Latency of pupillary reflex dilation during general anesthesia

2004 ◽  
Vol 97 (2) ◽  
pp. 725-730 ◽  
Author(s):  
Merlin D. Larson ◽  
Peter D. Berry ◽  
Jacqueline May ◽  
Andrew Bjorksten ◽  
Daniel I. Sessler
Keyword(s):  
General Anesthesia ◽  
Noxious Stimulation ◽  
Nerve Blocks ◽  
Pupillary Reflex ◽  
Individual Measurement ◽  
C Fibers ◽  
Long Latency ◽  
Nociceptive Fibers ◽  
High Concentrations ◽  
Fentanyl Administration

Areas of insensibility produced by neuraxial anesthesia or peripheral nerve blocks can be detected during general anesthesia by failure of noxious stimulation to trigger pupillary reflex dilation. We examined the latency of pupillary reflex dilation and the effect of fentanyl on the latency of reflex dilation during anesthesia in nine volunteers. We hypothesized that the reflex was generated by slowly conducting C nociceptive fibers and would be significantly delayed if a distal dermatome (L4) was stimulated compared with a proximal dermatome (C5). We also hypothesized that fentanyl would prolong the latency and alter the shape of the reflex. After induction of general anesthesia, pupillary reflex dilation was measured with an infrared pupillometer every 5 min after stimulations of the L4 and C5 dermatomes. Fentanyl (3 μg/kg) was then given intravenously. Pupillary reflex dilation latencies were calculated by examining each individual measurement. After 3 h, naloxone (400 μg) was given intravenously; anesthesia was then discontinued. Pupillary reflex dilation had a long latency and consisted of distinct early and late phases. No differences were found between latencies of reflex dilation after simulation of L4 and C5 dermatomes either before or after fentanyl administration. Fentanyl at high concentrations essentially eliminated pupillary reflex dilation; but over the 180-min observation period, first early and then late dilation returned. Fentanyl produced a small increase in the latency of the initial early dilation. We conclude that pupillary reflex dilation during anesthesia is not initiated by slowly conducting C fibers and that fentanyl depresses the reflex in a stereotypical manner.

Pattern differences in experimental fevers induced by endotoxin, endogenous pyrogen, and prostaglandins

1988 ◽  
Vol 254 (4) ◽  
pp. R633-R640 ◽  
Author(s):  
A. Morimoto ◽  
T. Nakamori ◽  
T. Watanabe ◽  
T. Ono ◽  
N. Murakami
Keyword(s):  
Time Course ◽  
Interleukin 1 ◽  
Bacterial Endotoxin ◽  
Endogenous Pyrogen ◽  
Prolonged Time ◽  
Fever Onset ◽  
Long Latency ◽  
Low Concentrations ◽  
High Concentrations ◽  
Experimentally Induced

To distinguish pattern differences in experimentally induced fevers, we investigated febrile responses induced by intravenous (IV), intracerebroventricular (ICV), and intra-preoptic/anterior hypothalamic (POA) administration of bacterial endotoxin (lipopolysaccharide, LPS), endogenous pyrogen (EP), human recombinant interleukin-1 alpha (IL-1), and prostaglandins E2 and F2 alpha (PGE2 and PGF2 alpha). Intravenous LPS, EP, or IL-1 in high concentrations caused biphasic fever. In low concentrations, they induced only the first phase of fever. Latency to onset and time to first peak of fever induced by IV injection of LPS or EP were almost the same as those after ICV or POA injection of PGE2. Fever induced by ICV or POA administration of LPS, EP, IL-1, or PGF2 alpha had a long latency to onset and a prolonged time course. There were significant differences among the latencies to fever onset exhibited by groups that received ICV or POA injections of LPS, EP, or PGF2 alpha and by groups given IV injections of LPS or EP and ICV or POA injections of PGE2. Present observations indicate different patterns of fever produced by several kinds of pyrogens when given by various routes. These results permit us to consider the possibility that there are several mediators or multiprocesses underlying the pathogenesis of fever.

scholarly journals Comparison of Combined Lumbosacral Plexus and T12 Paravertebral Nerve Blocks With General Anesthesia in Older Adults Undergoing Primary Total Hip Arthroplasty: A Retrospective, Propensity Score–Matched Cohort Study

