Adverse Events during Vitrectomy under Adequacy of Anesthesia—An Additional Report

The intraprocedural immobilization of selected subsets of patients undergoing pars plana vitrectomy (PPV) requires the performance of general anesthesia (GA), which entails the intraoperative use of hypnotics and titration of opioids. The Adequacy of Anesthesia (AoA) concept of GA guidance optimizes the intraoperative dosage of hypnotics and opioids. Pre-emptive analgesia (PA) is added to GA to minimize intraoperative opioid (IO) usage. The current additional analysis evaluated the advantages of PA using either COX-3 inhibitors or regional techniques when added to AoA-guided GA on the rate of presence of postoperative nausea and vomiting (PONV), oculo-emetic (OER), and oculo-cardiac reflex (OCR) in patients undergoing PPV. A total of 176 patients undergoing PPV were randomly allocated into 5 groups: (1) Group GA, including patients who received general anesthesia alone; (2) Group T, including patients who received preventive topical analgesia by triple instillation of 2% proparacaine 15 min before induction of GA; (3) Group PBB, including patients who received PBB; (4) Group M, including patients who received PA using a single dose of 1 g of metamizole; (5) Group P, including patients who received PA using a single dose of 1 g of acetaminophen. The incidence rates of PONV, OCR, and OER were studied as a secondary outcome. Despite the group allocation, intraoperative AoA-guided GA resulted in an overall incidence of PONV in 9%, OCR in 12%, and OER in none of the patients. No statistically significant differences were found between groups regarding the incidence of OCR. PA using COX-3 inhibitors, as compared to that of the T group, resulted in less overall PONV (p < 0.05). Conclusions: PA using regional techniques in patients undergoing PPV proved to have no advantage when AoA-guided GA was utilised. We recommend using intraoperative AoA-guided GA to reduce the presence of OCR, and the addition of PA using COX-3 inhibitors to reduce the rate of PONV.

Oral Sucrose Improves Analgesia During Retinopathy of Prematurity Screening

Purpose To determine whether sucrose provides significant analgesia during Retinopathy of Prematurity (ROP) screening Methods This was a prospective, randomized, sinlge masked audit. The examinations were performed by a single examiner. Forty-five (45) neonates were separated into two groups; Group 1 received oral sucrose while Group 2 received oral sucrose and non-nutritive suckling (NNS) at the discretion of the attending nurse. Pain was assessed using the Premature Infant Pain Profile (PIPP) score and recorded at baseline, immediately following lid speculum, at 3 minutes and 6 minutes following lid speculum insertion. Results The mean baseline PIPP score was 0.5. Fifteen (15) neonates (33%) received NNS. The mean PIPP scores at speculum insertion in both groups (Group 1: 7.24, Group 2: 5.50) were observed to be higher than at baseline and lower in Group 2 than in Group 1. In both groups, the scores at 3 minutes (Group 1: 4.70, Group 2: 4.20) and 6 minutes (Group 1 4.50, Group 2: 4.70) were observed to be higher than at baseline, lower than at speculum insertion, but not significantly different to each other. Conclusions Lid speculum insertion during ROP screening appears to be a significantly painful event. ROP examinations should be conducted with a combination of topical analgesia and sucrose and NNS for greatest pain-relieving effect.

Dermal delivery of amitriptyline for topical analgesia

Amitriptyline, administered orally, is currently one of the treatment options for the management of neuropathic pain and migraine. Because of the physicochemical properties of the molecule, amitriptyline is also a promising candidate for delivery as a topical analgesic. Here we report the dermal delivery of amitriptyline from a range of simple formulations. The first stage of the work required the conversion of amitriptyline hydrochloride to the free base form as confirmed by nuclear magnetic resonance (NMR). Distribution coefficient values were measured at pH 6, 6.5, 7, and 7.4. Solubility and stability of amitriptyline were assessed prior to conducting in vitro permeation and mass balance studies. The compound demonstrated instability in phosphate-buffered saline (PBS) dependent on pH. Volatile formulations comprising of isopropyl alcohol (IPA) and isopropyl myristate (IPM) or propylene glycol (PG) were evaluated in porcine skin under finite dose conditions. Compared with neat IPM, the IPM:IPA vehicles promoted 8-fold and 5-fold increases in the amount of amitriptyline that permeated at 24 h. Formulations containing PG also appear to be promising vehicles for dermal delivery of amitriptyline, typically delivering higher amounts of amitriptyline than the IPM:IPA vehicles. The results reported here suggest that further optimization of topical amitriptyline formulations should be pursued towards development of a product for clinical investigational studies. Graphical abstract

Ultrasonic-assisted wound debridement: report from a closed panel meeting

Mechanical debridement can be considered as an alternative to surgical debridement if surgery is not available, or is considered impractical or too high risk. One form of selective mechanical debridement is ultrasonic-assisted wound (UAW) debridement. As the published evidence on this is limited, a closed international expert meeting was held to review the existing evidence base on it, present preliminary findings of research currently in progress and discuss individual cases selected from the clinical experts’ own practice. The panel also explored the potential barriers to the implementation of UAW debridement and how these might be addressed. It concluded there is sufficient evidence that UAW debridement is an effective method of cleansing and debriding almost all hard-to-heal wounds. Patients who are most likely to benefit from it are not medically stable, on anticoagulants, unable to visit a hospital for wound treatment, and/or have wounds with a poor vascular supply or are close to critical structures. The panel also observed that UAW debridement can be used to prepare the wound for negative pressure wound therapy (NPWT) or as an adjunctive to it. Given the potential to experience pain during the procedure, the panel considered that patients will benefit from topical analgesia. The panel noted that health professionals, patients and visitors must be protected from the aerosolisation associated with UAW, to reduce risk of cross-contamination.