Tumul Chowdhury

Trigeminal Cardiac Reflex: New Thinking Model About the Definition Based on a Literature Review

AbstractTrigeminocardiac reflex (TCR) is a brainstem reflex that manifests as sudden onset of hemodynamic perturbation in blood pressure (MABP) and heart rate (HR), as apnea and as gastric hypermotility during stimulation of any branches of the trigeminal nerve. The molecular and clinical knowledge about the TCR is in a constant growth since 1999, what implies a current need of a review about its definition in this changing context.Relevant literature was identified through searching in PubMed (MEDLINE) and Google scholar database for the terms TCR, oculocardiac reflex, diving reflex, vasovagale response.The definition of the TCR varies in clinical as well as in research studies. The main difference applies the required change of MABP and sometimes also HR, which most varies between 10% and 20%. Due to this definition problem, we defined, related to actual literature, 2 major (plausibility, reversibility) and 2 minor criteria (repetition, prevention) for a more proper identification of the TCR in a clinical or research setting. Latest research implies that there is a need for a more extended classification with 2 additional subgroups, considering also the diving reflex and the brainstem reflex.In this review, we highlighted criteria for proper definition and classification of the TCR in the light of increased knowledge and present a thinking model to overcome this complexity. Further we separately discussed the role of HR and MABP and their variation in this context. As another subtopic we gave attention to is the chronic TCR; a variant that is rarely seen in clinical medicine.

Trigeminocardiac reflex: the current clinical and physiological knowledge.

The trigeminocardiac reflex (TCR) is defined as the sudden onset of parasympathetic dysrhythmia, sympathetic hypotension, apnea, or gastric hypermotility during stimulation of any of the sensory branches of the trigeminal nerve. Clinically, the TCR has been reported in all the surgical procedures in which a structure innervated by the trigeminal nerve is involved. Although, there is an abundant literature with reports of incidences and risk factors of the TCR; the physiological significance and function of this brainstem reflex has not yet been fully elucidated. In addition, there are complexities within the TCR that requires examination and clarification. There is also a growing need to discuss its cellular mechanism and functional consequences. Therefore, the current review provides an updated examination of the TCR with a particular focus on the mechanisms and diverse nature of the TCR.

Anesthetic Influence on Occurrence and Treatment of the Trigemino-Cardiac Reflex: A Systematic Literature Review

AbstractTrigeminocardiac reflex (TCR) is defined as sudden onset of parasympathetic dysrhythmia including hypotension, apnea, and gastric hypermotility during stimulation of any branches of the trigeminal nerve. Previous publications imply a relation between TCR and depth of anesthesia. To gain more detailed insights into this hypothesis, we performed a systematic literature review.Literature about occurrence of TCR was systematically identified through searching in Cochrane Central Register of Controlled Trials (CENTRAL), PubMed (MEDLINE), EMBASE (Ovid SP), and the Institute for Scientific Information (ISI Web of Sciences) databases until June 2013, as well as reference lists of articles for risk calculation. In this study, TCR was defined as drop in mean arterial blood pressure and heart rate, both >20% to baseline. We calculated intraoperative cerebral state index (CSI) of each TCR-case using a newly developed method. These data were further divided into 3 subgroups: CSI <40 (deep anesthesia), CSI 40–60 (regular anesthesia), and CSI >60 (slight anesthesia).Including 45 studies with 910 patients, 140 (15%) presented with TCR, and 770 (85%) without TCR during operation. TCR occurrence showed a 1.2-fold higher pooled risk slighter anesthesia (CSI <40: 13%, at CSI 40–60: 21%, and at CSI >60: 27%) compared with deeper anesthesia. In addition, we could discover a 1.3-fold higher pooled risk of higher MABP drop with a strong negative correlation (r = −0.935; r2 = 0.89) and a 4.5-fold higher pooled risk of asystole during TCR under slight anesthesia compared with deeper anesthesia.Our work is the first systematic review about TCR and demonstrates clear evidence for TCR occurrence and a more severe course of the TCR in slight anesthesia underlying the importance of skills in anesthesia management during skull base surgery. Furthermore, we have introduced a new standard method to calculate the depth of anesthesia.

Intraoperative asystole in a patient undergoing craniotomy under monitored anesthesia care: is it TCR?

nasal intubation has been used both in elective and emergent situations for maxillofacial trauma and other injuries. Checking for mouth opening is an important part of predicting difficult airway. Our patient had retrognathia and reduced thyromental distance predictive of a difficult laryngoscopy for which we were prepared, but reduced mouth opening was unanticipated; preoperative drowsiness of the patient prevented us from evaluating the mouth opening and interincisor distance. To conclude, although poliomyelitis has been largely eradicated, anesthesiologists should be aware of its uncommon sequelae that could have a bearing on anesthetic management of surgical patients. Byrappay Vinay, MD* Hanumanthapura R. Aravinda, MD, DMw Kadarapura N. Gopala Krishna, DNB, DM* Ganne S. Umamaheswara Rao, MD* Departments of *Neuroanaesthesia wNeuroimaging and Interventional Radiology, National Institute of Mental Health and Neurosciences (NIMHANS) Bangalore, India

Chronic trigemino-cardiac reflex in patient with orbital floor fracture: role of surgery and first description.

