Local Anesthetics – Toxicity – Maximum Doses

Local Anesthetics

Local anesthetics are used to anaesthetize areas of the body to perform surgical procedures, painful examinations, or simply to provide pain relief. Local anesthetics are pharmacologically divided into two groups; amino esters and amino amides.

Esters generally have higher toxicity than amino amides, and most of the preparations have been deregistered. The exception is Ampres, which is used spinally for short procedures lasting up to one hour. Some available preparations are:

• Mepivacaine (Carbocaine® )
• Lidocaine (Xylocaine®)
• Prilocaine (Citanest®, Takipril® )
• Ropivacaine (Naropin®)
• Levobupivacaine (Chirocaine®)
• Bupivacaine (Marcaine®, Sensorcaine®)
• Chloroprocaine (Ampres®, Nesacaine®)

Nesacaine (chloroprocaine) is available in a few clinics as a licensed drug. The preparations are available as solutions in various concentrations, usually half-percent (5 mg/ml) or one-percent solutions (10 mg/ml) with or without adrenaline. They are also available as sprays, ointments, oral solutions, and gels. Adding adrenaline allows for higher maximum doses as the agents spread more slowly in the systemic circulation. Toxic reactions are usually due to an overdose or too rapid injection. Amino amides are metabolized in the liver and have a high degree of protein binding.

Dosing for Nerve Blocks

Epidural Anesthesia for Postoperative Analgesia

Maximum Doses of Local Anesthetics

A toxic reaction can occur unexpectedly and suddenly after an injection of local anesthetics, dramatically affecting the patient’s condition. In pronounced cases, the reaction can be life-threatening. The reaction is usually due to an overdose or too rapid injection. In modern English literature, toxic reactions triggered by local anesthetics are referred to as LAST (Local Anesthetic Systemic Toxicity). Dominant symptoms in a toxic reaction are CNS symptoms and cardiovascular symptoms, in pronounced cases cardiovascular collapse. Usually, the reaction is short-lived and quickly subsides, but in pronounced cases, the condition can rapidly become life-threatening, with particularly severe symptoms being generalized convulsions and bradycardia.

Before major blocks (regional anesthesia), an intravenous peripheral venous catheter (PVK) must always be present on the patient to be able to provide intravenous treatment. Access to anesthesia equipment and the ability to provide artificial respiration and life-saving interventions must also be available. The same applies when administering more than 20 ml of local anesthetic.

Toxic reactions should be distinguished from allergic reactions, vasovagal reactions with fainting, and side effects of adrenaline additives. Vasovagal reactions with a drop in pulse and blood pressure occur easily with painful injections – especially in young, nervous, irritated, or gangly individuals. True allergic reactions to local anesthetics are extremely rare and are often confused with other unpleasant reactions, such as fainting, but allergic reactions to additives (carriers) in local anesthetics do occur. A referral to an allergist should be written if a true allergic reaction is suspected, and a skin provocation should be performed under supervision. The concept of “Cave” should be applied cautiously regarding local anesthetics.

High concentrations of local anesthetics in the bloodstream can occur due to inadvertent intravascular injection, overdose, or unusually rapid absorption from richly vascularized tissues. Rapid absorption occurs with infiltration anesthesia, especially if the injection is made in the face around the oral cavity, in the nose, or in the throat. Central blocks (face, neck, scalp) carry a higher risk of toxic reactions than peripheral blocks.

With epidural blocks, a toxic reaction is more likely if the injection occurs in a vein (epidural veins). The epidural space is richly vascularized, and it happens that an epidural catheter accidentally migrates into or perforates a vein. If a local anesthetic is administered in an epidural vein, it circulates to the heart within a minute, which can cause a severe toxic reaction with sudden circulatory arrest. If blood is aspirated into an epidural catheter, the catheter should be repositioned. Injection of a bolus dose of local anesthetic epidurally should therefore always be preceded by an aspiration test for blood and the administration of a test dose, which can detect excessively rapid uptake into the systemic circulation. The addition of adrenaline in the test dose can facilitate the detection of an intravenous injection by the patient reacting with a rapid pulse (tachycardia).

