Effect of 5 different cervical collars on optic nerve sheath diameter: A randomized crossover trial.
ABSTRACT: BACKGROUND:There is considerable evidence that prolonged use of cervical collars potentially cause detrimental effects including increase in optic nerve sheath diameter (ONSD) among healthy volunteers. Different types of cervical collars immobilize cervical spine variably well and may presumably differently influence the venous compression and hence the intracranial pressure. We therefore aimed to evaluate the influence of cervical spine immobilization with 5 different types of cervical collars on ONSD measured noninvasively by ultrasound on healthy volunteers. METHODS:We conducted a randomized crossover trial including 60 adult healthy volunteers. Control assessment of the optic nerve sheath thickness was performed in both sagittal and transverse planes. Patient was placed supine on a transport stretcher, cervical collar was placed, and ONSD measurement was performed after 5 and 20?minutes. During the next days, the procedure was repeated with random allocation of participants and random cervical collar. RESULTS:Sixty healthy volunteers were included in our study. ONSD left diameter [mm] for the baseline was 3.8 [interquartile range (IQR): 3.65-3.93)] mm. Using AMBU after 5?min, ONSD was changed up to 4.505 (IQR 4.285-4.61; P?
Project description:Cryptococcal meningitis is associated with increased intracranial pressure (ICP). Therapeutic lumbar puncture (LP) is recommended when the initial ICP is >250 mm H2O, yet the availability of manometers in Africa is limited and not always used where available. We assessed whether intraocular pressure could be a noninvasive surrogate predictor to determine when additional therapeutic LPs are necessary.Ninety-eight human immunodeficiency virus-infected Ugandans with suspected meningitis (81% Cryptococcus) had intraocular pressure measured using a handheld tonometer (n = 78) or optic nerve sheath diameter (ONSD) measured by ultrasound (n = 81). We determined the diagnostic performance of these methods for predicting ICP vs a standard manometer.The median ICP was 225 mm H2O (interquartile range [IQR], 135-405 mm H2O). The median intraocular pressure was 28 mm Hg (IQR, 22-37 mm Hg), and median ultrasound ONSD was 5.4 mm (IQR, 4.95-6.1 mm). ICP moderately correlated with intraocular pressure (ρ = 0.45, P < .001) and with ultrasound ONSD (ρ = 0.44, P < .001). There were not discrete threshold cutoff values for either tonometry or ultrasound ONSD that provided a suitable cutoff diagnostic value to predict elevated ICP (>200 mm H2O). However, risk of elevated ICP >200 mm H2O was increased with an average intraocular pressure >28 mm Hg (relative risk [RR] = 3.03; 95% confidence interval [CI], 1.55-5.92; P < .001) or an average of ONSD >5 mm (RR = 2.39; 95% CI, 1.42-4.03; P = .003). As either intraocular pressure or ONSD increased, probability of elevated ICP increased (ie, positive predictive value increased).Noninvasive intraocular pressure measurements by tonometry or ultrasound correlate with cerebrospinal fluid opening pressure, but both are a suboptimal replacement for actual ICP measurement with a manometer.
Project description:The measurement of optic nerve sheath diameter (ONSD) has been reported as a non-invasive marker for intracranial pressure (ICP). Nevertheless, it is uncertain whether possible ONSD differences occur with age and sex in healthy and brain-injured populations. The aim of this study was to investigate the effects of sex and age on ONSD in healthy volunteers and patients with traumatic brain injury. We prospectively included 122 healthy adult volunteers (Galliera Hospital, Genova, Italy), and compared age/sex dependence of ONSD to 95 adult patients (Addenbrooke's Hospital, Cambridge, UK) with severe traumatic brain injury (TBI) requiring intubation and invasive ICP monitoring. The two groups were stratified for sex and age. Age was divided into 3 subgroups: (1) young adults: 18-44 years; (2) middle-aged adults: 45-64 years; (3) old adults: >65 years. In healthy volunteers, ONSD was significantly different between males and females [median (interquartile range): 4.2 (3.9-4.6) mm vs. 4.1 (3.6-4.2) mm (p = 0.01), respectively] and was correlated with age (R = 0.50, p < 0.0001). ONSD was significantly increased in group 3 compared to groups 2 and 1, indicating that ONSD values are higher in elderly subjects. In TBI patients, no differences in ONSD were found for sex and the correlation between ONSD and age was non-significant (R = 0.13, p = 0.20). ONSD increases with age and is significantly larger for males in healthy volunteers but not in TBI patients. Different ONSD cut-off values need not be age- or sex-adjusted for the assessment of increased ICP in TBI patients.
