Slow versus fast subcutaneous injection of LMWH

Slow (30 seconds) subcutaneous injection of LMWH may reduce site pain intensity 48 hours after injection but may not reduce bruise size compared to fast (10 seconds) injection.

The quality of evidence is downgraded by inconsistency (statistical heterogeneity), and by imprecise results (few patients and wide confidence intervals).

Summary

A Cochrane review included 4 studies with a total of 459 subjects who received subcutaneous injections of low molecular weight heparin (LMWH) into the abdomen. Only one study reported the injected drug volume (0.4 mL). The duration of the fast injection was 10 seconds and the duration of the slow injection was 30 seconds in all included studies. 2 with the slow injection and 109.2 ± 468.66 mm2 with the fast injection, P = 0.033) and 72 hours follow-up (mean bruising size 21.72 ± 76.16 mm2 with the slow injection and 110.12 ± 472.86 mm2 with the fast injection, P = 0.025)."?> Three studies reported site pain intensity after each injection at different time points. Two studies assessed site pain intensity immediately after each injection, and meta-analysis (n=140) showed no clear difference in site pain intensity immediately post slow injection when compared to fast injection (MD -1.52, 95% CI -3.56 to 0.53, statistical heterogeneity I²=73%). In contrast, meta-analysis of 2 studies (n=59) showed that 48 hours after the heparin injection, slow injection was associated with less pain intensity compared to fast injection (MD -1.68, 95% CI -2.91 to -0.45, statistical heterogeneity I²=72%). One study (n=40) reported pain intensity at 60 and 72 hours after injection, and described no clear differences in site pain intensities at 60 hours (MD -1.0, 95% CI -2.15 to 0.15) or at 72 hours (MD -0.8, 95% CI -1.70 to 0.10). All included studies assessed bruise size at 48 hours after each injection. Meta-analysis (n=459) showed no difference in bruise size after slow injection compared to fast injection (MD -0.60, 95% CI -1.24 to 0.04; statistical heterogeneity I²=85%). None of the included studies measured the incidence of haematoma as an outcome.

Three studies reported site pain intensity after each injection at different time points. Two studies assessed site pain intensity immediately after each injection, and meta-analysis on 140 participants showed no clear difference in site pain intensity immediately post slow injection when compared to fast injection (low-quality evidence; P = 0.15). In contrast, meta-analysis of two studies with 59 participants showed that 48 hours after the heparin injection, slow injection was associated with less pain intensity compared to fast injection (low-quality evidence; P = 0.007). One study (40 participants) reported pain intensity at 60 and 72 hours after injection. This study described no clear difference in site pain intensity at 60 and 72 hours post slow injection compared to fast injection. All four included studies assessed bruise size at 48 hours after each injection. Meta-analysis on 459 participants showed no difference in bruise size after slow injection compared to fast injection (low-quality evidence; P = 0.07). None of the included studies measured the incidence of haematoma as an outcome.

Clinical comments

Note

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Ədəbiyyat

1. Mohammady M, Janani L, Akbari Sari A. Slow versus fast subcutaneous heparin injections for prevention of bruising and site pain intensity. Cochrane Database Syst Rev 2017;(11):CD008077. .