Toxic reactions are due to high plasma concentrations, usually short-lived. The addition of adrenaline to local anesthetics causes local vasoconstriction, which slows absorption and reduces the risk of systemic toxic reactions with a correctly placed epidural. As a rule, therefore, slightly higher doses of local anesthetics with adrenaline are tolerated than without.

Toxic Reaction and Treatment

A toxic reaction can occur unexpectedly and suddenly after an injection of local anesthetics, dramatically affecting the patient’s condition. In pronounced cases, the reaction can be life-threatening. The reaction is usually due to an overdose or too rapid injection. In modern English literature, toxic reactions triggered by local anesthetics are referred to as LAST (Local Anesthetic Systemic Toxicity). Dominant symptoms in a toxic reaction are CNS symptoms and cardiovascular symptoms, in pronounced cases cardiovascular collapse. Usually, the reaction is short-lived and quickly subsides but in pronounced cases, the condition can rapidly become life-threatening, with particularly severe symptoms being generalized convulsions and bradycardia.

Before major blocks (regional anesthesia), an intravenous peripheral venous catheter (PVK) must always be present on the patient to be able to provide intravenous treatment. Access to anesthesia equipment and the ability to provide artificial respiration and life-saving interventions must also be available. The same applies when administering more than 20 ml of local anesthetic. The risk of a toxic reaction is particularly high if bolus doses are given on top of a continuous infusion that runs in an infusion pump. It is particularly sensitive with continuous infusion of Marcaine (bupivacaine), which has a relatively long half-life. Extra bolus doses to a patient on a continuous infusion of Bupivacaine must be given with the utmost caution and preferably with another drug with lower toxicity, such as Lidocaine or Carbocain. The toxicity of different local anesthetics given simultaneously is additive.

Symptoms of Toxic Reaction

• Slow, slurred speech (dysarthria)
• Feeling of intoxication
• Circumoral paresthesia
• Numbness of the tongue
• Hyperacusis, tinnitus
• Visual disturbances
• Muscle twitches
• Tremor
• Generalized convulsions
• Unconsciousness
• Bradycardia
• Asystole

Treatment of Toxic Reaction

• Immediately stop the administration of local anesthetics.
• Lay the patient down in a supine position with the head slightly elevated.
• Oxygen via breathing mask (always!).
• Careful monitoring of consciousness and breathing.
• Support breathing and circulation, avoid hypoxia and carbon dioxide retention.
• If necessary: controlled manual ventilation, mask ventilation, or intubation.
• If seizures do not spontaneously stop within 15-20 seconds, administer Thiopentone (Pentocur) 1-3 mg/kg IV (50-100 mg) or diazepam (Stesolid) 0.1 mg/kg IV (5-10 mg, works slightly slower). Alternatively, to Pentocur, administer propofol (Propofol/Propolipid) 10-60 mg slowly IV.
• Injection of muscle relaxants, such as Celokurin (suxamethonium) 1 mg/kg creates more favorable conditions for manual ventilation and oxygenation of the patient.
• In case of hypotension/bradycardia, administer a vasopressor, such as ephedrine 5-10 mg IV (may be repeated after 2-3 minutes) or adrenaline 0.05-0.1 mg IV (repeated doses 0.1 mg/ml).
• Atropine 0.5-1 mg IV is given for bradycardia. Give repeated doses.
• Sodium bicarbonate (50-100 ml, 60-120 mmol) in case of acidosis on a liberal indication.
• Hypertonic saline is given for widened QRS complexes (200 mmol Sodium given rapidly IV).
• Lipid therapy (ILE).

