André van Zundert

New perspectives in the microscopic structure of human dura mater in the dorsolumbar region

Background and Objectives. The object of this study was to describe the three‐dimensional structure of the dura mater by use of scanning electron microscopy. Methods. Microscopic dissection of the dura mater from four fresh cadavers (aged 70, 75, 76, and 80 years) 8‐12 hours after death were investigated in three different planes (longitudinal, tangential, and transverse). Results. The external surface of the dura mater, facing the epidural space, consisted of a network of randomly oriented fine collagen fibers. The thicker elastic fibers (2 μm in diameter) were observed on the surface of the dura. In the inner part of the dura mater, there were very fine lamellae of collagen fibers, which were bundled into thicker (4‐5 μm) layers. The dura mater consisted of 78‐82 layers, each layer including 8‐12 very fine lamellae. Conclusions. The fibers of the dura mater do not run in a longitudinal direction and are not arranged in a parallel fashion. Cytoarchitecturally the dura mater is a laminated structure built up from well‐defined layers oriented concentrically around the medulla spinalis.

Forces applied to the maxillary incisors during video-assisted intubation

BACKGROUND: Modern, video laryngoscopes provide an easier view of the glottis, possibly facilitating easier intubations. We describe an objective method for evaluating the benefits of video-assisted laryngoscopy, compared with standard techniques using force measurements. METHOD: Macintosh and video laryngoscopes (both Karl Storz, Tuttlingen, Germany) were used on the patients until the anesthesiologist was convinced he or she had the best possible view of the glottis. Actual intubation was only performed with the second of the laryngoscopes. Sensors measured the forces directly applied to the patients’ maxillary incisors. Additionally, common subjective pre- (e.g., Mallampati) and intraintubation (e.g., Cormack-Lehane [C&L]) metrics of intubation difficulty were evaluated by the anesthesiologists. RESULTS: All patients (24 female, [50 ± 16 yr], 20 male [56 ± 13 yr]) included in the study were successfully intubated with both the classic and video laryngoscopes. The forces recorded for the classic Macintosh blade ranged from 0 to 87.4 N with a median of 15.3 N, whereas the video laryngoscope forces ranged from 0 to 45.2 N, with a median of 2.1 N. The only factor determined to be significantly influential on the associated forces applied to the maxillary incisors was the laryngoscope type (P < 0.01). Video-assisted laryngoscopes reduced the applied forces over standard blades. Mallampati and C&L grade were not predictive of the forces applied. CONCLUSIONS: Video-assisted laryngoscopes seem beneficial when considering forces applied to the maxillary incisors as an objective metric of intubation difficulty. In this study, we could not support that Mallampati and C&L grades predict the forces that are applied to the maxillary incisors.

Clonidine added to bupivacaine-epinephrine-sufentanil improves epidural analgesia during childbirth.

Background and Objectives. A double‐blind study was conducted to assess the efficacy and the side effects of a low dose of clonidine added to an epidural injection of bupivacaine and epinephrine, with or without sufentanil. Methods. One hundred healthy parturients (ASA 1) were randomly allocated into four groups according to the type of epidural analgesia administered. The bupivacaine/epinephrine (BE) group received a 10‐mL standard injection of bupivacaine (B) 1.25 mg/mL and epinephrine (E) 1.25 μg/mL. In the bupivacaine/epinephrine/sufentanil (BES) group, 7.5 μg sufentanil (S) was added to the BE mixture. For the bupivacaine/ epinephrine/clonidine (BEC) group, 50 μg clonidine (C) was added to the BE mixture, whereas for the bupivacaine/epinephrine/sufentanil/clonidine (BESC) group, both sufentanil and clonidine were added to BE. Fetal heart rate was monitored by continuous cardiotocography. Duration of analgesia, method of delivery, and neonatal outcome (measured using APGAR score, peripheral oxygen saturation, and neurologic adaptive capacity score) and side effects of clonidine were observed. The parturients were routinely asked for their global appreciation of the epidural analgesia technique by visual analog score, 2 hours postpartum. Results. The overall quality and duration of analgesia were superior in the BESC group compared with the other groups, as was the global appreciation by the parturient. The frequency of side effects in the clonidine groups was comparable, with the exception of hypotension and sedation. Hypotension was easily treated by fluids or ephedrine and caused no fetal distress. The level of sedation was mild, and all parturients aroused immediately after verbal commands. Conclusion. The addition of a low dose of clonidine to an epidural injection of bupivacaine with epinephrine and sufentanil provides better analgesia during labor, while keeping the side effects minimal and of minor clinical importance.

