Abstracts and Programme, EUROANAESTHESIA 2008: Obstetric Anaesthesia
Background and Goal of Study: Low back pain (LBP) in pregnancy is affecting a large number of patients (54.8-76.6%), nevertheless only 10% of these women receive any kind of pain therapy. We could recently demonstrate that superficial pain patterns and clinical examination allow a clear distinction of two different types of LBP. Women responding to specific manual pain provocation maneuvers revealing musculoskeletal low back pain (M-LBP) had significantly lower heat pain thresholds compared to patients with non-provocable pain (NP-LBP). We therefore hypothesized, that superficial cryotherapy of the low back provides acute pain relief only in patients suffering from provokable LBP compared to NP-LBP-patients.
Materials and Methods: After approval by the local ethics committee 30 pregnant women in the third trimester with low back pain were included into this prospective, double-blinded (in respect to the patient groups) study. Pregnant women suffering from LBP measured by a visual analog scale (VAS, 0-10 cm) > 3 were assigned to the 2 different study groups (M-LBP or NP-LBP) by means of 3 short pain provocation tests for muskuloskeletal pain (independent investigator). In a first study session a cool pack (35cm × 17cm, “blue bell”, Germany, 4°C) was applied for 15 minutes to the lower back region. Spontaneous pain scores were rated before and after treatment. The treatment was repeated at home 3 times a day during 5 days (pain diary). Mean differences (± SD) at baseline and after treatment were calculated and compared between the groups.
Results and Discussion: 18 patients of the 30 patients were assigned to the M-LBP-group. The baseline pain scores showed greater pain in the M-LBP group (VAS 5.4±1.5) compared to the NP-LBP group (VAS 4.6±1.4). Under the initial laboratory conditions the cool pack reduced LBP significantly in both groups (M-LBP: 5.4±1.5→/3.2±1.7 // NP-LBP: 4.6±1.4 → 2.6±1.9). Treatment at home lead to a highly significant pain reduction only in the M-LBP-group (6±0.7 → 3.6±0.6, p < 0.0001), whereas a small pain reduction was found in the NP-LBP-group (4±0.6 → 3.1±0.7). The mean reduction of pain for the NP-LBP-group was 0.8 cm and 2.5 cm in the M-LBP. Under short lab conditions the cryotherapy was helpful for all pregnant women with low back pain. However, during a daily treatment cryotherapy showed an important analgesic effect only in the M-LBP-group.
Conclusion(s): We showed for the first time that regular use of cryotherapy is a an efficient option to treat a typ of musculoskeletal low back pain during pregnancy.