scholarly journals The impact of transesophageal echocardiography based protocol for management of adults in the sitting position on the incidence of clinically significant venous air embolism

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Dmitry A. Averyanov ◽  
Roman S. Lakotko ◽  
Aleksey V. Shchyogolev ◽  
Dmitry V. Svistov ◽  
Aleksey I. Gayvoronsky
Keyword(s):  
Transesophageal Echocardiography ◽  
Postoperative Period ◽  
Valsalva Maneuver ◽  
Single Case ◽  
Air Embolism ◽  
Sitting Position ◽  
Venous Air Embolism ◽  
Prospective Group ◽  
Clinically Significant ◽  
The Impact

The purpose of the study was to evaluate the impact of transesophageal echocardiography (TEE) – based protocol for management of adults in the sitting position during elective neurosurgical interventions on the incidence of clinically significant venous air embolism (VAE). Material and Methods ― The study involved 155 adult neurosurgery patients (70 in prospective group and 85 in retrospective group). Surgery in both groups was done in the sitting position. In the prospective group TEE-based protocol was used. Retrospective group served as control. The primary endpoint was considered to be a decrease in the frequency of clinically significant VAE in the prospective group in comparison with the retrospective one. In the prospective group, VAE with Tuebingen grade 3-5 was considered clinically significant. The PFO incidence and severity and the effect of the number of episodes of VAE per case on its maximum severity during surgery were also analyzed. Any complication in the postoperative period believed to be associated with the position of the patient on the table during the surgery was recorded. Results ― The incidence of the clinically significant VAE in the retrospective group was 23.5% (95% CI 15-34) and was 16.4% higher than the frequency in the prospective group (chi-square=7.6197, df=1, p=0.005). 50% (95% CI 38-62) of patients in prospective group developed VAE during surgery. In 16 cases, the number of episodes was more than one. The number of episodes of VAE in the observation was reliably associated with the maximum severity of VAE during the observation (Z=4.11; p<0.001). A moderate strength relationship was determined between them (SomersDelta=0.43; 95% CI 0.17-0.7). Not a single case of paradoxical air embolism was detected in a series of observations. None of the patients has got a neurological deficit or cardiopulmonary complications associated with the position on the surgical table in the postoperative period. Pneumocephalus was found in 100% of cases on head computed tomography, which, however, did not need surgical treatment. PFO in the prospective group was detected in 62% (95% CI 52-73) of patients. In 25% (95% CI 16-35), shunting was significant. A large PFO without Valsalva maneuver was detected in 12.5% (95% CI 6-21) of cases. Conclusion ― The use of the TEE-based protocol for the management of adult patients in a sitting position during elective neurosurgical interventions can reduce the incidence of clinically significant VAE.

scholarly journals Investigating the impact of feedback update interval on the efficacy of restorative brain–computer interfaces

2017 ◽  
Vol 4 (8) ◽  
pp. 170660 ◽  
Author(s):  
Sam Darvishi ◽  
Michael C. Ridding ◽  
Brenton Hordacre ◽  
Derek Abbott ◽  
Mathias Baumert
Keyword(s):  
Sensory Feedback ◽  
Motor Evoked Potentials ◽  
Single Case ◽  
Maximum Voluntary Contraction ◽  
Voluntary Contraction ◽  
Brain Computer Interfaces ◽  
Computer Interfaces ◽  
Timely Fashion ◽  
Clinically Significant ◽  
The Impact

Restorative brain–computer interfaces (BCIs) have been proposed to enhance stroke rehabilitation. Restorative BCIs are able to close the sensorimotor loop by rewarding motor imagery (MI) with sensory feedback. Despite the promising results from early studies, reaching clinically significant outcomes in a timely fashion is yet to be achieved. This lack of efficacy may be due to suboptimal feedback provision. To the best of our knowledge, the optimal feedback update interval (FUI) during MI remains unexplored. There is evidence that sensory feedback disinhibits the motor cortex. Thus, in this study, we explore how shorter than usual FUIs affect behavioural and neurophysiological measures following BCI training for stroke patients using a single-case proof-of-principle study design. The action research arm test was used as the primary behavioural measure and showed a clinically significant increase (36%) over the course of training. The neurophysiological measures including motor evoked potentials and maximum voluntary contraction showed distinctive changes in early and late phases of BCI training. Thus, this preliminary study may pave the way for running larger studies to further investigate the effect of FUI magnitude on the efficacy of restorative BCIs. It may also elucidate the role of early and late phases of motor learning along the course of BCI training.