Understanding nurse anesthetists’intention to leave their job: How burnout and job satisfaction mediate the impact of personality and workplace characteristics

BACKGROUND The retention of nurse anesthetists is of paramount importance, particularly in view of the fact that the health care workforce is shrinking. Although many health care providers find their work satisfying, they often consider leaving their jobs because of the stress. Are there ways to improve this situation? PURPOSE This study investigated how work environment characteristics and personality dimensions relate to burnout and job satisfaction and ultimately to turnover intention among Dutch nurse anesthetists. METHODOLOGY An online self-reporting questionnaire survey was performed among Dutch nurse anesthetists. The questionnaire included scales to assess personality dimensions, work climate, work context factors, burnout, job satisfaction, and turnover intention. The research model stated that personality dimensions, work climate, and work context factors, mediated by burnout and job satisfaction, predict turnover intention. Structural equation modeling was used to test the research model. FINDINGS Nine hundred twenty-three questionnaires were completed (46% response rate). Burnout mediated the relationship between personality dimensions and turnover intention; job satisfaction mediated the relationship of work climate and work context factors to turnover intention. PRACTICE IMPLICATIONS To retain nursing staff and to maintain adequate staff strength, it is important to improve job satisfaction by creating a positive work climate and work context and to prevent burnout by selecting the most suitable employees through personality assessment.

Perioperative anesthesia care and tumor progression

This narrative review discusses the most recent up-to-date findings focused on the currently available “best clinical practice” regarding perioperative anesthesia care bundle factors and their effect on tumor progression. The main objective is to critically appraise the current literature on local anesthetics, regional outcome studies, opioids, and nonsteroidal anti-inflammatory drugs (NSAIDs) and their ability to decrease recurrence in patients undergoing cancer surgery. A brief discussion of additional topical perioperative factors relevant to the anesthesiologist including volatile and intravenous anesthetics, perioperative stress and anxiety, nutrition, and immune stimulation is included. The results of several recently published systematic reviews looking at the association between cancer recurrences and regional anesthesia have yielded inconclusive data and provide insufficient evidence regarding a definitive benefit of regional anesthesia. Basic science data suggests an anti tumor effect induced by local anesthetics. New refined animal models show that opioids can safely be used for perioperative pain management. Preliminary evidence suggests that NSAIDs should be an essential part of multimodal analgesia. Volatile anesthetics have been shown to increase tumor formation, whereas preclinical and emerging clinical data from propofol indicate tumor protective qualities. The perioperative period in the cancer patient represents a unique environment where surgically mediated stress response leads to immune suppression. Regional anesthesia techniques when indicated in combination with multimodal analgesia that include NSAIDs, opioids, and local anesthetics to prevent the pathophysiologic effects of pain and neuroendocrine stress response should be viewed as an essential part of balanced anesthesia.

Direct laryngoscopy and endotracheal intubation in the prone position following traumatic thoracic spine injury

Perioperative airway management in trauma victims presenting with penetrating thoracic spine injury poses a major challenge to the anesthesiologist. To avoid further neurological impairment it is essential to ensure maximal cervical and thoracic spine stability at the time of airway manipulation (e.g., direct laryngoscopy and endotracheal intubation). Airway management in the prone position additionally increases the incidence of cervical/thoracic spine injury, difficult ventilation, and difficult airway instrumentation. Although awake fiberoptic intubation of the trachea is considered the gold standard for airway instrumentation in patients with posterior thoracic/cervical trauma, this technique requires the patient’s cooperation, special equipment, and extensive training, all of which might be difficult to accomplish in emergency situations. We herein present the first reported case of an adult trauma patient who underwent direct laryngoscopy and endotracheal intubation under general anesthesia in the prone position. Although the prone position is not the standard position for airway instrumentation with direct laryngoscopy and endotracheal intubation under general anesthesia, our experience indicates that this technique is possible (and relatively easy to perform) and might be considered in an emergency situation.

Delayed convulsions and brief contralateral hemiparesis after retrobulbar block.

Objective: This case report describes convulsions and hemiparesis after retrobulbar injection with good outcome in a patient undergoing outpatient cryocoagulation of his right eye. Case Report: We report a young man in which localized convulsions of the ipsilateral face occurred 9 minutes after retrobulbar injection followed shortly by convulsions of the contralateral arm and leg. After the convulsions, the patient experienced left-sided hemiparesis resolving approximately 1 hour after the injection. There was no hemodynamic instability during this period. It was difficult to determine the exact cause of convulsions and hemiparesis. Conclusions: We believe these complications occurred because of unintentional injection of local anesthetic agent into the subarachnoid space without affecting the brainstem. Possible mechanisms of spread of local anesthetic agent into the central nervous system after retrobulbar block are discussed.

