Nursing Field Notes / Endocrine · Pituitary Disorders · Med-Surg: Endocrine

🩸 ENDOCRINE SET NG-278 Hormones I NG-279 Hormones II NG-280 Hormones III NG-281 Pituitary Disorders NG-282 SIADH vs DI (1) NG-283 SIADH vs DI (2)

Pituitary Disorders 🧠

Hyperpituitarism · hypopituitarism · prolactinoma · hypophysectomy

NG-281 ENDOCRINE · MASTER GLAND ADHD-friendly visual edition

The pituitary is a pea-sized gland in a bony pocket at the base of the skull, and almost everything that goes wrong with it is a tumor — a benign adenoma that either makes too much of one hormone or crushes the gland and makes too little of everything. Because of where it sits, the same tumor can also press on the optic chiasm. This page covers the anterior lobe; the posterior lobe's water disorders get their own pair of pages.

🧠 Almost always a tumorBenign adenoma. Too much of one hormone, or too little of all of them.

📈 HYPER = think HIGHHigh BP · tall height · long hands, feet, jaw · enlarged organs.

📉 HYPO = think LOWLow BP · low cardiac output · low height & energy · low sex drive.

🔪 Post-op #1 ruleNO sneezing, coughing, nose-blowing, straining or bending. Watch for DI.

🧠

THE GLAND ITSELF

STEP 1 · ORIENT

Two lobes with different tissue, different blood supply and completely different diseases.

🔬 Anterior vs posterior — blood supply and what breaks

hypothalamus anterior lobe · glandular posterior lobe · neural portal / capillary blood

🧠 "Front lobe = hormone diseases. Back lobe = water diseases." If the question is about growth, milk, cortisol or thyroid, look at the front. If it is about urine and sodium, look at the back.

📍 Why location causes half the symptoms

The pituitary sits in the sella turcica, a bony saddle. The only direction a growing tumor can easily expand is upward — straight into the optic chiasm.

So a pituitary adenoma produces two separate kinds of problem at once:

Hormonal — from what it secretes, or from what it destroys.
Mass effect — headache, visual field loss, and eventually hypopituitarism from pressure on healthy tissue.

🧠 "Nowhere to grow but up." Headache + visual change in an endocrine patient = think mass effect.

👁️ Mass effect — bitemporal hemianopsia

Assessment: test visual fields by confrontation, ask about driving, bumping into things and missing peripheral objects, and document any change. In a post-op patient, new visual loss is an urgent finding.

📈

HYPERPITUITARISM — TOO MUCH

STEP 2 · EXCESS

Increased secretion of hormone by the anterior pituitary, typically caused by a tumor.

🚨 The pathophysiology in one line

Increased secretion of growth hormone by the anterior pituitary gland, typically caused by a tumor. Which disease you get depends entirely on whether the epiphyseal growth plates were still open.

Gigantism — GH excess before puberty, plates still open → extreme height.
Acromegaly — GH excess after puberty, plates fused → bones widen and thicken instead.

Puberty generally occurs somewhere around 8–14 years of age, so that is roughly the dividing line.

🧠 "Gigantism grows you TALLER. Acromegaly grows you WIDER."

🔬 Gigantism · normal · GH deficiency, against a height scale

were the growth plates still open? 0123 4567 ft 0 m1 m2 m GIGANTISM GH excess BEFORE the plates close NORMAL GROWTH proportionate, plates closed on time GH DEFICIENCY short but proportionate ("pituitary dwarfism") taller than 7 ft is possible if untreated adult height reached falls off the growth chart GIGANTISM vs ACROMEGALY GIGANTISM — GH excess before puberty, while the epiphyseal plates are still open. The long bones keep lengthening → extreme height. ACROMEGALY — GH excess after the plates close. Bones can only thicken and widen — not lengthen.

🔬 The growth plate is the whole explanation

🧠 HE’S TALL — the sign list for GH excess

HHypertension & Height — high blood pressure; extreme height if it started before puberty

EEnlarged organs — organomegaly, including an enlarged heart (a real cause of heart failure here)

SSweating & oily skin — coarse, thickened, greasy skin

TToo much pain in the joints — cartilage overgrowth

AArthritis — degenerative joint disease from years of overgrowth

LLong hands & feet — rings and shoes stop fitting

LLong protruding jaw — prognathism, teeth spread apart, coarse facial features

🧠 "Hyper = think HIGH." High blood pressure, tall height, big hands and feet, enlarged organs.

