Ryle's Tube (Nasogastric Tube)

Figure: Nasogastric tubes - (a) Plastic; (b) Ryle; (c) Levin; (d) Salem; (e) Portex - Pye's Surgical Handicraft, 22nd Ed.

What is It?

Key Features

Indications (Uses)

1. Gastric Decompression

2. Enteral (Tube) Feeding

3. Gastric Function Tests (Acid Secretion Studies)

4. Medication Administration

5. Gastric Lavage

Insertion Procedure

1. Preparation: Patient is positioned semirecumbent. Nostril and pharynx are sprayed with 3% lignocaine in isotonic saline for local anaesthesia. The tube is well lubricated (liquid paraffin or water-soluble gel).
2. Insertion: Tube is passed through one nostril, directed posteriorly (not superiorly) toward the nasopharynx.
3. Advancement: As the tube reaches the back of the throat, the patient is asked to swallow repeatedly - this pulls the tube down through the oesophagus. A sip of water via straw can assist.
4. Depth estimation: A common method is to loop the tube over the patient's ear, place the tip at the xiphoid process, and use that distance (~55 cm in adults) as the target insertion length.
5. Securing: Tape the tube to the nose once at the correct depth.
6. Confirmation of placement:
   • Aspiration of gastric contents (pH < 5.5 on pH indicator strips)
   • Chest/upper abdominal X-ray (gold standard - the radio-opaque line confirms tip position)
   • Auscultation while injecting air is unreliable and should NOT be used alone.

Complications

• Epistaxis
• Rhinitis / sinusitis
• Pharyngitis / sore throat
• Gagging / discomfort

• Pulmonary misplacement - tube passed into trachea/bronchus; feeding into lungs is potentially fatal
• Aspiration pneumonia
• Oesophageal injury / perforation
• Intracranial placement (in patients with basilar skull fractures - an absolute contraindication to nasal insertion)
• Tube knotting (forceful removal)

Ryle's vs Other NG Tubes

Contraindications

• Suspected basilar skull fracture (risk of intracranial passage)
• Severe mid-face / nasal trauma
• Oesophageal varices / stricture (relative)
• Recent oesophagogastric surgery (relative)

• Bailey and Love's Short Practice of Surgery, 28th Ed. - Tube feeding, Supportive management
• S Das, A Manual on Clinical Surgery, 13th Ed. - Special investigations
• Pye's Surgical Handicraft, 22nd Ed. - NG tube types
• StatPearls - Nasogastric Tube Insertion (NIH)

Feeding Tubes (Enteral Nutrition Access)

Figure: Nasoenteric tube with stylet - Current Surgical Therapy, 14th Ed.

Overview

Indications for Tube Feeding

• Dysphagia (stroke, neurological disease, head and neck cancer)
• Severe neurologic impairment (reduced consciousness, dementia)
• Oropharyngeal or proximal GI tract pathology (tumors, trauma)
• Facial trauma
• Inadequate oral intake despite supplements
• Critical illness (start within 24-48 hours once hemodynamically stable)
• Prolonged post-operative period with anticipated poor oral intake

Types of Feeding Tubes

1. Nasogastric (NG) / Ryle's Tube

• Passed through the nose into the stomach
• Used for short-term feeding (< 4-6 weeks)
• Wide bore - can both feed and aspirate gastric contents
• PVC; change every 2 weeks
• Risk of rhinitis, pharyngitis, oesophageal erosions with prolonged use

2. Nasoenteric Tube (NET) - Nasoduodenal / Nasojejunal (NJ)

• Passed through the nose into the duodenum or jejunum (post-pyloric)
• Made of silicone or polyurethane; commonly 12 or 14F diameter
• Used when gastric feeding is not tolerated (gastroparesis, high aspiration risk)
• Bypasses the stomach - feeding must be delivered by continuous pump (not bolus), as the normal regulation of gastric emptying is bypassed
• Rate: typically begin at 15-40 mL/hr, advance to max ~125 mL/hr directly into small bowel
• Placement confirmed by abdominal X-ray
• Duration: also short-term (< 4-6 weeks) - Current Surgical Therapy, 14th Ed.

