Tubeless anaesthesia for microlaryngeal surgery

Modified tubeless anesthesia during endoscopy for assessment of head and neck cancers

We evaluated a modified technique of administering anesthesia without a tube and with spontaneous respiration during video-assisted tele-laryngo-tracheo-bronchoendoscopy (TLTBE). The endoscopy was performed as an alternative to rigid ventilatory bronchoscopy during screening for synchronous tumors in the tracheobronchial tree in patients who had head and neck malignancies. Thirty consecutive patients who required diagnostic panendoscopy were selected for this study. During direct-suspension laryngoscopy, anesthesia was delivered by administering intravenous bolus injections of propofol at 0.5 to 2 mg/kg every 5 to 10 minutes. A good view of the larynx, trachea, and main bronchi was obtained with a 50-cm 0° Hopkins telescope, which caused no obstruction of the airway. During laryngoscopy, arterial oxygen saturation levels, pulse rates, and blood pressures were stable in all patients. No apnea was associated with the use of propofol during any procedure, and we observed no intraoperative or postoperative complication in any patient. Video-assisted TLTBE is appropriate for patients with a grade 1 or 2 larynx, good cardiopulmonary function, and no significant airway obstruction. It is a safe and time-saving alternative to rigid ventilatory bronchoscopy for staging primary tumors and for screening for synchronous tumors in the respiratory tract.

Spontaneous Ventilation Using Target-Controlled Propofol Infusion for Microlaryngoscopy in Adults: A Retrospective Audit

Summary

We conducted a retrospective audit of 285 adult elective microlaryngoscopy cases in our institution over a three-and-a-half year period. Conventional anaesthesia with intubation and mechanical ventilation was the most common technique, used in 71% of cases. Tubeless spontaneous ventilation during total intravenous anaesthesia with a target-controlled infusion of propofol (SVTCI) was the most common alternative. Spontaneous ventilation with target-controlled infusion was used for 79 (27.7%) anaesthetic inductions and was continued through the maintenance phase for 60 patients (21.1%). Jet and intermittent ventilation were both used infrequently (1% each). The most common SVTCI technique since 2013 involved adjusting the target-controlled infusion rate during induction using a formula we developed based on intermittently increasing the target rate, such that the predicted plasma concentration minus the predicted effect site concentration was maintained at 1 μg/ml. We found that this method maintained ventilation during induction more reliably than other SVTCI strategies, and was associated with fewer complications than other spontaneous ventilation techniques or mechanical ventilation: it was associated with only one (3.1%) failed induction and one (3.9%) episode of apnoea. Jet ventilation was associated with the most severe complications, including two cases of barotrauma.

Tubeless anaesthesia with sevoflurane and propofol in adult laryngeal surgery

The presence of endotracheal intubation tube or jet ventilation cannula can compromise free view and access to operation area in certain endolaryngeal operations. The objective of this prospective study was to test whether adequate level of anaesthesia could be obtained in adults using tubeless sevoflurane inhalation anaesthesia with spontaneous breathing. In 23 ASA 1-2 patients, 31 treatments were included in the study of which 19 were laser-assisted papilloma or other tumour resections and 12 were fascia injection laryngoplasties. Anaesthesia was induced with propofol and maintained by insufflating sevoflurane mixture to the patient's oropharynx. The adequacy of the anaesthesia level was assessed by monitoring bispectral index, haemodynamic parameters and peripheral oxygen saturation during the anaesthesia. The ENT surgeon estimated operating conditions, whilst the two participating anaesthesiologists assessed the quality of anaesthesia using a 100 mm VAS scale. Sevoflurane contamination in the operating theatre was measured during five treatments. Mean bispectral index was below 40 throughout the operation. Haemodynamic parameters showed only minor changes during the anaesthesia. Both attending anaesthesiologists and operating ENT surgeon were satisfied with the quality of the anaesthesia and operating conditions (VAS 83 ± 15, mean ± SD, range 42-100, and VAS 93 ± 10, range 55-100, respectively). Sevoflurane room air contamination was high in most measured cases. The modification of tubeless inhalation anaesthesia used in this study produced adequate level of anaesthesia with stable haemodynamics and good operating conditions. Sevoflurane contamination can be reduced with more efficient scavenging systems.

A tubeless anaesthetic technique for paediatric laryngeal laser surgery

Laser surgery on the paediatric larynx requires cooperation between the surgeon and anaesthetist to carry out the procedure in the safest manner possible. Over a period of 3 years, 45 laser procedures have been undertaken on the upper airway of 14 patients at our institution. All procedures were performed with volatile gas anaesthesia supplied via a nasopharyngeal tube in a spontaneously ventilating patient, thus allowing the surgeon an unobstructed view of the larynx. In only one case, was a problem experienced with the technique, that of laryngospasm. The technique provides an unrivalled view of the larynx whilst allowing safe anaesthesia.

A modified technique of tubeless anaesthesia for microlaryngoscopy and bronchoscopy in young children with stridor

Sixty children including neonates and infants, with stridor undergoing investigations under general anaesthesia, were studied retrospectively. General anaesthesia was induced using an inhalational technique with halothane and was maintained with propofol infusion without the use of tracheal intubation. The ages ranged from three days to two years and five months. In most of the cases after propofol infusion, there was a slight drop in blood pressure without change in heart rate. This modified technique was found to be satisfactory in most of the cases.

Negative pressure ventilation vs. spontaneous assisted ventilation during rigid bronchoscopy. A controlled randomised trial

BACKGROUND

Ventilation during interventional rigid bronchoscopy (IRB) under general anaesthesia (jet ventilation, positive pressure ventilation and spontaneous assisted ventilation) may offer some difficulties. This study compares the effectiveness during IRB of intermittent negative pressure ventilation (INPV) and spontaneous assisted ventilation (SAV).