Treatment of Toxic Reaction

• Immediately discontinue the administration of the local anesthetic.
• Lay the patient down in a supine position with the head slightly elevated.
• Administer oxygen via face mask (always!).
• Careful monitoring of consciousness and respiration.
• Support breathing and circulation; avoid hypoxia and carbon dioxide retention.
• If necessary: provide controlled manual ventilation, mask ventilation, or intubation.
• If seizures do not stop spontaneously within 15–20 seconds, administer midazolam 1–5 mg IV (or diazepam [Stesolid] 0.1 mg/kg IV, 5–10 mg, which has a slightly slower onset). Alternatively, administer propofol (Propofol/Propolipid) 10–60 mg slowly IV or thiopental (Pentocur) 1–3 mg/kg IV (50–100 mg). Note: risk of hypotension.
• Injection of a muscle relaxant, such as suxamethonium (Celokurin) 1 mg/kg, creates more favorable conditions for manual ventilation and oxygenation of the patient.
• In the event of hypotension/bradycardia, administer a vasopressor, such as ephedrine 5–10 mg IV (can be repeated after 2–3 minutes) or adrenaline 0.05–0.1 mg IV (repeated doses of 0.1 mg/ml).
• Administer atropine 0.5–1 mg IV in cases of bradycardia. Repeat doses as needed.
• Sodium bicarbonate (50–100 ml, 60–120 mmol) in cases of acidosis, with a liberal indication.
• Hypertonic saline should be administered rapidly IV in the presence of widened QRS complexes (200 mmol sodium).
• Lipid treatment (ILE) is given in the event of cardiovascular collapse.

Lipid therapy

In the event of circulatory arrest, CPR should be performed immediately and lipid therapy should be attempted.

Administer a bolus of a 20% lipid emulsion Intralipid 1 ml/kg IV or 100-200 ml quickly intravenously. Start an infusion with the same lipid emulsion 0.25 ml/kg/min for 10 minutes, during which CPR is performed, or an additional 100 ml intravenously. Bolus doses may be repeated every 5 minutes, two or three times if needed, 1 ml/kg Intralipid. No more than 12 ml/kg lipid emulsion should be given.

Sampling: Arterial blood gas with acid-base status, frequent electrolyte checks (routine status), P-glucose. Further treatment is guided by the patient’s condition. Prolonged CPR may be needed in toxic reactions to Marcaine (bupivacaine) with high toxicity and a high apparent volume of distribution (Vd).

Maximum Doses of Local Anesthetics for Children

Maximum Doses of Local Anesthetics for Children by Body Weight

• Lidocaine: 5 mg/kg
• Lidocaine + adrenaline: 7 mg/kg
• Ropivacaine: 2-3 mg/kg
• Mepivacaine: 5 mg/kg
• Bupivacaine 2 mg/kg
• Levobupivacaine: 2 mg/kg

Applicable to children > 3 months based on ideal weight.

Lidocaine

Lidocaine (Xylocaine®) is a local anesthetic used for infiltration anesthesia, for peripheral and regional nerve blocks. Also used for surface anesthesia of skin and mucous membranes.

Brand names

• Lignospan Forte®
• Oraqix®
• Synera®
• Zingo®
• Xylocaine®
• Akten®
• ReadySharp®

Concentration

• Injection solution 10 mg/ml, 20 mg/ml, (30 mg/ml for dental use)
• Injection solution 10 mg/ml + adrenaline 5 μg/ml, 20 mg/ml + adrenaline 5 μg/ml
• Injection solution dental, 20 mg/ml + adrenaline 12.5 μg/ml
• Spray 10 mg/dose. Ointment 5%. Gel 2%. Oral solution 2%

Dosage

Lidocaine has low toxicity. Maximum dose 4 mg/kg without adrenaline, 7 mg/kg with adrenaline.

Single block 400 mg (maximum dose 4 mg/kg for weight 70 kg 280 mg, with adrenaline 7 mg/kg 490 mg).

Maximum daily dose 1200 mg. Half-life (t_1/2 h) 1.6 h. Lidocaine in spray form (10 mg/dose) give a maximum of 10 spray doses.

Infiltration Anesthesia

• Lidocaine 10 mg/ml, 5–40 ml (50–400 mg lidocaine).