3. Percutaneous Endoscopic Gastrostomy (PEG)

• Tube placed directly through the abdominal wall into the stomach under endoscopic guidance
• Used for long-term feeding (> 4-6 weeks) or when nasal placement is impossible
• No need for laparotomy or general anaesthesia - done at bedside with monitored anesthesia care
• Technique ("pull" method):
  1. Gastroscope advanced into stomach; tip transilluminates anterior gastric wall
  2. Small abdominal incision over area of maximal transillumination
  3. Angiocatheter inserted; wire passed into gastric lumen, snared, pulled out through mouth
  4. PEG tube looped onto wire and pulled through the abdominal wall
  5. Inner bumper confirmed in correct position; tube secured externally
• May be difficult in obese patients (difficult transillumination); fluoroscopic approaches are an alternative
• Goldman-Cecil Medicine; Mulholland and Greenfield's Surgery, 7th Ed.

4. PEG-J (Gastrojejunal) Tube

• A jejunal extension is passed through a gastrostomy into the jejunum
• Allows simultaneous jejunal feeding + gastric venting/decompression
• Used in gastroparesis, after oesophagectomy/gastrectomy

5. Feeding Jejunostomy (Surgical)

• A loop of proximal jejunum (typically 20-40 cm distal to the ligament of Treitz) is brought up and secured to the abdominal wall, with the tube passed transabdominally
• Witzel jejunostomy: tube is covered for a short distance with bowel serosa for stability
• Placed via laparoscopic approach during major abdominal procedures when prolonged feeding is anticipated
• Used when the stomach is absent or non-functional - Mulholland and Greenfield's Surgery, 7th Ed.

6. Surgical Gastrostomy (Stamm)

• Open or laparoscopic technique; small incision into gastric body with concentric purse-string sutures securing a large-bore tube
• Less common now that PEG is available

Choosing the Right Tube

Feeding Regimens

Enteral Formulas

Advantages of Intragastric vs Post-pyloric Feeding

• Stomach acts as a reservoir - tolerable as bolus feeds
• Stimulates biliary and pancreatic secretions - trophic for the small bowel
• Gastric secretions dilute osmolarity, reducing diarrhoea risk
• Risk: aspiration in obtunded or neurologically impaired patients

• Lower aspiration risk (bypasses stomach)
• Must be continuous pump feeding only (no reservoir function)
• Maximum ~125 mL/hr into the small bowel

Complications

Tube-Related (Mechanical)

• Misplacement into the tracheobronchial tree - potentially fatal if feeds are instilled into lungs
• Tube blockage (prevent by regular water flushing; chymotrypsin may unblock; guidewires are avoided due to perforation risk)
• Tube dislodgement (especially jejunostomy tubes)
• Epistaxis, sinusitis, pharyngitis (nasal tubes)
• Peristomal leakage, skin excoriation (PEG/jejunostomy)
• Peritonitis (if dislodged tube is replaced into peritoneal cavity)

Infectious

• Aspiration pneumonia (most serious)
• Peristomal infection

Formula-Related

• Diarrhoea (up to 50% in critically ill; more common with bolus feeding)
• Nausea, vomiting, abdominal distension - usually from gastroparesis
• Osmotic diarrhoea (high osmolarity formulas)
• Refeeding syndrome - hypophosphataemia on restarting feeds after prolonged starvation; can cause cardiac arrhythmias, respiratory failure, lactic acidosis. Start at low rates (15-20 mL/hr) in at-risk patients.

Important Clinical Points

• Placement must always be confirmed radiographically before starting feeds - auscultation ("air bubble" test) is unreliable
• Position patients at 30-45° head elevation during feeding and for 1-2 hours afterward to reduce aspiration risk
• PVC Ryle's tubes should be changed every 2 weeks (becomes brittle)
• For fine-bore tubes (8-12Fr), never use a guidewire to unblock - perforation risk
• Enteral nutrition can be deferred 24-48 hours in critically ill patients without adverse effects
• Do not start enteral feeding in haemodynamic shock (on high-dose vasopressors) - risk of non-occlusive mesenteric ischaemia

• Current Surgical Therapy, 14th Ed. - PEG/NET access
• Goldman-Cecil Medicine, International Ed. - Enteral nutrition
• Mulholland and Greenfield's Surgery, 7th Ed. - Enteral access, jejunostomy
• StatPearls - Enteral Feeding (NIH)
• Merck Manual - Enteral Nutrition

Suction Catheter

What is a Suction Catheter?

