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Compartment elasticity measured by pressure-related ultrasound to determine patients "at risk" for compartment syndrome: an experimental in vitro study.

Sellei RM, Hingmann SJ, Kobbe P, Weber C, Grice JE, Zimmerman F, Jeromin S, Hildebrand F, Pape HC - Patient Saf Surg (2015)

Bottom Line: The compartmental depth (mm) in the cross-section view was measured before and after manual probe compression (100 mmHg) upon the surface resulting in a linear compartmental displacement (∆d).The resulting displacements were related to the corresponding intra-compartmental pressures simulated in our model.The intra-observer reliability value kappa resulted in a statistically high reliability (κ = 0.840).

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopaedic Trauma, Aachen University Medical Center, Aachen, Germany ; Department of Orthopaedic Trauma, Sana Klinikum Offenbach am Main, Offenbach am Main, Germany.

ABSTRACT

Background: Decision-making in treatment of an acute compartment syndrome is based on clinical assessment, supported by invasive monitoring. Thus, evolving compartment syndrome may require repeated pressure measurements. In suspected cases of potential compartment syndromes clinical assessment alone seems to be unreliable. The objective of this study was to investigate the feasibility of a non-invasive application estimating whole compartmental elasticity by ultrasound, which may improve accuracy of diagnostics.

Methods: In an in vitro model, using an artificial container simulating dimensions of the human anterior tibial compartment, intra-compartmental pressures (p) were raised subsequently up to 80 mmHg by infusion of saline solution. The compartmental depth (mm) in the cross-section view was measured before and after manual probe compression (100 mmHg) upon the surface resulting in a linear compartmental displacement (∆d). This was repeated at rising compartmental pressures. The resulting displacements were related to the corresponding intra-compartmental pressures simulated in our model. A hypothesized relationship between pressures related compartmental displacement and the elasticity at elevated compartment pressures was investigated.

Results: With rising compartmental pressures, a non-linear, reciprocal proportional relation between the displacement (mm) and the intra-compartmental pressure (mmHg) occurred. The Pearson coefficient showed a high correlation (r(2) = -0.960). The intra-observer reliability value kappa resulted in a statistically high reliability (κ = 0.840). The inter-observer value indicated a fair reliability (κ = 0.640).

Conclusions: Our model reveals that a strong correlation between compartmental strain displacements assessed by ultrasound and the intra-compartmental pressure changes occurs. Further studies are required to prove whether this assessment is transferable to human muscle tissue. Determining the complete compartmental elasticity by ultrasound enhancement, this application may improve detection of early signs of potential compartment syndrome.

No MeSH data available.


Related in: MedlinePlus

Correlation between intra-compartmental pressure (p) and compartmental displacement (∆d) in the in-vitro model illustrated in absolute (3a) and relative values (3b).
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Fig3: Correlation between intra-compartmental pressure (p) and compartmental displacement (∆d) in the in-vitro model illustrated in absolute (3a) and relative values (3b).

Mentions: The in-vitro compartment model simulated an ICP between 0 mmHg and 80 mmHg. The assessment of the ultrasound cross-section view was used to measure ∆d. Each measurement at a specific level of ICP was repeated six times. The over all correlation, calculated with the Pearson’s correlation coefficient, revealed a value of r2 = − 0.958. The measurements and series were repeated to determine the reliability as described before. The model was free from any leakage at any the time of measurements. With rising compartmental pressures, an inversely proportional relation between ∆d and p occurred. The results are figured in absolute and relative values (Figure 3a,b). The intra-observer reliability, quantified with the Cohen coefficient kappa (κ), revealed a mean of κ = 0.840 (n = 10). This corresponds with a statistically very strong strength of agreement. Inter-observer reliability (n = 10) showed acceptable values (κ = 0.640). There was a statistically significant difference calculated between the ∆d at pressures less than 30 mmHg and greater than 50 mmHg (p < 0.005) using the Wilcoxon test to rank these values (Table 1).Figure 3


Compartment elasticity measured by pressure-related ultrasound to determine patients "at risk" for compartment syndrome: an experimental in vitro study.

