Grand Mal Epilepsy (Generalized Tonic-Clonic Seizure)

DEFINITION

ETIOLOGY / PREDISPOSING FACTORS

• No structural brain lesion
• Genetic predisposition (autosomal dominant patterns in many families)
• Examples: Juvenile myoclonic epilepsy, childhood/juvenile absence epilepsy

1. Head injury / traumatic brain injury
2. Cerebrovascular disease (stroke, intracranial hemorrhage)
3. Brain tumors (primary or metastatic)
4. CNS infections (meningitis, encephalitis, neurocysticercosis)
5. Congenital malformations / cortical dysplasia
6. Metabolic disorders: hypoglycemia, hypocalcemia, hyponatremia, uremia
7. Alcohol withdrawal / drug withdrawal
8. Hypoxic-ischemic encephalopathy

PATHOPHYSIOLOGY

• Normal neuronal excitability is maintained by a balance between excitatory (glutamate) and inhibitory (GABA) neurotransmitters.
• In grand mal epilepsy, there is excessive, synchronous, paroxysmal neuronal discharge involving both cerebral hemispheres simultaneously from the onset.
• Mechanism involves:
  • Failure of inhibitory GABA-ergic mechanisms
  • Hyperactivation of voltage-gated Na+ channels and NMDA-type glutamate receptors
  • Abnormal, repetitive depolarization shifts (paroxysmal depolarizing shifts, PDS) in neurons
• The tonic phase results from sustained neuronal firing; the clonic phase results from alternating inhibitory and excitatory surges.

CLINICAL FEATURES

Phase 1: Prodrome (Hours to Days Before)

• May occur hours before the attack
• Patient may feel irritable, depressed, apathetic, or, rarely, ecstatic
• Vague symptoms: headache, nausea, mood changes
• In juvenile myoclonic epilepsy: myoclonic jerks of the trunk or limbs on awakening may herald a seizure
• Note: Many patients have NO prodrome

Phase 2: Tonic Phase (10-20 Seconds)

• Sudden, complete loss of consciousness without warning in most cases
• Falls to the ground - may cause facial injury, tongue bite, limb fracture
• Tonic contraction of all body musculature:
  • Opisthotonus (arching of back)
  • Clenching of jaw (tongue may be bitten at this stage)
  • Arms: flexion / extension
  • Legs: extension
• Epileptic cry - forced expiration through closed glottis (laryngeal spasm + abdominal compression)
• Apnea - respiratory muscles in tonic spasm; cyanosis may develop
• Eyes deviate upward / to one side; pupils dilate
• Duration: approximately 10-20 seconds

Phase 3: Clonic Phase (30 Seconds - 2 Minutes)

• Violent, rhythmic jerking movements of all four limbs
• Gradual decrease in frequency and increase in amplitude of jerks
• Frothing / foaming at mouth (saliva + air forced through clenched teeth)
• Incontinence of urine (and less commonly feces) - due to relaxation of sphincters
• Tongue biting may occur (lateral border of tongue most commonly)
• Autonomic features: tachycardia, hypertension, sweating, hypersalivation
• Duration: approximately 30 seconds to 2 minutes

Phase 4: Postictal Phase (Minutes to Hours)

• Gradual recovery of consciousness
• Deep, stertorous (snoring) breathing - muscles begin to relax
• Patient is confused, disoriented, and exhausted
• Headache is common
• Retrograde and anterograde amnesia for the ictal event
• Todd's paralysis (postictal paresis): transient focal weakness of one limb or side of body lasting minutes to hours; indicates a focal cortical seizure focus
• Patient typically falls into a deep sleep for 1-2 hours
• On waking: complete recovery with no memory of the event; may have muscle soreness

INVESTIGATIONS / DIAGNOSIS

• Description of the ictal event, duration, tongue bite, incontinence, postictal confusion
• History of previous episodes, family history
• Precipitating factors: sleep deprivation, alcohol, fever, flashing lights

• Most important investigation
• Ictal: High-voltage, generalized spike or polyspike-and-wave discharges during the attack
• Interictal (between attacks): May show generalized spike-wave complexes at 3 Hz or other abnormalities
• Normal interictal EEG does NOT rule out epilepsy
• Sleep-deprived EEG or EEG with photic stimulation may increase yield

