A predictive test for difficult intubation in laryngeal microsurgery. Validation study. / Test predictivo de intubación difícil en microcirugía de laringe. Estudio de validación.

BACKGROUND: In 2003 a simple test to detect difficult intubation (DI) in patients underwent laryngeal microsurgery was described. The present study was conducted to validate the test. METHODS: Patients with laryngeal disease scheduled for laryngeal microsurgery were included. The variables evaluated were eleven parameters: Mallampati Score ≥III, thyromental distance <6.5cm, mouth opening <40mm, limitation of the temporomandibular joint, pathological dentition, arched paladet, maxillary deficiency, neck mobility <90°, body mass index, symptoms of laryngeal dysfunction, and tumour of supraglottic region. A rapid examination of the airway by an expert anaesthesiologist was carried out just before induction. DI was defined by a Cormack laryngeal view gradeiii-iv and/or if auxiliary equipment was required to achieve orotracheal intubation. A comparison of ROC curves was conducted to estimate the best predicting cut-off, as well as differences between the index described in 2003 and the rapid assessment by an expert anaesthesiologist. RESULTS: One hundred and five patients were included in the study. The incidence of DI according to the predefined criteria was 45% (47 patients). The score at the cut-off of 5 provides a sensitivity of 89% and a specificity of 55%. The fast-evaluation by an expert anaesthesiologist obtained similar sensitivity (89%) and better specificity (81%). Area under curve (AUC) was 0.87, similar to a fast evaluation (AUC: 0.85; P=.71). CONCLUSION: The index was validated at a cut-off of ≥5, being a useful and reliable test to predict DI in patients with laryngeal diseases and it is a useful tool for anaesthesiologists with conventional training.

Afección laríngea obstructiva y síndrome de apnea obstructiva del sueño, una asociación con severo riesgo perioperatorio / Obstructive laryngeal disease and obstructive sleep apnoea syndrome, a combination with serious peri-operative risk

Presentamos el caso de una paciente con diagnósticos de bronquitis crónica, síndrome de apnea obstructiva del sueño y edemas laríngeos de gran tamaño que se intervino para resección mediante microcirugía transoral láser. En el postoperatorio inmediato desarrolló una insuficiencia respiratoria aguda por colapso faríngeo que requirió reintubación en condiciones de urgencia y traslado a UCI no prevista, en la que se mantuvo la ventilación mecánica durante 18 h, procediendo a continuación a la extubación. La evolución posterior fue normal. Se describe la asociación de varios factores de riesgo para el tratamiento anestésico y la importancia de detectar en el preoperatorio la gravedad de cada una de las alteraciones, especialmente la severidad del síndrome de apnea obstructiva del sueño (AU)

We present the case of a patient who was diagnosed with chronic bronchitis, obstructive sleep apnoea syndrome, and large Reinke laryngeal oedemas that were removed by transoral laser microsurgery. In the immediate post-operative period acute respiratory insufficiency occurred due to pharyngeal collapse that required emergency re-intubation, after which the patient was transferred to the ICU where mechanical ventilation was given for18 h. Subsequent progress was normal. We describe the combination of various risk-factors related to anaesthetic management and the importance of considering each one of them, especially the preoperative detection of the severity of obstructive sleep apnoea syndrome (AU)

[Obstructive laryngeal disease and obstructive sleep apnoea syndrome, a combination with serious peri-operative risk]. / Afección laríngea obstructiva y síndrome de apnea obstructiva del sueño, una asociación con severo riesgo perioperatorio.

We present the case of a patient who was diagnosed with chronic bronchitis, obstructive sleep apnoea syndrome, and large Reinke laryngeal oedemas that were removed by transoral laser microsurgery. In the immediate post-operative period acute respiratory insufficiency occurred due to pharyngeal collapse that required emergency re-intubation, after which the patient was transferred to the ICU where mechanical ventilation was given for 18h. Subsequent progress was normal. We describe the combination of various risk-factors related to anaesthetic management and the importance of considering each one of them, especially the preoperative detection of the severity of obstructive sleep apnoea syndrome.

Utilidad del laringoscopio de suspensión de Kleinsasser para facilitar la intubación orotraqueal en tumores supraglóticos de laringe / No disponible

No disponible

[Incidence of pain upon injection of a new formula of propofol in a fat emulsion of medium- and long-chain triglycerides]. / Estudio de la incidencia de dolor a la inyección de una nueva preparación de propofol en emulsión grasa conteniendo triglicéridos de cadena media y larga.

OBJECTIVE: To study the incidence of pain upon injection of 1% propofol (Propofol-Lipuro 1%, B. Braun, Melsungen, Germany) in a 10% fat emulsion containing equal proportions (50:50) of medium- and long-chain triglycerides. PATIENTS AND METHODS: The subjects were 600 adult patients scheduled for elective surgery. The use of premedication was left to the discretion of the anesthesiologist. All patients received the study anesthetic injected slowly (20-40 mg per 10 seconds) at a dose of 1.5 to 2.5 mg/Kg. Variables recorded were incidence and type of pain upon administering the anesthetic, the patients' clinical characteristics, premedication administered, and method of venous puncture. Bivariate and multivariate statistical analyses were performed to determine factors associated with the appearance of pain. RESULTS: The overall incidence of pain upon administration of propofol-lipuro was 27%. Pain was moderate to intense in 9%. Premedication did not affect the incidence of pain with injection. The risk factors that predicted the appearance of pain were injection through a small-caliber catheter (> 18 G) and injection on the dorsal hand (P < 0.05). CONCLUSIONS: The incidence of pain upon injection of propofol-lipuro is low in comparison with incidence rates reported in the literature for the traditional formula, but administration of the fat emulsion formula through a vein on the dorsal side of the hand or through a venous catheter smaller than 18 G should be avoided. Double-blind randomized controlled trials should be conducted to clarify the advantages that propofol-lipuro seems to offer.

