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Evaluation of clinical efficacy and safety of cervical trauma collars: differences in immobilization, effect on jugular venous pressure and patient comfort.

Karason S, Reynisson K, Sigvaldason K, Sigurdsson GH - Scand J Trauma Resusc Emerg Med (2014)

Bottom Line: The mean neck movement (53 ± 9°) decreased significantly with all the collars (p < 0.001) from 18 ± 7° to 25 ± 9° (SN < MJ < PH < VI).Stifneck and Miami J collars offered the most efficient immobilization of the neck with the least effect on JVP.The methodology used in this study may offer a new approach to evaluate clinical efficacy and safety of neck collars and aid their continued development.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Anesthesia and Intensive Care, Landspitali University Hospital, Reykjavik, Iceland. skarason@landspitali.is.

ABSTRACT

Background: Concern has been raised that cervical collars may increase intracranial pressure in traumatic brain injury. The purpose of this study was to compare four types of cervical collars regarding efficacy of immobilizing the neck, effect on jugular venous pressure (JVP), as a surrogate for possible effect on intracranial pressure, and patient comfort in healthy volunteers.

Methods: The characteristics of four widely used cervical collars (Laerdal Stifneck(®) (SN), Vista(®) (VI), Miami J Advanced(®) (MJ), Philadelphia(®) (PH)) were studied in ten volunteers. Neck movement was measured with goniometry, JVP was measured directly through an endovascular catheter and participants graded the collars according to comfort on a scale 1-5.

Results: The mean age of participants was 27 ± 5 yr and BMI 26 ± 5. The mean neck movement (53 ± 9°) decreased significantly with all the collars (p < 0.001) from 18 ± 7° to 25 ± 9° (SN < MJ < PH < VI). There was a significant increase in mean JVP (9.4 ± 1.4 mmHg) with three of the collars, but not with SN, from 10.5 ± 2.1 mmHg to 16.3 ± 3.3 mmHg (SN < MJ < VI < PH). The grade of comfort between collars varied from 4.2 ± 0.8 to 2.2 ± 0.8 (VI > MJ > SN > PH).

Conclusion: Stifneck and Miami J collars offered the most efficient immobilization of the neck with the least effect on JVP. Vista and Miami J were the most comfortable ones. The methodology used in this study may offer a new approach to evaluate clinical efficacy and safety of neck collars and aid their continued development.

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The relationship between intracranial volumes and intracranial pressures (ICP). The figure shows the different compartments within the skull, and what happens to them and the ICP (broken line) when a new pathological compartment appears. As volume increases inside the skull compensation may occur up to a certain limit by decreasing cerebrospinal fluid (CSF) and venous blood inside it. A neck collar may obstruct venous outflow, hampering this mechanism and causing a move to the right on the ICP curve. How much ICP will increase will depend on where on the pressure curve the patient is positioned.
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Figure 1: The relationship between intracranial volumes and intracranial pressures (ICP). The figure shows the different compartments within the skull, and what happens to them and the ICP (broken line) when a new pathological compartment appears. As volume increases inside the skull compensation may occur up to a certain limit by decreasing cerebrospinal fluid (CSF) and venous blood inside it. A neck collar may obstruct venous outflow, hampering this mechanism and causing a move to the right on the ICP curve. How much ICP will increase will depend on where on the pressure curve the patient is positioned.

Mentions: It has been shown that different types of cervical collars immobilize the cervical spine variably well [6-10]. Also, concern has been raised that neck collars may increase intracranial pressure (ICP) [11] in patients with head injury by hindering venous outflow through neck veins, acting as a tourniquet around the neck, adding to intracranial blood volume and pressure (Figure 1) [12]. The effect of a rigid neck collar on ICP has been studied in head trauma patients with direct intracranial pressure measurement showing a mean increase of 4.5 mmHg [13-15]. Since it is difficult to perform comparative studies on such a vulnerable population as trauma victims, risking increase of ICP to dangerous levels, surrogate markers have been sought. In healthy subjects a 37% increase in the cross-sectional area of the internal jugular vein, measured by ultrasound, has been shown after application of a cervical collar thought to reflect increased jugular vein pressure [16]. However, measurement with ultrasound is technically difficult as most collars do not allow access of an ultrasound probe to the area over the jugular veins, and, even so, just the pressure exerted by the probe on the skin above the jugular vein may influence the results of measurements.


