Respiratory complications associated with tracheal intubation and extubation

We conducted a prospective survey on the incidence of respiratory complications associated with tracheal intubation and extubation in 1005 patients who underwent elective general anaesthesia over a 4-month period. During induction of anaesthesia, respiratory complications occurred in 46 patients (4.6%; 95% confidence limits (CL): 3.3, 5.9%). The common complications were coughing (1.5%) and difficult ventilation through a facemask (1.4%). Tracheal intubation was difficult in eight patients (0.8%). Complications occurred immediately after tracheal extubation in 127 patients (12.6%; 95% CL: 10.6, 14.7) and in the recovery room in 95 patients (9.5%; 95% CL: 7.6, 11.3%). The common complications immediately after extubation were coughing (6.6%) and oxygen desaturation (SaO2 < 90%) (2.4%), and in the recovery room, airway obstruction (3.8%) and coughing (3.1%). The incidence of complications was significantly higher immediately after tracheal extubation than during induction of anaesthesia (P << 0.001). Even when all incidents of coughing that occurred after tracheal extubation were disregarded as a complication, the overall incidence was still higher immediately after extubation (7.4%) than during induction of anaesthesia (P < 0.01). We conclude that the incidence of respiratory complications associated with tracheal extubation may be higher than that during tracheal intubation.      

Arterial desaturation in healthy children during and after minor surgery

Pulse oximetry (PO) was applied to 79 otherwise healthy children during and after minor ENT surgery under general anaesthesia in private practice. The PO data were not available to the anaesthetist unless desaturation to less than or equal to 85% was present for greater than or equal to 30 s. This occurred in 12 and 9 cases during anaesthesia and recovery, respectively, only 8 and 5 cases, respectively, being diagnosed clinically. Desaturation during and after anaesthesia was more common in children undergoing adenoidectomy than during procedures for which endotracheal intubation was not performed. During recovery, desaturation was more likely to occur in the same patients again. Lower values of SaO2 were found in younger children and in children resisting or crying at induction. There was a (weak) negative correlation between SaO2 and HR. As clinically undiagnosed desaturation occurs even in healthy children undergoing minor surgical procedures, a more widespread use of PO during and after anaesthesia may be advisable.     

Incidents in obstetric anaesthesia and analgesia: an analysis of 5000 AIMS reports.

We aimed to explore the first 5000 incidents reported to the Australian Incident Monitoring Study (AIMS) involving anaesthesia for obstetric patients and found 203 such incidents. Analysis and classification identified seven main incident groups; regional anaesthetic techniques (33%), anaesthetic equipment problems (13%), "wrong drug" errors (10%), other drug-related problems (16%), difficult/failed intubation (9%), problems with the endotracheal tube (9%) and other problems (10%). When compared to the incidents in the main database, obstetric cases were found to be over-represented with respect to accidental dural puncture, post dural puncture headache, failed intubation in emergency situations and the incidence of certain types of "wrong drug" error. The implications of these reports regarding safe practice of obstetric anaesthesia are discussed.     

Inability to detect unintentional endobronchial intubation by conventional signs and its detection by the radiologist during fluoroscopy for cerebral aneurysm coiling

It is routine practice to auscultate the chest for equal bilateral breath sounds after tracheal intubation to verify that the tracheal tube tip is properly positioned. Signs of bronchial intubation also include desaturation, an increase or decrease in end-tidal carbon dioxide, and an increase in peak airway pressures. We report a case in which, during the course of endovascular coiling of a cerebral aneurysm during general anesthesia, desaturation occurred despite seemingly equal air entry on chest auscultation. The clinical picture was confused further by the presence of normal airway pressures and capnography. Incidental detection of bronchial intubation by the radiologist while performing fluoroscopy prevented any adverse sequelae to the patient and also presented an unusual method of diagnosis.     

Incidence,causes, and management of failed awake fibreoptic intubation—A retrospective study of 833 procedures

Awake fibreoptic intubation has been considered a gold standard in the management of the difficult airway. However, failure may cause critical situations. The aim of this study was to investigate the incidence and causes of failed awake fibreoptic intubation at a tertiary care hospital. The study was conducted at St. Olav University Hospital in Trondheim, Norway. Problems occurring during anaesthesia are routinely recorded in the electronic anaesthesia information system (Picis Clinical Solutions Inc.), including difficult intubations. We applied text search on all anaesthesia records between 2011 and 2021 and identified 833 awake fibreoptic intubations. The anaesthesia records were examined to identify failed awake fibreoptic intubations, the cause of failure and how the airway ultimately was secured. Among 233,938 patients who received anaesthesia, 90,397 received tracheal intubation and 833 received awake fibreoptic intubation. Twenty-nine of the procedures failed. In nine patients the failure caused loss of airway control with desaturation and hypoventilation. The major causes of failure were dislodged tube after induction of general anaesthesia (n = 8), patient distress (n = 5), tube not able to pass (n = 5), and airway bleeding (n = 3). The situations were primarily solved using direct laryngoscopy, with or without bougie, or with video laryngoscopy. Tracheostomy was performed in four patients. Awake fibreoptic intubation failed in 3.5% of patients, most often due to dislocation, problems passing the tracheal tube, or patient discomfort. The failure rate was higher than in previous studies.     