To JNA Readers:Isolated orbital floor fracture comprises 10% of all the facial fractures. The surgical repair is usually indicated in patients when enopthalmos or diplopia interfere with patients’ physical activities or if there is severe entrapment. However, we have highlighted the mechanism of deb

Trigeminocardiac reflex: current trends.

Since the first introduction of the trigeminocardiac reflex (TCR) in 1999, substantial new knowledge about this brainstem reflex has been created. First, by different clinical case reports and case studies, and second, from basic research that gives inputs from bench to bedside. In the present work, the authors therefore introduce the molecular/anatomical knowledge of the TCR and show its different connections to clinical aspects. Special reference is given to prevention and treatment of the TCR; but always with a link to knowledge of the basis sciences. In such a context different topics of future interest are introduced.

Coronary Spasm in Neurosurgical Patients and Role of Trigeminocardiac Reflex

Background. Coronary artery spasm (CAS) is a rarely reported complication in neurosurgical patients and its main causative mechanism was attributed to vagal mediated responses. However, these may be the unusual manifestations of trigeminal cardiac reflex (TCR) which is a well established brain stem reflex observed in various neurosurgical patients. Methods and Results. In this review, we have searched for the case reports/papers related to intraoperative coronary spasm in neurosurgical patients and described the role of TCR in this regard. TCR is a possible mechanism in producing CAS in most of the cases in which stimulation occurred at or near the vicinity of trigeminal nerve. It is likely that TCR mediated coronary spasm may be a physiological mechanism and not related to actual myocardial insult apparent by cardiac enzymes or echocardiography studies in most of the cases. Some common risk factors may also exist related to occurrence of CAS as well as TCR. Conclusions. In conclusion, neurosurgical procedures occurring at the vicinity of trigeminal nerve may produce CAS even in previously healthy patients and may produce catastrophic consequences. There is a need for future reports and experimental studies on the interaction of TCR and pathophysiological mechanisms related to CAS.

Topical lidocaine to suppress trigemino-cardiac reflex

cardiac reflex Editor—We appreciate Chigurupati and colleagues for the manuscript related to the topical administration of lidocaine during intra-operative repetitive occurrence of the trigeminocardiac reflex (TCR) during microvascular decompression (MVD). As the senior author of this letter was the first to introduce the TCR in skull base surgery and in MVD, we would like to give our views related to this case. – 3 As discussed in the case, the effectiveness of atropine use alone is questionable because it does not completely prevent bradycardia or hypotension as described in the related physiological contexts. 4 However, the combination of both atropine and topical instillation of local anaesthetic lidocaine has been shown to suppress the TCR completely in a few cases. Till now, the pathophysiological mechanism and the risk factors related to TCR are not fully elucidated; therefore, it does not seem plausible to make recommendation for the use of combination therapy (atropine and local anaesthetic). 4 In addition, during these types of procedures, the traction over nerve or related zone is found to be the commonest and the most potent stimulus for inciting TCR; therefore, avoidance or minimization of traction is usually recommended as first line of therapy. – 5 Moreover, block of nerve stimuli by local anaesthetics do not always prevent or abort the TCR episodes. In summary, the knowledge of pathophysiological mechanisms and risk factors related to TCR needs further extensive research and future recommendations for specific management of TCR would be guided by these results.

How to apply case reports in clinical practice using surrogate models via example of the trigeminocardiac reflex

Case reports are an increasing source of evidence in clinical medicine. Until a few years ago, such case reports were emerged into systematic reviews and nowadays they are often fitted to the development of clinical (thinking) models. We describe this modern progress of knowledge creation by the example of the trigeminocardiac reflex that was first described in 1999 by a case series and was developed over the cause-and-effect relationship, triangulation to systematic reviews and finally to thinking models. Therefore, this editorial not only underlines the increasing and outstanding importance of (unique) case reports in current science, but also in current clinical decision-making and therefore also that of specific journals like the Journal of Medical Case Reports.

Controversies in the Anesthetic Management of Intraoperative Rupture of Intracranial Aneurysm

Despite great advancements in the management of aneurysmal subarachnoid hemorrhage (SAH), outcomes following SAH rupture have remained relatively unchanged. In addition, little data exists to guide the anesthetic management of intraoperative aneurysm rupture (IAR), though intraoperative management may have a significant effect on overall neurological outcomes. This review highlights the various controversies related to different anesthetic management related to aneurysm rupture. The first controversy relates to management of preexisting factors that affect risk of IAR. The second controversy relates to diagnostic techniques, particularly neurophysiological monitoring. The third controversy pertains to hemodynamic goals. The neuroprotective effects of various factors, including hypothermia, various anesthetic/pharmacologic agents, and burst suppression, remain poorly understood and have yet to be further elucidated. Different management strategies for IAR during aneurysmal clipping versus coiling also need further attention.