes
Sodium Loss and Sickle Cell Trait
E. Randy Eichner, MD
Team Internist, OU Sooners
OU Health Sciences Center
Not All Cramps Are Alike
None Below from Salty Sweating
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Writer’s cramp
Fiddler’s cramp
Golfer’s yips
Hurdler hamstring
Runner side stitch
Hypervent. tetany
Sleeper calf cramp
Sickler cramping
Heat-Cramping Controversy
Muscle fatigue and what else?
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Dehydration?
Low potassium?
Low calcium?
Low magnesium?
Muscle spindle/Golgi organ?
Is it quinine deficiency?
Or the dreaded Cramp-O-Ray?
Heat Cramps: Salty
Solutions
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Stokers
Miners
Military
Hoover Dam
McCance
Tennis
Football
Hoover Dam Saline Solution
Talbott & Michelsen, JCI 1933
• “An important
criterion (was)
…marked relief
after (infusing)…
normal saline. All
cases…free from
symptoms within
six hours…”
King of Tennis
Mike Bergeron (JSMS 2003)
• 17 male players
• All crampers, but
heat-acclimatized
• Hot/humid match
• Sweat 2.6 L/hr
• Na+ loss/hr 2.7 g
• One lost 12 g salt
an hour!
Chris Legh in Lab
Top Australian Triathlete
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2-hr run; 2-h bike
Mimic Kona clime
Lost 8.8 L sweat
Drank 5.5 L fluid
Lost 3.8% body wt
Lost > 25 g salt!
Cystic Fibrosis?
• One gene: 1 in 20
or 25 whites
• Mitigates typhoid,
cholera
• Sweat sodium up
to 60-80 mmol?
• Cake with salt
Heat-Fit Football Player
• 250 lb, 60-65% H2O
• 17-18 gal water
• 100 gm sodium or
50 tsp salt
• In hot game, can
sweat 1-2 gal fluid,
5-10 tsp salt
Fluid Turnover in 2-a-Days
Stofan JR et al., at ACSM 2005
Players
Crampers
Non-crampers
10.3 ±2.2 L/d (9 - 14 L/d)
11.2 L/d
9.7 L/d
Note that top turnover is 3.5 gallons of fluid
a day! No wonder they’re thirsty!
SWEATY SOONER STUDY
Two groups (n=5): Crampers vs. Non-Crampers
Matched:
Age, Weight, Race, Position
Measures:
Sweat out, fluids in, sweat [Na], [K]
Pilot Studies:
Final Study:
June, July (Field Skills, Indoor Weights)
August (2-a-days; 2.5 hr practices)
Crampers Are
“Salty Sweaters”
Sweat sodium levels
are always higher in
crampers…
Trends similar in all
three studies, June,
July, August…
Cramp Non-Cramp
Sweat Sodium, mEq/L
100
1.7
1.4
2.1(P<.01)
80
60
40
20
0
June
July
OU Studies
August
Crampers Dehydrate More
ES = 0.98
Despite drinking, high
sweat rates dehydrate
0
C
NC
ES = 0.32
C
NC
-0.2
Dehydration%
-0.4
-0.6
-0.8
-1
-1.2
-1.4
-1.6
Morning
Evening
Crampers Lose More Salt
Grams sodium
6
5
4
3
C
NC
2
× Sweat [Na] x × Sweat rate =
1
GREATER TOTAL LOSS (P=.01) 0
AM
ES = 1.8
PM
ES = 1.1
Salt Depletion: NFL 2-a-Days
Godek et al, ACSM 2004
• 6 NFL players, age ~ 26, wt. ~ 104k
• Serum Na+ fell, 140 to 137 mmol/L,
by Day 3 (~ 200 mEq Na+ lost)
• Or ~ 12 gm of salt lost by Day 3!
• Plasma volume fell ~ 5% by Day 3
• Conclusion: They need more Na+
during early 2-a-days
Clues to Salt Depletion
Warning signs for athletes
• Salt on your skin
• Your sweat
– Burns eyes
– Stings abrasions
– Tastes salty
• Heat cramping
• Dizzy standing up
Get More Salt in Diet!
And in Sports Drinks Onfield
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Tomato juice
Salty soups
Baked beans
Pickles
Pretzels
Pizza
GLytes
Endurance formula
The Water Hazard
- HS linebacker locks up in 2nd half
- Quaffs 9 L water
- Seizure, Na+ 120
- College LB locks up in practice
- Quaffs 12 L water
- Goofy, Na+ 121
- College FB player with leg cramps
- Given 8 L hypotonic fluid IV and po
- Goofy, wet lungs, Na+ 121
Cramp-Prone?
