Locating the epidural space in obstetric patients—ultrasound a useful tool: Continuing Professional Development

Purpose

The objective of this continuing professional development module is to describe the role of ultrasound for spine demarcation before placement of neuraxial blocks and to provide a comprehensive systematic approach towards ultrasound scanning in obstetric patients.

Principal findings

Ultrasound imaging of the lumbar spine has been shown to be effective in improving the success rate of neuraxial blocks in obstetric patients. The success rate of ultrasound-guided epidural insertions at first attempt was found to be 30-60% greater when compared with the traditional epidural method. Pre-puncture ultrasound scanning can provide reliable and accurate information on several critical aspects needed for successful epidural placement, such as the interspace level, the midline of the spine, the optimal puncture point, the optimal angle for needle insertion, and the depth to the epidural space. Ultrasound scanning of the lumbar spine can generate images in two distinct patterns — one in the transverse plane represented by a “flying bat” and the other in the paramedian longitudinal plane represented by a “saw-tooth” configuration. Both approaches allow the visualization of the ligamentum flavum and the dura mater in addition to other adjacent bony landmarks. A stepwise scanning approach can serve as a useful guide to facilitate the successful placement of epidural needles in patients with both normal and abnormal spinal anatomy.

Conclusions

Incorporating the use of lumbar spine ultrasound scanning into day-to-day clinical practice may improve the ease of performing epidurals as well as add to patient safety and comfort.     

Perioperative glucose control: living in uncertain times—Continuing Professional Development

Purpose

Hyperglycemia occurs frequently in surgical patients. The objective of this Continuing Professional Development (CPD) module is to review glucose physiology and pathophysiology and provide an update on the practical management of perioperative glucose based on recently published randomized controlled trials (RCTs).

Principal findings

In the mid 2000s, several professional medical organizations recommended the implementation of strict glucose control (glucose concentrations 4.4 to 6.1 mmol·L^?1). However, the publication of new randomized controlled trials has dampened the initial enthusiasm. While the optimal glucose target range remains a matter of debate, hyperglycemia has been associated with increased morbidity and mortality in a variety of clinical settings. However, strict glucose control is associated with a sixfold increase in episodes of severe hypoglycemia (glucose levels < 2.2 mmol·L^?1), which has also been linked with increased mortality. For critically ill patients, the American Diabetes Association and the American Association of Clinical Endocrinologists recommend aiming for a blood glucose level from 7.8 to 10.0 mmol·L^?1. While no specific target range can be recommended as yet during major surgery, glucose levels should be kept < 10.0 mmol·L^?1. In critically ill patients, glucose measured from capillary blood may give a falsely elevated value, so arterial blood sampling is preferred when measuring glucose. Frequent arterial blood glucose determination using an arterial blood gas analyzer or an International Organization for Standardization (ISO) 15197-compliant glucometer is crucial to avoid and detect deleterious hypoglycemic episodes.

Conclusions

Although there is agreement that both hyperglycemia and hypoglycemia are deleterious, there is no consensus on the target glucose values to enhance clinical outcomes.     

Extubation of a difficult airway after thyroidectomy: use of a flexible bronchoscope via the LMA-Classic?

Purpose

We report an extubation strategy for a patient scheduled for thyroidectomy who had several factors indicating that it would be a difficult extubation.

Clinical features

A 75-yr-old man with thyroid cancer presented for total thyroidectomy. He had anatomical features predictive of a difficult upper airway. Therefore, his trachea was intubated while he was awake using a flexible bronchoscope. The tumour had invaded the trachea, necessitating total thyroidectomy, 3-cm tracheal resection, and primary tracheal anastomosis. The left recurrent laryngeal nerve (RLN) was inherently involved in the tumour and sacrificed. A ??guardian suture?? placed between the chin and the chest maintained the head and neck in flexion, thereby avoiding traction on the tracheal anastomosis. Immediate postoperative extubation was desirable, given the new tracheal anastomosis; however, complicating factors included left RLN paralysis, tracheal anastomosis, potential for tracheomalacia or supraglottic airway swelling, and the guardian suture preventing neck extension. In addition, there were anatomical features raising the suspicion of difficult reintubation should it be necessary. With the patient deeply anesthetized, the endotracheal tube was removed and replaced with the Laryngeal Mask Airway (LMA)-Classic? as a bridging device to facilitate bronchoscopic examination. It allowed us to visualize the tracheal repair, tracheal movement, vocal cord function, and supraglottic structures. The patient emerged from anesthesia and was extubated uneventfully.