Types of Suction Catheters

1. Yankauer (Tonsil-Tip) Suction

• Rigid or semi-rigid, angled plastic catheter
• Used for oropharyngeal suctioning - clears blood, secretions from the mouth and pharynx
• Rounded tip minimises soft tissue trauma
• Limitation: not large-bore enough to clear vomitus effectively
• Most commonly used in emergency airway management

2. Large-Bore Dental / Wide-Bore Suction Tip (e.g., HI-D Big Stick)

• Large-bore rigid tip (5/8 to 3/4 inch inner diameter)
• Best for clearing vomitus and particulate matter from the upper airway - standard catheters (1/4 inch) become obstructed by thick/particulate material
• Should be available at the bedside during all emergency airway management

3. Flexible / Soft Suction Catheter

• Soft, pliable catheter for nasopharyngeal, nasotracheal, and endotracheal suctioning
• Available in multiple sizes (French gauge)
• Tips may be:
  • Single end-hole
  • Multiple side ports (reduces mucosal invagination and trauma)
  • Coude (directional) tip - angled tip for selective suctioning of the left or right main stem bronchus

4. Closed-System (In-Line) Suction Catheter

• Catheter enclosed in a sterile plastic sheath, permanently attached to the ventilator circuit
• Allows tracheal suctioning without disconnecting the ventilator - continuous oxygen delivery and positive pressure ventilation are maintained
• Used for ventilator-dependent patients (ICU, intubated patients)
• Reduces infection risk (avoids exposure to environment)

5. Bulb Syringe

• Simple hand-operated suction device
• Used in neonates and infants for clearing nose and oropharynx (e.g., at delivery, after amniotic fluid)

Catheter Sizing

Catheter size (French) = 2 × (ETT size - 2)

Indications

• Oropharyngeal: Blood, vomitus, secretions during emergency airway management
• Nasopharyngeal: Secretions in infants, unconscious patients who cannot expectorate
• Endotracheal / Tracheostomy: Retained secretions in intubated or tracheostomised patients; signs include:
  • Audible secretions / rattling breath sounds
  • Sawtooth pattern on ventilator waveform
  • Increased airway resistance / peak pressures
  • Visible secretions in the airway tube
• Selective bronchial: Coude-tip catheter to suction a specific lung zone

Procedure & Technique (Tracheal/Tracheostomy Suctioning)

1. Monitoring: Attach continuous pulse oximetry, cardiac monitor, and capnography if available
2. Position: Awake patients - sitting upright, head neutral. Ventilated patients - head of bed elevated 30°
3. Preoxygenate: At least 30-60 seconds of 100% FiO₂ (ventilated) or 10-15 L high-flow O₂ (non-ventilated). Routine instillation of normal saline is no longer recommended - no proven benefit
4. Aseptic technique: Sterile gloves, sterile catheter throughout
5. Insert catheter through the inner cannula without applying suction
6. Advance to desired depth. If carina is reached, a vigorous cough reflex is triggered - withdraw 1-2 cm
7. Apply suction while slowly withdrawing the catheter with a gentle rotating motion
8. Duration: Maximum 10-15 seconds per pass; no more than 3 passes in succession
9. Monitor throughout for desaturation, dysrhythmia, or rise in end-tidal CO₂ - stop immediately if these occur
10. Re-oxygenate between passes

Complications

Hypoxaemia

• Most common complication - from interruption of ventilation + aspiration of airway gases + atelectasis
• Can trigger increased ICP, dysrhythmias, or death
• Prevented by preoxygenation and limiting duration to ≤15 seconds
• Use in-line (closed) catheters in ventilated patients to avoid desaturation

Dysrhythmias

• Caused by hypoxia, vagal stimulation (bradycardia, hypotension), catecholamine release
• Bradycardia in hypoxia → risk of ventricular fibrillation
• Pre-treat at-risk patients (especially infants) with nebulised or IV atropine
• Stop suctioning immediately if dysrhythmia develops

Raised Intracranial Pressure (ICP)

• ET suctioning triggers cough → raised intrathoracic pressure → reduced cerebral perfusion pressure
• Prevention: adequate sedation, preoxygenation, hyperventilation (increase RR to ~30/min for 1 min pre-suction), intratracheal lidocaine to blunt the cough reflex

Mucosal Injury

• Invagination of mucosa into catheter side ports
• Risk reduced by multi-port tip catheters, avoiding excessive suction pressure, and rotating the catheter on withdrawal

Atelectasis

• Caused by negative pressure evacuating airway gases
• Resolved by limiting catheter size (<50% ETT lumen) and limiting vacuum pressure