Nerve Block

• Large blocks: Lidocaine 20 mg/ml, 10–17.5 ml (200–350 mg lidocaine)
• Small to medium blocks: Lidocaine 10 mg/ml, 10–20 ml (100–200 mg lidocaine)
• Fingers and toes: Lidocaine 10 mg/ml, 1–5 ml (10–50 mg lidocaine)

Intravenous Regional Anesthesia (IVRA – Bier’s Block)

• Arm: Lidocaine 5 mg/ml, 20–40 ml (100–200 mg lidocaine)
• Leg: Lidocaine 5 mg/ml, 40 ml (200 mg lidocaine)

Nerve Block on Fingers and Toes

• Lidocaine 10 mg/ml, 2–4 ml (20–40 mg lidocaine)

Sacral Surgical Analgesia

• Lidocaine 10 mg/ml, 40 ml (400 mg lidocaine)
• Sacral obstetric analgesia: Lidocaine 10 mg/ml, 20–30 ml (200–300 mg lidocaine)

Mepivacaine

Mepivacaine (Carbocaine®) is used for infiltration anesthesia, intravenous regional anesthesia (IVRA), peripheral and regional nerve blocks. Mepivacaine has low acute toxicity.

Brand names

• Carbocaine®
• Polocaine®
• Scandonest Plain®
• Isocaine®
• Polocaine-MPF®

Concentration

Injection solution 10 mg/ml, 20 mg/ml, (30 mg/ml for dental use). Injection solution 10 mg/ml + adrenaline 5 μg/ml, 20 mg/ml + adrenaline 5 μg/ml.

Dosage

Maximum dose 5 mg/kg, single block 400 mg = 40 ml 10 mg/ml (for 80 kg body weight).

Maximum daily dose 1000 mg.

Half-life (t_1/2 h 1.9 h). (Maximum dose 5 mg/kg and weight 70 kg gives a dose of 350 mg, 10 mg/ml = 35 ml, with adrenaline 7 mg/kg = 490 mg = 49 ml. If 20 mg/ml maximum volume –> 17.5 ml). For a patient weight of 70 kg, maximum 350 mg/4 hours.

Nerve Block on Fingers and Toes

• Mepivacaine 10 mg/ml, 2–5 ml (20–50 mg mepivacaine) or Mepivacaine
  
  20 mg/ml, up to 5 ml (100 mg mepivacaine)

Sacral Surgical Analgesia

• Mepivacaine 10 mg/ml, 15–20–30 ml (150–200–300 mg mepivacaine) or Mepivacaine 20 mg/ml, up to 17.5 ml (350 mg mepivacaine)

Infiltration Anesthesia

• Mepivacaine 10 mg/ml, 1–20 ml (10–200 mg mepivacaine)

Nerve Block

• Large blocks: Mepivacaine 20 mg/ml, 10–17.5 ml (200–350 mg mepivacaine)
• Small to medium blocks: Mepivacaine 10 mg/ml, 10–20 ml (100–200 mg mepivacaine)
• Fingers and toes: Mepivacaine 10 mg/ml, 1–5 ml (10–50 mg mepivacaine)

Epidural Anesthesia

• Mepivacaine 10 mg/ml, 10–20 ml (100–200 mg mepivacaine) or Mepivacaine 20 mg/ml, 10–17.5 ml (200–350 mg mepivacaine)

Levobupivacaine

Levobupivacain (Chirocaine®) is used for infiltration anesthesia, for peripheral and regional nerve blocks, for epidural anesthesia, and spinal anesthesia. Not used for nerve blocks in small children.

Brand names

• Chirocaine®

Concentration

Injection solution 2.5 mg/ml, 5 mg/ml, 7.5 mg/ml. Infusion solution 0.625 mg/ml, 1.25 mg/ml. The infusion solution is mainly used for continuous epidural infusion.

Dosage

Levobupivacain has intermediate toxicity.

Maximum dose 2 mg/kg without adrenaline, 3 mg/kg with adrenaline, maximum dose single block 150 mg (4 hours). Maximum daily dose 400 mg (24 hours).

Half-life (t_1/2 h) 1.3 h. Maximum amount for 70 kg body weight in volume: Strength 2.5 mg/ml –> 60 ml, strength 5 mg/ml –> 30 ml.