METHODS

Thirty-eight patients submitted to IRB were randomised into two groups: SAV or INPV. All patients received a total intravenous anaesthesia; INPV patients were paralysed. Pre- and intra-operative arterial blood gases and O2 flow through a rigid bronchoscope were assessed. The endoscopist applying a subjective score evaluated the operating conditions.

RESULTS

Patients of the INPV group, as compared to the SAV group, required a lower dosage of fentanyl (2.6 +/- 1.8 micrograms.kg-1.h-1 vs. 6.6 +/- 4.8 micrograms.kg-1.h-1), a lower O2 supply (3.3 +/- 2.8 l/min vs. 11.6 +/- 3.4 l/min), a shorter recovery time (5.4 +/- 2.9 min vs. 9.8 +/- 7.1 min) and no manually assisted ventilation (0 +/- 0 vs. 1 +/- 1.1 n degree/procedure). Intraoperative PaCO2 was higher in the SAV (8.1 +/- 1.3 kPa) than in the INPV group (5.0 +/- 1.6 kPa) and intraoperative pH differed in the two groups (7.26 +/- 0.05, SAV vs. 7.47 +/- 0.08, INPV). Operating conditions, as assessed by a subjective score, were considered better with INPV than with SAV (4.9 vs. 4.3).

CONCLUSIONS

As compared to SAV, INPV in paralysed patients during IRB reduces administration of opioids, shortens recovery time, prevents respiratory acidosis, excludes the need for manually assisted ventilation, reduces O2 need and affords optimal surgical conditions. INPV appears a safe, non-invasive and effective ventilatory management during IRB.

Anaesthetic implications of Maffucci's syndrome

Maffucci's syndrome is a rare, congenital disease due to neuro-ectodermal dysplasia and is characterized by enchondromatosis and multiple soft tissue haemangiomata. A case of Maffucci's syndrome with haemangiomata along the upper airways requiring laser surgery is described. The literature on Maffucci's syndrome is reviewed.

Anesthesia for a child with complex I respiratory chain enzyme deficiency

The mitochondrial myopathies are a rare group of conditions affecting the respiratory chain and oxidative phosphorylation. The anesthetic management of a 6-year-old girl with complex I respiratory chain deficiency requiring surgery for a fractured hip is presented and discussed. Potential problems were masseter spasm, tendency to develop lactate acidosis, and malignant hyperthermia susceptibility. These problems were avoided by the use of a laryngeal mask airway, allowing the patient to spontaneously ventilate; caudal analgesia; and maintenance of anesthesia with a proprofol infusion.

The use of the Hayek Oscillator during microlaryngeal surgery

An extremely mounted cuirass ventilator, the Hayek Oscillator, was used on 41 patients undergoing surgery to the larynx without the use of tracheal tube. Gas exchange and cardiovascular parameters remained satisfactory during the use of this technique, which offers a significant advance over existing tubeless methods of anaesthesia.

[Use of Diprivan in ENT and stomatology]

Irrespective of the type of surgery, patient monitoring, including ECG-automated non-invasive blood pressure measurements, SpO2, FIO2 and capnography, is compulsory. Sedation: no initial bolus injection of propofol; continuous infusion of propofol at a rate of 1 to 4 mg.kg-1.h-1, using a syringe pump, combined with a short-acting opioid such as alfentanil. General anaesthesia: initial bolus injection of propofol between 2 and 3.5 mg.kg-1, combined with 10 mg of lidocaine in the same syringe; maintenance with a syringe pump: 6 to 9 mg.kg-1.h-1 combined with an opioid, with or without coadministration of muscle relaxants. Intubation avoiding respiratory depression: syringe pump with a fast infusion rate (50 to 100 mg.min-1), which allows induction with propofol and intubation without co-administration of muscle relaxants.

Tubeless anesthetic technique for optimal carbon dioxide laser surgery of the larynx

PURPOSE

To evaluate the operative conditions and safety of a tubeless technique of anesthesia for carbon dioxide laser surgery of the larynx.

MATERIALS AND METHODS

This prospective study evaluated 78 consecutive procedures in 72 adult patients undergoing carbon dioxide laser microlaryngeal surgery. Anesthesia was maintained by an intravenous infusion of Propofol (ICI Pharmaceuticals, Cheshire, UK) while the patient breathed spontaneously without endotracheal intubation.

RESULTS

The operative conditions were optimal in 76 of the 78 procedures providing a clear uninterrupted view of the larynx with no combustible material in the surgical field.

CONCLUSIONS

This series shows the technique described to be safe without risk of combustion and provides an unobstructed view to the larynx.

The Hayek oscillator: a new method of ventilation in microlaryngeal surgery

The Hayek oscillator is an externally (body) mounted cuirass ventilator used in the intensive care unit. We have used it to ventilate patients undergoing microlaryngeal surgery. It was found to be a relatively safe method of ventilation in these cases, with the advantage of dispensing with any form of endolaryngeal or endotracheal intubation.

A very small dose of suxamethonium relieves laryngospasm

Intravenous suxamethonium, in a dose as small as 0.1 mg.kg-1, has been found to be reliable in the treatment of laryngeal spasm. Three episodes of vocal cord spasm observed during direct laryngoscopy were relieved by this dose of suxamethonium.

Teflon injection for unilateral vocal cord paralysis and its effect on lung function

We present a prospective analysis of the lung function of 22 patients with unilateral vocal cord paralysis before and after Teflon injection. In the majority of patients the vocal cord paralysis was caused by an underlying malignant condition. Full spirometric and flow-volume loop studies demonstrated an increase in airway resistance after Teflon injection which was not clinically evident. The improvement in symptom score for aspiration was greater than that for dysphonia.