Use of the laryngeal mask airway during ophthalmic surgery results in stable circulation and few complications: a prospective audit

Background: This study was performed to investigate airway complications related to Laryngeal Mask Airway (LMA) use in a selected group of paediatric patients undergoing ophthalmic surgery.
Methods: Ninety-four paediatric patients were enrolled. LMA was inserted under deep general anaesthesia with the standard technique previously described by Brain. Complications during induction, insertion of the LMA, maintenance of anaesthesia, removal of the LMA, emergence and on the first postoperative day were recorded. Failure of insertion, desaturation, laryngospasm, bronchospasm, vomiting, bucking, dislocation of the LMA, breath-holding, and coughing were noted.
Results: There was no significant age-related difference in successful insertion ratio of the LMA. In two patients (2%), the LMA could not be inserted with three attempts and tracheal intubation was performed. Laryngospasm was recorded in three patients (3%), leading to desaturation in two patients (SaO₂95%) during insertion of the LMA. During maintenance of anaesthesia bucking occurred in one patient (1%). After removal of the LMA, incidence of early desaturation following upper airway suctioning was higher in patients with a history of frequent upper respiratory tract infection ( P <0.01). Five patients (5%) had laryngospasm following the LMA removal; breath-holding and coughing were noted in 21 (22%) patients. Circulatory reactions to insertion and removal of the LMA were minimal. The incidence of sore throat on the first postoperative day was only 1%.
Conclusion: LMA can be regarded as a safe product for airway maintenance during ophthalmic surgery with a stable circulation and few complications.     

Selective left bronchial intubation and left-lung isolation in infants and toddlers: analysis of a new technique

OBJECTIVES: The purpose of this study was to analyze and compare a new technique for left bronchial intubation and left-lung isolation in infants and toddlers without the help of bronchoscopes. METHODS: In this prospective, unique comparative study, 3 different techniques for left mainstem bronchus intubation and left-lung isolation using a Fogarty catheter as a bronchial blocker were conducted in 11 children under age 4 who required left-lung isolation for left-lung surgery. A new technique for Fogarty catheter insertion and balloon inflation for proper positioning and avoiding displacement during lung handling was used. The first technique was a blind introduction to the left bronchus of the endotracheal tube (ETT) with the head turned to the right and the tube turned to the left at 180 degrees . The second one was to introduce the preshaped Fogarty catheter to the left bronchus. The third one was to intubate the left bronchus using the new technique of a preshaped ETT. RESULTS: No left bronchial intubation could be achieved with the first technique. Left bronchial intubation and isolation were achieved in 2 of 11 by the second technique and 10 of 11 using the third technique. No bulb displacement occurred in any of these during lung handling. CONCLUSION: The new technique of left bronchial intubation with a preshaped endotracheal tube was simple, safe, and easily accomplished. A Fogarty catheter can be positioned properly without the aid of a smaller bronchoscope once the left bronchus is intubated. Balloon displacement can be avoided completely if the left lung is collapsed properly and completely before the final balloon inflation.     

BRONCHOPLEURAL FISTULA MANAGEMENT DURING ANAESTHESIA

The anaesthetic management of operations for bronchopleuralfistula in twenty-two patients is discussed. The fistulae followedpulmonary resection for tuberculosis or tuberculous empyema.A fistula may cause air leakage leading to spontaneous pneumothorax,collapse of the lung or mediastinal shift. Spillover of empyemafluid may lead to respiratory obstruction. Empyema fluid wasaspirated before operation and the intercostal catheter underwater seal was kept working during operation. In each case acuffed endotracheal tube was passed under general anaesthesia,thiopentone and suxamethonium being administered to the patientin the head-up position. Frequent aspiration through the endotrachealtube was required. These patients were not considered suitablefor intubation under local anaesthesia, nor was one-lung anaesthesia,or the use of bronchial blockers, considered necessary.     

