A recent study by Tulane graduate student William
Lippert (below) suggests that federal guidelines on the
length of needles used to vaccinate children may not be
safe for all patients.
| A recent study by Tulane graduate student William C. Lippert suggests that federal guidelines on the length of needles used to vaccinate children may not be safe for all patients.
“The current needle length requirements from CDC [Centers for Disease Control and Prevention] do not account for variability in fat thickness among patients and can cause pain or damage to the bone in the patient who receives the vaccination,” explains Lippert, who recently published the results of his study in the American Academy of Pediatrics Journal.
The study is the first to determine the risk for overpenetration and underpenetration with MRI/CT measurements of a wide range of children within the United States.
Several research groups have studied the risk for short needles' inadvertently underpenetrating the muscle layers and delivering the vaccine in the fat tissue. However, the potential for needle overpenetration into the bone has been given little examination because of its perception as being a minor problem, says Lippert.
Lippert and Dr. Eric Wall, director of orthopaedic surgery at the Cincinnati Children’s Hospital, reviewed a total of 250 MRI and computed tomography scans of shoulders and thighs of children who were 2 months to 18 years of age at a large children’s hospital. The authors began the study in 2005, collecting data from the previous ten years. The thicknesses of fat tissue and muscle layers were measured and correlated with age and weight.
The study found that nearly four in 10 babies under the age of one would suffer from overpenetration of needles if they received injections in the thigh with the size needles that are typically recommended. One-inch needles, also recommended by CDC, would cause overpenetration 11 percent of the time, according to the study.
“Nurses commonly say that if they feel they have hit the bone, they simply pull the needle back. However, by then the damage may have already been done. By puncturing the bone, needles can stunt a child’s growth,” said Lippert.
Lippert proposes new guidelines that vary according to a patient’s age, weight, and gender. His findings show that his recommendations would ensure safe vaccinations for 90 percent of patients and eliminate the risk of overpenetration for all patients.
“We believe that our findings should be considered with clinical judgment. Overpenetration is an issue that hasn’t really been explored before, and our study raises important questions," says Lippert. “We would like to see other researchers replicate the study.”
Lippert expects to graduate with an MPH in epidemiology in May 2009. |