Infiltration Anesthesia

• Levobupivacain 2.5–5 mg/ml, 1–20 ml (2.5–100 mg Levobupivacain)

Epidural Anesthesia

• Levobupivacain 5.0–7.5 mg/ml, bolus for surgery (slow), adults 10–20 ml (50–150 mg)

Epidural for Cesarean Section

• Levobupivacain slow injection, 15–30 ml (75–150 mg), 5.0 mg/ml

Epidural Anesthesia for Labor

• Levobupivacain 2.5 mg/ml, bolus 6–10 ml (15–25 mg) plus continuous infusion 1.25 mg/ml, 4–10 ml/hour (5–12.5 mg/hour)

Epidural Anesthesia for Postoperative Pain Relief

• Levobupivacain 1.25 mg/ml 10–15 ml/hour (12.5–18.75 mg/hour)
• Levobupivacain 2.5 mg/ml 5–7.5 ml/hour (12.5–18.75 mg/hour)

Spinal Anesthesia for Surgery

• Levobupivacain 5 mg/ml. Procedures in the lower extremities including hip surgery. Dose: 3 ml, 15 mg

Opiates in Spinal Anesthesia

• Morphine 0.1–0.3 mg (0.4 mg/ml)
• Fentanyl 20–40 μg (50 micrograms/ml)
• Sufentanil 5–10–(15) μg (5 μg/ml)

Prilocaine

Prilocaine (Citanest®) is used for infiltration anesthesia, for peripheral and regional nerve blocks. Also used as an oral anesthetic by dentists and for topical anesthesia.

Brand names

• Agoneaze®
• Anodyne Lpt®
• Citanest®
• Citanest Forte®
• Takipril®
• Dermacinrx Prikaan®
• Emla®
• Fortacin®
• Lido Bdk®
• Lido-prilo Caine Pack®
• Lidopril®
• Oraqix®
• Prilolid®
• Prizotral®
• Relador®

Concentration

Injection solution 5 mg/ml. Injection solution dental, 30 mg/ml + octapressin 0.54 μg/ml.

Dosage

Low toxicity. Maximum dose 5 mg/kg, maximum dose single block 400 mg (80 ml). Maximum dose with adrenaline 8 mg/kg. Maximum daily dose 1200 mg. Half-life (t_1/2 h) 1.6 h.

Infiltration Anesthesia

• Citanest 5 mg/ml, 1-20 ml (5-100 mg prilocaine)

Intravenous Regional Anesthesia (IVRA – Bier’s Block)

• Arm: Citanest 5 mg/ml, 20-40 ml (100-200 mg prilocaine)
• Leg: Citanest 5 mg/ml, 60-80 ml (300-400 mg Prilocaine)

Opiates in Spinal Anesthesia

• Morphine 0.1-0.3 mg (0.4 mg/ml)
• Fentanyl 20-40 μg (50 micrograms/ml)
• Sufentanil 5-10-(15) μg (5 μg/ml)

Bupivacaine

Bupivacaine (Marcaine®) is used for infiltration anesthesia, for nerve blocks, for epidural anesthesia, and spinal anesthesia. Bupivacaine should not be used for IVRA (Bier’s block).

Brand name

• Marcaine HCl®
• Marcaine Spinal®
• Sensorcaine®
• Sensorcaine-MPF®

Concentration

Injection solution 2.5 mg/ml, 5 mg/ml. Injection solution 2.5 mg/ml + adrenaline 5 μg/ml, 5 mg/ml + adrenaline 5 μg/ml. Bupivacaine spinal 5 mg/ml. Bupivacaine spinal heavy 5 mg/ml.

Dosage

Marcaine (bupivacaine) has high toxicity.

Maximum dose 2 mg/kg, without adrenaline, 2-3 mg/kg with adrenaline.

Maximum dose single block 150 mg within 4 hours. Give 5 mg/ml at most 30 ml, 2.5 mg/ml at most 60 ml.

Maximum daily dose 400 mg. Half-life (t_1/2 h) 2.7 h (maximum 2.0 mg/kg at 70 kg gives 140 mg, 5 mg/ml = 28 ml, with adrenaline 3 mg/kg = 210 mg give at most 42 ml).

