Postprocedural pain in shoulder arthrography: differences between using preservative-free normal saline and normal saline with benzyl alcohol as an intraarticular contrast diluent

TRPA1-dependent and -independent activation by commonly used preservatives

Background and purpose: Addition of preservatives ensures microbial stability, especially in multidose containers of parenterally administered pharmaceuticals. These compounds can cause side effects, and particularly at the site of application, might elicit or facilitate pain. TRPA1 is a cation channel expressed in peripheral neurons which contributes to pain and inflammation and is sensitive to many irritants. The most commonly used preservatives, in particular with a focus on parenteral formulations, were investigated for their potential to activate TRPA1. Experimental approach: Sixteen preservatives were screened for mediating calcium influx in human TRPA1-transfected HEK293t cells. Untransfected cells served as control, results were further validated in mouse sensory neurons. In addition, proinflammatory mediators serotonin, histamine and prostaglandin E2 were co-administered to probe a potential sensitisation of preservative-induced TRPA1 activation. Key results: Butylparaben, propylparaben, ethylparaben, bronopol, methylparaben, phenylethyl alcohol and phenol induced a TRPA1-dependent calcium influx in transfected HEK293t cells at concentrations used for preservation. Other preservatives increased calcium within the used concentration ranges, but to a similar degree in untransfected controls. Serotonin, histamine, and prostaglandin enhanced TRPA1 activation of phenylethyl alcohol, bronopol, ethylparaben, propylparaben and butylparaben. Conclusion and implications: Systematic screening of common preservatives applied for parenterally administered drugs resulted in identifying several preservatives with substantial TRPA1 channel activation. This activation was enhanced by the addition of proinflammatory meditators. This allows selecting a preservative without TRPA1 activation, particularly in case of pharmaceuticals that could act proinflammatory.

Bacteriostatic preserved saline for pain-free periocular injections: review

We review evidence regarding the use of 0.9% benzyl alcohol in 0.9% sodium chloride solution for periocular injections (‘preserved saline’) including botulinum toxin A injections and local anaesthesia. A literature search was undertaken using search terms ‘bacteriostatic saline’, ‘benzyl-alcohol saline’, ‘benzyl alcohol sodium chloride’ and ‘preserved saline’. Bibliographies identified further sources. There have been 62 studies published on the subject of preserved-saline since 1928. Significantly lower injection-associated pain levels for periocular/facial botulinum toxin injections reconstituted with preserved-saline rather than preservative-free saline are reported by 5 studies. Significantly lower injection-associated pain with preserved-saline diluted lidocaine and epinephrine solution for eyelid anaesthesia compared with unmodified or buffered lidocaine with epinephrine, and adequate anaesthesia, was reported by one study. Thirty-one studies have explored preserved-saline for anaesthetic and seven for bacteriostatic properties, with very low infection rates after periocular botulinum toxin injections, and reduced rates of infection in indwelling catheters when preserved saline is used to flush. A meta-analysis concluded that lidocaine-containing solutions are more effective at reducing pain from insertion of intravenous catheters. Patient-perceived pain related to periorbital injections of local anaesthesia is reduced when the anaesthetic is diluted with benzyl alcohol-preserved saline compared with other dilution or buffering options. Pain is similarly reduced for periocular botulinum toxin injections reconstituted with preserved saline compared with unpreserved saline. Benzyl-alcohol preserved-saline is inexpensive but costlier than unpreserved-saline, with minimal reported complications, particularly with periocular administration, and offers the opportunity to improve the patient experience.

Predictors of Pain and Discomfort Associated with CT Arthrography of the Shoulder

RATIONALE AND OBJECTIVES

The objective of this study was to investigate predictors of pain associated with computed tomographic arthrography of the shoulder.

