Effectiveness and safety of prehospital analgesia including nalbuphine and paracetamol by paramedics: an observational study.

Background: The aim of this study was to examine the effectiveness and safety of prehospital analgesia with nalbuphine and/or paracetamol by paramedics.

Methods: In this retrospective trial, following the implementation of a standard-operating-procedure for pain requiring treatment as defined as a score ≥4 on the 0-10 Numeric Rating Scale for pain, all emergency operations in the district of Gütersloh between January 1, 2020, and June 30, 2022, with analgesic administration by paramedics in patients ≥18 years were included in the study. Analgesic agents employed by the paramedics included nalbuphine and/or paracetamol, butylscopolamine for abdominal colic, and esketamine in case of failure of the other analgesics. The primary endpoint was the patients' rating of their pain on the Numeric Rating Scale at the end of the operation. Additional covariates included sex, cause of pain, analgesics used, Numeric Rating Scale at beginning and analgesic-associated complications (reduced level of consciousness, hypotension, desaturation, a- or bradypnea).

Results: A total of 1931 emergency operations (female: N.=1039 [53.8%]) with pain requiring treatment (non-traumatic cause: N.=1106 [57.3%]; initial Numeric Rating Scale: 8.0±1.4). Analgesics applied were nalbuphine + paracetamol (50.6%), paracetamol (38.7%), butylscopolamine (13.4%), nalbuphine (7.7%), and esketamine (4.9%). Mean pain reduction was 4.3±2.3 (nalbuphine + paracetamol: 5.0±2.1; nalbuphine: 4.7±2.3) and paracetamol: 3.3±2.2, respectively. Factors influencing a change in the Numeric Rating Scale were trauma (regression-coefficient: -0.308, 95% CI: -0.496 - -0.119, P=0.0014 vs. non-trauma; nalbuphine [yes vs. no]: regression-coefficient 0.684, 95% CI 0.0774-1.291, P=0.03; nalbuphine + paracetamol: regression-coefficient 0.763, 95% CI 0.227-1.299, P=0.005). At the end of the operation, 49.7% had a Numeric Rating Scale <4, 34.3% had a Numeric Rating Scale 4-5, and 16.0% had a Numeric Rating Scale ≥6. Factors influencing a Numeric Rating Scale <4 at end of use were trauma vs. non-trauma: odds ratio 0.788, 95% CI 0.649-0.957, P=0.02. The Numeric Rating Scale at beginning reported: odds ratios 0.754, 95% CI 0.700-0.812, P<0.0001. Analgesic-associated complications were not observed.

Conclusions: Prehospital analgesia by paramedics with nalbuphine as monotherapy or in combination with paracetamol allows for sufficient analgesia without the occurrence of complications.