2020 ◽  
Vol 11 ◽  
pp. 215145932097653
Author(s):  
Li Min ◽  
Chen Chen ◽  
Yuan Yan ◽  
Shen Jiang ◽  
Yang Linyi ◽  
...  
Keyword(s):  
Total Hip Arthroplasty ◽  
Propensity Score ◽  
General Anesthesia ◽  
Hip Arthroplasty ◽  
Perioperative Complications ◽  
Lumbosacral Plexus ◽  
Cardiac Events ◽  
Nerve Blocks ◽  
Total Hip ◽  
Hip Disease

Background: Total Hip Arthroplasty(THA) is a surgical treatment for hip disease. A large amount of evidence has been reported on comparing outcomes of neuraxial(spinal or epidural) anesthesia and general anesthesia. However, it is unclear whether nerve blocks(NB) as main anesthesia technique compared with general anesthesia(GA) for THA could reduce perioperative complications. We conducted a retrospective evaluation of NB and GA, using a propensity score-matched analysis(PSMA). Methods: A total of 902 patients older than 60 years old with hip disease undergoing primary THA received combined lumbosacral plexus and T12 paravertebral nerve blocks (n = 143) or GA (n = 759) at our institution from 2012 to 2018.Binary logistic regression was used for comparison of the primary outcomes(the incidence of delirium) and the secondary outcomes(the percentage of postoperative hemoglobin(>10g/dl), transfusion(>2 units), major cardiac events(MACE), postoperative pulmonary complications (PPC) and 30-day mortality) in the matched cohorts.Statistical analysis was performed using SPSS v 23.0. Results: Both cohorts were balanced in all included parameters after PSMA. The incidence of delirium was lower (OR 0.233,95% CI 0.064-0.845, p = 0.030) in NB group in matched cohorts. In the unmatched and matched cohorts, the percentage of Hb(>10g/dl) was higher in GA group but the incidence of transfusion(>2 units) was higher in NB group. No difference was found in the incidence of 30-day mortality in the unmatched and matched cohorts. In the unmatched cohorts, the incidence of PPC was higher and LOS was longer in NB cohort, but no difference was observed in the matched cohorts. Conclusion: In patients older than 60 years old receiving primary THA, NB could be associated with a lower incidence of delirium.

Nerve Blocks Under General Anesthesia

2017 ◽  
Vol 42 (3) ◽  
pp. 299-301 ◽  
Author(s):  
Melissa M. Masaracchia ◽  
Michael D. Herrick ◽  
Ellen A. Seiffert ◽  
Brian D. Sites
Keyword(s):  
General Anesthesia ◽  
Nerve Blocks

scholarly journals Anesthetic Substitute of Intraoperative Regional Anesthesia of Nonintubated or Endotracheal-intubated Video-assisted Thoracoscopic Surgery With Thoracoscopic Multilevel Intercostal Nerve Blocks: a Randomized Study

2021 ◽  
Author(s):  
Kuang-Cheng Chan ◽  
Li-Lin Wu ◽  
Su-Chuan Han ◽  
Jin-Shing Chen ◽  
Ya-Jung Cheng
Keyword(s):  
General Anesthesia ◽  
Regional Anesthesia ◽  
Surgical Stress ◽  
Thoracoscopic Surgery ◽  
Intercostal Nerve ◽  
General Anesthetics ◽  
Nerve Blocks ◽  
Video Assisted ◽  
First Case ◽  
Video Assisted Thoracoscopic Surgery

