Chapter 4: Basic Practical Medical Procedures

Basic venepuncture

Purpose

Collection of blood, including large volume collection for transfusion. The ideal site is the basilic vein or median cubital vein, otherwise the dorsum of the hand or others according to availability (Fig. 4.1). Use local anaesthetic for large volume blood collection.

Method

1. Explain the method to the patient. Ensure the patient is warm and comfortable.

2. Dilate the vein by means of a tourniquet applied to occlude venous return.

3. Place a padded block under the arm to keep it straight.

4. After using a sterile swab to prepare the site, place the needle with attached syringe on the skin. Using downwards oblique pressure, puncture the vein firmly, ensuring the needle lies well within the vein. Remove the tourniquet.

Venepuncture in children

The same process for adults applies to adolescents and older children, but in infants and small children a 23-gauge butterfly needle provides more stability. A palpable vein is more likely to be successful than a visible but non-palpable vein. An assistant is necessary to support the limb and provide a tourniquet in small children.

For analgesia consider topical anaesthesia (amethocaine or EMLA^®), sucrose in infants < 3 months or consider sedation with midazolam (oral, intranasal or buccal) or nitrous oxide in children > 2 years.

Tips to aid dilation of veins

There are several ways in which peripheral veins can be dilated to facilitate venepuncture. The following are some of the methods used.

Vasodilation methods

• Apply a warm flannel for 60 seconds, or

• Rub glyceryl trinitrate ointment over the vein, or

• Give the patient half a glyceryl trinitrate tablet (if no contraindications).¹

Sphygmomanometer methods²

• Dilate the vein by means of the sphygmomanometer to keep BP at about 80–90 mmHg (veins will stand out).

        or

• Using the sphygmomanometer, inflate it to a pressure around 30 mmHg above systolic arterial pressure for 1 to 2 minutes while the patient opens and closes their hand. Thereafter it is deflated to around 80 mmHg and the resulting reactive hyperaemia is effective in filling even the shyest of veins. According to Wishaw this is the method par excellence.

Venesection tourniquet method³

Apply the tourniquet tightly and then release. After a reactive hyperaemia occurs reapply it and the veins should stand out well.

Intravenous cannulation

Use sterile gloves for this procedure.

Best site

• Choose a suitable prominent vein in the non-dominant forearm (not over a joint), e.g. dorsum of hand, cephalic vein just above wrist (dorsolateral position).

• Use elbow veins as last resort.

• Choose a relatively fixed vein, e.g. where it penetrates the fascia.

• Choose a vein running parallel to the long axis of the arm.

Method

1. Apply a small bleb, e.g. 0.2–0.5 mL of local anaesthetic, over or adjacent to the vein (keep very superficial) and wait 5 minutes, or apply EMLA^® cream at least 60 to 90 minutes beforehand (note that all cannulae hurt).

2. Insert the needle and catheter unit (6-gauge is suitable) through the skin beyond the shoulder of the plastic part.

3. Pierce the vein and ensure that the unit lies flat as it is guided along the vein lumen for a short distance, at an angle of 10–15°.

4. When blood enters the chamber, put a finger over the vein to stop backflow. Remove the tourniquet and guide the plastic catheter into the vein.

5. Fix the cannulae in position, e.g. use transparent ‘Tegaderm™’.

Cannulation in children

The preferred site is the dorsum of the non-dominant hand and consider the need for subsequent splinting. The same rules of local anaesthesia apply with an injection of LA considered for older children (see Intravenous cannula insertion).

Note the advisory grasp if using the dorsum of the hand for infants (Fig. 4.2). Grasp the wrist between the index and middle finger, with the thumb over the child’s fingers, flexing the wrist.⁴

Indications

• Intestinal obstruction—to drain stomach.

• Diagnostic—aspiration of stomach contents.

• Administer enteral nutrition.

Equipment

• Radio-opaque nasogastric tube e.g. 16 FG for aspiration, fine bore for feeding (more comfortable).

• Assess correct length of tube—measure from the end of the nose to the earlobe and then 5 cm below the end of the xiphisternum.

