When doing any anaesthetic, it is important to always be well prepared. Good preparation, good clinical practice and adherence to national guidelines will decrease the incidence and severity of common and predictable anaesthetic complications. Difficulty can arise in low-resource settings where a reliable supply of electricity, pulse oximeters and oxygen is often lacking. However, as a basic standard of care in an ED setting, standard monitoring and functional resuscitation equipment and drugs are required. The skills and equipment to convert to a GA if required should always be in place.⁷ Not all generalists are comfortable with converting to GA. Adequately trained providers are, however, essential, an ongoing challenge where there is a high turnover of staff and a lack of training and support. Valid informed consent must always be obtained from the patient, advising them on the most appropriate technique that will depend on patient characteristics and experience of the clinician. Risks and benefits of the proposed technique and alternatives should be discussed. In the theatre setting, patients must be aware that a GA may still be required if RA is used as an adjunct or if an incomplete block occurs. The patient should be provided with enough information, covering risks and benefits, complications, expected duration of action of the block, how to care for the insensate limb (particularly minor blocks seen in the ED that are discharged), red flags, the socioeconomic setting and when to return to the clinic or district hospital.⁷ As a general rule, there are no clear-cut indications for one type of anaesthesia over another when either would be appropriate. Absolute contraindications should be excluded, such as known allergy to drugs or patient refusal. Bleeding diathesis is a relative contraindication, especially if the block is performed in an area where compression is possible. Active infection at the site of injection, pre-existing neurological deficit and poor patient cooperation are further relative contraindications. Anti-coagulation therapy is not a contraindication if stopped within the minimum recommended time before the block is performed.⁷ Thorough documentation should be done. Resuscitation equipment must be immediately available, and intravenous (IV) access established before the procedure. The practitioner must ensure the block is fully established, vital signs and physiological parameters are within normal limits and the patient is stable.¹ Ensure an emergency trolley is immediately available for the management of complications and that the practitioner is skilled to rapidly recognise and treat these. Ensure appropriate measures are taken to minimise the risk of inadvertent nerve damage during the procedure. Always check and label drugs to be used to prevent error. In an ideal setting, a multidisciplinary team including nurses, doctors and clinical associates should work together to perform RA blocks. The team should be trained to prepare equipment and drugs, provide monitoring and have basic knowledge in evaluating the levels of pain and effects of RA.¹ In the chaos of busy district casualties, there needs to be guidance as to which patients are good candidates for RA and which patients are not.

Local anaesthetic drugs with or without adjuvants are used for RA. They are chosen according to their onset and duration of action, the degree of motor blockade and toxicity profiles. Lignocaine has a quick onset and short duration of action, and bupivacaine is longer acting.¹ Local anaesthetic drugs produce transient loss of sensory, motor and autonomic function when injected or applied in proximity to neuronal tissue. Although LA is relatively free from side effects, accidental IV injection or excessive dose can lead to toxicity. The central nervous system tends to be affected first (perioral numbness and tinnitus followed by seizures and coma), followed by the cardiovascular system (severe bradycardia and dysrhythmias).² Lipid emulsion (Intralipid) is used for bupivacaine toxicity, but is expensive, has a short half-life and is not readily available. Prolonged resuscitation may be required following bupivacaine toxicity. Cardiopulmonary resuscitation (CPR) should be continued for at least 60 min, as good neurological recovery can occur following LA systemic toxicity. The maximum dose of LA must not be exceeded.¹

A standard 2 mL dental cartridge (see Table 2)^7,8 of lignocaine in South Africa contains 36 mg of lignocaine.

Equipment will depend on the technique used. The correct needle monitors as per the American Society of Anaesthesiologists’ standards for basic anaesthetic monitoring (pulse oximetry, electrocardiogram [ECG], blood pressure [BP]), IV access for rescue medications and possible sedation and supplemental oxygen should be available. An emergency trolley including emergency drugs (e.g., adrenaline, atropine and lignocaine), anaesthetic drugs (e.g., suxamethonium, propofol and ketamine), along with airway and intubation equipment, should be readily available to treat RA-related complications. An aseptic technique must be used for all blocks (sterile gloves, masks and surgical drapes).¹

When performing a peripheral nerve block, the goal is to inject LA close to the nerve. Several methods have been used to identify the proximity of the needle to a nerve:

In many public facilities at the district level in South Africa, nerve stimulators and ultrasound are not available, and there is a lack of training in the use of these techniques, and therefore, it will not be discussed in detail for the purpose of this article.

The role of ultrasound-guided RA is direct visualisation of the needle in relation to the nerve and other structures. Portable ultrasound machines are available, with high- and low-frequency probes, to identify both superficial and deep structures.¹

Anatomical landmarks, combined with ultrasound guidance, can be used simultaneously to improve the success rate of the block, decrease the onset of action of the block, reduce the volume of LA required and reduce the risk of vascular puncture.

Each technique may be associated with specific complications. The main complications of RA are block failure, nerve injury and LA toxicity. Local anaesthetic toxicity and allergic reactions to LA drugs occur very rarely.¹

When injecting LA, do not inject more than the maximum dose and be aware of the volume. Never inject under high pressure as the pressure effects could cause nerve damage. If there is pain or increased resistance, stop and reposition the needle. Always aspirate before injecting to avoid inadvertent injection into a vessel. If there is severe pain, stop and aspirate and the pain should stop immediately. You could be injecting directly into a nerve instead of around it. Allow 5 min – 10 min for maximal effect. Check on the sensory and motor effects depending on the block used. Warn the patient that they may feel numb for a few hours depending on the LA used.

Common blocks that can be used in the emergency departments and for minor procedures in district hospitals and clinics (see Table 3 for common limb blocks):

Used for circumcision or reduction of a paraphimosis.

A dorsal penile nerve block is typically achieved through a ring block at the base of the penis or a dorsal penile nerve block at the level of the pubic symphysis or a combination of both. It is an effective technique for RA using small volumes of LA.¹³

For a dorsal penile nerve block, LA is injected into the bilateral spaces deep into the fascia on either side of the suspensory ligament. Insert a 25 G needle about 1 cm at the root of the penis on the dorsal aspect (at 01:30 and 11:30 positions) to penetrate Buck’s fascia and inject 5 mL on each side. Aspirate to prevent intravascular injection. Additional subcutaneous infiltration around the root of the penis (ring block) augments this block, as it covers cutaneous branches of the ilioinguinal and genitofemoral nerves. Always calculate the volume of anaesthetic required for circumcision in a child, which is much less.¹³ Never ever use adrenaline for penile blocks (Figure 5).¹³