Abstract Background:A reduced need for general anesthetics and enhanced effectiveness of postoperative analgesia have been reported for multimodal anesthesia, which involves combining regional and general anesthesia. Ideal regional anesthesia to combine with general anesthesia should match but not overdo with the surgical stress from corresponding operations. However, as thoracic operation becomes less invasive, the substitute effects on intraoperative analgesia or consciousness by regional anesthesia such as with thoracoscopic intercostal nerve blocks (TINBs) for managing corresponding surgical stress in intubated or non-intubated video-assisted thoracoscopic surgery (VATS) have been inadequately studied. The goals of this study is to investigate the substituve of TINBs on analgesia and consciousness for intubated and non-intubated uniport VATS operations.Methods:Sixty patients who received VATS with target-controlled infusions of propofol and remifentanil were recruited. Patients were randomized into intubated and nonintubated groups. Intraoperative multilevel (T3–T8) TINBs were performed after artificial pneumothorax and before VATS operations. The effects of substitute on analgesia by TINBs for VATS operations were indicated by changes on blood pressure and the Ce of remifentanil to maintain normotension. EEG data with a density spectral array (DSA) and data on the effect-site concentration (Ce) of propofol goaled with bispectral index (BIS) levels between 40-60were compared to determine whether TINBs affect consciousness. Results:TINBs with 0.5% bupivacaine provide substitute more than required on analgesia for intubated and non-intubated uniport VATS operations. The Ce of remifentanil was significantly decreased beginning 10 min after TINBs in both groups (p < 0.001). In the nonintubated VATS (NIVATS) group, a significantly lower mean arterial pressure after introducing TINBs persisted for 20 min. TINBs demonstrated a DSA smoothing effect despite the subsequent VATS. The Ce of the propofol infusion decreased 5 min after TINBs in both NIVATS (p < 0.001) and intubated VATS (IVATS; p = 0.252) groups. The Ce of remifentanil was significantly higher in parallel for the IVATS group than for the NIVATS group (p < 0.001).Conclusions:Intraoperative TINBs with 0.5 % bupivacaine provides substitutes on analgesia and hyponosis more than required for uniportal intubated or non-intubated VATS operations. Situations involving endotracheal tubes required more analgesia but does not affect the substitute effects of TINBs.Trial registration: ClinicalTrials. gov, NCT03874403. This study was approved by the Research Ethics Committee of National Taiwan University Hospital, Taipei, Taiwan (201712125RINB) on February 2, 2018. We then enrolled our first case on November 1, 2018 - Retrospective registered on February 28, 2019, https://clinicaltrials.gov/ct2/show/record/NCT03874403

A novel long-latency response of locus coeruleus neurons to noxious stimuli: mediation by peripheral C-fibers

1994 ◽  
Vol 71 (5) ◽  
pp. 1752-1761 ◽  
Author(s):  
H. Hirata ◽  
G. Aston-Jones
Keyword(s):  
Sciatic Nerve ◽  
Locus Coeruleus ◽  
Short Latency ◽  
Late Response ◽  
Excitatory Response ◽  
C Fibers ◽  
Long Latency ◽  
C Fiber ◽  
Latency Response ◽  
Noxious Stimuli

1. Extracellular recordings were obtained from single presumed noradrenergic neurons in the nucleus locus coeruleus (LC) in response to percutaneous electrical foot shock (FS) stimulation in the rat. We employed long-duration stimulus pulses to examine the possible contribution of peripheral C-fibers to evoked activity in LC. 2. As in previous studies, 0.5-ms FS stimuli produced a short-latency excitatory response (onset 20.8 ms) followed by a prolonged postactivation inhibition. However, 2.0- or 5.0-ms FS stimuli yielded an additional late excitatory response. 3. The onset and termination latency of this late excitatory response were approximately 200 and 400 ms, respectively, after the FS. The conduction velocity for this late response (peripheral plus central pathway) was estimated to be < 1.2 m/s. 4. The percentages of LC neurons that exhibited a significant late response was 4% (3/85) with 0.5-ms stimuli, 53% (31/59) with 2.0-ms stimuli, and 73% (47/64) with 5.0-ms FS stimuli. 5. The average number of spikes evoked per FS stimulus (presented at 0.5 Hz) increased from the 1st to the 21st FS stimulus. This increased response occurred selectively in the late, not in the early, response. This result was interpreted to represent a “windup” phenomenon reflected at the level of LC. 6. Direct application of capsaicin onto the sciatic nerve reduced the average magnitude of the late response of LC neurons to 17% of control 42.5 min after application. The magnitude of the short-latency response components showed little or no change. 7. Averaged compound action potential (cAP) recordings from the sciatic nerve revealed that C-fiber responses were more consistently observed and much larger with 5.0-ms compared with 0.5-ms FS stimuli. 8. C-fiber cAPs were reduced or eliminated after application of capsaicin distal to the recording site with a time course similar to that of the late response of LC neurons, with little or no effect on A-fiber cAPs. 9. These data show that a previously undescribed long-latency response of LC neurons to noxious FS stimulation in rat results from C-fiber activation in the sciatic nerve. This late response may be involved in generating descending noradrenergic analgesia induced by electrical stimulation of the foot pad or other body regions. Future studies of the pharmacology of this late response to noxious stimuli in LC may aid in developing new therapies for the treatment of acute or chronic pain.