• Lidocaine spray and lubricating jelly (consider lidocaine).

• 50–60 mL syringe for aspiration.

Method

1. Explain the procedure to the patient including anticipated times of discomfort.

2. Sit the patient upright. Inspect the nose for any deformity and the best possible passage.

3. Use a local anaesthetic spray to anaesthetise the nasal passage. Consider also lubrication with lidocaine jelly. Wait 5 minutes.

4. Lubricate the tube and pass it backwards along the floor of the nasal passage (Fig. 4.3). Resistance will be felt when the tube passes from the nasopharynx to the oropharynx. Warn the patient that a retching sensation may be experienced.

5. The patient is now asked to swallow (with the assistance of a ‘feeder’ of water if not contraindicated) as the tube continues to advance with each swallow.

6. The tube should pass down the oesophagus without resistance (never force it down. If retching, take it slowly and only advance with each act of swallowing).

7. Ideally 10–15 cm of tube should be placed in the stomach. Confirmation of its presence in the stomach is confirmed by free aspiration of gastric contents and testing for acidity with litmus paper.

8. Once in place, the tube is fixed to the nose with adhesive tape.

See Fig. 4.4.

Indications

• Decompression of stomach, e.g. intestinal obstruction

• Administration of medication, e.g. charcoal

• Oral rehydration/enteral nutrition

Method

• Same principles as for adults, including topical anaesthetic spray.

• Tube size: 8 FG neonates, 10–12 FG 1–2 years, 14–16 FG adolescents.

• Correct length: Place distal end of tube at end of nose, run it to the ear and 3.5 cm beyond the xiphisternum.

• If the child coughs and gasps, or gets a hoarse voice or the tube appears in the mouth, pull the tube back into the nasopharynx and retry.

‘To start catheterising before the anaesthetic works is barbarous’—C.G. Fowler, British Medical Journal.

The adult male urethra is 18–20 cm long.

Preliminary questions

1. What is the aim of this procedure and can it be achieved without urethral catheterisation?

2. How long must the catheter remain in situ?

3. Can I avoid introducing urinary infection?

4. Do I have the skill to perform the procedure safely?

Equipment

You will need:

• prepackaged set including swabs

• aqueous (not alcoholic) skin antiseptic

• one or two pairs of forceps

• sterile kidney dish to collect urine

• suitable catheter—usually medium size

• sterile lubricant, e.g. lidocaine jelly in syringe

• sterile syringe

• suitable catheter drainage bag

• catheter dressing

• sterile gown and mask.

Technique essentials

1. Explain the procedure to the patient, who is best placed in the heel-to-heel position.

2. Sterile preparation/clean suprapubic area and glans penis. A sterile drape is placed over the scrotum and thighs and the penis is lowered onto this.

3. A small amount of lidocaine jelly (2%) is put aside onto a sterile bowl to lubricate the tip of the catheter. Fit nozzle to the syringe of lidocaine jelly and insert gently into the penile meatus (warn the patient that this brief introduction is very uncomfortable)—instil the 10–20 mL jelly slowly: massage the gel carefully down the urethra to the sphincter; compress the glans and leave for a minimum of 5 minutes.

4. Grasp the catheter a few centimetres from its tip with forceps (the funnel end rests in the kidney dish). Apply lidocaine jelly to the tip of the catheter.

5. Hold the penis upwards and straight with one hand and gently insert and slowly advance the catheter. Ask the patient to slowly take deep breaths in and out. Do not rush or use force (Fig. 4.5).

6. When the catheter reaches the penoscrotal junction (it now rests against the external sphincter), pull the penis downwards between the patient’s thighs.

7. Continue insertion through the sphincter or prostatic urethra until the entire length is inserted, even if urine emerges before then.

8. Non-retaining catheter: Ensure urine is flowing, then withdraw a few centimetres. Eventually press on the abdomen to ensure the bladder is empty.

   Retaining catheter: Inflate balloon (usually 5 mL of water) and gently withdraw until the balloon impinges on the bladder neck.

   Note: Ensure the catheter is in the bladder with urine coming out (get the patient to cough to confirm this) before inflating the balloon.

