In: Anatomy and Physiology
The mountain wind rattled the window of the small cabin as Drew sifted through the papers covering the kitchen table, looking for his physiology notes. Instead of his blue notebook, a pink sheet of paper from Mountain View Labs caught his eye. A closer look showed it to be his 73-year-old grandmother’s lab report from some recent blood tests. Mimi had protested all the way to the appointment and all the way home, but Drew had insisted that if he came home for Tanksgiving break, then she was going for the check-up that she had put of for far too long. Mimi had chronic kidney disease, and the doctors wanted her to start dialysis more than a year ago. Not surprisingly, his stubborn Kentucky-born-and-raised grandmother had refused. She was not a good candidate for home dialysis and the nearest dialysis clinic was an hour away. She didn’t drive much because of cataracts, and there was no one else to take her. Drew had immediately ofered to delay his junior year at the University of Kentucky to stay home and care for her. Mimi was adamantly opposed. “You will stay in school, Andrew Paul Killian! Te best way out of these mountains is college, and you’re not dropping out because of me.” Even after Drew discovered the county ofered senior citizens free transportation to medical appointments, she shook her head. “God the Almighty will take me home when He’s ready, dialysis or not.” Mimi had raised Drew since the age of three, and he knew when she made up her mind, no one on Earth could change it. Drew glanced at Mimi as she watched TV. He knew her kidney disease was advancing. He had noticed over the summer that she tired easily and her feet and ankles were badly swollen. She had always loved to debate politics with anyone who dared, but now she had trouble keeping track of conversation. Last week she only picked at her turkey and cranberry sauce, saying that she was too nauseated to eat much. She blamed it on the doctor scaring her about her high blood pressure at the appointment the day before, but Drew saw how baggy her clothes were and knew she hadn’t been eating much for quite some time. Drew started to scan the lab report, thinking his physiology class might help him understand the results. He had just enough time to note that Mimi’s blood urea nitrogen (BUN) was 208 mg/dL and creatinine was 15 mg/dL before she interrupted him. “Drew, there’s a Star Wars marathon starting!” She patted the sofa beside her. “Bring the rest of the snickerdoodle cookies and watch with me.” Drew found it hard to resist Star Wars or Mimi, so he laid the test results aside and spent the rest of the evening cheering for Luke and the Jedi. Te next morning Drew packed his car for the drive back to Lexington. He found his physiology notes, but Mimi had squirreled away the lab results. When he asked, Mimi fapped her hands at him. “Pffft, stop worrying! You just keep calling every morning to check on me like you have been. And Jimmy lives right over the hill. I’ll call him if I need anything.” Drew shook his head. Jimmy Seavers was at least a decade older than Mimi and relied on two canes to walk. He didn’t know how much help Jimmy would be, but Mimi was shooing him into the car to avoid any further protest. He hugged her long and hard, and reluctantly headed down the mountain road.
It is very obvious that the patient is suffering from chronic kidney disease, in most of these patients metabolic acidosis develops due to inablity to produce bicarbonate or retain bicarbonate, impaired ammonia excretion and all this results in accumulation of acids in the body leading to metabolic acidosis.
a) As a compensation mechanism to her metabolic acidosis, lungs play an important role, they do this by hyperventillation, which involves increase in depth and rate of breathing, so that excess CO2 is expelled out of the body, with reduced CO2 concentration, the PCO2 reduces. Respiratory compensation for metabolic disorders is quite fast it can occur within minutes and reaches maximal values within 24 hours, unlike renal compensation which takes days.
Note : If the kidney were functioning properly they would have compensated by excreting urine, the renal excretion of H+ is enhanced as the renal ability to produce ammonium from glutamine is induced