Role of pulmonary C fibers in adenosine-induced respiratory inhibition in anesthetized rats

1998 ◽  
Vol 84 (2) ◽  
pp. 417-424 ◽  
Author(s):  
Kevin Kwong ◽  
Ju-Lun Hong ◽  
Robert F. Morton ◽  
Lu-Yuan Lee
Keyword(s):  
Left Ventricular ◽  
Right Atrial ◽  
Dependent Manner ◽  
Sensory Afferents ◽  
C Fibers ◽  
Respiratory Inhibition ◽  
Anesthetized Rats ◽  
Long Latency ◽  
Therapeutic Doses

Kwong, Kevin, Ju-Lun Hong, Robert F. Morton, and Lu-Yuan Lee. Role of pulmonary C fibers in adenosine-induced respiratory inhibition in anesthetized rats. J. Appl. Physiol. 84(2): 417–424, 1998.—The clinical use of adenosine is commonly associated with pulmonary side effects, namely dyspnea, that suggest the possible involvement of bronchopulmonary sensory afferents. Our objective in this study was to characterize the effects of adenosine on breathing and to determine whether the vagal pulmonary afferents play a role in mediating these effects. We measured respiratory and cardiovascular changes in anesthetized, spontaneously breathing rats after bolus injections of adenosine at therapeutic doses. Right atrial injection of adenosine (0.04–0.6 mg/kg) elicits, in a dose-dependent manner, a pulmonary chemoreflex-like response consisting of a delayed apnea, bradycardia, and hypotension. In contrast, the classic capsaicin-elicited pulmonary chemoreflex occurs immediately after injection. Perineural capsaicin treatment of the cervical vagi blocked the adenosine-induced respiratory inhibition. Left ventricular administration of adenosine failed to elicit an apneic response. Pretreatment with the adenosine A1-receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine attenuated the adenosine-induced apnea. These results indicate that adenosine elicits a respiratory inhibition via stimulation of pulmonary C fibers and that activation of the A1-receptor is probably involved. It is unclear, however, what accounts for the exceedingly long latency in this response.

Anesthetic Principles

2020 ◽  
Author(s):  
Britlyn D. Orgill ◽  
Douglas L. Helm
Keyword(s):  
General Anesthesia ◽  
Local Anesthetic ◽  
Enhanced Recovery ◽  
Physical Status ◽  
Preoperative Risk ◽  
Nerve Blocks ◽  
Surgical Emergencies ◽  
Post Operative Pain ◽  
Joint Decisions ◽  
Selection Of

Advances in anesthesia have expanded the field of plastic surgery by allowing more procedures to be done, while also increasing the safety of the patient. Anesthesia is a spectrum ranging from local anesthetic injected by the surgeon, to regional and neuraxial blocks or general anesthesia with an anesthesia team. Anesthesiologists work with the surgeon to assess a patient’s preoperative risk and make joint decisions to determine if additional medical optimization is needed prior to surgery. New peripheral blocks allow alternatives to general anesthesia or serve as adjuncts to improve post-operative pain. Selection of drugs used to induce and maintain anesthesia are changing with the advent of Enhanced Recovery After Surgery Protocols and emphasis on decreasing opioids. Teamwork and excellent communication are imperative to navigate anesthetic and surgical emergencies.  This review contains 3 figures, 4 tables, and 29 references. Keywords: sedation, general anesthesia, regional anesthesia, peripheral nerve blocks, local anesthetic toxicity syndrome, ASA physical status, preoperative fasting guidelines, opioids, multi-modal analgesia, ERAS, crisis checklists

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