Anaesthetic considerations in laryngology
Declan Costello, Guri Sandhu in Practical Laryngology, 2015
The size of the lesion gives an indication of potential airflow obstruction and, depending on severity, will influence which technique is appropriate. Generally, as an obstructing lesion increases in size, the placement of a tracheal tube becomes more difficult and eventually will not be possible. Stridor indicates a significantly narrowed airway with critical airway obstruction of over 50% and in adults an airway diameter of less than 4–5 mm. Stridor on exertion suggests airway obstruction is becoming critical and stridor at rest suggests critical airway obstruction is present. The absence of stridor is generally reassuring, but in exhausted adults and children there is limited chest movement and insufficient airflow to generate enough turbulent flow for stridor. These circumstances suggest life-threatening compromise.
Airway Surgery
T.M. Craft, P.M. Upton in Key Topics In Anaesthesia, 2021
Conduct of anaesthesia. A smooth induction without coughing maintains haemodynamic stability and reduces operative haemorrhage. Oxygen saturation and end tidal CO2 should be maintained in the patient’s normal range. A pharyngeal pack soaks up blood and secretions and is used where surgical access will not be impeded. Care must be taken to ensure the tracheal tube does not become dislodged or obstructed. A pre-formed or reinforced tube may be helpful. Eye and teeth protection should be considered, although some surgeons prefer to see the eyes during nasal operations. The use of 10-15° of head-up tilt (reverse Trendelenburg) will increase venous drainage and decrease haemorrhage.
General anaesthesia and failure to ventilate
Daryl Dob, Griselda Cooper, Anita Holdcroft, Philip Steer, Gwyneth Lewis in Crises in Childbirth Why Mothers Survive, 2018
If a second attempt at intubation is considered (although patient care must not be compromised), a ‘left molar approach’ may be successful where conventional laryngoscopy is not.11 This is described as inserting the laryngoscope directly down the left side of the mouth to access the larynx. It is thought to improve the view because the tongue does not need to be compressed in order to obtain a view of the larynx. Again this particular technique can and should be practised on an intubation manikin or on elective cases before being used in the emergency situation. If the larynx can be seen but cannot be intubated, a smaller tracheal tube may need to be utilised, perhaps using a bougie or Magill forceps to aid intubation. A second ampoule of suxamethonium is kept in the tray in case the first ampoule is dropped, and not to provide further paralysis.
Effects of nitrous acid exposure on baseline pulmonary resistance and Muc5ac in rats
Published in Inhalation Toxicology, 2018
Masayuki Ohyama, Ichiro Horie, Yoichiro Isohama, Kenichi Azuma, Shuichi Adachi, Chika Minejima, Norimichi Takenaka
Baseline RLung and baseline Cdyn were measured by tracheal cannulation using a PULMOS-II system (MIPS Co. Ltd., Osaka, Japan) in three consecutive days. Three rats were measured per day in each group in the order of C group, M group, and H group. The rats were anesthetized i.p. with urethane (1 g/kg, 20% w/v). The tip of the tracheal tube was inserted into the trachea through an open tracheostomy. The transpulmonary pressure was determined by monitoring the difference between pressure in the external end of the tracheal cannula and the esophageal cannula using a Statham differential transducer (DP-45; Validyne Engineering corp., Northridge, CA, USA). The intrapleural pressure was measured through a water-filled cannula that was placed in the lower third of the esophagus and connected to one port of a differential pressure transducer (DP-45; Validyne Engineering corp., Northridge, CA, USA). A Fleisch pneumotachograph and a differential transducer were used to monitor the respiratory flow rate (PULMOS-II system; MIPS Co. Ltd., Osaka, Japan). Baseline RLung and baseline Cdyn were estimated under artificial ventilation with a Shinano Respirator (Model SN-480-7; Shinano, Tokyo, Japan) at a respiration rate of 70 breaths/min and a tidal volume of 7 mL/kg (Giles et al., 1971; Filep et al., 2016). The baseline RLung and baseline Cdyn are calculated for each breath. The mean of 20 breaths for the baseline RLung and baseline Cdyn was taken for each rat. The PULMOS-II system was calibrated before and after the measurement, and the calibration error was less than 5%.
Decannulation and improvement of responsiveness in patients with disorders of consciousness
Published in Neuropsychological Rehabilitation, 2022
Bahia Hakiki, Silvia Pancani, Francesca Draghi, Emilio Portaccio, Ariela Tofani, Barbara Binazzi, Romoli Anna Maria, Maenia Scarpino, Claudio Macchi, Francesca Cecchi
Two hundred and thirty six patients (UWS:107 (45.3%); MCS:129 (54.7%); females: 86 (36.4%)) were included in the analysis and presented the following characteristics at admission: median age: 67 years (IQR: 20), aetiology: traumatic (n = 69) 29.2%, anoxic (n = 42) 17.8%, vascular and others: (n = 125) 53.0%, CRS-R median score: 9.5 (IQR: 9); median time post-onset: 45 days (IQR: 33). The median LOS was 132.5 days (IQR: 97). After a median time from admission of 55 days (IQR: 65), the tracheal tube was removed in 116 (49.2%) patients (39 traumatic (33.6%), 13 anoxic (11.2%), and 64 vascular and others (55.2%)) (Table 1). Eighteen patients (7.6%) died during the IRU stay. Among the 236 included patients, 133 (56.4%) presented an IR at discharge. Baseline clinical data of the study sample are reported in Table 2.
Association of red blood cell distribution width with post-operative new-onset atrial fibrillation following cardiac valve replacement surgery: a retrospective study
Published in Biomarkers, 2022
Li Xin, Chu Chenghao, Hou Shuwen, Ge Shenglin, Zhang Chengxin
Preoperative laboratory and imaging examinations, intraoperative anaesthesia and surgical procedures [including sternotomy, establishment and weaning of cardiopulmonary bypass (CPB), valve replacement, cardiac incision suture, and closure of the thoracic cavity], and post-operative cardiac intensive care unit (CICU) management were performed in accordance with standard institutional practices. All patients were mechanically ventilated and monitored by five-lead electrocardiogram after admission to the CICU. The tracheal tube was removed when patients met the following criteria: (1) complete wakefulness; (2) stable hemodynamics; (3) satisfactory arterial blood gas analysis results; and (4) no excess bleeding. Patients were discharged from the CICU when their major vital signs were stable, and they were continuously monitored by telemetry in the regular ward for at least 3 days. In addition, ECG monitoring was used if patients had symptoms of palpitation, dyspnoea, and angina or arrhythmia.