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Lean and fit
Explosive
Many reps
Intense
Heavy sweater
Cakes in salt
Low salt diet
Methods
• Measure
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Body weight change
Fluid intake
Core temperature
• Calculate
– Sweat rate
– % dehydration
8 subjects
129 +12 kg
190 +3 cm
22% fat
Pre-session USG:
1.025 +0.007 (1002 mOsm/kg)
Results - Pre-Season
Core Temp, ºC
• Heat Stress
40.5
40
39.5
39
38.5
38
37.5
37
36.5
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35.5
35
WBGT 22.9 +07 ºC
No radiant contribution
• Sweat rate
1.5 +0.3L/h
• Dehydration
0.8 +0.4%
Pre
End
Peak avg 39.4 +0.6 ºC
DB
23.9 +0.3
25 +0.4
~24ºC
RH
77.5 +1.6
76.8 +1.7
75%
WBGT 22.3 +0.4
23.4 +0.5
22.5 ºC
Change in Tc from Baseline, °C
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
Field Drills (Vest)
-10
0
10
20
Heavy Lifting (Wts)
30
40
50
Time (min)
60
Break, then Sprints
70
80
90
100
Lessons Learned
Radiopills hold promise in football
• Can heat up fast and
even cramp up
• In a June drill
• No football gear
• Dehydrated at start
• Salt-depleted too?
• Cool fast when stop,
despite cramping
Features of Heatstroke
• Fuzzy thinking
- Confused, can’t follow plays, runs wrong way
• Bizarre behavior
- Blank stare, talks nonsense
- Yells in rage, wants to fight
• Physical decline
- Incoordination, N/V, hyperventilation
- Wobbles, staggers, collapses
- Seizure, coma
Day One Death in Dallas
Eric Brown, 17, Carter High, 8/2/04
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Starting center
3 ½-hr practice
Heat index 105
Sprints at end
Collapsed once?
Got through it
Seizure at home
Risky Ways for 2-a-Days
High schools; Dallas Morning News; Aug ’04
• “Our first practice
the longest” (3.5 h)
• Breaks in sun
• End with 16 sprints
• K+ pills at end
• If collapse: “Get
fluid in them”
• Wrong! Get them
in fluid! (Ice bath)
Ice water
immersion
on-site
Dehydration Curbs Cycling
Walsh et al: Int J Sports Med 1994
• Twice, in the heat, 6 cyclists ride for
1 hr at 70% VO2 peak, then closing
sprint to exhaustion at 90%
• One trial, oral fluids; one, without
• Without fluids, dehydrated 1.8%
• Without fluids, sprint 7 minutes
• With fluids, sprint 10 minutes
Learn Your Sweat Rate
And drink to match; don’t overdrink!
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Weight lost in drill (in oz)
Plus fluid drunk in drill (in oz)
Equals how much to drink
Example:
– If loses 3 pounds (3 pints: 48 oz)
– And drinks 16 oz (1 pint)
– Drink 48 + 16 = 64 oz (4 pints) next drill
Sickling Forces in Football
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Severe hypoxemia
Hyperthermia
Acidosis
Dehydration
12 Deaths, College Football
All From Sickling; Some Controversial
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1974 Colo., ran 800 m
1985 Ark., ran ¾ mile
1986 Miss., ran 1 mile
1987 Ind., ran 1200 m
1989 Utah, ran ¾ mile
1990 NM, ran 800 m
1992 Ga., ran 1000 m
1995 Ariz., ran 900 m
2000 Tenn., ran 800 m
2001 Fla., 1 hr. mat drill
2004 Ohio, ran ~ 10 min.
2005 Mo., 1 hr. field drill
Sickle Cell Trait
Another “Do or Die” Syndrome
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1 in 12 blacks
1 in 10,000 whites
Generally benign
No anemia
No barrier to top
athleticism (e.g.,
NFL)
Sickling Deaths in Military
• All deaths in basic training of 2 M.
recruits in 5 yrs. (NEJM 1987)
• Risk of puzzling sudden death 28-40
times higher with sickle trait
• 12 such deaths; all tied to exertion
• Absolute risk: One in ~ 3,000
Air Force Cadets
• 3 of 20,000: acute
renal failure from
rhabdo
• All 3 sickle trait; all
fit; one set record
• 2 the same year,
when just 10 had
sickle trait
Death at Bowling Green
Aaron Richardson, Died 9/15/04
• 3-sport HS athlete
• Track champ, 100
to 400 m
• Walked on for FB
• Day 1, sprints for
10 min: cramps
• Died, locker room
• Autopsy: Sickling
Risk: All-out exertion for 2-3
minutes without a breather
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Windsprints, e.g., 300-m repeats x 3-4
Timed miles or half-miles
Running repeat hills, steps, ramps
Intense mat or conditioning drills
Accelerated weight lifting
Rarely, even in the game itself
Sickle Trait Precautions
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No d. 1 fitness test
No sprints > 500 m
No timed miles
Regular fluids
Stop at 1st sign of
trouble
• Report to trainer
Treatment: Presumed Sickling
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Lie down
Oxygen by face mask
Vital signs
Immediate cooling
If not improved in 5 min., or if vital signs
or alertness decline
– Call 911, attach AED, start an IV, to ER fast
Conclusions
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Salty sweating: key in heat cramping
Radiopills: can prevent heatstroke?
If you lose weight: Drink more
If you gain weight: Drink less
If in doubt: Ice ’em down!
Mandatory testing and precautions
for sickle cell trait!