Effect of head posture on tracheal tube position in children

Changes in the tracheal tube tip to carina distance were measured by radiographic screening following various head postures in 45 children undergoing cardiac catheterisation under general anaesthesia who were intubated via nasal and oral routes. Extension of the head moved the tracheal tube away from the carina and flexion moved it towards the carina in both routes. Endobronchial intubation was noted during neck flexion in a significant proportion of children intubated orally but none occurred during nasal intubation. Extension produced greater upward movement of the tracheal tube tip in the oral route than the nasal route. In contrast, flexion produced greater downward movement in the nasal route in some patients. The direction of movement with lateral rotation and use of a shoulder roll was inconsistent.     

Awake fibrecapnic intubation in head and neck cancer patients with difficult airways: new findings and refinements to the technique

Recently, we described an adaptation of awake fibreoptic intubation that we call awake fibrecapnic intubation. The aim of this study was to evaluate the efficacy and risk of complications with this novel technique in a consecutive case series of head and neck cancer patients known to have difficult airways. We prospectively studied 40 consecutive intubations in head and neck cancer patients prior to a diagnostic or surgical procedure. Following topical anaesthesia, a flexible bronchoscope was introduced into the pharynx; spontaneous respiration was maintained in all patients. A special suction catheter was advanced into the airway through the suction channel of the bronchoscope for carbon dioxide measurements. When four capnograms were obtained, the bronchoscope was railroaded over the catheter and a tracheal tube was placed. All adverse events and complications were recorded. There were no complications associated with the technique. The median (range) time to intubation was 3 min (1.5-15 min). All patients were intubated successfully, 39 (98%) of them using awake fibrecapnic intubation. There was one patient with severe tumour bleeding and acute airway obstruction caused by advancement of the tube over the bronchoscope. This was not considered to be a complication of the fibrecapnic technique. Awake fibrecapnic intubation is a safe and valuable technique in head and neck cancer patients with a difficult airway.     

Use of a lighted flexible catheter as a detector for accidental oesophageal intubation through the intubating laryngeal mask: a preliminary study

We have evaluated the use of a prototype lighted flexible catheter using the transillumination of the light through the soft tissues of the neck, as a detector of the accidental oesophageal intubation during the tracheal intubation through the intubating laryngeal mask. Two hundred patients undergoing general anaesthesia were studied. Accidental oesophageal intubation occurred in 12 patients (6%) during the first intubating attempt and was diagnosed by noting absence of glow on the neck during the tracheal tube advancement and was confirmed by capnography. However, 11/12 (92%) of the above patients were finally intubated successfully, using the lighted flexible catheter. In one patient persistent accidental oesophageal intubation occurred and was classified as failure.     

Comparison of a propofol target-controlled infusion and inhalational sevoflurane for fibreoptic intubation under spontaneous ventilation

BACKGROUND: A propofol target-controlled infusion (TCI) is often proposed for the management of difficult airway intubation and fibreoptic intubation under anaesthesia and spontaneous ventilation. No data are available about sevoflurane. The aim of the present study was to compare propofol and sevoflurane as hypnotics during fibreoptic intubation under spontaneous ventilation. METHODS: After regional ethical committee approval, 52 ASA I-II patients without any predictors for difficult intubation gave their informed consent. They were randomly assigned to one of two groups. After 3 min of pre-oxygenation, patients received either propofol with a plasmatic target concentration of 4 mg/l (group P; n= 26) or sevoflurane 4% with tidal volume ventilation (group S; n= 26). After 2 min, propofol was increased by 1 mg/l and sevoflurane was increased by 1% every 2 min until there was no reaction during mandible translation. This concentration was maintained for 4 min before starting nasotracheal fibrescopy for intubation. During both induction and fibrescopy, pulse oximetry, bispectral index (BIS), heart rate, and arterial blood pressure were monitored. Quality of intubation and operator satisfaction were evaluated. Data were compared using Student's t-test, Mann-Withney U-test or chi-square test. A P-value < 0.05% was considered to be significant. RESULTS: During induction, no difference in pulse oximetry, BIS values at the end of induction, or duration of induction were noticed. Five episodes of desaturation under 90% occurred during fibreoptic intubation in group P compared with none in group S. CONCLUSION: Sevoflurane provides good fibreoptic intubation conditions to spontaneously breathing patients without any hypoxemic episodes such as those observed with propofol.     