MATERIALS AND METHODS

Before shoulder arthrography, all participants were assessed with the Hospital Anxiety and Depression Scale (HADS) and the World Health Organization Quality of Life Short Version Instrument (WHOQOL-BREF). The participants were nonrandomized into two groups: the anesthesia group, who underwent prior local infiltration anesthesia before shoulder arthrography, and the nonanesthesia group, who did not undergo prior local infiltration anesthesia. The pain levels at intraprocedure, at 1, 2, 6, and 12 hours, and at 1 and 2 days after injection were assessed by using a visual analog scale. Univariate and multivariate generalized linear model analyses were conducted.

RESULTS

Sixty participants in the anesthesia group and 60 participants in the nonanesthesia group were included. The pain level at intraprocedure (3.37 ± 1.94 in the anesthesia group and 3.20 ± 1.34 in the nonanesthesia group) was the highest of the whole pain course. The psychological domain (P = .0013) of WHOQOL-BREF, gender (P = .042), body mass index (P = .0001), and the total number of reinsertion and redirection of needle (P< .0001) were independent predictors of arthrography-related pain.

CONCLUSIONS

The pain associated with shoulder computed tomographic arthrography depends on the psychological domain of WHOQOL-BREF, gender, body mass index, and the total number of reinsertion and redirection of needle.

Utility of pre- and post-MR arthrogram imaging of the shoulder: effect on patient care

OBJECTIVE

MR arthrogram imaging of the shoulder is considered more accurate in assessing shoulder pathology than conventional MRI. Arthrography is a minimally invasive procedure. However, most patients prefer to have conventional MRI rather than MR arthrogram imaging. We report the benefit of assessing pre-arthrogram conventional MRI, to determine whether an MR arthrogram is needed for further evaluation.

METHODS

100 consecutive conventional shoulder MR and MR arthrography examinations performed on the same patients were reviewed retrospectively by independent reading of 2 musculoskeletal radiologists. Both conventional MR and MR arthrogram examinations were performed on each patient on the same day. Conventional MR and MR arthrogram examinations were assessed for labral tears and supraspinatus tendon tears. All patients went on to arthroscopy.

RESULTS

Of these 100 patients, 43 patients had superior labral anterior to posterior (SLAP) tears, 28 patients had posterior labral tears, 23 patients had anterior labral tears and 47 patients had full-thickness supraspinatus tendon tears on conventional MR examination reading by Reader 1. There were 42 SLAP tears, 26 posterior labral tears, 24 anterior labral tears and 47 full-thickness supraspinatus tendon tears on conventional MR examination read by Reader 2. On MR arthrogram examination, 51 patients had SLAP tears, 33 patients had posterior labral tears, 29 patients had anterior labral tears and 49 patients had full-thickness supraspinatus tendon tears on reading by Reader 1. On MR arthrogram examination, 50 patients had SLAP tears, 31 patients had posterior labral tears, 30 patients had anterior labral tears and 49 patients had full-thickness supraspinatus tendon tears read by Reader 2. MR arthrogram detected eight SLAP tears, five posterior labral tears, six anterior labral tears and two supraspinatus tendon tears not detected on conventional MR examination read by Reader 1. MR arthrogram detected eight SLAP tears, five posterior labral tears, six anterior labral tears and two supraspinatus tendon tears not detected on conventional MR examination read by Reader 2. 18 of the 21 patients with additional finding on MR arthrogram examination had normal appearing conventional MR examinations.

CONCLUSION

Use of pre- and post-MR arthrogram imaging may benefit patient care. When positive findings are demonstrated on MR examination, few additional findings are demonstrated on MR arthrogram examination. These patients may not need to proceed to MR arthrography. If the conventional MR examination is negative, then additional information may be obtained by proceeding to MR arthrography.

ADVANCES IN KNOWLEDGE

When positive findings are demonstrated on MR examination, few additional findings are demonstrated on MR arthrogram examination. These patients may not need to proceed to MR arthrography. If the conventional MR examination is negative, then additional information may be obtained by proceeding to MR arthrography.