Clinical Perspectives

The Metabolic Café

You are sitting in a small cafe’ in Provincetown on Cape Codwhile studying for your upcoming anatomy and physiology II test onfluid, electrolyte, and acid-base homeostasis. The followingcharacters share your company in the café.

1. Determine if each character is in fluid balance, waterintoxication, or dehydration. Determine the compensation mechanismthat is taking place to return their body to homeostasis. Explainany hormone or electrolyte changes that are causing the conditionand the hormone and electrolyte changes that occur during thecompensatory stage. (ADH, angiotensin II, aldosterone, atrialnatriuretic peptide, Na, Cl, K)

2. Determine if each character is in acid-base balance or is atrisk for: metabolic acidosis, metabolic alkalosis, respiratoryacidosis, or respiratory alkalosis. What are the compensatorymechanisms that are taking place in each one of the followingcharacters? For example: Metabolic compensation involves renalexcretion of H+ ion and reabsorption of bicarbonate ion to correctrespiratory acidosis.

For example, compensatory formula for metabolic alkalosis: Youneed to increase the H+ ions in the body so the respiratorycompensation is Hypoventilation

H2O + CO2 à H2CO3 à H + HCO3

What are the three Buffer Systems doing to quickly andtemporarily try to return the acid-base balance to homeostasis ineach of the characters that are out of homeostasis?

• Protein buffer system: -COOH, NH2, Hb
• Carbonic acid-bicarbonate buffer system: H2CO3, -HCO3
• Phosphate buffer system: HPO4, H2PO4

Mr. Bud. He is a construction worker that has been working onthe Cape Cod Canal for the past ten years. He has been workingoutdoors in the direct sunlight where the temperature is 95 degreesFahrenheit and humidity is 80%. He's sitting at the bar at 4 PMdrinking 16 oz. Bud Lite beers with an equal number of bourbonshots. He's not eating the salty bar snacks because he is watchinghis weight although he's on his third Budweiser and weighs 255pounds, 5’ 8” tall. His lunch also consisted of 3 Bud Lites.

Questions: Is Mr. Bud at risk for water intoxication,dehydration, or in fluid balance? What factors are affecting Mr.Bud's body fluid level and which hormones for fluid balance areaffected by his lifestyle? Is his fluid volume dropping? If so,which hormones are released to compensate for this loss?

Mrs. Lovely and Mr. Money. Mrs. Lovely is closing in on 40 yearsold. She's the first one at the exercise club in the morning at 6AM (the nanny takes the kids to school) and performs aerobicexercise for no less than two hours, five days a week. She does notbelieve in rehydration because she's afraid of water weight gain.She wants to return to a size O before her 40^thbirthday. Her percentage body fat is around 5%. Following herworkout, she spends 20 minutes in the dry heat sauna then has a45-minute massage. Her total caloric intake for a typical day is1300 calories with few carbohydrates. She's sipping Lady Grey blacktea.

Questions: Is Mrs. Lovely at risk for water intoxication,dehydrated, or in fluid balance? What factors are affecting herbody fluid level and which hormones for fluid balance are affectedby her lifestyle? Is her fluid volume dropping? If so, whichhormones are released to compensate for this loss? Is Mrs. Lovelyat risk for respiratory or metabolic alkalosis or acidosis? What isthe compensatory mechanism working to rectify her self-inducedcondition?

Mr. Money works 60 hours per week and does not pay muchattention to what he eats or drinks. Breakfast consists of two cupsof black coffee. He suffers from a hiatal hernia and despite hisdoctor's advice he continues to work long stressful hours, drinkcoffee and alcohol, and eat fatty foods. Consequently, heexperiences vomiting first thing in the morning and several timesper day. His BP is 145/90 and higher during stress. He also has amild heart condition for which he takes diuretics. He takesPrilosec and a handful of over-the-counter antacids daily. Hedrinks a glass full of sodium bicarbonate and water each nightbefore bed to quell the heartburn. He and Mrs. Lovely usually eatout together for dinner (nanny cooks and puts the kids to bed too)at which time he tries to impress Mrs. Lovely with a show ofconcern for healthful eating by ordering a salad with grilledsalmon for dinner accompanied by several glasses of white wine.

Questions: Is Mr. Money at risk for water intoxication,dehydrated, or in fluid balance? What factors are affecting hisbody fluid level and which hormones for fluid balance are affectedby his lifestyle? Is his fluid volume dropping? If so, whichhormones are released to compensate for this loss? Is Mr. Money atrisk for respiratory or metabolic / alkalosis or acidosis? What isthe compensatory mechanism working to rectify his self-inducedcondition?

Mr. Macho. He is sitting at the bar with his friends. He is thesole surviving bachelor of his over 30 group of friends. He stilllives in his parent’s house, is 31 years old, and exercises at thegym six days per week. He takes laxatives daily to keep his bodyweight down so he can maintain the same physique he had in highschool. He's trying to impress his friends by eating 12 jalapenopeppers stuffed with cheese accompanied by an equal number oftequila shots.