• CT scan of brain: rapid, useful in emergency to rule out hemorrhage, mass lesion
• MRI brain (preferred): better soft-tissue resolution; detects cortical dysplasia, hippocampal sclerosis, tumors, vascular malformations

• Blood glucose (hypoglycemia)
• Serum electrolytes: Na+, K+, Ca2+, Mg2+
• Complete blood count (CBC)
• Liver function tests (LFTs) and renal function tests (RFTs)
• Toxicology screen (drugs/alcohol)
• HIV serology (in high-risk groups)

• Indicated if meningitis/encephalitis suspected
• NOT routine

MANAGEMENT

A. First Aid / Immediate Management (During a Seizure)

1. Do NOT restrain the patient forcibly
2. Protect from injury: Move sharp or hard objects away; cushion the head
3. Position: Place in lateral/recovery position to prevent aspiration of secretions
4. Nothing in the mouth - do NOT insert any object between teeth (this is an outdated practice and causes injury)
5. Maintain airway: Loosen tight clothing; suction secretions if available
6. Observe and time the seizure
7. If seizure > 5 minutes: Treat as status epilepticus (emergency)

B. Pharmacological Management

• Monotherapy is preferred; start with a single drug at low dose, increase gradually
• The target is seizure freedom with minimal side effects
• Drug level monitoring is useful for phenytoin and carbamazepine
• Continue medication for 2-5 years after the last seizure before considering withdrawal
• Abrupt discontinuation must be avoided (risk of status epilepticus)

C. Status Epilepticus (Emergency Management)

1. IV Diazepam (0.1-0.2 mg/kg) or IV Lorazepam - first-line, stops 80% of cases
2. IV Phenytoin (15-20 mg/kg) - second-line, slow infusion
3. IV Valproate or Levetiracetam - alternatives
4. General anesthesia (propofol / thiopentone) if refractory

DENTAL CONSIDERATIONS IN A PATIENT WITH GRAND MAL EPILEPSY

1. Drug history: Phenytoin causes gingival hyperplasia (in 50% of patients) - a major dental concern; lamotrigine and valproate are preferred alternatives.
2. Avoid precipitating factors: Anxiety, stress, hyperventilation, flickering lights in the dental operatory.
3. Premedication: Oral benzodiazepine (e.g., diazepam) as anxiolytic may reduce seizure threshold.
4. Drug interactions:
   • Carbamazepine: induces CYP3A4 - increases metabolism of many drugs including doxycycline, metronidazole, paracetamol.
   • Valproate: inhibits drug metabolism - can increase levels of other drugs.
5. If a seizure occurs in the dental chair: Recline chair, protect from injury, do NOT force instruments in the mouth, turn patient to side, call for help, administer IV/buccal midazolam if available.
6. Informed consent: Document seizure history and frequency.

10 MARKER QUESTIONS (Dental Student Level)

• Prodrome: Occurs hours before the attack. Irritability, mood changes, headache, myoclonic jerks (in juvenile myoclonic epilepsy). Many patients have no prodrome.
• Tonic Phase (10-20 sec): Sudden loss of consciousness, fall to ground (risk of injury), epileptic cry (forced expiration through closed glottis), opisthotonus, jaw clenching (tongue bite may occur), apnea with cyanosis, upward eye deviation, pupillary dilation.
• Clonic Phase (30 sec-2 min): Rhythmic jerking of all four limbs, frothing at mouth, urinary incontinence, tongue biting, tachycardia, hypertension.
• Postictal Phase: Deep stertorous breathing, confusion, headache, deep sleep, amnesia for the event, Todd's paralysis (transient focal paresis) if focal onset.

• Most important: EEG (electroencephalography)
  • Ictal: generalized spike/polyspike-and-wave discharges
  • Interictal: may show spike-wave complexes; normal EEG does not rule out epilepsy
• Neuroimaging: CT brain (emergency) / MRI brain (preferred) - to rule out structural causes
• Blood: Blood glucose, serum electrolytes (Na, Ca, Mg), CBC, LFT, RFT, toxicology screen, HIV serology
• Lumbar puncture: Only if meningitis / encephalitis suspected
• History from witness: Most valuable clinical tool - description of ictal event, duration, postictal features

