Local Anesthetics and Additives

This chapter is a basic review of local anesthetics and additives commonly used in regional anesthesia. Local anesthetic toxicity is also discussed.

Complication rate of ultrasound-guided paravertebral block for breast surgery

Background and objectivesThoracic paravertebral blockade is often used as an anesthetic and/or analgesic technique for breast surgery. With ultrasound guidance, the rate of complications is speculated to be lower than when using landmark-based techniques. This investigation aimed to quantify the incidence of pleural puncture and pneumothorax following non-continuous ultrasound-guided thoracic paravertebral blockade for breast surgery.MethodsPatients who received thoracic paravertebral blockade for breast surgery were identified by retrospective query of our institution’s electronic database over a 5-year period. Data collected included patient demographics, level of block, type and volume of local anesthetic, occurrence of pleural puncture, occurrence of pneumothorax, evidence of local anesthetic toxicity, and patient vital signs. The incidence of block complications, including pleural puncture, pneumothorax, and local anesthetic toxicity, were ascertained.Results529 patients underwent 2163 thoracic paravertebral injections. Zero pleural punctures were identified during block performance; however, two patients were found to have a pneumothorax on postoperative chest X-ray (3.6 per 1000 surgeries, 95% CI 0.5 to 13.6; 0.9 per 1000 levels blocked, 95% CI 0.1 to 3.3). There were no cases of local anesthetic systemic toxicity or associated lipid emulsion therapy administration.ConclusionsPneumothorax following non-continuous ultrasound-guided thoracic paravertebral block using a parasagittal approach is an uncommon occurrence, with a similar rate to pneumothorax following breast surgery alone.

Preparation for Advanced Airway Management: Preparation for Awake Intubation

Awake intubation is a key technique in anesthesia, allowing for the safe management of a patient with signs and predictors of a difficult airway/intubation. It is commonly undertaken electively, but can also be used in an emergency. An appropriate history must be taken, along with review of investigations (e.g CT scan, nasendoscopy), followed by a physical examination and development of a safe management plan. A variety of local anesthetic methods exist for topicalization of the airway (2-4% lidocaine), including nerve blocks (glossopharyngeal, recurrent laryngeal, superior laryngeal) to assist this. Sedation and amnesic techniques commonly include the use of benzodiazepines (midazolam), opioids (remifentanil infusion) and alpha agonists (dexmedetomidine). Knowledge of the side effects of these are paramount, including the cardiac and central nervous system with local anesthetic toxicity. 20% lipid emulsions are available in the event of this. This review contains 4 figures, 5 tables, and 25 references. Keywords: awake flexible bronchoscopic intubation, awake endoscopic intubation, remifentanil, dexmedetomidine, airway anesthesia, glossopharyngeal nerve block, recurrent laryngeal nerve block, superior laryngeal nerve block, local anesthetic toxicity, lipid emulation.