Others

• Bleeding (epistaxis with nasal suction, tracheal bleeding)
• Infection / tracheitis (use strict aseptic technique)
• Bronchospasm

Key Safety Rules (AARC Guidelines)

• Roberts and Hedges' Clinical Procedures in Emergency Medicine, Chapters 3 & 7 - Suctioning technique, equipment, complications
• Tintinalli's Emergency Medicine - Emergency airway suctioning
• Scott-Brown's Otorhinolaryngology - Tracheostomy suctioning
• AARC Clinical Practice Guidelines - Artificial Airway Suctioning
• StatPearls - Surgical Airway Suctioning

K-90 Tube (Urethral Catheter)

What is a K-90 Tube?

Key Features

Sizes (French Gauge)

French (Fr) to mm conversion: Diameter (mm) = Fr ÷ 3. So 12 Fr = 4 mm, 14 Fr = 4.7 mm, 16 Fr = 5.3 mm.

Indications / Uses

1. Acute Urinary Retention (AUR)

2. Intermittent Self-Catheterisation (ISC)

3. Sterile Urine Specimen Collection

4. Post-Void Residual (PVR) Measurement

5. Clot Evacuation / Haematuria

6. Peri-operative Bladder Drainage

K-90 vs Foley Catheter - Key Differences

Insertion Technique (Same as Urethral Catheterisation)

1. Position: Supine (frog-legged for female); supine with penis held straight and taut for male
2. Preparation: Sterile field, sterile gloves, antiseptic cleansing of meatus
3. Lubrication: 10-15 mL sterile lidocaine/lubricant jelly injected into the meatus (male); lubricant jelly on catheter tip (female)
4. Insert gently with slow steady pressure; slight resistance at the external sphincter is normal - maintain steady pressure until it yields (asking patient to take a deep breath helps)
5. Drain urine completely
6. Remove immediately - the catheter is not left in place
7. Important: Never force the catheter; blood at the meatus, a perineal haematoma, or a high-riding prostate suggest urethral injury - do not attempt catheterisation

Contraindications

• Suspected urethral disruption (pelvic trauma, blood at meatus, perineal haematoma)
• Recent urethral/bladder neck reconstructive surgery
• Known urethral stricture (relative - may need dilatation with filiform bougies first)
• Acute prostatitis / urethritis (relative)

Complications

• Urethral trauma / false passage (from forceful insertion)
• Urinary tract infection (risk is low with intermittent technique but increases with repeated use)
• Haematuria
• Urethral stricture formation (with repeated traumatic catheterisation)
• Paraphimosis in uncircumcised males (if foreskin not reduced after insertion)

Popular Indian Brands

• Pfenninger and Fowler's Procedures for Primary Care, 3rd Ed. - Robinson catheter, equipment
• Campbell-Walsh-Wein Urology - Types of urethral catheters, sizing, technique
• Meddeygo - K90 Catheter Overview

Ryle's Tube vs Fine-Bore Feeding Tube

Side-by-Side Comparison

The Core Clinical Rule

"Use a Ryle's tube when you also need to drain or decompress the stomach. Use a fine-bore feeding tube when feeding is the only goal and comfort/duration matters."

• Bailey and Love's Surgery, 28th Ed.

When to Use Which

Use a Ryle's Tube (Wide-Bore NG) when:

• Gastric decompression is needed (intestinal obstruction, ileus, post-op)
• Short-term feeding (< 2 weeks)
• You need to both feed and aspirate gastric residuals
• Gastric function tests / acid secretion studies
• Gastric lavage
• Emergency use (easier to insert without a stylet)

Use a Fine-Bore Feeding Tube when:

• Feeding is the only purpose (no drainage needed)
• Longer-term enteral nutrition (2-6 weeks)
• Patient needs to remain comfortable and continue eating/drinking orally
• Patients with sensitive airways (less rhinitis, pharyngitis, oesophageal erosion risk)
• Patients who are awake and ambulant

Use Neither (switch to PEG/gastrostomy) when:

• Feeding will be needed for > 4-6 weeks

Insertion Differences

Material Matters

Summary in One Line

A Ryle's tube is wide, stiff, PVC, dual-purpose (feed + drain), short-term (≤2 weeks). A fine-bore feeding tube is narrow, soft, polyurethane/silicone, feeding-only, longer-term (up to 6 weeks). Both are nasogastric tubes - the difference is calibre, material, purpose, and duration.