• Mechanism: Blocks voltage-gated Na+ channels (use-dependent block) - reduces repetitive, high-frequency neuronal firing
• Dose: 200-400 mg/day (adult); can be started at full dose (unique among antiepileptics)
• Pharmacokinetics: Exhibits zero-order (saturable) kinetics at therapeutic doses - small dose increases can cause disproportionate rise in blood levels
• Adverse effects: Nystagmus, ataxia, sedation (dose-dependent); Gingival hyperplasia (most important for dentists - occurs in ~50%); hirsutism, coarse facial features, megaloblastic anemia (long-term); teratogenic (fetal hydantoin syndrome)
• IV use: Treatment of status epilepticus; must be given slowly (risk of hypotension, cardiac arrhythmia)
• Drug interactions: Induces CYP enzymes; displaces drugs from protein binding

1. Gingival Hyperplasia (Drug-Induced Gingival Overgrowth):
   • Occurs in ~50% of patients on phenytoin
   • More severe in anterior labial gingiva
   • Due to increased collagen synthesis and decreased collagen degradation in fibroblasts
   • Worsened by poor oral hygiene
   • Management: Improve oral hygiene; in severe cases, surgical gingivectomy; consider switching to a non-phenytoin antiepileptic (e.g., levetiracetam, lamotrigine)
2. Increased infection risk (some immunological effects)
3. Drug interactions with dental drugs (see above)
4. Contraindication: Lignocaine (lidocaine) - large doses can lower seizure threshold; use with care

1. STOP dental procedure immediately; remove all instruments from mouth
2. Do NOT restrain the patient; lower/recline the dental chair to supine position
3. Protect from injury: Clear the area; protect head; do NOT insert anything into mouth
4. Lateral/recovery position after tonic-clonic phase ends - to prevent aspiration
5. Monitor airway: Maintain patency; suction secretions
6. Oxygen if available via face mask (do not force)
7. Time the seizure: If > 5 minutes - medical emergency (status epilepticus)
8. Call emergency services (ambulance)
9. Midazolam (buccal/intranasal) or IV diazepam if available and trained to use
10. Do NOT give anything by mouth during or immediately after the seizure
11. Reassure patient when consciousness returns; do NOT restart dental procedure on that visit

• Stage 1 (0-5 min): Secure airway, IV access, O2, blood glucose check, thiamine if alcoholism suspected
• Stage 2 (5-20 min, Benzodiazepine phase):
  • IV Lorazepam 0.1 mg/kg (preferred) OR IV Diazepam 0.1-0.2 mg/kg
  • Buccal/Intranasal Midazolam if no IV access
• Stage 3 (20-40 min, Second-line drugs):
  • IV Phenytoin 15-20 mg/kg (slow infusion, rate < 50 mg/min) OR
  • IV Valproate OR IV Levetiracetam
• Stage 4 (> 40 min, Refractory SE):
  • General anesthesia: IV Propofol, Thiopentone, or Midazolam infusion under EEG monitoring in ICU

• Sudden loss of consciousness; patient falls (risk of head injury, fractures)
• Epileptic cry: Forced expiration through the partially closed glottis due to tonic contraction of respiratory and laryngeal muscles - produces a characteristic cry or groan
• Opisthotonus: Sustained extension/arching of the trunk and neck
• Jaw is forcibly clenched (risk of tongue bite between molars)
• Arms: initially flex then extend; legs extend
• Apnea develops due to tonic contraction of respiratory muscles - cyanosis may appear
• Eyes deviate upward or laterally; pupils dilate and are unresponsive
• Profuse sweating, tachycardia, hypertension (autonomic storm)
• Duration: approximately 10-20 seconds

1. Idiopathic/Genetic (most common in young patients): no structural lesion; genetic predisposition; juvenile myoclonic epilepsy
2. Structural: head trauma, stroke, brain tumor, cortical dysplasia, hippocampal sclerosis
3. Metabolic: hypoglycemia, hypocalcemia, hyponatremia, hypomagnesemia, uremia, hepatic failure
4. Infective: meningitis, encephalitis, cerebral abscess, neurocysticercosis
5. Toxic: alcohol withdrawal, benzodiazepine withdrawal, cocaine, isoniazid overdose
6. Perinatal: hypoxic-ischemic encephalopathy

• Sleep deprivation
• Alcohol intake / withdrawal
• Missed antiepileptic doses
• Fever / systemic illness
• Emotional stress / anxiety
• Flickering lights (photosensitivity, especially juvenile myoclonic epilepsy)
• Hyperventilation (can precipitate absence seizures; rarely tonic-clonic)
• Menstruation (catamenial epilepsy)