🔬 What changes in the face and hands

The clue that gets missed: because these changes take years, patients and families do not notice them. Ask to see an old photograph or driving license, and ask whether ring, hat, glove or shoe size has changed.

🚨 The complications that actually hurt people

Cardiomyopathy and heart failure — the enlarged heart is the leading cause of death in untreated acromegaly.
Hypertension.
Glucose intolerance and diabetes — GH is an anti-insulin hormone.
Obstructive sleep apnea from the thickened tongue and soft tissue of the airway.
Difficult airway — anesthesia and intubation are harder; this belongs in your pre-op handover.
Carpal tunnel syndrome from soft tissue swelling.

🧠 "Big heart, big tongue, big sugar." Those three kill or complicate far more often than the appearance does.

💊 Pharmacology for GH excess

NSAIDs — for joint pain.
Growth hormone receptor antagonists — they work by blocking GH at its receptor, so IGF-1 falls even though GH itself stays high.
Dopamine agonists — work by stopping the release of GH (and of prolactin) from the tumor.
Somatostatin analogs — synthetic versions of the body's own GH-inhibiting hormone; they switch GH release off at the source.

Drug therapy is usually an adjunct or a fallback. Surgery is first-line.

🧠 Remember from Part 1: the hypothalamus already has a natural GH brake (somatostatin / GHIH) and a natural prolactin brake (dopamine). Both drug classes are just copies of a brake the body already uses.

🥛 Prolactinoma — the commonest pituitary tumor

A benign adenoma secreting prolactin. Presentation splits by sex:

Women	Men
Amenorrhoea or irregular periods	Erectile dysfunction, low libido
Galactorrhoea — milk when not breastfeeding	Loss of body hair, gynaecomastia
Infertility, low bone density	Infertility, low bone density
Usually found early (periods stop)	Often found late — bigger tumor, more mass effect

Treatment is medical first, not surgical: dopamine agonists shrink most prolactinomas, because dopamine is prolactin's natural brake.

🧠 Check the medication list before you diagnose a tumor. Antipsychotics and metoclopramide block dopamine and raise prolactin — a common, reversible mimic.

📋 The other secreting adenomas

ACTH-secreting → Cushing disease (cortisol excess coming from the pituitary — different from Cushing syndrome, which is cortisol excess from any cause). See NG-280.
TSH-secreting → hyperthyroidism with a TSH that is high or normal instead of suppressed — a rare but memorable pattern.
Non-functioning → no hormone at all; presents purely with headache, visual loss and hypopituitarism.

🧠 A "normal" TSH with clear hyperthyroid symptoms is not reassuring — it is a clue that the pituitary is the problem.

📉

HYPOPITUITARISM — TOO LITTLE

STEP 3 · DEFICIENCY

Decreased secretion or production of hormones within the pituitary — from a tumor, trauma, stroke, surgery or radiation.

🔬 One gland fails, every gland below it fails

📉 The sign list — "HYPO = think LOW"

Hypotension — low blood pressure.
Low cardiac output.
Low height (in a child) and low energy.
Low sex drive and infertility.
Obesity — from a low metabolic rate.
Headaches — usually the mass that caused it.

🧠 Everything sags. Blood pressure, energy, libido, metabolism — the only thing that goes up is weight.

🚨 The order in which hormones are lost

When a mass slowly compresses the anterior lobe, the hormones tend to fail in a fairly predictable order — GH and the gonadotropins first, then TSH, then ACTH.

That matters clinically because ACTH is the one that kills. A patient can live for years with low GH; a patient with no cortisol who gets an infection can be in adrenal crisis within hours.

🧠 "Go Look For The Adrenals." GH → LH/FSH → TSH → ACTH. The last one to go is the one that matters most.

🚨 Sheehan syndrome — the obstetric cause

The pituitary roughly doubles in size during pregnancy but its blood supply does not. A severe postpartum hemorrhage can infarct it.

The classic first clue is that the mother cannot breastfeed (no prolactin), followed by failure of menses to return, fatigue, cold intolerance and hypotension.