scholarly journals A case report of anaesthesia for craniotomy in sitting position

2021 ◽  
Vol 8 (4) ◽  
pp. 611-614
Author(s):  
Dinesh Suryanarayana Rao ◽  
Veena Velmurugan
Keyword(s):  
Case Report ◽  
High Risk ◽  
Air Embolism ◽  
Hemodynamic Instability ◽  
Anaesthetic Management ◽  
Sitting Position ◽  
Venous Air Embolism ◽  
Long Duration ◽  
Exact Position ◽  
Space Occupying Lesion

Tumors in the posterior fossa can be done in lateral, supine, prone, sitting and in park bench positions. Depending on the exact position of the lesion and the technical preference of the surgeon, sitting position may be preferred. Sitting position grants best possible access to deeper structures with minimal retraction. However, maintenance of anaesthesia in this position for long duration pose some serious challenges to the anaesthesiologist including high risk of venous air embolism (VAE), hemodynamic instability and respiratory disturbances. Here, we present a case report of a 36year old male diagnosed with pineal gland space occupying lesion (SOL), operated in the sitting position under general anaesthesia. We discuss about anaesthetic management and possible complications that can be encountered.

Massive venous air embolism in the semi-sitting position during surgery for a cervical spinal cord tumor: anatomic and surgical pitfalls

2009 ◽  
Vol 16 (7) ◽  
pp. 972-975 ◽  
Author(s):  
Luca Basaldella ◽  
Valentina Ortolani ◽  
Ulisse Corbanese ◽  
Carlo Sorbara ◽  
Pierluigi Longatti
Keyword(s):  
Spinal Cord ◽  
Cervical Spinal Cord ◽  
Spinal Cord Tumor ◽  
Air Embolism ◽  
Sitting Position ◽  
Venous Air Embolism

Effects of positive end-expiratory pressure ventilation on cerebral venous pressure with head elevation in dogs

2000 ◽  
Vol 88 (2) ◽  
pp. 655-661 ◽  
Author(s):  
Thomas J. K. Toung ◽  
H. Aizawa ◽  
Richard J. Traystman
Keyword(s):  
Prone Position ◽  
Venous Pressure ◽  
Air Embolism ◽  
Right Atrial ◽  
Sitting Position ◽  
Positive End Expiratory Pressure ◽  
Jugular Veins ◽  
Venous Air Embolism ◽  
Head Elevation ◽  
Cerebral Venous Pressure

Mechanical ventilation with positive end-expiratory pressure (PEEP) may prevent venous air embolism in the sitting position because cerebral venous pressure (Pcev) could be increased by the PEEP-induced increase in right atrial pressure (Pra). Whereas it is clear that there is a linear transmission of the PEEP-induced increase in Pra to Pcev while the dog is in the prone position, the mechanism of the transmission with the dog in the head-elevated position is unclear. We tested the hypothesis that a Starling resistor-type mechanism exists in the jugular veins when the head is elevated. In one group of dogs, increasing PEEP linearly increased Pcev with the dog in the prone position (head at heart level, slope = 0.851) but did not increase Pcev when the head was elevated. In another group of dogs, an external chest binder was used to produce a larger PEEP-induced increase in Pra. Further increasing Pra increased Pcev only after Pra exceeded a pressure of 19 mmHg (break pressure). This sharp inflection in the upstream (Pcev)-downstream (Pra) relationship suggests that this may be caused by a Starling resistor-type mechanism. We conclude that jugular venous collapse serves as a significant resistance in the transmission of Pra to Pcev in the head-elevated position.