• Blocks voltage-gated Na+ channels (reduces high-frequency neuronal firing)
• Blocks T-type calcium channels (relevant for absence seizures)
• Increases brain GABA levels (inhibits GABA transaminase enzyme, the enzyme that degrades GABA)

• Well absorbed orally; peak levels in 1-4 hours
• Protein binding ~90%
• Hepatic metabolism (glucuronidation, beta-oxidation)
• Half-life: 8-17 hours
• Available as enteric-coated tablets, syrup, IV formulation

• Nausea, vomiting, dyspepsia (GI common; give with food)
• Weight gain
• Alopecia (hair loss) - transient
• Hepatotoxicity (rare but potentially fatal, especially in children < 2 years on polytherapy)
• Pancreatitis (rare)
• Teratogenicity: Neural tube defects (spina bifida) - avoid in pregnancy if possible; supplement folic acid
• Tremor, sedation
• Thrombocytopenia, platelet dysfunction (important for dental surgery - check bleeding time)

• Inhibits hepatic enzymes - increases levels of phenobarbital, lamotrigine
• Displaces phenytoin from protein binding

• Definition: Todd's paralysis (Todd's paresis) is a transient, focal neurological deficit - most commonly a unilateral weakness or paralysis of a limb - occurring in the postictal phase (after a seizure), lasting minutes to several hours, and resolving completely.
• Mechanism: Believed to result from exhaustion of neurons or inhibitory mechanisms in the motor cortex following the ictal discharge.
• Clinical Significance:
  1. It strongly indicates that the seizure was focal in onset (even if it appeared generalized clinically) - helps in seizure classification
  2. It can mimic a stroke or TIA (transient ischemic attack) - important differential diagnosis
  3. Its presence helps localize the seizure focus (contralateral to the paretic limb)
  4. If paralysis lasts > 24 hours, an alternative diagnosis (e.g., stroke) should be considered and neuroimaging performed
• Example: A patient who has a right-sided tonic-clonic seizure and then has a left arm weakness lasting 2 hours has Todd's paralysis pointing to a right cortical focus.

SOURCES

• Adams and Victor's Principles of Neurology, 12th Edition - Sections on Generalized Onset Seizures, Grand Mal
• Katzung's Basic and Clinical Pharmacology, 16th Edition - Chapter on Antiseizure Medications
• Swanson's Family Medicine Review - Epilepsy Section
• Note: AK Tripathi's Essentials of Medical Pharmacology was not available in the textbook library; this answer follows the AK Tripathi chapter format and style based on the dental pharmacology curriculum structure.

ACUTE RENAL FAILURE (ARF) — DIAGNOSIS

Note on source: AK Tripathi's textbook is not in the available library. This answer follows the exact AK Tripathi chapter format (as used in Indian dental curricula) and is cross-referenced with: Fischer's Mastery of Surgery (8th ed), Washington Manual of Medical Therapeutics, National Kidney Foundation Primer on Kidney Diseases (8th ed), and Brenner & Rector's The Kidney (2-Vol Set).

DEFINITION

KDIGO Diagnostic Criteria (2012 - the universally accepted standard)

STAGING OF AKI (KDIGO)

CLASSIFICATION OF ARF (Etiological)

ARF
├── 1. PRERENAL (most common, ~55-60%)
├── 2. INTRINSIC RENAL (Renal proper, ~35-40%)
│   ├── Tubular (ATN)
│   ├── Glomerular
│   ├── Vascular
│   └── Interstitial
└── 3. POSTRENAL (Obstructive, ~5%)

APPROACH TO DIAGNOSIS OF ARF

Step 1: History + Clinical examination
Step 2: Urine output monitoring
Step 3: Blood investigations (serum creatinine, BUN, electrolytes)
Step 4: Urine examination (dipstick + microscopy + indices)
Step 5: Imaging (Renal USG)
Step 6: Renal biopsy (if cause unclear)
Step 7: Novel biomarkers (if available)

STEP 1: HISTORY AND CLINICAL EXAMINATION

History

• Vomiting, diarrhea, excessive sweating, burns (volume loss)
• Poor oral intake, history of heart failure, liver cirrhosis
• Use of NSAIDs, ACE inhibitors, ARBs, diuretics
• Recent surgery, hemorrhage, hypotensive episodes, sepsis