🧠 "No milk after a big bleed." Any new mother with an obstetric hemorrhage who cannot lactate needs pituitary function checked.

💊 Replacement therapy — you replace the TARGET hormone

Corticosteroids to replace steroid hormones — the drug names end in “-sone”: prednisone, hydrocortisone.
Levothyroxine to replace thyroid hormone.
Growth hormone replacement — essential in children, and used in some adults.
Sex hormone replacement — estrogen/progesterone or testosterone, per the prescriber.
Desmopressin if the posterior lobe is also involved — a synthetic ADH analog, not a blood-pressure drug.

Steroid replacement is given BEFORE thyroid replacement. Starting levothyroxine first speeds up metabolism and can burn through what little cortisol remains, precipitating an adrenal crisis.

🧠 "Steroid before thyroid." One of the highest-yield sequencing rules in endocrine nursing.

✅ Teaching a patient on lifelong replacement

Never stop the steroid abruptly. Doses are tapered, never stopped cold.
Sick-day rules: illness, fever, vomiting or surgery may require a higher steroid dose — the patient must know to call, not guess.
Wear medical alert identification and carry a card listing the replacements.
Report dizziness on standing, persistent vomiting, weakness or confusion — these are early crisis signs.
Take levothyroxine on an empty stomach, at the same time daily, separated from calcium and iron.

🧠 "Stress needs steroid." Any physiological stressor means the patient needs more, not less.

🔪

SURGERY & POST-OP CARE

STEP 4 · THE NURSING

Hypophysectomy is first-line treatment — and the post-op care is where the exam questions live.

🔬 Transsphenoidal hypophysectomy — the route and the risks

🚨 Post-operative complications

Increased intracranial pressure — the priority assessment. Falling level of consciousness is the earliest reliable sign.
Meningitis — infection reaching the brain through the surgical tract.
Hypopituitarism — the healthy gland may be lost along with the tumor.
CSF leakage — clear drainage from the nose that will not stop.
Diabetes insipidus — sudden huge urine output, indicating pituitary or stalk damage.

🧠 "I-M-H-C-D": ICP · Meningitis · Hypopituitarism · CSF leak · DI. Five words, the whole complication list.

✅ Post-op nursing interventions

Monitor ICP, vital signs and neuro status on the ordered schedule.
Elevate the head of the bed — this decreases intracranial pressure and venous congestion.
NO sneezing, coughing or blowing the nose — each one spikes the pressure across a fresh surgical seal. Teach the patient to open the mouth if a sneeze is unavoidable.
Avoid straining — stool softeners are usually ordered; no bending at the waist; no heavy lifting.
Monitor for diabetes insipidus — strict intake and output, urine specific gravity, daily weights. Sudden dilute polyuria means the ADH supply has failed.
Mouth care without a toothbrush until the incision under the upper lip has healed — rinses and flossing instead.
Expect and reinforce that numbness of the upper lip and gums, and loss of smell, are common and often temporary.

🧠 "Nothing that raises pressure." Cough, sneeze, blow, bend, strain, bear down — all forbidden.

🩸 Recognizing a CSF leak

The other clue: a patient who keeps swallowing, or who reports a persistent postnasal drip that tastes salty or sweet, after this surgery is describing CSF — not congestion.

🧠 Halo on the gauze + glucose-positive drainage = CSF until proven otherwise.

⭐ The post-op urine question

The single most tested post-hypophysectomy complication is diabetes insipidus, because the surgery sits right where ADH is delivered.

What you see: urine output that suddenly becomes enormous and pale, watery and dilute, with a low specific gravity, plus intense thirst.
What you do: measure hourly output, check specific gravity, weigh daily, watch sodium, and notify the surgeon.
What it is treated with: fluid replacement and desmopressin — a synthetic ADH analog.

🧠 Big pale urine after brain-adjacent surgery = DI. Small dark urine with a falling sodium = SIADH. Both can follow neurosurgery.

CONTINUES The full comparison is on NG-282 · SIADH vs DI (1) and NG-283 · SIADH vs DI (2).

⚡

QUICK RECALL

SAY IT OUT LOUD

🧠 Plates open = gigantismPlates closed = acromegaly. Same hormone, different timing.