Evaluation of clinical efficacy and safety of cervical trauma collars: differences in immobilization, effect on jugular venous pressure and patient comfort.

Karason S, Reynisson K, Sigvaldason K, Sigurdsson GH - Scand J Trauma Resusc Emerg Med (2014)

The relationship between intracranial volumes and intracranial pressures (ICP). The figure shows the different compartments within the skull, and what happens to them and the ICP (broken line) when a new pathological compartment appears. As volume increases inside the skull compensation may occur up to a certain limit by decreasing cerebrospinal fluid (CSF) and venous blood inside it. A neck collar may obstruct venous outflow, hampering this mechanism and causing a move to the right on the ICP curve. How much ICP will increase will depend on where on the pressure curve the patient is positioned.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4066830&req=5

Figure 1: The relationship between intracranial volumes and intracranial pressures (ICP). The figure shows the different compartments within the skull, and what happens to them and the ICP (broken line) when a new pathological compartment appears. As volume increases inside the skull compensation may occur up to a certain limit by decreasing cerebrospinal fluid (CSF) and venous blood inside it. A neck collar may obstruct venous outflow, hampering this mechanism and causing a move to the right on the ICP curve. How much ICP will increase will depend on where on the pressure curve the patient is positioned.
Mentions: It has been shown that different types of cervical collars immobilize the cervical spine variably well [6-10]. Also, concern has been raised that neck collars may increase intracranial pressure (ICP) [11] in patients with head injury by hindering venous outflow through neck veins, acting as a tourniquet around the neck, adding to intracranial blood volume and pressure (Figure 1) [12]. The effect of a rigid neck collar on ICP has been studied in head trauma patients with direct intracranial pressure measurement showing a mean increase of 4.5 mmHg [13-15]. Since it is difficult to perform comparative studies on such a vulnerable population as trauma victims, risking increase of ICP to dangerous levels, surrogate markers have been sought. In healthy subjects a 37% increase in the cross-sectional area of the internal jugular vein, measured by ultrasound, has been shown after application of a cervical collar thought to reflect increased jugular vein pressure [16]. However, measurement with ultrasound is technically difficult as most collars do not allow access of an ultrasound probe to the area over the jugular veins, and, even so, just the pressure exerted by the probe on the skin above the jugular vein may influence the results of measurements.

Bottom Line: The mean neck movement (53 ± 9°) decreased significantly with all the collars (p < 0.001) from 18 ± 7° to 25 ± 9° (SN < MJ < PH < VI).Stifneck and Miami J collars offered the most efficient immobilization of the neck with the least effect on JVP.The methodology used in this study may offer a new approach to evaluate clinical efficacy and safety of neck collars and aid their continued development.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Anesthesia and Intensive Care, Landspitali University Hospital, Reykjavik, Iceland. skarason@landspitali.is.

ABSTRACT

Background: Concern has been raised that cervical collars may increase intracranial pressure in traumatic brain injury. The purpose of this study was to compare four types of cervical collars regarding efficacy of immobilizing the neck, effect on jugular venous pressure (JVP), as a surrogate for possible effect on intracranial pressure, and patient comfort in healthy volunteers.

Methods: The characteristics of four widely used cervical collars (Laerdal Stifneck(®) (SN), Vista(®) (VI), Miami J Advanced(®) (MJ), Philadelphia(®) (PH)) were studied in ten volunteers. Neck movement was measured with goniometry, JVP was measured directly through an endovascular catheter and participants graded the collars according to comfort on a scale 1-5.

Results: The mean age of participants was 27 ± 5 yr and BMI 26 ± 5. The mean neck movement (53 ± 9°) decreased significantly with all the collars (p < 0.001) from 18 ± 7° to 25 ± 9° (SN < MJ < PH < VI). There was a significant increase in mean JVP (9.4 ± 1.4 mmHg) with three of the collars, but not with SN, from 10.5 ± 2.1 mmHg to 16.3 ± 3.3 mmHg (SN < MJ < VI < PH). The grade of comfort between collars varied from 4.2 ± 0.8 to 2.2 ± 0.8 (VI > MJ > SN > PH).

Conclusion: Stifneck and Miami J collars offered the most efficient immobilization of the neck with the least effect on JVP. Vista and Miami J were the most comfortable ones. The methodology used in this study may offer a new approach to evaluate clinical efficacy and safety of neck collars and aid their continued development.

Show MeSH
Related in: MedlinePlus