• Recent respiratory infection or skin infection (suggests post-streptococcal GN)
• Sinusitis, hemoptysis, rash, arthralgia (vasculitis, Wegener's, Goodpasture's)
• Recent use of nephrotoxic drugs: aminoglycosides, contrast agents, cisplatin, vancomycin
• Recent blood transfusion (pigment nephropathy - hemoglobinuria)
• Crush injury, heavy exercise, rhabdomyolysis (myoglobinuria)

• Difficulty in micturition, reduced stream (prostatic hypertrophy)
• Flank pain, history of renal stones
• History of pelvic malignancy, retroperitoneal fibrosis
• Sudden anuria (obstruction is more likely)

Clinical Examination Findings

• Pallor (anemia of ARF)
• Edema (fluid retention) - periorbital, pedal, ascites
• Puffy face (nephrotic features if glomerulonephritis)
• Signs of dehydration (dry tongue, sunken eyes, poor skin turgor) in prerenal ARF

• Hypertension (common in intrinsic renal ARF)
• Pericardial friction rub (uremic pericarditis in severe/late ARF)
• Elevated JVP (fluid overload) or flat JVP (volume depletion - prerenal)
• Orthostatic hypotension (prerenal - drop in BP >20/10 mmHg on standing)

• Kussmaul's breathing (deep, rapid - metabolic acidosis)
• Pulmonary edema (fluid overload)

• Altered sensorium, confusion, restlessness (uremic encephalopathy - late)
• Asterixis (flapping tremor) - uremia

• Bladder distension (palpable, dull on percussion) - postrenal ARF
• Renal angle tenderness (bilateral in intrinsic renal disease; unilateral in obstruction)
• Enlarged prostate on PR examination (postrenal)

• Oliguria: < 400 mL/24 hours (most common in ARF)
• Anuria: < 100 mL/24 hours (suggests complete obstruction or cortical necrosis)
• Non-oliguric ARF: Normal or increased urine output despite rising creatinine (common with nephrotoxic ATN)

STEP 2: URINE OUTPUT MONITORING

• Monitor urine output hourly in suspected ARF (catheterize the patient)
• Urine output is sensitive to changes in renal perfusion

STEP 3: BLOOD INVESTIGATIONS

A. Serum Creatinine (sCr)

• Most important and widely used marker of GFR
• Reflects muscle mass - a product of creatine phosphate metabolism
• Normal: ~0.6-1.2 mg/dL (males); ~0.5-1.0 mg/dL (females)
• In ARF: rises 0.5-1 mg/dL/day (in catabolic states, may rise faster)
• Limitation: sCr is an insensitive early marker - GFR may fall by 50% before sCr doubles; influenced by age, sex, muscle mass, hydration status
• Creatinine clearance (GFR in mL/min): = (Urine creatinine × Urine volume) / Serum creatinine

B. Blood Urea Nitrogen (BUN) / Serum Urea

• Normal BUN: 8-20 mg/dL
• Rises in ARF due to reduced excretion
• BUN:Creatinine ratio - very important for differentiating prerenal from intrinsic ARF:

• BUN also elevated in: GI bleeding, high protein diet, catabolic states (burns), corticosteroid use

C. Serum Electrolytes

• Hyperkalemia (K+ > 5.5 mEq/L): Most dangerous complication of ARF; can cause fatal arrhythmias
• Hyponatremia: Dilutional (excess water retention)
• Hypocalcemia: Due to reduced renal activation of vitamin D
• Hyperphosphatemia: Reduced phosphate excretion
• Metabolic acidosis: Reduced excretion of H+ ions; bicarbonate (HCO3-) falls

D. Complete Blood Count (CBC)

• Anemia: Normocytic normochromic (due to reduced EPO, hemolysis, blood loss)
• Leucocytosis: If sepsis is the cause
• Eosinophilia: Suggests acute interstitial nephritis (AIN) or atheroembolism
• Thrombocytopenia + microangiopathic hemolytic anemia: Think HUS/TTP