9. Replace the retracted prepuce over the glans (to prevent paraphimosis).

Anatomical considerations

The female urethra is comparatively short and straight—being 3–4 cm long and 6 mm in diameter. The urethral orifice lies approximately halfway between the clitoris and the vaginal opening and may be partly obscured by a fringe of soft tissue (Fig. 4.6).

Explanation

Despite the size of the urethra the procedure is most uncomfortable and local anaesthesia is important. Explain the procedure to the patient with appropriate reassurance. Indicate that the introduction of the nozzle and anaesthetic jelly is uncomfortable and advise about slow deep breathing during introduction of the jelly and subsequently the catheter.

Technique

1. Lie the patient down with the thighs apart and the knees comfortably flexed.

2. The pubic region, groin, vulva and perineum are initially cleaned with antiseptic solution (after washing your hands).

3. The labia minora are separated with the thumb and forefinger of the non-dominant hand to expose the vaginal orifice and the urethral opening. Two swabs are used with each sweeping from anterior to posterior across this area and then discarded.

4. A sterile split sheet is applied to expose the vagina and urethral opening and the hands rewashed and sterile gloves donned. The urethral orifice is again exposed and lightly swabbed.

5. A small amount of lidocaine jelly is put aside for lubrication of the tip of the catheter and then the nozzle, which is attached to the tube of the jelly, is introduced into the urethra and approximately 10 mL slowly introduced. The labia should be kept apart with the V-shaped arrangement of the fingers. Wait at least 5 minutes for local anaesthesia to develop.

6. Expose the tip of the catheter (e.g. 16 FG) from its envelope, dip it in the gel in the sterile bowl and, using a ‘no touch’ technique, insert the catheter into the urethral opening and guide it in smoothly. It should pass directly without difficulty.

7. Inflate the balloon and connect the catheter to a sterile closed drainage system (if required).

The female child should lie with legs apart in the frog leg position. Catheter size guidelines:

• 5 FG for diagnostic purposes

• for indwelling 0–6 months: 6 FG

• 2 years: 8 FG

• 5 years: 10 FG

• 6–12 years: 12 FG.

Main indications

• Diagnostic purposes, e.g. meningitis, MS, Guillain–Barre syndrome, SAH, CNS syphilis.

• Introducing contrast media.

• Introducing chemotherapeutic agents.

In children:

• Febrile, sick infant with no focus of infection.

• Fever with meningism.

• Prolonged seizure with fever.

Contraindications

• Absolute: Local skin infection, bleeding diathesis.

• Relative: Raised intracranial pressure.

Depressed conscious state, focal neurological signs.

Essentials of lumbar puncture 1: Preparation

1. Explain the procedure to the patient.

2. The patient should be in the lateral recumbent position, with the back maximally flexed and vertical to the table (Fig. 4.7). The shoulders and hips must be perpendicular to the bed.

3. The patient should be well immobilised. Avoid slumping.

4. Open the spinal pack, if required, and have 3 plain sterile tubes and 1 fluoride tube (for glucose) ready.

5. Adopt the sterile procedure (wash hands, mask, gloves, antiseptic prep).

6. Apply 1% lidocaine to skin and subcutaneous tissue (not necessary in infants). Inject 0.5–1 mL and wait 2 minutes.

Surface anatomy

Imaginary line between tops of iliac crests lies at spinous process of L₄ or between L₃ and L₄. Insert the needle at L₄–L₅ interspace (preferably) or L₃–L₄ (the conus medullaris of the spinal cord ends at L₁–L₂ but finishes near L₃ at birth).

Essentials of lumbar puncture 2: Procedure

1. Use a 21- to 22-gauge LP needle (9 cm) for an average adult; 22–23 gauge × 4 cm for infants, × 5 cm for 4 to 10 years, × 6 cm for older children.

2. Insert the needle at right angles to the skin.

3. Slowly advance slightly cephalad (about 10°: aim for the umbilicus), otherwise perfectly parallel.

4. Keeping the bevel of the needle facing up, advance 1 mm at a time. You will feel a ‘give’ when the dura is pierced (about 4–7 cm in adults, 2–3 cm in children).

