Efficacy of conscious sedation for laser ambulatory ablation of benign thyroid nodules


Manuel López*, Felicia Hanzu**, Mattia Squarcia***, Mireia Mora**, Ricard Valero*, Enrique Carrero*
*Servicio de Anestesiologia, Hospital Clínic, Universidad de Barcelona
**Servicio de Endocrinologia, Hospital Clínic, Universidad de Barcelona
*** Centro Diagnóstico por la Imagen Clínic, Universidad de Barcelona



Background and Goal
Laser ablation therapy(LAT) is a new and minimally invasive technique to treat benign thyroid nodules(TN). LAT has potential complications (tracheal and vascular injury, neck hematoma). Pharyngeal edema is the main immediate post-surgical risk,

In our hospital LAT is performed in an echography room under sedation in supine position and cervical hyperextension. Laser protection goggles are indispensable.

During sedation, it is important to maintain spontaneous respiration and patient collaboration to the verbal stimulus (Ramsay3) ensuring adequate comfort and analgesia. During the laser use oxygen us stopped to avoid ignition complications and its related comorbidity.

The goal of the study is to value the efficacy of conscious sedation for LAT ambulatory procedures.

Materials and Methods
Monitoring: Standard noninvasive (EKG, NIBP, SpO2, RR, HR, ETCO2) and nasal cannula oxygen(2-3L/min). IV premedication: pantoprazole 40mg, ondansetron4mg, acetaminophen 1g, metilprednisolone 0.5mg/Kg and diazepam 5mg oral. None antibiotic prophylaxis is used. Anesthesia technique: local infiltration (mepivacaine/lidocaine)+conscious sedation with propofol(0.5-1 mcg/mL) TCI. Ketamine 10-20mg and/or phentanyl 25-50mcg. Post-anesthesia recuperation: patient seated+cervical ice. 1h in specific box. Analgesia: acetaminophen/dexketoprofen alternated and tramadol rescue. 3-day descending corticoids. 

Results and Discussion
25 patients (March2014-December2015). Age 62,6±16,6 years, 72%♀; weight and height 76,9±18,3Kg and 1,64±0,09m. ASA I-II-III-IV. Comorbidities: HBP(48%), COPD(16%), OSA(12%), heart-disease(12%), diabetes-mellitus(1%). Duration 83,7±19,8min. Infiltration: Mepivacaine 88%, lidocaine 4%. Propofol-TCI 60,4±27,6min (dose 125,3±76,6mg). Ketamine 40%, phentanyl 32%.

Respiratory complications: apnea(≥10s)8%, bradypnea(RR<10)20%, desaturation (SpO2<90%)16%, Ramsay-4 12%, reinhalation4%, cough4%. Maneuver requirements: verbal stimulation20%, tactile stimulation4%. FiO2 increasing, upper-airway opening, oropharyngeal cannula, ambu, laryngeal mask or intubation were not required(o%). Other complications: post-discharge fatigue 20%(corticoid abstinence), stridor 4%, perioral paresthesia 4%, PACU prolongation (HBP 4%), VAS 4-7 12%, EVA>7 12%, re-consultation 8% (TN inflammation).
Conclusions
Conscious sedation is an effective technique to ambulatory LAT procedures. Patient vigilance and monitoring allow

Efficacy of conscient sedation for laser ambulatory ablation of benign thyroid nodules