Conclusion

We describe a viable extubation strategy used in a patient after complex thyroid surgery involving tracheal resection. By using the LMA-Classic? as a bridging device and to facilitate bronchoscopic examination, we were able to address the above concerns and safely manage the extubation phase in this patient.     

Rehabilitation of a parotidectomy patient—A systematic approach

Parotidectomy is a common surgical procedure. Resultant contour defect, Frey's syndrome, and facial nerve rehabilitation deserve special consideration. Microsurgical techniques provide unparallel advantage for reconstruction of large-volume defects. Same-stage reconstruction of the defect is advocated and often beneficial to the patient. The importance of full communication between the extirpative and reconstructive surgeon cannot be underscored. Often, institutional and personal biases must be overcome to provide best quality care for the patient. This article provides a comprehensive review of the medical literature on the subject and contrives a systematic approach to the use of various reconstructive techniques. © 2012 Wiley Periodicals, Inc. Head Neck, 2013     

Fastrach — a new intubating laryngeal mask airway: successful use in patients with difficult airways

Purpose

The Laryngeal Mask Airway — Fastrach? (Fastrach) is a new modified laryngeal mask with the capability for guided tracheal intubation while maintaining ventilation. We report the use of this device in patients with proven difficult airways, following induction of general anaesthesia.

Clinical features

After induction of general anaesthesia, having failed tracheal intubation with conventional laryngoscopy, the first patient’s trachea was intubated via the Fastrach with fibreoptic guidance. In the second and third patients, who had documented histories of difficult tracheal intubation, tracheal intubation was performed electively with the Fastrach following induction of inhalational anaesthesia with spontaneous respiration.

Conclusion

The Fastrach is an option in the management of the airway following failed tracheal intubation or for elective tracheal intubation in patients with anatomically difficult airways.     

The proseal™laryngeal mask airway: a review of the literature

PURPOSE: To analyze and summarize the published literature relating to the ProSeal LMA (PLMA): a modification of the "classic LMA" (cLMA) with an esophageal drain tube (DT), designed to improve controlled ventilation, airway protection and diagnosis of misplacement. SOURCE: Articles identified through Medline and EMBASE searches using keywords "Proseal", "ProSeal" and "PLMA". Hand searches of these articles and major anesthetic journals from January 1998 to March 2005. PRINCIPAL FINDINGS: Searches identified 59 randomized controlled trials or clinical studies and 79 other publications. Compared to the cLMA, PLMA insertion takes a few seconds longer. First attempt insertion success for the PLMA is lower, but overall success is equivalent. Airway seal is improved by 50%. The DT enables early diagnosis of mask misplacement, allows gastric drainage, reduces gastric inflation and may vent regurgitated stomach contents. Evidence suggests, but does not prove, that the correctly placed PLMA reduces aspiration risk compared with the cLMA. PLMA use is associated with less coughing and less hemodynamic disturbance than use of a tracheal tube (TT). Comparative trials of the PLMA with other supraglottic airways favour the PLMA. Clinicians have extended the use of the PLMA inside and outside the operating theatre including use for difficult airway management and airway rescue. CONCLUSIONS: The PLMA has similar insertion characteristics and complications to other laryngeal masks. The DT enables rapid diagnosis of misplacement. The PLMA offers significant benefits over both the cLMA and TT in some clinical circumstances. These and clinical experience with the PLMA are discussed.