scholarly journals Effects of acute controlled changes in end-tidal carbon dioxide on the diameter of the optic nerve sheath: a transorbital ultrasonographic study in healthy volunteers

Anaesthesia ◽  
2017 ◽  
Vol 72 (5) ◽  
pp. 618-623 ◽  
Author(s):  
M. Dinsmore ◽  
J. S. Han ◽  
J. A. Fisher ◽  
V. W. S. Chan ◽  
L. Venkatraghavan
Keyword(s):  
Carbon Dioxide ◽  
Optic Nerve ◽  
Healthy Volunteers ◽  
Optic Nerve Sheath ◽  
Nerve Sheath ◽  
End Tidal Carbon Dioxide ◽  
End Tidal

scholarly journals Changes in Optic Nerve Sheath Diameter in Response to Various Levels of End-Tidal Carbon Dioxide in Healthy Patients under General Anesthesia

2018 ◽  
Vol 05 (02) ◽  
pp. 94-97
Author(s):  
Indu Kapoor ◽  
Ankur Khandelwal ◽  
Charu Mahajan ◽  
Hemanshu Prabhakar ◽  
Parmod Kumar Bithal
Keyword(s):  
Carbon Dioxide ◽  
Optic Nerve ◽  
General Anesthesia ◽  
Optic Nerve Sheath Diameter ◽  
Nerve Sheath ◽  
End Tidal Carbon Dioxide ◽  
Two Measures ◽  
The Difference ◽  
End Tidal ◽  
Different Levels

Abstract Background Intracranial pressure (ICP) monitoring is an essential component in management of traumatic brain-injured (TBI) patients. While invasive techniques are associated with many complications, noninvasive nature of ultrasonographic measurement of optic nerve sheath diameter (ONSD) is now becoming popular. Carbon dioxide (CO2) alters the ICP by changing the size of cerebral vasculature. We aimed to assess the effect of (hypercarbia and hypocarbia) different levels of end-tidal carbon dioxide (EtCO2) on ONSD. Methods Thirty adult patients aged between 18 and 65 years, undergoing brachial plexus injury surgery under general anesthesia, were enrolled. Following standard anesthetic protocol, ONSD was measured at different time points of EtCO2. ONSD was measured at EtCO2 of 40 and then 30 mm Hg to assess change in ONSD due to hypocarbia (Thypocarbia). Similarly, ONSD was measured at EtCO2 of 50 mm Hg to assess change in ONSD due to hypercarbia (Thypercarbia). The mean of three ONSD values at each time point was taken as the final value. The generalized estimating equation (GEE) was used to analyze correlation between different levels of EtCO2 and ONSD. Results The calculated 95% confidence interval (CI) for the difference of two measures (Thypocarbia, EtCO2 40 and 30 mm Hg) on ONSD was −0.056 to −0.036, and the calculated CI for the difference of other two measures (Thypercarbia, EtCO2 40 and 50 mm Hg) on ONSD was 0.044 to 0.077, and thus were observed to be significant. Conclusions ONSD changes significantly in response to different EtCO2 levels in healthy non-neurosurgical patients under general anesthesia.

Phase I Safety Assessment of Intrathecal Neostigmine Methylsulfate in Humans 

1995 ◽  
Vol 82 (2) ◽  
pp. 331-343 ◽  
Author(s):  
David D. Hood ◽  
James C. Eisenach ◽  
Robin Tuttle
Keyword(s):  
Carbon Dioxide ◽  
Blood Pressure ◽  
Heart Rate ◽  
Side Effects ◽  
Healthy Volunteers ◽  
Nausea And Vomiting ◽  
Severe Nausea ◽  
End Tidal Carbon Dioxide ◽  
End Tidal ◽  
Ice Water

Background In dogs, sheep, and rats, spinal neostigmine produces analgesia alone and enhances analgesia from alpha 2-adrenergic agonists. This study assesses side effects and analgesia from intrathecal neostigmine in healthy volunteers. Methods After institutional review board approval and informed consent, 28 healthy volunteers were studied. The first 14 volunteers received neostigmine (50-750 micrograms) through a #19.5 spinal needle followed by insertion of a spinal catheter. The remaining 14 volunteers received neostigmine through a #25 or #27 spinal needle without a catheter. Safety measurements included blood pressure, heart rate, oxyhemoglobin saturation, end-tidal carbon dioxide, neurologic evaluation, and computer tests of vigilance and memory. Analgesia in response to ice water immersion was measured. Results Neostigmine (50 micrograms) through the #19.5 needle did not affect any measured variable. Neostigmine (150 micrograms) caused mild nausea, and 500-750 micrograms caused severe nausea and vomiting. Neostigmine (150-750 micrograms) produced subjective leg weakness, decreased deep tendon reflexes, and sedation. The 750-micrograms dose was associated with anxiety, increased blood pressure and heart rate, and decreased end-tidal carbon dioxide. Neostigmine (100-200 micrograms) in saline, injected through a #25 or #27 needle, caused protracted, severe nausea, and vomiting. This did not occur when dextrose was added to neostigmine. Neostigmine by either method of administration reduced visual analog pain scores to immersion of the foot in ice water. Conclusions The incidence and severity of these adverse events from intrathecal neostigmine appears to be affected by dose, method of administration, and baricity of solution. These effects in humans are consistent with studies in animals. Because no unexpected or dangerous side effects occurred, cautious examination of intrathecal neostigmine alone and in combination with other agents for analgesia is warranted.

scholarly journals Correction: Transorbital Sonographic Evaluation of Normal Optic Nerve Sheath Diameter in Healthy Volunteers in Bangladesh

PLoS ONE ◽  
2014 ◽  
Vol 9 (1) ◽  
Author(s):  
Rapeephan R. Maude ◽  
Md Amir Hossain ◽  
Mahtab Uddin Hassan ◽  
Sophie Osbourne ◽  
Katherine Langan ◽  
...  
Keyword(s):  
Optic Nerve ◽  
Healthy Volunteers ◽  
Optic Nerve Sheath Diameter ◽  
Optic Nerve Sheath ◽  
Sonographic Evaluation ◽  
Nerve Sheath
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