E. Other Blood Tests

• LFT: Elevated LDH with normal transaminases - suggests renal artery thrombosis
• Serum albumin: Low in nephrotic syndrome (glomerular cause)
• Complement levels (C3, C4): Low in post-streptococcal GN, lupus nephritis, MPGN
• ANCA (anti-neutrophil cytoplasmic antibodies): Positive in Wegener's granulomatosis, microscopic polyangiitis
• Anti-GBM antibodies: Positive in Goodpasture's syndrome
• Anti-dsDNA, ANA: Positive in Lupus nephritis
• ASO titre (Anti-streptolysin O): Elevated in post-streptococcal GN
• Cryoglobulins: Cryoglobulinemic GN
• Serum protein electrophoresis: Myeloma (light chain nephropathy)
• Creatine phosphokinase (CPK): Markedly elevated in rhabdomyolysis (myoglobinuric ARF)

STEP 4: URINE EXAMINATION

A. Urine Dipstick

B. Urine Microscopy (Most Valuable)

C. Urine Biochemical Indices (Critical for Prerenal vs ATN Differentiation)

FENa formula: FENa (%) = (Urine Na / Serum Na) ÷ (Urine Cr / Serum Cr) × 100

Key point: FENa < 1% = kidneys working hard to retain sodium = prerenal (low flow, intact tubules). FENa > 2% = tubules damaged, cannot reabsorb sodium = ATN.

Limitation of FENa: NOT reliable in patients on diuretics. Use FEUrea instead in such patients (FEUrea < 35% = prerenal; > 50% = ATN).

STEP 5: IMAGING

A. Renal Ultrasound (USG) - FIRST-LINE IMAGING

• Investigation of choice for initial evaluation
• Can be done at bedside; no radiation; no nephrotoxic contrast
• Findings:

Note: Hydronephrosis may be absent even in obstruction if there is concomitant volume depletion or retroperitoneal fibrosis. Repeat USG after fluid resuscitation if obstruction still suspected.

B. CT Scan Abdomen (Non-contrast)

• Detects: renal stones, retroperitoneal masses, papillary necrosis
• Avoid IV contrast in ARF (nephrotoxic)

C. CT/MR Angiography

• Renal artery stenosis, renal artery thrombosis, renal vein thrombosis
• Used when vascular cause is suspected

D. Radionuclide Renal Scan (MAG-3 / DTPA Scan)

• Assesses renal perfusion and function separately in each kidney
• Used when renal artery thrombosis or obstruction is suspected

E. Plain X-ray KUB (Kidney-Ureter-Bladder)

• Detects radio-opaque stones

STEP 6: RENAL BIOPSY

Indications (when to biopsy):

1. ARF of unknown cause despite history, labs, and imaging
2. Suspected glomerulonephritis (RBC casts, heavy proteinuria, low complement)
3. Suspected acute interstitial nephritis (especially if offending drug is not obvious)
4. ARF in a renal transplant patient
5. Prolonged ARF (> 4-6 weeks) without obvious cause - to rule out irreversible damage
6. Systemic disease with renal involvement (lupus, vasculitis, amyloidosis)

Contraindications:

• Uncontrolled hypertension
• Bleeding diathesis / coagulopathy
• Solitary kidney
• Hydronephrosis / infected kidney
• Uncooperative patient

Biopsy Findings:

STEP 7: NOVEL / NEW BIOMARKERS (For Early Detection)

DIFFERENTIAL DIAGNOSIS: PRERENAL vs ATN vs POSTRENAL

SUMMARY TABLE: INVESTIGATIONS IN ARF AT A GLANCE

DENTAL RELEVANCE OF ARF / AKI

1. Drug dosing: Many drugs used in dentistry (NSAIDs, aminoglycosides, some antibiotics) are nephrotoxic or renally excreted - dose adjustment needed in ARF
2. Avoid NSAIDs in patients with ARF or at risk (dehydrated, elderly, on ACE inhibitors)
3. Contrast agents (if dental imaging with contrast) are nephrotoxic in ARF patients - avoid
4. Bleeding tendency: ARF causes platelet dysfunction (uremic platelet dysfunction) - bleeding risk in dental procedures
5. Drug interactions: ACE inhibitors / ARBs in patients on anti-hypertensive therapy can impair GFR - check drug history
6. Metformin: If patient is diabetic and on metformin - metformin is contraindicated in ARF (risk of lactic acidosis)
7. Oral manifestations of uremia: Uremic stomatitis, pallor, xerostomia, metallic taste, uremic frost (rare), ammoniacal breath (fetor uremica)

SOURCES

• Fischer's Mastery of Surgery, 8th Edition
• Washington Manual of Medical Therapeutics
• National Kidney Foundation Primer on Kidney Diseases, 8th Edition
• Brenner and Rector's The Kidney, 2-Volume Set

AK Tripathi's Textbook of General Medicine is not in the available textbook library. The content above follows the AK Tripathi chapter format (definition → classification → diagnostic steps → investigations with tables → differential diagnosis → dental relevance) as used in Indian dental curricula.

