Ketamine and decrease of oculocardiac reflex

The clinical surrogate definition of the trigeminocardiac reflex: Development of an optimized model according to a PRISMA-compliant systematic review

BACKGROUND

The trigeminocardiac reflex (TCR) is defined as sudden onset of parasympathetic dysrhythmias including hemodynamic irregularities, apnea, and gastric hypermotility during stimulation of sensory branches of the trigeminal nerve. Since the first description of the TCR 1999, there is an ongoing discussion about a more flexible than the existing clinical definition. Aim of this work was to create a clinical surrogate definition through a systematic review of the literature.

METHODS

In this meta-analysis study, literature about TCR occurrences was, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement, systematically identified through various search engines including PubMed (Medline), Embase (Ovid SP), and ISI Web of Sciences databases from January 2005 to August 2015. TCR was defined as a drop of heart rate (HR) below 60 bpm or 20% to the baseline. We extracted detailed data about hemodynamic changes and searched for connections between arterial blood pressure (BP) and HR changes during such episodes.

RESULTS

Overall 45 studies harboring 57 patients were included in the study but only 32 patients showed sufficient data for final analyze. HR showed a nonlinear behavior with a "tipping point" phenomena that differs in variance from the central/peripheral (20-30% drop) to ganglion (40-49% drop). BP showed a linear behavior with a "central limit" phenomena not differing in variance in the whole subgroup (30-39% drop). An analyzation of the correlation between BP and HR showed a trend to a linear correlation.

CONCLUSIONS

We can show for the first time that HR is the dominant variable in the TCR and present a new surrogate definition model. This model and the role of BP must be better investigated in further studies.

Sudden Infant Death Syndrome - Role of Trigeminocardiac Reflex: A Review

Sudden infant death syndrome (SIDS) is an unexplained death in infants, which usually occurs during sleep. The cause of SIDS remains unknown and multifactorial. In this regard, the diving reflex (DR), a peripheral subtype of trigeminocardiac reflex (TCR), is also hypothesized as one of the possible mechanisms for this condition. The TCR is a well-established neurogenic reflex that manifests as bradycardia, hypotension, apnea, and gastric hypermotility. The TCR shares many similarities with the DR, which is a significant physiological adaptation to withstand hypoxia during apnea in many animal species including humans in clinical manifestation and mechanism of action. The DR is characterized by breath holding (apnea), bradycardia, and vasoconstriction, leading to increase in blood pressure. Several studies have described congenital anomalies of autonomic nervous system in the pathogenesis of SIDS such as hypoplasia, delayed neuronal maturation, or decreased neuronal density of arcuate nucleus, hypoplasia, and neuronal immaturity of the hypoglossal nucleus. The abnormalities of autonomic nervous system in SIDS may explain the role of TCR in this syndrome involving sympathetic and parasympathetic nervous system. We reviewed the available literature to identify the role of TCR in the etiopathogenesis of SIDS and the pathways and cellular mechanism involved in it. This synthesis will help to update our knowledge and improve our understanding about this mysterious, yet common condition and will open the door for further research in this field.

Comparative Study of Atropine Combined with Sodium Nitroprusside Pretreatment to Prevent Trigemino Cardiac Reflex after Trigeminal Ganglion Compression

INTRODUCTION

Manipulation of percutaneous compression of the trigeminal ganglion (PCTG) for trigeminal neuralgia (TN) can lead to significant haemodynamic changes, which were termed trigemino cardiac reflex (TCR). Nevertheless, many studies indicated that atropine pretreatment can reduce the incidence of bradycardia and cardiac arrest, but do not take precautions against abrupt rise of blood pressure.

AIM

The purpose of our study was to compare control group {patients receiving Sodium Nitro-Prusside (SNP) pretreatment before PCTG} with study groups (patients receiving different doses of atropine combined with SNP pretreatment before PCTG) in cardiovascular parameters {Systolic Blood Pressure (SBP), Diastolic Blood Pressure (DBP) and Heart Rate (HR)} at 5 periods during Total Intravenous Anaesthesia (TIVA).