[Comparative study of high-frequency jet ventilation in 4 types of patients undergoing laryngeal microsurgery]. / Estudio comparativo de la ventilación con jet a alta frecuencia en cuatro tipos de pacientes sometidos a microcirugía laríngea.

OBJECTIVE: To study high frequency jet ventilation (HFJV) in patients with chronic obstructive pulmonary disease (COPD) who are obese or who have tracheal or laryngeal stenosis, conditions which are often found in patients undergoing microsurgery of the larynx (MSL), comparing the results with those for a group of controls, patients with no stenosis who were also undergoing MSL. PATIENTS AND METHOD: Eighty patients were distributed in four groups as follows: those meeting the criteria for a diagnosis of COPD (n = 20), those who were overweight (n = 24), those with stenosis over 50% of the laryngeal opening (stenosis group, n = 10) and those with no associated pathology (control group, n = 26). HFJV was administered through a 2.2 mm internal diameter orotracheal injection catheter, using an Ergojet CVT (Temel, S.A.). The ventilatory protocol was as follows: rate 100 breaths/min, inspiratory time 30%, generator pressure (GP) 2.2 to 3.3 kg/cm2 and FiO2 70% to 90%. We analyzed the GP administered, jet volume (Vjet) delivered, maximum (PAWmax) and minimum (PAWmin) airway pressures, oxygen hemoglobin saturation (SpO2), partial pressures of O2 (pO2) and CO2 (pCO2) in arterial blood, and end-tidal pressure of CO2 (PETCO2) at baseline and 10 and 20 min after the start of HFJV. Because monitoring was invasive, the study was designed for a small series of patients and we believe it should not be generalized to include all patients undergoing MSL under normal conditions. RESULTS: HFJV had to be abandoned and conventional ventilation used in 4 patients (2 in the COPD group and 2 in the obese group). Ventilation was judged adequate in the remaining patients, with the observations that in the COPD group, pO2 levels were lower than in the control group at the 10 min readings and pCO2 levels were higher at both the 10 and 20 min readings. PAW levels were higher throughout the procedure in both the COPD and stenosis groups. In the obese patients, pCO2 was higher at both the 10 and 20 min recordings. CONCLUSION: HFJV provides effective ventilation for most patients undergoing MSL, even if they are obese or have COPD or laryngeal stenosis.

[External laryngeal injuries. Study of 12 cases]. / Traumatimos laríngeos externos. Estudio de 12 casos.

Laryngeal trauma can cause severe, life-threatening damage in the upper respiratory tract. Management of trauma presents difficulties with respect to airway control and the procedural decisions are challenging. We studied 12 patients treated at our hospital after laryngeal trauma of various degrees of severity. Respiratory failure detected in some cases was critical from the moment of trauma, whereas other patients were asymptomatic at first but experienced progressive respiratory failure over the next few hours. We looked at the method applied to gain initial control of the upper airway and also considered the laryngeal lesions themselves, associated lesions and established treatment. We then looked for relationships between these and evolution and laryngeal sequelae 6 months after trauma. In agreement with other studies we found that the severity of sequelae depends on the severity of the lesion incurred and on how early treatment is established. The choice of whether to use orotracheal intubation or tracheotomy to control the upper airway was less important, as that decision would depend largely on severity of the lesion, although orotracheal intubation is recommended whenever possible.

[Comparative study between anesthesia by continuous perfusion with propofol or thiopental-isoflurane in laryngeal surgery]. / Estudio comparativo entre la anestesia con perfusión continua de propofol o tiopental-isoflurano en cirugía de laringe.

OBJECTIVE: To compare two anesthetic protocols for maintenance of anesthesia during laryngectomy (propofol vs thiopental-isoflurane), assessing its effects on intraoperative hemodynamic stability and recovery time after withdrawal of anesthesia. PATIENTS AND METHOD: Thirty-one patients undergoing laryngectomy. Anesthetic technique was the same except for the maintenance anesthetic used (isoflurane in group I [n = 16]; propofol in group P [n = 15]). We recorded heart rate and systolic/diastolic arterial pressure before surgery, 10 minutes after induction, at 10, 60 and 120 min after start of surgery and at the end of the procedure. Postanesthesia recovery time was measured by the Steward test (recovery of consciousness, control of voluntary movement and of breathing) applied at 3, 5, 10, 30 and 60 min after withdrawal of anesthesia. RESULTS: There were no demographic differences between the two groups and heart rate and systolic/diastolic pressures were comparable. Postanesthetic recovery time was shorter in group P than in group I, with a statistically significant difference 5 min after withdrawal of drug (p < 0.05) owing to the item recovery of consciousness in the Steward test (p < 0.05 at times 5 and 10 min for this item). There were no significant differences in control of breathing or movement. CONCLUSIONS: Propofol for anesthetic maintenance is effective and safe. There are no differences in hemodynamic changes produced by propofol and isoflurane. Time until recovery of consciousness is longer with isoflurane, although we believe that this is not clinically relevant in this type of procedure.