Diagnosis of ARF — Quick Bullet Summary

Definition

• ARF = sudden decline in GFR → retention of urea, creatinine, electrolyte imbalance
• Now termed Acute Kidney Injury (AKI)

KDIGO Criteria (Any ONE):

• sCr rise ≥ 0.3 mg/dL within 48 hours
• sCr rise ≥ 1.5× baseline within 7 days
• Urine output < 0.5 mL/kg/hr for ≥ 6 hours

Types

• Prerenal - low blood flow to kidney (dehydration, heart failure, bleeding)
• Intrinsic Renal - kidney damage (ATN, glomerulonephritis, interstitial nephritis)
• Postrenal - obstruction (stones, prostate, tumor)

History Clues

• Vomiting/diarrhea/burns → Prerenal
• Nephrotoxic drugs (NSAIDs, aminoglycosides, contrast) → ATN
• Poor urine stream, flank pain → Postrenal

Key Signs

• Oliguria (< 400 mL/day) or anuria (< 100 mL/day)
• Edema, hypertension, puffy face
• Kussmaul breathing (acidosis), uremic fetor

Blood Tests

• Serum creatinine — confirms ARF; rises daily
• BUN:Creatinine ratio — >20:1 = prerenal; 10-15:1 = ATN
• Serum K+ — hyperkalemia (most dangerous complication)
• HCO3- — low (metabolic acidosis)
• CBC — anemia, eosinophilia (AIN), thrombocytopenia (HUS/TTP)
• ANCA, Anti-GBM, ANA, C3/C4 — if glomerulonephritis suspected

Urine Tests (Most Informative)

• < 1% → Prerenal

• 2% → ATN

• < 20 mEq/L → Prerenal

• 40 mEq/L → ATN

Imaging

• Renal USG — first-line; detects hydronephrosis (postrenal), kidney size
• CT abdomen — stones, masses (avoid IV contrast in ARF)

Renal Biopsy

• Done when cause is unclear
• Useful in: suspected GN, AIN, prolonged unexplained ARF

New Biomarkers

• NGAL, KIM-1, Cystatin-C — detect injury before creatinine rises

Dental Points

• Avoid NSAIDs — nephrotoxic
• Uremic bleeding risk — platelet dysfunction
• Fetor uremica, uremic stomatitis — oral manifestations
• Dose adjust renally-excreted drugs (antibiotics, analgesics)

Management of ARF in Dental Practice

OVERVIEW

1. Patient with known ARF / CKD on dialysis presenting for dental treatment
2. ARF occurring as a complication triggered by dental drugs or procedures (e.g., NSAID use, contrast agents, aminoglycosides)

PART A: GENERAL MEDICAL MANAGEMENT OF ARF

1. Treat the Underlying Cause

2. Fluid Management

• Restore adequate blood flow to kidneys with IV fluids in prerenal ARF
• Strict fluid balance monitoring (input vs output)
• Avoid fluid overload in oliguric patients

3. Electrolyte Management

• Hyperkalemia - most dangerous; treat with calcium gluconate (cardiac protection), insulin + dextrose, sodium bicarbonate, salbutamol; dialysis if severe
• Metabolic acidosis - sodium bicarbonate; dialysis if severe
• Hyponatremia, hypocalcemia, hyperphosphatemia - correct individually

4. Indications for Renal Replacement Therapy (Dialysis)

• A - Acidosis (severe metabolic acidosis unresponsive to bicarbonate)
• E - Electrolyte abnormality (refractory hyperkalemia - most common fatal complication)
• I - Intoxication (drugs/toxins - aspirin, methanol, lithium)
• O - Overload (volume overload with pulmonary edema unresponsive to diuretics)
• U - Uremia (BUN > 60 mg/dL with uremic pericarditis, encephalopathy, bleeding)

5. Avoid Nephrotoxins

• Stop aminoglycosides, IV contrast, NSAIDs, vancomycin in high-risk patients
• Adjust doses of renally excreted drugs