Project description:Purpose Monitoring of raised intracranial pressure (ICP) in patients with idiopathic intracranial hypertension (IIH) is required to prevent secondary optic nerve damage. Sonographic measurement of the optic nerve sheath diameter (ONSD) is a noninvasive method to evaluate intracranial hypertension. Different ONSD cut-off values have been reported probably due to ethnic variations. Our aim was to determine optic nerve sonographic examination cut-off points to predict raised ICP in IIH patients. Methods This case-control study was conducted on 99 IIH post-pubertal female patients (both probable and definite) and 35 age- and sex-matched healthy volunteers. Sonographic ONSD and optic nerve diameter (OND) were obtained 3 mm behind the posterior edge of the globe in a horizontal plane via a 7-13 MHz linear probe. Lumbar puncture was then carried out on the patients. Results The opening cerebrospinal fluid pressure documented in the patient group was 279.64 ± 65.97 mm H2O. A statistically significant difference was found between IIH patients and controls regarding ONSD. The best ONSD cut-off value indicating raised ICP was 6.05 mm with an area under the curve of 0.850 (95% confidence interval 0.805 to 0.894, 73.2% sensitivity and 91.4% specificity). Regarding OND/ONSD ratio, there was an insignificant difference between both groups. Conclusion Sonographic ONSD but not OND/ONSD ratio could offer a bedside adjunct or alternative indicator of elevated ICP in IIH patients. Ethnic differences, however, should be noted when using this parameter.
Project description:BACKGROUND:Pneumoperitoneum and steep Trendelenburg position during robot-assisted laparoscopic prostatectomy (RALP) can increase intracranial pressure (ICP). Dexmedetomidine, a highly selective alpha-2 adrenergic receptor agonist, can cause cerebral vasoconstriction and decrease cerebral blood flow by stimulating the postsynaptic alpha-2 adrenergic receptors on cerebral blood vessels. However, the effects of dexmedetomidine on ICP are controversial and have not been evaluated during RALP under the establishment of pneumoperitoneum in the steep Trendelenburg position. Therefore, we evaluated the effect of dexmedetomidine on optic nerve sheath diameter (ONSD) as a surrogate for assessing ICP during RALP. METHODS:Patients were randomly allocated to receive dexmedetomidine (n =?63) (loading dose, 1??g/kg for 10 minutes and continuous infusion, 0.4??g/kg/hr) or normal saline (n =?63). The ONSD was measured at 10 minutes after induction of anesthesia in the supine position (T1), 30 minutes (T2) and 60 minutes (T3) after establishment of pneumoperitoneum in the steep Trendelenburg position, and at closing the skin in the supine position (T4). Hemodynamic and respiratory variables were measured at every time point. RESULTS:ONSDs at T2, T3, and T4 were significantly smaller in the dexmedetomidine group than in the control group (5.26?±?0.25?mm vs 5.71?±?0.26?mm, 5.29?±?0.24?mm vs 5.81?±?0.23?mm, and 4.97?±?0.24?mm vs 5.15?±?0.28?mm, all P?<.001). ONSDs at T2, T3, and T4 were significantly increased compared to T1 in both groups. Hemodynamic and respiratory variables, except heart rate, did not significantly differ between the 2 groups. The bradycardia and atropine administration were not significantly different between the 2 groups. CONCLUSION:Dexmedetomidine attenuates the increase of ONSD during RALP, suggesting that intraoperative dexmedetomidine administration may effectively attenuate the ICP increase during pneumoperitoneum in the Trendelenburg position.
Project description:OBJECTIVE:Spontaneous intracranial hypotension (SIH) is most commonly caused by cerebrospinal fluid (CSF) leakage. Therefore, we hypothesised that patients with orthostatic headache (OH) would show decreased optic nerve sheath diameter (ONSD) during changes from supine to upright position. METHODS:Transorbital B-mode ultrasound was performed employing a high-frequency transducer for ONSD measurements in the supine and upright positions. Absolute values and changes of ONSD from supine to upright were assessed. Ultrasound was performed in 39 SIH patients, 18 with OH and 21 without OH, and in 39 age-matched control subjects. The control group comprised 20 patients admitted for back surgery without headache or any orthostatic symptoms, and 19 healthy controls. RESULTS:In supine position, mean ONSD (±SD) was similar in patients with (5.38±0.91?mm) or without OH (5.48±0.89?mm; p=0.921). However, in upright position, mean ONSD was different between patients with (4.84±0.99?mm) and without OH (5.53±0.99?mm; p=0.044). Furthermore, the change in ONSD from supine to upright position was significantly greater in SIH patients with OH (-0.53±0.34?mm) than in SIH patients without OH (0.05±0.41?mm; p?0.001) or in control subjects (0.01±0.38?mm; p?0.001; area under the curve: 0.874 in receiver operating characteristics analysis). CONCLUSIONS:Symptomatic patients with SIH showed a significant decrease of ONSD, as assessed by ultrasound, when changing from the supine to the upright position. Ultrasound assessment of the ONSD in two positions may be a novel, non-invasive tool for the diagnosis and follow-up of SIH and for elucidating the pathophysiology of SIH.
