Chapter 27.
I. Answers A, B, D, and E are true statements, whereas C is false.
II. Answers B, C, and E are true statements, whereas A is false.
1. The young man was in a hypertermic state due to an acute tonsillitis. This had increased his insulin demand and manifested his juvenile diabetes mellitus. In his case the first sign of the latent disease is diabetic coma. Juvenile diabetes is a life threatening metabolic condition. Probably all b-cells are destroyed, so insulin treatment is imperative in order to keep him alive. The patient has a low glucose tolerance and burns fat, which explain his ketoacidosis.
The patient developed a metabolic acidaemia partly compensated by hyperventilation. The hypocapnia must reduce cerebral blood flow, which contributed to the cerebral condition.
Glucosuria lead to osmotic diuresis. This had caused a serious dehydration. Both the extracellular volume and the total blood volume was insufficient. The patient was in an imminent shock (circulatory insufficiency). This condition would have killed the patient, if his friend had not found him.
2. Insulin treatment is imperative. Antibiotics must be given for the infection. The fever does not demand drastic procedures. Intravenous infusion of isotonic sodium bicarbonate solution (167 mM) is given for the metabolic acidosis and physiological saline for dehydration.
The ECV of this patient is assumed to be 20% of the body weight, i.e. 80 kg × 0.20 = 16 kg or litres. According to the principles outlined in Chapter 17, the primary compensation of the base deficit in the ECV necessitates the administration of 15 mmol × 16 l = 240 mmol of bicarbonate.
The treatment is controlled by frequent blood analyses of glucose, gas tensions and alkali-metals. Circulatory collapse may occur, so one must be ready to give a transfusion.
3. The rise in PaCO2 increases the PCO2 of the cerebrospinal fluid (CSF). Since CSF has a low buffer capacity - and now a low bicarbonate - the pH is reduced in the CSF. The high H+ in the CSF is a strong stimulus to the central chemoreceptors, and explains the hyperventilation.
4. Treatment with bicarbonate, and the patient’s own renal bicarbonate reabsorption for 24 hours, lead to a rise in bicarbonate all over the body including the CSF. Its low pH is normalised, and thus the stimulus for hyperventilation is eliminated.
1. The dilution principle.
2. The distribution volume is the relevant mass of indicator divided by its representative concentration.
The mass of indicator at the time of distribution was [55 000 000 - 3/2(1 598 400 × 0.095)] = 54 722 228 Bq.
The distribution volume: 54 722 228/1 520 700 = 36 l or (36/74) = 49%.
3. Compared to a sedentary person containing 55% water the result is low.
4. The normal weight for a female of this height is (152 cm - 110) = 42 kg.
She is not a dwarf. Female dwarfs are below 1.4 m in Anglo‑Saxon populations.
Her overweight is 32 kg or in percentage (74 × 100)/42 = 176%.
According to WHO any overweight above 120% has serious, clinical consequences (increased morbidity and mortality).
When less than 50% of her body weight is water, she must have a very low body density and a high body fat fraction.
5. Her fasting blood [glucose] is higher than normal. She does not pass her renal plasma appearance threshold (10 mM glucose) in the fasting state. Glucose is most likely only excreted in the urine after meals.
Patients often develop multiple boils and mycoses before diabetes is diagnosed.
1. The glycogen stores of the liver and striated muscles amount to approximately 400 g, so they are rapidly used. From the 3.th day the essential energy source is lipid. Mobilisation of the triglyceride stores is illustrated by the rise in plasma FFA, and the fatty acids are metabolised to acetylCoA at a rate faster than the oxidation rate for acetyl CoA in the mitochondria. The insufficient carbohydrate turnover produces insufficient pyruvate for the Krebs cycle, so the fatty acids accumulate in the liver, where they are converted to ketone bodies ( acetone, b-hydroxybutyrate and acetoacetate).
2. Acetone is volatile at body temperature and is expired from the alveolar air, which is loaded with acetone from the blood during its passage of the lungs.
3. The patient has hunger diabetes, since the result of the glucose tolerance test is pathognomonic for diabetes mellitus. Only 24 hours of hunger is necessary to develop insufficient enzyme systems.
4. Tissue proteins - in particular from the striated muscles - are degraded to amino acids, which are taken up by the liver. The high activity of the liver transaminases convert the amino acids into oxaloacetate and pyruvate. Both are substrates for the gluconeogenesis. Nitrogen from the degraded amino acids is excreted in the urine. As long as the lipid stores are available and the main energy source, the degradation of tissue proteins is modest. In the terminal state, vital tissue proteins are degraded, and a high premortal nitrogen loss takes place.