5. Withdraw the stylus, and wait 30 seconds for CSF flow. Rotating the needle through 90–180° may allow CSF to flow. Measure CSF opening pressure with manometer.

6. If CSF is bloodstained, get three samples.

7. Remove the needle with one quick motion.

Recordings

• CSF pressure with manometer (N < 180 mm).

• CSF biochemistry, microbiology, immunology (oligoclonal bands).

Note: Don’t aspirate CSF.

Post-care

Lie flat for at least 1 hour.

Careful observation and bed rest (8 to 12 hours).

The same principles apply: use the L₃–L₄ or L₄–L₅ space for insertion (provide analgesia as for venepuncture). Give local anaesthesia to dural level with 1% lidocaine. Have an assistant restrain the child, who should have the spine maximally flexed, in the lateral position on the edge of a flat surface.

Abdominal paracentesis is often required as a therapeutic procedure to drain ascitic fluid in patients with terminal malignancy. The method is very simple. Select a site where there is shifting dullness and under which there are no solid organs (including an enlarged spleen). The ideal site is in the left iliac fossa midway between the umbilicus and the anterior superior iliac spine (the LHS equivalent of McBurney’s point) and lateral to the line of the inferior epigastric artery (Fig. 4.8).

Tip: a PleurX^® drainage system which consists of an indwelling catheter and vacuum collection system is a recommended system for safe portable drainage which can be used in the home. It has been specifically designed for thoracocentesis.

Method

1. After the bladder is emptied, ask the patient to lie supine.

2. Put on a mask and sterile gloves.

3. Swab the skin with antiseptic.

4. Infiltrate 5 mL of 1% or 2% Xylocaine^® into the anterior abdominal wall down to the parietal peritoneum at the chosen site.

5. Insert a 19-gauge intravenous cannula on a 20 mL syringe. Aspirate gently.

6. When ascitic fluid is obtained, remove the stilette and syringe and connect the plastic indwelling catheter via intravenous tubing to a sterile drainage bag, so that drainage occurs by gravity into a sterile closed drainage system.

7. The rate of flow can be regulated by the control on the IV tubing. It is recommended that the maximum fluid drainage is 2000 mL at any one time.

The main indications for this are:

• pneumothorax, e.g. large spontaneous, ventilated, tension (Chapter 17)

• malignant pleural effusion

• traumatic haemopneumothorax

• postoperative e.g. thoracotomy.

Location for chest aspiration

The majority of chest aspirations are performed in the ‘triangle of safety’ (Fig. 4.9), which is a triangle situated in the anterior half of axilla above the level of the 5th intercostal spaces. It contains no important or dangerous structures in the chest wall. The boundaries are:

• anteriorly: the anterior axillary line

• posteriorly: the mid-axillary line

• inferiorly: a horizontal line drawn posteriorly from the level of the nipple in a man or the 4th intercostal space in a woman.

Methods

The method of aspiration of a pneumothorax via the ‘triangle of safety’ is outlined in Chapter 17 under ‘Pneumothorax’, and for a pleural effusion, which is performed where it is located in the pleural cavity, follows.

Use a recent chest X-ray to aid the clinical examination in order to select the best site for aspiration. A common site for a malignant effusion is on the posterior chest wall medial to the angle of the scapula, in the intercostal space below the upper limit of dullness to percussion. Avoid going too low. Beware of pneumothorax either from puncture of the visceral pleura or from air entry via the chest wall or apparatus.

Method

1. Explain the procedure to the patient, who sits on a chair facing the bed and leaning slightly forwards with the arms folded in front resting on a pillow on the bed.

2. Using a sterile procedure with gloves and gown, swab the skin with antiseptic.

3. Infiltrate the overlying skin with 1% lidocaine with adrenaline (25-gauge needle) and change to a 21-gauge needle and two-way or three-way with Leur stop cock or other connectors. Slowly infiltrate the chest wall down to pleura. Fluid appears in the syringe on aspiration (apply steady suction as you advance carefully) after the pleura is penetrated (Fig. 4.10).