Project description:The correlation of optic nerve sheath diameter (ONSD) as seen on ultrasonography (US) and directly measured intracranial pressure (ICP) has been well described. Nevertheless, differences in ethnicity and type of ICP monitor used are obstacles to the interpretation. Therefore, we investigated the direct correlation between ONSD and ventricular ICP and defined an optimal cut-off point for identifying increased ICP (IICP) in Korean adults with brain lesions.This prospective study included patients who required an external ventricular drainage (EVD) catheter for ICP control. IICP was defined as an opening pressure over 20 mmHg. ONSD was measured using a 13 MHz US probe before the procedure. Linear regression analysis and receiver operator characteristic (ROC) curve were used to assess the association between ONSD and ICP. Optimal cut-off value for identifying IICP was defined.A total of 62 patients who underwent ONSD measurement with simultaneous EVD catheter placement were enrolled in this study. Thirty-two patients (51.6%) were found to have IICP. ONSD in patients with IICP (5.80 ± 0.45 mm) was significantly higher than in those without IICP (5.30 ± 0.61 mm) (P < 0.01). The IICP group showed more significant linear correlation with ONSD (r = 0.57, P < 0.01) compared to the non-IICP group (r = 0.42, P = 0.02). ONSD > 5.6 mm disclosed a sensitivity of 93.75% and a specificity of 86.67% for identifying IICP.ONSD as seen on bedside US correlated well with directly measured ICP in Korean adults with brain lesions. The optimal cut-off point of ONSD for detecting IICP was 5.6 mm.
Project description:To evaluate the effectiveness of treatment with collar or physiotherapy compared with a wait and see policy in recent onset cervical radiculopathy.Randomised controlled trial.Neurology outpatient clinics in three Dutch hospitals.205 patients with symptoms and signs of cervical radiculopathy of less than one month's durationTreatment with a semi-hard collar and taking rest for three to six weeks; 12 twice weekly sessions of physiotherapy and home exercises for six weeks; or continuation of daily activities as much as possible without specific treatment (control group).Time course of changes in pain scores for arm and neck pain on a 100 mm visual analogue scale and in the neck disability index during the first six weeks.In the wait and see group, arm pain diminished by 3 mm/week on the visual analogue scale (beta=-3.1 mm, 95% confidence interval -4.0 to -2.2 mm) and by 19 mm in total over six weeks. Patients who were treated with cervical collar or physiotherapy achieved additional pain reduction (collar: beta=-1.9 mm, -3.3 to -0.5 mm; physiotherapy: beta=-1.9, -3.3 to -0.8), resulting in an extra pain reduction compared with the control group of 12 mm after six weeks. In the wait and see group, neck pain did not decrease significantly in the first six weeks (beta=-0.9 mm, -2.0 to 0.3). Treatment with the collar resulted in a weekly reduction on the visual analogue scale of 2.8 mm (-4.2 to -1.3), amounting to 17 mm in six weeks, whereas physiotherapy gave a weekly reduction of 2.4 mm (-3.9 to -0.8) resulting in a decrease of 14 mm after six weeks. Compared with a wait and see policy, the neck disability index showed a significant change with the use of the collar and rest (beta=-0.9 mm, -1.6 to -0.1) and a non-significant effect with physiotherapy and home exercises.A semi-hard cervical collar and rest for three to six weeks or physiotherapy accompanied by home exercises for six weeks reduced neck and arm pain substantially compared with a wait and see policy in the early phase of cervical radiculopathy. Trial registration Clinical trials NCT00129714.