MATERIALS AND METHODS

In total, 120 patients, who underwent PTCG, were enrolled and randomly assigned into control group {group A (SNP pretreatment before PCTG, n=29)} and study groups {group B (0.002mg /kg atropine combined with SNP pretreatment before PCTG, n=30), C (0.004mg/kg atropine pretreatment before PCTG, n=31) and D (0.006mg/kg atropine combined with SNP pretreatment before PCTG, n=30)}, the relationship between haemodynamic changes and using atropine pretreatment or not was compared. Cardiovascular parameters were measured at five periods: preoperative (T0); before puncture (T1); during compression (T2); 1 min after the compression ended (T3); and 1 min after the procedure ended (T4). Multivariate analysis of variance (MANOVA) and Pearson's χ(2) test were used, and a value of p < 0.05 was considered statistically significant.

RESULTS

Compared with the group A, means of SBP and DBP in the study groups (group B, C and D) were not observed significant differences at all time points (p>0.05), the mean values of HR showed significant differences, when compared to group C and group D at T2 and T3 (p<0.001). Meanwhile, means of SBP, DBP and HR comparison in the same group were observed between T1 and T2, to the group A, B and D, means of HR (p>0.05 vs. T1) indicated significant differences, however, there was no significant difference in group C (p>0.05). Furthermore, the incidence of post-compression tachycardia was observed in each group.

CONCLUSION

By comparison, it seemed that 0.004mg/kg atropine pretreatment before PCTG was more reasonable for preventing significant haemodynamic changes.

Functional Outcome Changes in Surgery for Pituitary Adenomas After Intraoperative Occurrence of the Trigeminocardiac Reflex: First Description in a Retrospective Observational Study

Trigeminocardiac reflex (TCR) represents now a nearly ubiquitary phenomenon in skull base surgery. Functional relevance of the intrainterventional TCR occurrence is hitherto only proven for vestibular schwannoma. In a retrospective observational study, 19 out of 338 (8%) enrolled adult patients demonstrated a TCR during transsphenoidal/transcranial surgery for pituitary adenomas. The 2 subgroups (TCR vs non-TCR) had similar patient's characteristics, risk factors, and histology. Preoperatively, there was a similar distribution of normal pituitary function in the TCR and non-TCR subgroups. In this TCR subgroup, there was a significant decrease of that normal pituitary function after operation (37%) compared to the non-TCR group (60%) (P < 0.03). The TCR subgroup therefore demonstrated a 3.15 times (95%CI 1.15-8.68) higher risk for non-normalizing of postoperative pituitary function compared with the non-TCR subgroup (P < 0.03). It is presented, for the first time, an impact of TCR on the functional hormonal outcome after pituitary surgery and strongly underline again the importance of the TCR in clinical daily practice. As a consequence, TCR should be considered as a negative prognostic factor of hormonal normalization after surgery for pituitary adenomas that should be included into routine practice.

Trigeminocardiac reflex during cerebellopontine angle surgery: anatomical location as a new risk factor

ABSTRACT 

Aim: Trigeminocardicac reflex (TCR), a brainstem reflex, can be manifested in almost all types of surgery in the head and neck region. Patients & methods: Retrospective review of 125 patients operated on cerebellopontine angle (CPA) tumors according to strict inclusion/exclusion criteria. Results: A total of 14 out of 125 patients showed TCR during CPA tumor operation. In total, 29% of those patients presented with a meningioma located exclusively premeatal, but not retromeatal in the CPA. There was significant relationship between meningiomas subgroups and TCR (Barnard test; p < 0.05). Conclusion: Anatomical location may represent an important, but not yet described risk factor for the TCR having therefore an important role in the understanding of the TCR.