4. Aspirate the fluid and by turning the tap, direct the fluid into the collecting container. To aspirate large volumes of fluid insert an intravenous catheter and connect to a three-way tap. This is repeated until all the fluid is tapped. It is normally recommended that no more than 1 to 1.5 litres of fluid be removed at any one time.

   Caution: Ensure that air does not enter the pleural space at any stage. Reposition or withdraw the cannula or needle if pain on aspiration or coughing.

5. Upon withdrawing the catheter, immediately apply a sterile collodion dressing. Order a follow-up chest X-ray.

A simpler technique

This technique is useful for tapping recurrent malignant effusions and can be performed at home. Insert a size 18 intravenous cannula. Withdraw the stilette and connect the plastic cannula to an intravenous tubing set with the end draining into a drainage bag by gravity.

PleurX^® drainage system

This is ideal to drain malignant effusions when the catheter can be retained for ongoing drainage.

Subcutaneous fluids are useful when:

• relatively small amounts of crystalloid are needed (15 mL/kg per 12 hours)

• intravenous access is not required for systemic therapy.

This method of administering fluid has been used for more than 30 years. It can be sited and supervised by the nursing staff.

Complications are rare and usually relate to local oedema, which settles spontaneously once the infusion has been ceased.

Practical aspects

• Access to the subcutaneous space is via a 21-gauge butterfly needle, which is replaced daily.

• One ampoule of hyaluronidase (Hyalase^®) is given prior to infusion and before subsequent bags of crystalloid. (This is necessary when skin elasticity is high, as in children.)

• Crystalloid solution (normal saline or 4% dextrose and 1/5 normal saline) with infusion set is then connected to the butterfly needle.

• The infusion is usually run at a maximum of 15 mL per kg over 4 to 12 hours per 24 hours. (This enables the patient to move about.)

• Most regions are suitable. The more convenient are the abdomen, the anterior thigh and the shoulder.

• The drip rate can be reduced if any discomfort is produced.

When the oral and/or rectal routes are not possible or are ineffective, a subcutaneous infusion of morphine (for terminal pain) with a syringe pump can be used.

It is also useful for symptom control when there is a need for a combination of drugs, e.g. for pain, nausea and agitation. It may avoid bolus peak effects (sedation, nausea or vomiting) or trough effects (breakthrough pain) with intermittent parenteral morphine injections.

Practical aspects

• Access to the deep subcutaneous space is via a 21-gauge butterfly needle, which is replaced regularly (1, 2, 3 or 4 days).

• Most regions are suitable. The more convenient are the abdomen, the anterior thigh and the anterior upper arm. (Usually the anterior abdominal wall is used.)

• The infusion can be managed at home.

• About one-half to two-thirds of the 24-hour oral morphine requirement is placed in the syringe.

• The syringe is placed into the pump driver, which is set for 24-hour delivery.

• Areas of oedema are not suitable.

Substance: Ferric carboxymaltose (Ferinject^®) available as 100 mg/2 mL, 500 mg/10 mL ampoules

Criteria: Symptomatic iron deficiency: anaemia (Hb <100 and ferritin <20 µg/L)

Failed trial oral iron for iron deficiency anaemia and persistent anaemia

Anaemia of chronic disease e.g. chronic kidney failure

Precautions: Obtain specialist advice and recommendation

History of allergic disorders

Others—see Product information (PI)

Contraindications: Hypophosphataemia

First trimester of pregnancy

Hypersensitivity to the substance or any of its excipients

Other—see PI

Basic equipment requirements:

Tourniquet

0.9% (N) saline 100 mL bags

20 mL ampoule saline flush

Butterfly cannulas 21 and 23g

Accessories

NB: functional accessible resuscitation equipment, drugs (adrenaline and hydrocortisone) and oxygen

Dosing regimen (simplified):

maximum single dose of Ferinject^®: patients with body weight < 35 kg–500 mg

body weight ≥ 35 kg–1000 kg

Max. single dose should not exceed 1000 mg (20 mL)/day nor once a week

NB: if adverse effects develop cease infusion immediately and monitor vital signs

Recommended administration volume time and rate