Maximum volume for 70 kg body weight: conc 2.5 mg/ml –> 60 ml, conc 5 mg/ml –> 30 ml.

Sacral Surgical Analgesia

• Sacral in small children: Bupivacaine 2.5 mg/ml with adrenaline, give 0.5 ml/kg.

Epidural Anesthesia

• Bupivacaine 2.5 mg/ml 20 ml (50 mg bupivacaine) then Bupivacaine 2.5 mg/ml 6-16 ml (15-40 mg bupivacaine) every 4-6 hours depending on the desired number of anesthetized segments and the patient’s age.
• Bupivacaine 5 mg/ml 15-30 ml (75-150 mg bupivacaine).

Epidural for Cesarean Section

• Bupivacaine 5 mg/ml, 15-30 ml (75-150 mg bupivacaine).

Epidural Anesthesia for Labor

• Bupivacaine 2.5 mg/ml, bolus 6-10 ml (15-25 mg) plus continuous infusion 2.5 mg/ml 2-5 ml/hour (5-12.5 mg/hour).
• Bupivacaine 1 mg/ml + Sufenta 1 μg/ml, bolus 12 ml plus continuous infusion 9 ml/hour.

Epidural Anesthesia for Postoperative Pain Relief

• Bupivacaine 2.5 mg/ml, bolus 5-10 ml, 12.5-25 mg
• Continuous infusion: Bupivacaine 2.5 mg/ml 5-7.5 ml/hour 12.5-18.75 mg.

Spinal Anesthesia for Surgery

• Bupivacaine Spinal 5 mg/ml. Procedures in the lower extremities including hip surgery. Dose: 2-4 ml, 10-20 mg. Onset time 5-8 min. Duration 1.5-4 hours.
• Bupivacaine Spinal Heavy 5 mg/ml. Procedures in the lower extremities including hip surgery. Dose: 2-4 ml, 10-20 mg. Onset time 5-8 min. Duration 1.5-4 hours.
• Urological surgery: Dose: 1.5-3 ml, 7.5-15 mg. Onset time 5-8 min. Duration 2-3 hours.
• Abdominal surgery: Dose: 2-4 ml, 10-20 mg. Onset time 5-8 min, Duration 45-60 min.
• Cesarean section: Dose: 1.5-3 ml, 7.5-15 mg. Onset time 5-8 min, Duration 45-60 min.

Spinal Anesthesia for Cesarean Section

• Bupivacaine Spinal Heavy 5 mg/ml. Dose: 1.5-2.5 ml, 7.5-12.5 mg. Onset time 5-8 min, Duration 45-60 min.

Combined Spinal for Cesarean Section

• Bupivacaine Spinal Heavy 5 mg/ml. Dose: 1.5-1.8 ml + Fentanyl 15-25 μg + Morphine 0.1 mg (0.4 mg/ml 0.25 ml).
• Bupivacaine Spinal Heavy 5 mg/ml. Dose: 1.5-1.8 ml + Fentanyl 15-25 μg.
• Bupivacaine Spinal Heavy 5 mg/ml. Dose: 1.5-1.8 ml + Morphine 0.1 mg (0.4 mg/ml 0.25 ml).

Opiates in Spinal Anesthesia

• Morphine 0.1-0.3 mg (0.4 mg/ml)
• Fentanyl 20-40 μg (50 micrograms/ml)
• Sufentanil 5-10-(15) μg (5 μg/ml)

Ropivacaine

Ropivacaine (Naropin®) is a local anesthetic used for infiltration anesthesia, for peripheral and regional nerve blocks, for epidural anesthesia, and spinal anesthesia. For caudal blocks (sacral) in children.

Brand names

• Naropin®
• Narop®

Concentration

Injection solution 2 mg/ml, 5 mg/ml, 7.5 mg/ml, 10 mg/ml. Not available with adrenaline.

Dosage

Naropin (ropivacaine) has intermediate toxicity.

Maximum dose 3 mg/kg, maximum dose for a single block 300 mg.

Maximum daily dose 800 mg (3 mg/kg). For weight 70 kg, give a maximum of 210 mg.