Airway crises

Airway crisis is an ever-present risk of general anaesthesia. One study of 5454 computerized anaesthetic records found evidence of critical incidents in 434 (8%) of cases. Human error has been implicated in over three-quarters of all critical incidents. In a study of serious negligence claims, adverse outcomes associated with respiratory events comprised the largest class of injury. Death or brain damage occurred in 85% of these cases. Three-quarters of these adverse respiratory events were accounted for by three mechanisms of injury: inadequate ventilation, oesophageal intubation and difficult intubation. Avoiding airway crisis depends on the skill and vigilance of the anaesthetic team. Key steps for avoiding trouble are: (1) careful patient pre-assessment, (2) thorough anaesthetic equipment checks, (3) adequate monitoring and (4) having a pre-planned crisis management plan. This paper reviews current knowledge and practice relating to airway difficulties in general anaesthesia and outlines a practical approach to managing common causes of crisis.     

Anesthesia induction with sevoflurane in adult patients with predictive signs of difficult intubation

OBJECTIVE: This work was carried out to study induction with sevoflurane in adult patients with predictive signs of difficult intubation. STUDY DESIGN: Randomised prospective study. PATIENTS AND METHODS: The study had two parts. Part I: 15 patients without predictive signs of difficult intubation but with a cervical collar. Eight patients were anaesthetised with propofol 3 mg.kg-1 and fentanyl 2 micrograms.kg-1, seven with sevoflurane 8%. Part II: 20 patients with predictive signs of difficult intubation anaesthetised with sevoflurane 8%. RESULTS: In part I, all patients were intubated, the time for intubation was longer with sevoflurane, 6 vs 4 min. They were apneic only in the propofol group. After intubation, 7 cases of coughing (4 severe) occurred in the propofol group and 3 moderate coughing in the sevoflurane group. In part II, one patient experienced considerable agitation after oral airway insertion and was excluded. Other patients were intubated with sevoflurane. Seven patients were intubated with a bougie, three patients through an intubating LMA and one patient with a rigid bronchoscope. The other patients were intubated with a Macintosh blade. The mean time for intubation was 10 +/- 7 min and end tidal sevoflurane concentration after intubation was 4 +/- 0.6%. After intubation, 7 cases of coughing (3 severe) occurred but no desaturation < 95%. No significant haemodynamic variations occurred. CONCLUSION: Induction with sevoflurane 8% allowed tracheal intubation without major incidents. All patients breathed spontaneously. Sevoflurane can be recommended for induction in cases of predictive difficult intubation.     

Electrocardiographic monitoring in healthy young adult outpatients: mandatory or optional?

Purpose

To determine the incidence and duration of ECG abnormalities in healthy adults during short duration outpatient surgery and their relationship to important clinical events.

Method

In 381, ASA Class I, day surgery patients undergoing short surgical procedures the ECG was monitored prospectively for evidence of abnormalities. The attending anaesthetist administered the anaesthetic and made all clinical decisions while relying on routine monitors (ECG, oximeter, BR capnometer, oxygen analyser, low pressure alarm and anaesthetic gas monitors). Intra-operative events of clinical significance (e.g., light anaesthesia, regurgitation, coughing, hypotension, arterial desaturation, hiccoughs etc), ECG abnormalities and their duration were documented.

Results

Electrocardiographic abnormalities were detected in 21 % of patients as follows: sinus tachycardia (11 %), artifacts (7%), premature atrial contractions (1.6%), lead disconnects (1%), sinus bradycardia (0.5%) and premature ventricular contractions (0.3%). All abnormalities resolved spontaneously within three minutes. Intra-operative incidents of consequence occurred in only 2.6%: light anaesthesia (5), arterial desaturation > 5% (2), hypotension (1), hiccough (1) and régurgitation (1). All incidents were detected clinically and by pulse oximetry. The ECG did not detect any of the incidents and was normal during the events.

Conclusion

Routine ECG monitoring did not detect intra-operative incidents in healthy adults during short outpatient procedures. Detected ECG abnormalities were benign and resolved spontaneously within three minutes. Firm conclusions as to the safety implications of withdrawing ECG monitoring cannot be drawn from this study. Guidelines may need to be reviewed to determine whether ECG monitoring in such cases should be optional rather than mandatory.     

Diagnosis of clinically unrecognized endobronchial intubation in paediatric anaesthesia: which is more sensitive,pulse oximetry or capnography?