PART B: DENTAL MANAGEMENT OF A PATIENT WITH ARF / RENAL FAILURE

STEP 1: PRE-TREATMENT ASSESSMENT

• Type of renal disease, current GFR/creatinine level
• Is patient on dialysis? What type? (hemodialysis vs peritoneal)
• Dialysis schedule (very important for timing of dental appointments)
• Current medications (antihypertensives, immunosuppressants, anticoagulants)
• History of renal transplantation
• Any bleeding tendency or easy bruising

• Serum creatinine and BUN (current renal function status)
• Serum potassium (hyperkalemia risk)
• CBC (anemia, thrombocytopenia)
• Bleeding time / platelet count (uremic platelet dysfunction)
• PT/INR (if on anticoagulants - heparin during dialysis)
• Blood pressure measurement

STEP 2: TIMING OF DENTAL APPOINTMENTS (Dialysis Patients)

• Schedule dental treatment on the day AFTER dialysis (not on dialysis day)
• Reason: On dialysis day, patient receives heparin (anticoagulant) to prevent clotting in dialysis circuit - increases bleeding risk for dental procedures
• On the day after dialysis: patient is in best metabolic state, fluid/electrolyte balance is restored, heparin effect has worn off
• Avoid morning appointments if patient is fatigued after dialysis

STEP 3: DRUG PRESCRIBING IN ARF / RENAL FAILURE

• Nephrotoxic (damage the kidneys further)
• Renally excreted (accumulate to toxic levels in ARF)

A. ANALGESICS

Key Point for Exam: NSAIDs are absolutely contraindicated in ARF patients. Always substitute with Paracetamol.

B. ANTIBIOTICS

C. LOCAL ANAESTHETICS

D. SEDATIVES / ANXIOLYTICS

E. OTHER DRUGS

STEP 4: MANAGEMENT OF SPECIFIC DENTAL COMPLICATIONS IN ARF PATIENTS

A. Bleeding Management (Uremic Bleeding)

• Assess bleeding time pre-operatively
• For minor procedures: local hemostatic measures (sutures, gelatin sponge, tranexamic acid mouthwash)
• For major surgery: consult nephrologist; may need DDAVP (desmopressin 0.3 µg/kg IV) - temporarily improves platelet function in uremia
• Avoid aspirin and NSAIDs - worsen platelet dysfunction
• Schedule procedures on day after dialysis (heparin effect resolved)
• Control hypertension before procedure (uncontrolled BP > 180/110 - defer elective treatment)

B. Infection Management

• Maintain strict aseptic technique
• Oral infections can disseminate systemically - treat aggressively
• Prophylactic antibiotics may be needed for immunosuppressed renal transplant patients before invasive procedures
• Treat periodontal disease actively - oral sepsis worsens systemic inflammation

C. Hypertension Management in ARF Patients

• Measure BP before every dental appointment
• Defer elective treatment if systolic BP > 180 mmHg or diastolic > 110 mmHg
• Avoid vasoconstrictors in LA (adrenaline) in severe hypertension
• Dental stress and pain can precipitate hypertensive crisis - adequate pain control and anxiolysis is important

D. Anemia Management

• ARF causes normocytic normochromic anemia (reduced EPO)
• Anemic patients tolerate blood loss poorly
• Minimize surgical trauma; ensure meticulous hemostasis
• GA is hazardous in severely anemic patients (Hb < 8 g/dL) - consult physician before GA

STEP 5: ORAL MANIFESTATIONS OF ARF / UREMIA TO RECOGNIZE

STEP 6: POST-TRANSPLANT RENAL PATIENT - SPECIAL CONSIDERATIONS

• On long-term immunosuppressants: cyclosporine, tacrolimus, mycophenolate, prednisolone
• Cyclosporine → gingival hyperplasia (similar to phenytoin); treat with good oral hygiene; may need gingivectomy
• Steroid cover may be needed for major dental procedures (adrenal suppression risk)
• Higher risk of oral candidiasis, viral infections (HSV, HPV), oral cancer of lip
• Require pre-transplant dental clearance to eliminate all oral foci of infection before transplant surgery
• Antibiotic prophylaxis before invasive dental procedures if immunosuppressed

SUMMARY: DO'S AND DON'TS IN DENTAL PRACTICE FOR ARF PATIENTS