Mastication overload causes an increase in O2- production into the subnucleus oralis of the spinal trigeminal nucleus

The aim of the present study was to evaluate the production of superoxide anion (O(2)(-)) in the trigeminal complex nuclei after a functional mechanical overload of the teeth due to the preference for masticating on one side in rats. The preference for masticating on one side was induced by the discomfort due to a small abrasion of one molar; such lateralisation in mastication was confirmed by electromyography. The production of O(2)(-) was evaluated in the trigeminal nuclei by fluorescence microscopy after an injection of dihydroethidium. The results showed that there was an increased production of O(2)(-) in the subnucleus oralis of the spinal trigeminal nucleus in the same side where the mastication was preferred. This result demonstrates that an increased activity of non-painful sensory neurons can enhance the production of reactive oxygen species within the central second order sensory nuclei.

Effect of different anesthetic agents on oculocardiac reflex in pediatric strabismus surgery

PURPOSE

The oculocardiac reflex (OCR) occurs frequently during pediatric strabismus surgery. The aim of this study was to assess the effects of various anesthetic regimens on the incidence of OCR during the surgery.

METHODS

Two hundred and eighty children, 1 to 9 years old, undergoing elective strabismus surgery, were randomly assigned to eight groups; ketamine-sevoflurane (KS), ketamine-desflurane (KD), ketamine-propofol (KP), ketamine-remifentanil (KR), midazolam-sevoflurane (MS), midazolam-desflurane (MD), midazolam-propofol (MP), and midazolam-remifentanil (MR). No premedication was given. Anesthesia was induced using ketamine 1 mg kg(-1) or midazolam 0.15 mg kg(-1) with 66% N(2)O in O(2). Laryngeal mask airways (LMAs) were placed with rocuronium 0.5 mg kg(-1). Anesthesia was maintained with sevoflurane 2-3 vol. %, desflurane 5-6 vol. %, propofol 7-8 mg kg(-1) h(-1), or remifentanil 0.75 microg kg(-1) over 1 min, followed by a continuous infusion of remifentanil 0.5 microg kg(-1) min(-1) with 66% N(2)O in O(2). Heart rate (HR) was recorded during extraocular muscle (EOM) manipulation. OCR was defined as a reduction in HR of more than 20% induced by the traction of an EOM.

RESULTS

In patients given ketamine, OCR occurred more frequently in the KP (65.7%) and KR (62.9%) groups than in the KD (29.4%) and KS (37.1%) groups (P < 0.05). In patients given midazolam, OCR occurred more frequently in the MP (54.3%) and MR (60.6%) groups than in the MD (36.4%) and MS (31.4%) groups (P < 0.05).

CONCLUSION

Propofol or remifentanil anesthesia was associated with a higher incidence of OCR during pediatric strabismus surgery than sevoflurane and desflurane anesthesia, when either ketamine or midazolam was used as an induction agent.

The trigemino-cardiac reflex: an update of the current knowledge

The trigemino-cardiac reflex (TCR) is clinically defined as the sudden onset of parasympathetic activity, sympathetic hypotension, apnea, or gastric hypermotility during central or peripheral stimulation of any of the sensory branches of the trigeminal nerve. Clinically, the TCR has been reported to occur during craniofacial surgery, manipulation of the trigeminal nerve/ganglion and during surgery for lesion in the cerebellopontine angle, cavernous sinus, and the pituitary fossa. Apart from the few clinical reports, the physiologic function of this brainstem reflex has not yet been fully explored. The manifestation of the TCR can vary from bradycardia and hypotension to asystole. From the experimental findings, the TCR represents an expression of a central reflex leading to rapid cerebrovascular vasodilatation generated from excitation of oxygen-sensitive neurons in the rostral ventro-lateral medulla oblongata. By this physiologic response, the systemic and cerebral circulations may be adjusted in a way that augments cerebral perfusion. This review summarizes the current state of knowledge about TCR.