[Verse 1]
Gravida carries a hidden sea inside,
Cardiac output climbs, MAC values slide,
Forty percent more blood, the plasma leads the cells,
Dilutional anemia — the body overspells,
Gastric emptying slows, aspiration looms,
Progesterone relaxes the esophageal rooms,
Functional residual capacity drops fast,
Oxygen reserves won't let the apnea last
[Chorus]
Corpi diversi, fisiologia cambia —
The gravid, the newborn, the ancient, the ample,
Each body rewrites the pharmacokinetic script,
Corpi diversi — know the difference or slip,
MAC goes down in pregnancy, up in infancy,
La conoscenza — that's what sets the clinician free
[Verse 2]
Neonates breathe with obligate nasal grace,
Fetal hemoglobin holds oxygen in place,
Higher affinity — the curve shifts left with pride,
But oxygen offloads slow to the tissue tide,
Myelin is thin, the blocks spread wide and far,
Hepatic enzymes immature — dose by the gram, not jar,
Hypothermia stalks the small and surface-wide,
High body-to-surface ratio, nowhere left to hide
[Chorus]
Corpi diversi, fisiologia cambia —
The gravid, the newborn, the ancient, the ample,
Each body rewrites the pharmacokinetic script,
Corpi diversi — know the difference or slip,
MAC goes down in pregnancy, up in infancy,
La conoscenza — that's what sets the clinician free
[Verse 3]
The senescent frame — a word for what time sculpts —
Organ reserves hollowed like forgotten vaults,
Glomerular filtration fades across the years,
Hepatic blood flow thins, drug clearance disappears,
Decreased albumin means the free drug roams unchecked,
Volatile requirements fall — their nervous systems flecked,
Atrophy of muscle, fat percentage climbs instead,
Volume of distribution shifts — recalibrate your head
[Bridge]
Obesity tilts the axis of the assumed —
Airway redundant, FRC entombed,
Obstructive apnea primes the hypoxic knife,
Increased cardiac output, a paradox of life,
Dose to ideal or lean? The choice is not a guess,
Adipose as depot — prolonged drug egress,
Pulmonary hypertension waits offstage,
Every body writes a pharmacologic page
[Chorus]
Corpi diversi, fisiologia cambia —
The gravid, the newborn, the ancient, the ample,
Each body rewrites the pharmacokinetic script,
Corpi diversi — know the difference or slip,
MAC goes down in pregnancy, up in infancy,
La conoscenza — that's what sets the clinician free
[Outro]
Senescent, gravid, neonatal, obese —
No universal dose can grant you peace,
Read the body like a manuscript, each chapter rare,
Fisiologia — the only constant is that bodies dare to vary,
Corpi diversi — sempre