Intubation difficulties in obese patients

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Videolaryngoscopy offers advantages over classic laryngoscopy in a patient with seriously limited lip opening

To the Editor: Inability to intubate the trachea is a leading cause of anesthesia-related injury [1]. Videolaryngoscopy offers advantages over direct laryngoscopy and is less traumatic [2, 3], as the miniature videocamera on the tip of the blade enables the intubator to provide an indirect view of the upper airway. We report a patient with limited lip opening in whom videolaryngoscopy proved to be helpful to provide a patent airway. A 73-year-old woman (160 cm; 75 kg; American Society of Anesthesiologists [ASA] physical status II), scheduled for lip reconstruction following lower lip cancer, underwent extensive lower lip resection with upper lip rotation (AbbeEstlander flap) to fill the lower lip defect [4]. Both lips were sewn together for 6 weeks, leaving an oral opening of 2.6 cm (intercommissural width). At the time of lip reconstruction (dividing the pedicle and releasing the lips), the patient showed asymmetric and limited mouth opening (interincisor distance 1.2 cm, oral width 2.6 cm; thyromental distance 6.8 cm; Mallampati grade IV), normal neck movement, and an adequate oral space. Precautions were taken to deal with a difficult airway: i.e., the provision of a difficult airway trolley, and personnel skilled in performing a surgical airway. After preoxygenation, anesthesia was induced with i.v. propofol 200 mg. Face mask ventilation was successful with capnographic tracing, and 100 mg succinylcholine was administered. The narrow mouth orifice prohibited any direct vision of the oral cavity during direct classic laryngoscopy (Cormack–Lehane grade IV), resulting in excessive tension on both lips. Channeled indirect videolaryngoscopes (Pentax-AWS , Tokyo, Japan; Airtraq , Prodol-Meditec, Vizcaya, Spain) were considered, but they were found to be too bulky to fit into the patient’s mouth, and failed to work, indicating that the wider blades of channeled videolaryngoscopes are a weak point. The insertion of a V-MAC videolaryngoscope (Karl Storz , Tutlingen, Germany), which consists of a less wide Macintosh-blade size three, into the mouth (Fig. 1) showed a Cormack–Lehane grade I on the monitor, and oral endotracheal intubation was successful at the first attempt, without the need to use a stylet. Normally a Macintosh-blade laryngoscope is introduced into the right side of the mouth, deflecting the tongue to the left, and the length of the blade is passed over the contour of the tongue. Subsequently the tongue is lifted upwards and forwards, so that enough room is created next to the blade to both visualize the glottic entrance and to insert the endotracheal tube in situ. In this patient no such maneuvers were an option. This case highlights the advantage of indirect videolaryngoscopy (Macintosh intubation blades incorporating optics in the tip for video-imaging) in patients with very limited mouth openings. The intubator does not need to see the vocal cords directly, as videolaryngoscopy offers both better laryngoscopic views and more successful intubations than classic laryngoscopy [2, 3, 5]. Management of difficult laryngoscopy in the patient with seriously reduced opening of the lips offers a unique and ongoing challenge for the anesthetist. With the present A. van Zundert (&) B. Pieters Department of Anesthesiology, Intensive Care and Pain Therapy, Catharina Hospital-Brabant Medical School, Michelangelolaan 2, NL-5623EJ, Eindhoven, The Netherlands e-mail: zundert@iae.nl

In reference to Is multidisciplinary team care for head and neck cancer worth it? and Does a multidisciplinary approach to voice and swallowing disorders improve therapy adherence and outcome?

Recently, The Laryngoscope promoted the idea of multidisciplinary team care as the gold standard of practice for head and neck cancer, as advocated by Badran et al., and for voice and swallowing disorders, as evidenced by Litts and Abaza, resulting in improved patient outcome. However, not all oral lesions present with hoarseness and voice changes and may be asymptomatic for some time. Delays between diagnosis and treatment may potentially influence outcome and survival of oral lesions. Anesthesiologists have used direct laryngoscopy as the sole method of laryngoscopy for over 60 years. Videolaryngoscopy has a wider viewing angle (commonly 608 vs. 158 for direct laryngoscopy) and offers better views of the oropharynx and larynx than conventional direct laryngoscopy. The videolaryngoscope blade tip has integrated light-emitting diode lighting and complementary metal-oxide semiconductor optics to provide a magnified image that is transmitted to a screen or monitor. Videolaryngoscopy ensures all members of the operating team engaged in airway management by displaying airway anatomy, understanding the difficulties encountered in managing the airway and the progress through difficult airway algorithms. Incidental discovery of asymptomatic lesions may be found by anesthesiologists at an early stage during routine laryngoscopy and tracheal intubation, sometimes presenting a serious challenge in airway management. Images obtained with videolaryngoscopy can play an important role in 1) offering better airway management options for normal and difficult airway management, 2) diagnosis of early-stage asymptomatic pharyngeal and laryngeal lesions, 3) clear photo documentation of lesions in symptomatic patients to be used for planning airway management (e.g., extubation strategies and planning tumor debulking surgery), 4) evaluating airway patency after intraoral surgery (e.g., free flap transfer, laser excision of tongue cancer, treatment of unilateral vocal cord paralysis, requiring frequent daily evaluations of postsurgery laryngeal edema), and 5) as part of photo-documenting airway lesions following treatment. The latter replaces the surgeon’s traditional freehand drawings documented in the patient’s medical record with an accurate image capture. In summary, videolaryngoscopy image capture may have an impact on early diagnosis, rapid referral, and ongoing tumor surveillance in airway management. A close liaison between anesthesiology and otolaryngology through videolaryngoscopy image capture further improves interdisciplinary communication and patient safety.