Project description:Introduction. Airway management plays an essential role in anaesthesia practice, during both elective and urgent surgery procedures and emergency medicine. Aim:The aim of the study was to compare Macintosh laryngoscope (MAC), McGrath, and TruView PCD in 5 separate airway management scenarios. Methods:This prospective cross-over simulation study involved 93 paramedics. All paramedics performed intubation using direct laryngoscope (MAC), McGrath, and TruView PCD video laryngoscopes. The study was performed in 5 different scenarios: (A) normal airway, (B) tongue oedema, (C) pharyngeal obstruction, (D) cervical collar stabilization with tongue oedema, and (E) cervical collar stabilization with pharyngeal obstruction. Results:In scenario A, the success rate was 99% with MAC, 100% with McGrath, and 94% with PCD. Intubation time was 17?s (IQR: 16-21) for MAC, 18?s (IQR: 16-21) for McGrath, and 27?s (IQR: 23-34) for PCD. In scenario B, the success rate was 61% with MAC, 97% with McGrath, and 97% with PCD (p < 0.001). Intubation time was 44?s (IQR: 24-46) for MAC, 22?s (IQR: 20-27) for McGrath, and 39?s (IQR: 30-57) for PCD. In scenario C, the success rate with MAC was 74%, 97% with McGrath, and 72% with PCD (p < 0.001). Intubation time was 44?s (IQR: 24-46) for MAC, 22?s (IQR: 20-27) for McGrath, and 39?s (IQR: 30-57) for PCD. In scenario C, the success rate with MAC was 74%, 97% with McGrath, and 72% with PCD (p < 0.001). Intubation time was 44?s (IQR: 24-46) for MAC, 22?s (IQR: 20-27) for McGrath, and 39?s (IQR: 30-57) for PCD. In scenario C, the success rate with MAC was 74%, 97% with McGrath, and 72% with PCD (p < 0.001). Intubation time was 44?s (IQR: 24-46) for MAC, 22?s (IQR: 20-27) for McGrath, and 39?s (IQR: 30-57) for PCD. In scenario C, the success rate with MAC was 74%, 97% with McGrath, and 72% with PCD (. Conclusions:The McGrath video laryngoscope proved better than Truview PCD and direct intubation with Macintosh laryngoscope in terms of success rate, duration of first intubation attempt, number of intubation attempts, Cormack-Lehane grade, percentage of glottis opening (POGO score), number of optimization manoeuvres, severity of dental compression, and ease of use.
Project description:Unstable conditions of the craniocervical junction such as atlanto-occipital dislocation (AOD) or atlanto-axial instability (AAI) are severe injuries with a high risk of tetraplegia or death. Immobilization by a cervical collar to protect the patient from secondary damage is a standard procedure in trauma patients. If the application of a cervical collar to a patient with an unstable craniocervical condition may cause segmental motion and secondary injury to the spinal cord is unknown. The aim of the current study is (i) to analyze compression on the dural sac and (ii) to determine relative motion of the cervical spine during the procedure of applying a cervical collar in case of ligamentous unstable craniocervical junction.Ligamentous AOD as well as AOD combined with ligamentous AAI was simulated in two newly developed cadaveric trauma models. Compression of the dural sac and segmental angulation in the upper cervical spine were measured on video fluoroscopy after myelography during the application of a cervical collar. Furthermore, overall three-dimensional motion of the cervical spine was measured by a motion tracking system. In six cadavers each, the two new trauma models on AOD and AOD combined with AAI could be implemented. Mean dural sac compression was significantly increased to -1.1 mm (-1.3 to -0.7 mm) in case of AOD and -1.2 mm (-1.6 to -0.6 mm) in the combined model of AOD and AAI. Furthermore, there is a significant increased angulation at the C0/C1 level in the AOD model. Immense three-dimensional movement up to 22.9° of cervical spine flexion was documented during the procedure.The current study pointed out that applying a cervical collar in general will cause immense three-dimensional movement. In case of unstable craniocervical junction, this leads to a dural sac compression and thus to possible damage to the spinal cord.
Project description:In humans intimal thickening is aprerequisite of atherosclerosis. Application of a silicone collar around the rabbit carotid artery induces an intimal thickening but in addition it increases the sensitivity to the vasoconstrictor action of serotonin (5-hydroxytryptamine, 5-HT). The 5-HT receptors involved in collar-induced hypersensitivity to 5-HT were investigated using several agonists and antagonists. One week after placement of collars around both carotid arteries of anaesthetized rabbits, rings (2 mm width) from inside (=collar) and outside (=sham) the collars were mounted in organ baths (10 ml) for isometric force measurements at 6 g loading tension. Collared rings were more sensitive to the contractile effect of 5-HT (7.6 fold) and 5-carboxamidotryptamine (31 fold, 5-CT, 5-HT1 agonist) in cumulative concentration response curves. Sumatriptan (5-HT1B/1D agonist) caused concentration-dependent constrictions in collared rings only. Collar placement did not significantly alter pA2 values (Schild regression) or apparent pKb values (non-linear regression) of spiperone and methysergide (mixed 5-HT2A/5-HT1 antagonists) or ketanserin and ritanserin (5-HT2A antagonists), indicating unchanged binding characteristics of the 5-HT2A receptor. However, the reduced slope of the Schild regression pointed to a heterogeneous receptor population in collared rings. In contrast, the apparent pKb value of methiothepin (5-HT1B antagonist) was significantly reduced by collar placement, and its antagonism shifted from non-surmountable in sham rings to surmountable in collared segments. Taken together, this study demonstrates that the serotonergic receptor involved in the hypersensitivity to 5-HT of rabbit collared carotid artery is a 5-HT1B receptor subtype.