📈 HE'S TALLHypertension/Height · Enlarged organs · Sweating · Too much joint pain · Arthritis · Long hands · Long jaw.

🔪 Post-op: no pressureNo cough, sneeze, nose-blow, bend or strain. HOB elevated.

💊 Steroid BEFORE thyroidReplacing thyroid first can trigger an adrenal crisis.

⚠️ Six traps from this page

Desmopressin is a synthetic ADH analog, not a vasopressor. It is given to conserve water. Watch for a falling sodium and fluid overload, not for blood pressure effects.
Acromegaly does not make adults taller. The plates are already closed.
The biggest killer in acromegaly is the heart, not the appearance.
Prolactinoma is treated with drugs first — dopamine agonists — not surgery.
Cushing disease is pituitary; Cushing syndrome is any cause. The words are not interchangeable.
Do not brush the teeth after a transsphenoidal approach until the surgeon clears it — the incision is under the upper lip.

🔗 Related pages

NG-278 · Hall of Fame I — the anterior pituitary's six hormones and negative feedback.
NG-279 · Hall of Fame II — ADH and oxytocin from the posterior lobe.
NG-280 · Hall of Fame III — cortisol, Cushing and Addison.
NG-282 · SIADH vs DI (1) · NG-283 (2) — the posterior lobe water disorders.

🎯 Cover & check — 10 rapid-fire questions

Q1: A 9-year-old is growing far faster than every peer and has a GH-secreting adenoma. Gigantism or acromegaly?

Gigantism. The epiphyseal growth plates are still open, so the long bones can keep lengthening. The same tumor in a 40-year-old would cause acromegaly instead.

Q2: Recite HE'S TALL.

Hypertension & Height · Enlarged organs · Sweating & oily skin · Too much pain in the joints · Arthritis · Long hands & feet · Long protruding jaw.

Q3: Which post-operative complication after hypophysectomy is your priority assessment?

Increased intracranial pressure. Monitor level of consciousness, pupils, vital signs and neuro status; keep the head of the bed elevated; prevent anything that raises pressure.

Q4: Your post-op patient has put out 900 mL of pale watery urine in two hours and is desperately thirsty. What is happening?

Diabetes insipidus from pituitary or stalk damage — ADH is not being delivered. Check urine specific gravity (it will be low), measure hourly output, weigh, watch the serum sodium (it will rise) and notify the surgeon. Treatment is fluid replacement and desmopressin.

Q5: The patient reports a constant salty drip down the back of the throat and there is a clear ring around the blood on the nasal drip pad. What is it?

A cerebrospinal fluid leak — the halo or ring sign. CSF is glucose-positive on testing. Notify the surgeon, keep the head of the bed elevated, and reinforce no nose-blowing, sneezing or straining. The leak is also a route for meningitis.

Q6: Why is a patient with acromegaly a difficult airway?

Soft tissue and bony overgrowth — a thickened tongue, enlarged soft palate and pharyngeal tissue, and a protruding jaw — make mask ventilation and intubation harder. It also causes obstructive sleep apnea. This belongs in your pre-op handover.

Q7: Why do you give hydrocortisone before levothyroxine in hypopituitarism?

Thyroid hormone raises the metabolic rate, which increases cortisol demand and clearance. If cortisol is already deficient, starting thyroid replacement first can precipitate an adrenal crisis. Steroid before thyroid.

Q8: What is the classic first clue of Sheehan syndrome?

Failure to lactate after delivery following a severe postpartum hemorrhage — prolactin is gone. Menses do not return, and fatigue, cold intolerance and hypotension follow.

Q9: A young woman has amenorrhoea and milky nipple discharge. Name two very different causes you would consider.

A prolactin-secreting pituitary adenoma, or a dopamine-blocking medication such as an antipsychotic or metoclopramide (dopamine normally keeps prolactin suppressed). Pregnancy and hypothyroidism are also on the list. Review the medication history before assuming a tumor.

Q10: Why does a pituitary tumor cause loss of the OUTER half of vision in both eyes?

The gland sits directly under the optic chiasm. The fibers that cross at the chiasm come from the nasal half of each retina, and they carry the temporal (outer) visual field. A tumor growing upward crushes exactly those crossing fibers, producing bitemporal hemianopsia.