Acute unilateral submandibular gland swelling associated with the laryngeal mask airway

A case of acute postoperative transitory sialadenosis of the submandibular glands in a healthy dog

A 1-year-old healthy female cross-breed dog, weighing 4.5 kg, was scheduled for elective neutering. Fentanyl (5 µg/kg) and propofol (4 mg/kg) were administered intravenously (IV) to induce anesthesia, which was maintained with isoflurane and a constant fentanyl infusion rate (10 µg/kg/hr). During the recovery from the anesthesia, the presence of bilateral dense submandibular masses was recognized, as was the excessive secretion of saliva. An ultrasound examination was performed and revealed bilateral abnormally-diffused enlargement of the submandibular salivary glands. A cytology examination was conducted, and no signs of abnormality were found. The size of the swellings subsequently diminished, completely subsiding after 2 hr, as did the hyper-salivation. To the authors' knowledge, this represents the first case report of an acute transient swelling of submandibular glands after general anesthesia in a dog.

Optimal head rotation and puncture site for internal jugular vein cannulation after laryngeal mask airway insertion

INTRODUCTION

We studied the effect of head rotation on the relative position of the right common carotid artery (CCA) and the right internal jugular vein (IJV) in patients with laryngeal mask airway (LMA) insertion to evaluate the accuracy of anatomical landmarks for right IJV cannulation.

METHODS

We simulated needle insertion to the right IJV on sonograms via the central landmark approach and an approach using the external jugular vein, in patients with LMA insertion (n = 50) or endotracheal intubation (E-tube, n = 50). Overlap index and successful simulation rates were measured according to the different degrees of head rotation.

RESULTS

The overlap index between the right CCA and the right IJV increased with greater degrees of head rotation. It was significantly greater in the LMA insertion group than in the E-tube group in the following head rotation positions: neutral, 15° and 45°. The success rate of the simulation was lower in the LMA insertion group than in the E-tube group. In the LMA insertion group, the success rate of the simulation was highest (62%) with the central landmark approach and in the 15° head rotation position.

CONCLUSION

In the LMA insertion group, the overlap index increased incrementally with greater head rotation degrees (from neutral to 45°). The central landmark approach and 15° head rotation position appear to be the optimal puncture site and degree of head rotation for right IJV cannulation in patients with LMA insertion.

Ultrasound: A promising tool for contemporary airway management

Airway evaluation and its management remains an ever emerging clinical science. Present airway management tools are static and do not provide dynamic airway management option. Visualized procedures like ultrasound (US) provide point of care real time dynamic views of the airway in perioperative, emergency and critical care settings. US can provide dynamic anatomical assessment which is not possible by clinical examination alone. US aids in detecting gastric contents and the nature of gastric contents (clear fluid, thick turbid or solid) as well. US can help in predicting endotracheal tube size by measuring subglottic diameter and diameter of left main stem bronchus. US was found to be a sensitive in detecting rotational malposition of LMA in children. Also, US is the fastest and highly sensitive tool to rule out a suspected intraoperative pneumothorax. In intensive care units, US helps torule out causes of inadequate ventilation, determine the tracheal width and distance from the skin to predict tracheotomy tube size and shape and assist with percutaneous dilatational tracheostomy. US can help in confirming the correct tracheal tube placement by dynamic visualisation of the endotracheal tube insertion, widening of vocal cords (children), and bilateral lung-sliding and diaphragmatic movement. Thus, ultrasonography has brought a paradigm shift in the practise of airway management. With increasing awareness, portability, accessibility and further sophistication in technology, it is likely to find a place in routine airway management. We are not far from the time when all of us will be carrying a pocket US machine like stethoscopes to corroborate our clinical findings at point of care.

Ultrasonography for clinical decision-making and intervention in airway management: from the mouth to the lungs and pleurae

OBJECTIVES

To create a state-of-the-art overview of the new and expanding role of ultrasonography in clinical decision-making, intervention and management of the upper and lower airways, that is clinically relevant, up-to-date and practically useful for clinicians.

METHODS

This is a narrative review combined with a structured Medline literature search.

RESULTS

Ultrasonography can be utilised to predict airway difficulty during induction of anaesthesia, evaluate if the stomach is empty or possesses gastric content that poses an aspiration risk, localise the essential cricothyroid membrane prior to difficult airway management, perform nerve blocks for awake intubation, confirm tracheal or oesophageal intubation and facilitate localisation of tracheal rings for tracheostomy. Ultrasonography is an excellent diagnostic tool in intraoperative and emergency diagnosis of pneumothorax. It also enables diagnosis and treatment of interstitial syndrome, lung consolidation, atelectasis, pleural effusion and differentiates causes of acute breathlessness during pregnancy. Patient safety can be enhanced by performing procedures under ultrasound guidance, e.g. thoracocentesis, vascular line access and help guide timing of removal of chest tubes by quantification of residual pneumothorax size.

CONCLUSIONS

Ultrasonography used in conjunction with hands-on management of the upper and lower airways has multiple advantages. There is a rapidly growing body of evidence showing its benefits.

TEACHING POINTS

• Ultrasonography is becoming essential in management of the upper and lower airways. • The tracheal structures can be identified by ultrasonography, even when unidentifiable by palpation. • Ultrasonography is the primary diagnostic approach in suspicion of intraoperative pneumothorax. • Point-of-care ultrasonography of the airways has a steep learning curve. • Lung ultrasonography allows treatment of interstitial syndrome, consolidation, atelectasis and effusion.