Example solution 2 mg/ml, give a maximum of 100 ml for weight 70 kg; if conc. 5 mg/ml, give a maximum of 40 ml; if conc. 7.5 mg/ml, give a maximum of 26 ml; if conc. 10 mg/ml, give a maximum of 20 ml.

Half-life (t _1/2 h) 1.8 h.

Small to Medium Peripheral Blocks

• Naropin 7.5 mg/ml, 1–30 ml, 7.5–225 mg. Onset 1–15 min, 2–6 hours.

Sacral Surgical Analgesia

• Sacral in small children: Naropin 2 mg/ml, 1 ml/kg.

Brachial Plexus Block

• Naropin 7.5 mg/ml. 10-40 ml, 75-300 mg. Onset 10-25 min, duration 6-10 hours.

Epidural Anesthesia

• Naropin 5–7.5 mg/ml
  
  15–20 ml (100–200 mg ropivacaine), then Narop 5 mg/ml 6–10 ml (30–50 mg ropivacaine) every 4–6 hours, or continuously depending on the desired number of anesthetized segments and the patient’s age.

Epidural Anesthesia for Postoperative Pain Relief

• Naropin 2 mg/ml, 6–14 ml/hour, 12–28 mg/hour.

Epidural for Cesarean Section

• Naropin 7.5 mg/ml, 15–20 ml (113–150 mg ropivacaine).

Epidural Anesthesia for Labor

• Naropin 2 mg/ml, bolus 10–15 ml (20–30 mg) plus continuous infusion 2 mg/ml 2–5 ml/hour (4–10 mg/hour).
• Naropin 1 mg/ml + Sufenta 1 μg/ml, bolus 12 ml plus continuous infusion 6–9 ml/hour.

Spinal Anesthesia for Surgery

• Naropin 5 mg/ml. Procedures in the lower extremities including hip surgery. Dose: 3–4 ml, 15–20 mg. Onset time 1–5 min. Duration 2–6 hours.
• Urological surgery: Dose: 1.5–3 ml, 7.5–15 mg. Onset time 1–5 min. Duration 2–6 hours.
• Abdominal surgery: Dose: 2–4 ml, 10–20 mg.

Spinal Anesthesia for Cesarean Section

• Cesarean section: Dose: 1.5–3 ml, 7.5–15 mg. Onset time 1–5 min. Duration 2–6 hours.

Combined Spinal with Opiates

• Naropin 5 mg/ml. Dose: 1.5–1.8 ml + Fentanyl 15–25 μg.
• Naropin 5 mg/ml. Dose: 1.5–1.8 ml + Morphine 0.1 mg (0.4 mg/ml 0.25 ml).
• Naropin 5 mg/ml. Dose: 1.5–1.8 ml + Fentanyl 15–25 μg + Morphine 0.1 mg (0.4 mg/ml 0.25 ml).

Opiates in Spinal Anesthesia

• Morphine 0.1–0.3 mg (0.4 mg/ml)
• Fentanyl 20–40 μg (50 micrograms/ml)
• Sufentanil 5–10–(15) μg (5 μg/ml)

Chloroprocaine

Chloroprocaine (Ampres®) is used in spinal anesthesia for short surgical procedures lasting up to about 60 minutes. Ampres has less hemodynamic impact compared to bupivacaine and can be dosed in higher doses. Caution should be exercised when using class III antiarrhythmics such as amiodarone. Elimination of chloroprocaine from cerebrospinal fluid occurs only through diffusion and vascular absorption, either in nerve tissue in the intrathecal space or after passing through the dura along the concentration gradient between cerebrospinal fluid and the epidural space. Elderly and frail patients have an increased risk of high or total spinal block, so the dose of anesthetic should be reduced.

Brand names

• Nesacaine®
• Ampres®
• Clorotekal®
• Nesacaine-MPF®

Concentration

Injection solution 10 mg/ml.

Dosage

Normally 40-50 mg (4-5 ml) is given spinally. A dose of 40 mg provides effective anesthesia for up to 80 minutes and 50 mg for up to 100 minutes.