Questions: Is Mr. Macho at risk for water intoxication,dehydrated, or in fluid balance? What factors are affecting hisbody fluid level and which hormones for fluid balance are affectedby his lifestyle? Is his fluid volume dropping? If so, whichhormones are released to compensate for this loss? Is Mr. Macho atrisk for respiratory or metabolic / alkalosis or acidosis? What isthe compensatory mechanism working to rectify his self-inducedcondition?

The Lovers. They are sitting in the corner at a small table.Dante is finishing his masters’ degree in philosophy and plans towork at the nonprofit agency until he can form his own cultmovement and ultimately run for a political office at the federallevel to convert our government to Socialism. He's drinking histhird cappuccino, which is the only thing he has had to drink allday. He has labored, slow, shallow breathing resulting from agunshot wound to his chest when he was a teenager. He rolls his owncigarettes and smokes the equivalent of one pack per day.

Questions: Is Dante at risk for water intoxication, dehydrated,or in fluid balance? What factors are affecting his body fluidlevel and which hormones for fluid balance are affected by hislifestyle? Is his fluid volume dropping? If so, which hormones arereleased to compensate for this loss? Is Dante at risk forrespiratory or metabolic / alkalosis or acidosis? What is thecompensatory mechanism working to rectify his self-inducedcondition?

Sally loves everything sweet and suffers from a moderate tosevere anxiety problem. She also loves carbonated drinks andfrequently drinks soda and water. She also drinks no less than two12 oz. glasses of water with bicarbonate soda every day because herfriend told her it was good for her skin. Sally takes 10-12 tabletsof TUMS per day for the “calcium” and she likes the taste. She iseating a candy cane ice cream sundae with marshmallow sauceaccompanied by an orange sherbet Sunkist soda float. She’sbeginning to nervously hyperventilate while listening to Dante ashe begins pontificating again about the need for Communism in theUnited States.

Questions: Is Sally at risk for water intoxication, dehydrated,or in fluid balance? What factors are affecting her body fluidlevel and which hormones for fluid balance are affected by herlifestyle? Is her fluid volume dropping? If so, which hormones arereleased to compensate for this loss? Is Sally at risk forrespiratory or metabolic / alkalosis or acidosis? What is thecompensatory mechanism working to rectify her self-inducedcondition?

Mr. Salty. This is not his lucky day. He just turned 50 and it’stime for his first Colonoscopy. He is consuming 4 liters of thehorrid hypertonic solution of sodium bicarbonate, sodium chloride,and potassium chloride. He’s had dibs on the men’s room allafternoon.

Questions: Is Mr. Salty at risk for water intoxication,dehydrated, or in fluid balance? What factors are affecting hisbody fluid level and which hormones for fluid balance? Is his fluidvolume dropping? If so, which hormones are released to compensatefor this loss? Is Mr. Salty at risk for respiratory or metabolic /alkalosis or acidosis?

Mr. Puffy. This gentleman is 65 years old. He has smoked twopacks of non-filter cigarettes per day since he was 15 years old.His face is ruddy with a nose like WC Fields. His lips and nose areblue and he is breathing through pursed lips, having troubleevacuating the air from his lungs. He has a barrel chest. Theexpiratory area of his respiratory center is fully activated. Hesips a small glass of port wine and reminisces about the olddays.

Questions: What is your understanding of Mr. Puffy’s respiratorydiagnosis? Is Mr. Puffy at risk for respiratory or metabolic /alkalosis or acidosis? What is the compensatory mechanism workingto rectify his self-induced condition?

Young couple with their first baby. This is their firstexcursion out of the house with baby. They’ve been unable to sleepbecause baby is awaking all-night and asleep all day. Baby has beenvomiting for the past 2-3 days, unable to keep down clear liquid orformula. Her mother told them not to worry; “spitting up” isnormal. They're both exhausted and trying to enjoy their firstrestaurant dinner together for months. Baby is in her car seattrying to sleep but appears fidgety.

Questions: Is baby at risk for an acid- base imbalance? If so,is it respiratory or metabolic alkalosis or acidosis? What is thecompensatory mechanism working to rectify this condition?

Aquarius. She's sitting alone at a table drinking distilledwater hoping to be discovered by a famous movie producer. She hasthe lead role in a small off-Broadway play. Directors in the pasthave often told her that she should drink a lot of water before aperformance to help with her voice quality. Her aestheticianrecommends 4-5 liters of pure water per day for her skin hydration.Taking this to heart, she has been drinking at least this muchwater a day and more. She will only eat protein, no carbohydrates,and takes laxatives to maintain a slender figure. She's also anovice jogger with great determination, putting in at least fivemiles per day. She rehydrates with pure water only. The only thingshe has had to drink today is distilled water.

Questions: Is Aquarius at risk for water intoxication,dehydrated, or in fluid balance? What factors are affecting herbody fluid level and which hormones are affected by her lifestyle?Is her fluid volume dropping? If so, which hormones are released tocompensate for this loss? Is Aquarius at risk for respiratory ormetabolic / alkalosis or acidosis? What is the compensatorymechanism working to rectify her self-induced condition?