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265 Intramedullary Effects of Power-Infused Contrast by Intraosseous Access

2015; Elsevier BV; Volume: 66; Issue: 4 Linguagem: Inglês

10.1016/j.annemergmed.2015.07.299

1097-6760

Tatiana Puga, Michelle Hanes, L.J. Miller, Diana Montez, Chris Davlantes, Thomas Philbeck, Juliette Saussy,

Reconstructive Surgery and Microvascular Techniques

Study ObjectivesVascular access is critical in managing unstable patients in the emergency department (ED). For difficult vascular access patients, intraosseous (IO) vascular access is an option. Often, they may need computed tomography (CT) scans with contrast for diagnostics; administered by a power injector. IO access to deliver contrast for CT examination has been reported as safe and successful. However, evidence is limited; and consists of a few case reports, preclinical studies and one clinical study with the focus on diagnostic image adequacy. A preclinical study was conducted to examine the immediate effects of power injection of contrast media on the medullary cavity and marrow in mature swine.MethodsInstitutional Animal Care Use Committee approval was obtained. IO access was established bilaterally in the proximal humeri (PH) of anesthetized swine (N=8). One unit of blood was transfused in each site, prior to power injection, as part of another study. One proximal humerus then received power injection of 150 mL of contrast media at a rate of 5 mL/second and the contralateral limb served as the control, yielding a sample size of 7 matched pairs (one infusion malfunctioned). Fluoroscopy was used to evaluate for extravasation. Both PHIO sites were flushed with 10 mL of normal saline post-contrast injection. After the swine were euthanized both front limbs were separated from the body, at a level superior to the PHIO insertion site with the IO needle left in situ. Cross sections of the proximal humeri were cut with a diamond saw to identify the needle tip insertion site and attempts were made to include the needle tract. The pathologist was unaware of which limb had received power injection and was asked to identify any cellular or structural damage to the area immediately adjacent to the injection site in a necropsy examination of both limbs. After rapid decalcification (RDO), cassettes with tissues were processed thru graded alcohols and xylene, infused with paraffin, stained, and observed under light microscopy for lesions. Sections were observed and graded for physical differences including hematopoetic bone marrow wash out, intact stroma/fat, hemorrhage, presence of trabecula, and cortical thickness.ResultsThe mean maximum infusion pressure was 80.1 psi (range 61-95). Marrow wash-out varied by one degree or less for each pig when limbs were compared. The amount of trabecular fracture caused by the placement of the IO needle could not be histologically separated from possible loss of trabecula due to high pressure power-infusion of contrast or administration of blood. Of all samples evaluated, 6 had some degree of hemorrhage in one level, which was graded the same in 4 of the pigs, +1 in the limb without the injection for pig B and +2 for one level in an injected limb for pig F. Humeri from 2 swine showed small extraosseal extravasations. Limitations of this study include use of a swine model; and the clinical significance of the small extraosseal extravasations is unknown.ConclusionIn swine receiving power-injected contrast there was essentially no histological difference between the limbs examined post-infusion. This supports the safety of IO power infusion of CT contrast. When considered with previous studies demonstrating CT image adequacy after IO contrast administration, these findings may further support the utility of power-injected contrast delivered via the IO route. Study ObjectivesVascular access is critical in managing unstable patients in the emergency department (ED). For difficult vascular access patients, intraosseous (IO) vascular access is an option. Often, they may need computed tomography (CT) scans with contrast for diagnostics; administered by a power injector. IO access to deliver contrast for CT examination has been reported as safe and successful. However, evidence is limited; and consists of a few case reports, preclinical studies and one clinical study with the focus on diagnostic image adequacy. A preclinical study was conducted to examine the immediate effects of power injection of contrast media on the medullary cavity and marrow in mature swine. Vascular access is critical in managing unstable patients in the emergency department (ED). For difficult vascular access patients, intraosseous (IO) vascular access is an option. Often, they may need computed tomography (CT) scans with contrast for diagnostics; administered by a power injector. IO access to deliver contrast for CT examination has been reported as safe and successful. However, evidence is limited; and consists of a few case reports, preclinical studies and one clinical study with the focus on diagnostic image adequacy. A preclinical study was conducted to examine the immediate effects of power injection of contrast media on the medullary cavity and marrow in mature swine. MethodsInstitutional Animal Care Use Committee approval was obtained. IO access was established