In a prospective, randomized, single-blind study of combined pulse oximetry and capnography in 196 children whose anaesthetic was managed by endotracheal intubation we observed 10 patients with 14 episodes of endobronchial intubation (EBI). Pulse oximetry provided the first diagnostic clue in 13 events; the one event first diagnosed by capnography was also accompanied by oxygen desaturation. Two EBI occurred immediately after the initial intubation (‘primary’ EBI). Twelve episodes of EBI in eight patients occurred after correct initial endotracheal tube position (‘secondary’ EBI). EBI gave rise to eight episodes of ‘minor’ desaturation (oxygen saturation (Spo₂) ≤ 95%≥ 60 s); four resulted in ‘major’ desaturation (Spo₂≤ 85% for 30 s). Only three EBI events produced clinical signs or symptoms. Seven patients were less than 1 year; EBI was not, however, related to age. A high frequency (5.1%) of clinically unrecognized EBI was found in infants and children. A persistent yet small, reduction in oxygen saturation provided the early evidence of secondary EBI in the majority of cases. Clinical signs and capnography proved least effective in the early diagnosis of secondary EBI.     

Inflation with air via a facepiece for facilitating insertion of a nasogastric tube: a prospective, randomised, double-blind study

Insertion of a nasogastric tube is a routine procedure but during anaesthesia it is often difficult and time consuming. One hundred and sixty adults undergoing elective surgery under general anaesthesia were randomly divided into two groups. After induction of anaesthesia, neuromuscular blockade and tracheal intubation, a nasogastric tube was inserted through the nose with the head of the patient in the neutral position, either with or without prior inflation with air via a facepiece attached to a self-inflating bag applied firmly with the face. Insertion of the nasogastric tube was successful in 75/78 (96%) following inflation compared with 54/80 (68%) without inflation (p  <  0.001). In four patients receiving inflation, a fibreoptic endoscope was passed as far as the upper oesophageal sphincter; this revealed opening of the upper oesophageal sphincter during inflation.     

Selective bronchial intubation for one lung anaesthesia in thoracic surgery

A new method for one lung anaesthesia in thoracic surgery is described. Separate lung ventilation is obtained with selective main bronchus intubation, by means of an appropriate cuffed tube inserted through a standard orotracheal tube. Ventilation is carried out separately through the bronchial tube on one side and the residual tracheal tube lumen on the other side. This method greatly simplifies the technique of bronchial intubation and offers many advantages over commercially available double-lumen tubes.     

Hypoxaemia during tracheal intubation in patients with hypertensive disorders of pregnancy: analysis of data from an obstetric airway management registry

BackgroundIn South Africa, hypertensive disorders of pregnancy are the leading cause of maternal mortality. More than 50% of anaesthesia-related maternal deaths are attributed to complications of airway management. We compared the prevalence and risk factors for hypoxaemia during induction of general anaesthesia in parturients with and without hypertensive disorders of pregnancy. We hypothesised that hypertensive disorders of pregnancy are associated with desaturation during tracheal intubation.MethodsData from 402 cases in a multicentre obstetric airway management registry were analysed. The prevalence of peri-induction hypoxaemia (SpO₂ <90%) was compared in patients with and without hypertensive disorders of pregnancy. Quantile regression of SpO₂ nadir was performed to identify confounding variables associated with, and mediators of, hypoxaemia.ResultsIn the cohort of 402 cases, hypoxaemia occurred in 19% with and 9% without hypertension (estimated risk difference, 10%; 95% CI 2% to 17%; P=0.005). Quantile regression demonstrated a lower SpO₂ nadir associated with hypertensive disorders of pregnancy as body mass index increased. Room-air oxygen saturation, Mallampati grade, and number of intubation attempts were associated with the relationship.ConclusionsClinically significant oxygen desaturation during airway management occurred twice as often in patients with hypertensive disorders of pregnancy, compounded by increasing body mass index. Intermediary factors in the pathway from hypertension to hypoxaemia were also identified.     

单肺通气中应用支气管封堵器与双腔支气管导管的比较

目的比较支气管封堵器与双腔支气管导管在胸腔镜下肺大疱切除术中的应用。方法择期80例行胸腔镜下肺大疱切除术患者,随机均分为支气管封堵器组(Ⅰ组)和双腔支气管导管组(Ⅱ组)。Ⅰ组通过支气管封堵器实现单肺通气,Ⅱ组通过插入双腔支气管导管实现单肺通气,所有气管插管均由同一个熟练的麻醉医师完成。观察两组插管时间、定位时间、外科术野暴露程度和术后咽喉疼痛发生情况。结果Ⅰ组插管时间明显短于Ⅱ组(P<0.05),两组定位时间、外科术野暴露程度差异无统计学意义;Ⅰ组术后咽喉痛评分明显低于Ⅱ组(P<0.05)。结论支气管封堵器与双腔支气管导管均能有效应用在胸腔镜下肺大疱切除术患者单肺通气中,应用支气管封堵器可缩短插管时间及减轻患者术后咽喉疼痛。