An angled insertion technique using 6-mm needles markedly reduces the risk of intramuscular injections in children and adolescents.
OBJECTIVE
The aims of this study were (i) to establish which children with Type 1 diabetes are at risk of intramuscular or intradermal insulin injections and (ii) to determine a needle length and technique that reliably administers insulin into subcutaneous fat.


METHODS
Seventy-two healthy diabetic children (age 6.3-14.3 years, body mass index standard deviation score 1.0 +/- 1.4) were recruited for study 1 and 37 of this cohort participated in study 2. In study 1, 200 microl air was injected into the abdomen and anterior thigh by a pinched skin-fold technique using either a perpendicular insertion of NovoFine(R) 31G 6-mm or an angled insertion of NovoFine(R) 30G 8-mm needles. In study 2, subjects received injections into abdomen and anterior thigh via angled 6-mm needles with either an unpinched or pinched technique. The site of air injection was visualized by ultrasound scan and measurements taken of subcutaneous fat thickness.


RESULTS
In study 1, intramuscular injections were detected in 32% of subjects, and in a further 22% air was visualized at the muscle fascia. In study 2, intramuscular injections occurred in 3% of subjects and a further 11% had muscle fascia air detected. No intramuscular injections occurred in subjects injecting with a 6-mm needle and an angled pinched skin-fold technique. Pinching abdomen and thigh skin folds increased the subcutaneous fat thickness by 192 +/- 16% and 22 +/- 6%, respectively. In very lean subjects, pinching thighs actually reduced subcutaneous fat thickness.


CONCLUSIONS
While intramuscular injections were observed frequently using standard injection protocols, an angled 6-mm needle technique reliably injects into the subcutaneous fat.
Liggins Institute, University of Auckland, Auckland, New Zealand. p.hofman@aucland.ac.nz
P L
PL
Hofman
S A
SA
Lawton
J M
JM
Peart
J A
JA
Holt
C A
CA
Jefferies
E
E
Robinson
W S
WS
Cutfield
D000293:Adolescent; D002648:Child; D003922:Diabetes Mellitus, Type 1 / Q000188:drug therapy*; D004867:Equipment Design; D005260:Female; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage*; D007273:Injections, Intramuscular; D007279:Injections, Subcutaneous / Q000379:methods*; D007328:Insulin / Q000008:administration & dosage*; D008297:Male; D009339:Needles / Q000009:adverse effects; D012885:Skinfold Thickness
D007004:Hypoglycemic Agents; D007328:Insulin