scholarly journals Anaesthesia for Neurosurgery in the Sitting Position: A Practical Approach

2005 ◽  
Vol 33 (3) ◽  
pp. 323-331 ◽  
Author(s):  
C. M. Domaingue
Keyword(s):  
Superior Vena ◽  
Venous Pressure ◽  
Vena Cava ◽  
Air Embolism ◽  
Transoesophageal Echocardiography ◽  
Systemic Circulation ◽  
Right Atrial ◽  
Sitting Position ◽  
Volume Loading ◽  
Venous Air Embolism

Neurosurgery in the sitting position offers advantages for certain operations. However, the approach is associated with potential complications, in particular venous air embolism. As the venous pressure at wound level is usually negative, air can be entrained. This air may follow any of four pathways. Most commonly it passes through the right heart into the pulmonary circulation, diffuses through the alveolar-capillary membrane and appears in expelled gas. It may pass through a pulmonary-systemic shunt such as a probe patent foramen ovale (paradoxical air embolism); it may collect at the superior vena cava-right atrial junction. Rarely it may traverse through lung capillaries into the systemic circulation. Many monitors, such as the precordial Doppler, capnography, pulmonary artery catheter, transoesophageal echocardiography are useful for venous air embolism detection, with transoesophageal echocardiography being today's gold standard. Various manoeuvres, including neck compression and volume loading, are also useful in reducing the incidence of venous air embolism. Volume loading, in particular, is very helpful as it reduces the risk of hypotension. Other particular concerns to the anaesthetist are airway management, avoidance of pressure injuries, and the risk of pneumocephalus, oral trauma, and quadriplegia. Newer anaesthetic agents have made the choice of anaesthetic technique easier. An appreciation of the implications of neurosurgery in the sitting position can make the procedure safer.

Image-Guided Lateral Suboccipital Approach: Part 2—Impact on Complication Rates and Operation Times

2008 ◽  
Vol 62 (suppl_1) ◽  
pp. ONS24-ONS29 ◽  
Author(s):  
Alireza Gharabaghi ◽  
Steffen K. Rosahl ◽  
Günther C. Feigl ◽  
Sam Safavi-Abbasi ◽  
Javad M. Mirzayan ◽  
...  
Keyword(s):  
Image Guidance ◽  
Postoperative Morbidity ◽  
Three Dimensional ◽  
Air Embolism ◽  
Venous Sinus ◽  
Complication Rates ◽  
Venous Air Embolism ◽  
Image Guided ◽  
Neurosurgical Planning ◽  
The Impact

Abstract Objective: Image-guidance systems are widely available for surgical planning and intraoperative navigation. Recently, three-dimensional volumetric image rendering technology that increasingly applies in navigation systems to assist neurosurgical planning, e.g., for cranial base approaches. However, there is no systematic clinical study available that focuses on the impact of this image-guidance technology on outcome parameters in suboccipital craniotomies. Methods: A total of 200 patients with pathologies located in the cerebellopontine angle were reviewed, 100 of whom underwent volumetric neuronavigation and 100 of whom underwent treatment without intraoperative image guidance. This retrospective study analyzed the impact of image guidance on complication rates (venous sinus injury, venous air embolism, postoperative morbidity caused by venous air embolism) and operation times for the lateral suboccipital craniotomies performed with the patient in the semi-sitting position. Result: This study demonstrated a 4% incidence of injury to the transverse-sigmoid sinus complex in the image-guided group compared with a 15% incidence in the non-image-guided group. Venous air embolisms were detected in 8% of the image-guided patients and in 19% of the non-image-guided patients. These differences in terms of complication rates were significant for both venous sinus injury and venous air embolism (P &lt; 0.05). There was no difference in postoperative morbidity secondary to venous air embolism between both groups. The mean time for craniotomy was 21 minutes in the image-guided group and 39 minutes in non-image-guided group (P = 0.036). Conclusion: Volumetric image guidance provides fast and reliable three-dimensional visualization of sinus anatomy in the posterior fossa, thereby significantly increasing speed and safety in lateral suboccipital approaches.

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