Sellei RM, Hingmann SJ, Kobbe P, Weber C, Grice JE, Zimmerman F, Jeromin S, Hildebrand F, Pape HC - Patient Saf Surg (2015)

Correlation between intra-compartmental pressure (p) and compartmental displacement (∆d) in the in-vitro model illustrated in absolute (3a) and relative values (3b).
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4305259&req=5

Fig3: Correlation between intra-compartmental pressure (p) and compartmental displacement (∆d) in the in-vitro model illustrated in absolute (3a) and relative values (3b).
Mentions: The in-vitro compartment model simulated an ICP between 0 mmHg and 80 mmHg. The assessment of the ultrasound cross-section view was used to measure ∆d. Each measurement at a specific level of ICP was repeated six times. The over all correlation, calculated with the Pearson’s correlation coefficient, revealed a value of r2 = − 0.958. The measurements and series were repeated to determine the reliability as described before. The model was free from any leakage at any the time of measurements. With rising compartmental pressures, an inversely proportional relation between ∆d and p occurred. The results are figured in absolute and relative values (Figure 3a,b). The intra-observer reliability, quantified with the Cohen coefficient kappa (κ), revealed a mean of κ = 0.840 (n = 10). This corresponds with a statistically very strong strength of agreement. Inter-observer reliability (n = 10) showed acceptable values (κ = 0.640). There was a statistically significant difference calculated between the ∆d at pressures less than 30 mmHg and greater than 50 mmHg (p < 0.005) using the Wilcoxon test to rank these values (Table 1).Figure 3

Bottom Line: The compartmental depth (mm) in the cross-section view was measured before and after manual probe compression (100 mmHg) upon the surface resulting in a linear compartmental displacement (∆d).The resulting displacements were related to the corresponding intra-compartmental pressures simulated in our model.The intra-observer reliability value kappa resulted in a statistically high reliability (κ = 0.840).

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopaedic Trauma, Aachen University Medical Center, Aachen, Germany ; Department of Orthopaedic Trauma, Sana Klinikum Offenbach am Main, Offenbach am Main, Germany.

ABSTRACT

Background: Decision-making in treatment of an acute compartment syndrome is based on clinical assessment, supported by invasive monitoring. Thus, evolving compartment syndrome may require repeated pressure measurements. In suspected cases of potential compartment syndromes clinical assessment alone seems to be unreliable. The objective of this study was to investigate the feasibility of a non-invasive application estimating whole compartmental elasticity by ultrasound, which may improve accuracy of diagnostics.

Methods: In an in vitro model, using an artificial container simulating dimensions of the human anterior tibial compartment, intra-compartmental pressures (p) were raised subsequently up to 80 mmHg by infusion of saline solution. The compartmental depth (mm) in the cross-section view was measured before and after manual probe compression (100 mmHg) upon the surface resulting in a linear compartmental displacement (∆d). This was repeated at rising compartmental pressures. The resulting displacements were related to the corresponding intra-compartmental pressures simulated in our model. A hypothesized relationship between pressures related compartmental displacement and the elasticity at elevated compartment pressures was investigated.

Results: With rising compartmental pressures, a non-linear, reciprocal proportional relation between the displacement (mm) and the intra-compartmental pressure (mmHg) occurred. The Pearson coefficient showed a high correlation (r(2) = -0.960). The intra-observer reliability value kappa resulted in a statistically high reliability (κ = 0.840). The inter-observer value indicated a fair reliability (κ = 0.640).

Conclusions: Our model reveals that a strong correlation between compartmental strain displacements assessed by ultrasound and the intra-compartmental pressure changes occurs. Further studies are required to prove whether this assessment is transferable to human muscle tissue. Determining the complete compartmental elasticity by ultrasound enhancement, this application may improve detection of early signs of potential compartment syndrome.

No MeSH data available.


Related in: MedlinePlus