bilaterally in the proximal humeri (PH) of anesthetized swine (N=8). One unit of blood was transfused in each site, prior to power injection, as part of another study. One proximal humerus then received power injection of 150 mL of contrast media at a rate of 5 mL/second and the contralateral limb served as the control, yielding a sample size of 7 matched pairs (one infusion malfunctioned). Fluoroscopy was used to evaluate for extravasation. Both PHIO sites were flushed with 10 mL of normal saline post-contrast injection. After the swine were euthanized both front limbs were separated from the body, at a level superior to the PHIO insertion site with the IO needle left in situ. Cross sections of the proximal humeri were cut with a diamond saw to identify the needle tip insertion site and attempts were made to include the needle tract. The pathologist was unaware of which limb had received power injection and was asked to identify any cellular or structural damage to the area immediately adjacent to the injection site in a necropsy examination of both limbs. After rapid decalcification (RDO), cassettes with tissues were processed thru graded alcohols and xylene, infused with paraffin, stained, and observed under light microscopy for lesions. Sections were observed and graded for physical differences including hematopoetic bone marrow wash out, intact stroma/fat, hemorrhage, presence of trabecula, and cortical thickness. Institutional Animal Care Use Committee approval was obtained. IO access was established bilaterally in the proximal humeri (PH) of anesthetized swine (N=8). One unit of blood was transfused in each site, prior to power injection, as part of another study. One proximal humerus then received power injection of 150 mL of contrast media at a rate of 5 mL/second and the contralateral limb served as the control, yielding a sample size of 7 matched pairs (one infusion malfunctioned). Fluoroscopy was used to evaluate for extravasation. Both PHIO sites were flushed with 10 mL of normal saline post-contrast injection. After the swine were euthanized both front limbs were separated from the body, at a level superior to the PHIO insertion site with the IO needle left in situ. Cross sections of the proximal humeri were cut with a diamond saw to identify the needle tip insertion site and attempts were made to include the needle tract. The pathologist was unaware of which limb had received power injection and was asked to identify any cellular or structural damage to the area immediately adjacent to the injection site in a necropsy examination of both limbs. After rapid decalcification (RDO), cassettes with tissues were processed thru graded alcohols and xylene, infused with paraffin, stained, and observed under light microscopy for lesions. Sections were observed and graded for physical differences including hematopoetic bone marrow wash out, intact stroma/fat, hemorrhage, presence of trabecula, and cortical thickness. ResultsThe mean maximum infusion pressure was 80.1 psi (range 61-95). Marrow wash-out varied by one degree or less for each pig when limbs were compared. The amount of trabecular fracture caused by the placement of the IO needle could not be histologically separated from possible loss of trabecula due to high pressure power-infusion of contrast or administration of blood. Of all samples evaluated, 6 had some degree of hemorrhage in one level, which was graded the same in 4 of the pigs, +1 in the limb without the injection for pig B and +2 for one level in an injected limb for pig F. Humeri from 2 swine showed small extraosseal extravasations. Limitations of this study include use of a swine model; and the clinical significance of the small extraosseal extravasations is unknown. The mean maximum infusion pressure was 80.1 psi (range 61-95). Marrow wash-out varied by one degree or less for each pig when limbs were compared. The amount of trabecular fracture caused by the placement of the IO needle could not be histologically separated from possible loss of trabecula due to high pressure power-infusion of contrast or administration of blood. Of all samples evaluated, 6 had some degree of hemorrhage in one level, which was graded the same in 4 of the pigs, +1 in the limb without the injection for pig B and +2 for one level in an injected limb for pig F. Humeri from 2 swine showed small extraosseal extravasations. Limitations of this study include use of a swine model; and the clinical significance of the small extraosseal extravasations is unknown. ConclusionIn swine receiving power-injected contrast there was essentially no histological difference between the limbs examined post-infusion. This supports the safety of IO power infusion of CT contrast. When considered with previous studies demonstrating CT image adequacy after IO contrast administration, these findings may further support the utility of power-injected contrast delivered via the IO route. In swine receiving power-injected contrast there was essentially no histological difference between the limbs examined post-infusion. This supports the safety of IO power infusion of CT contrast. When considered with previous studies demonstrating CT image adequacy after IO contrast administration, these findings may further support the utility of power-injected contrast delivered via the IO route.