Chronic pain treatment with pregabalin in end stage respiratory failure patients awaiting lung transplantation on ambulatory veno-venous extra corporeal membrane oxygenator support; a series of nine cases

Background

End-stage respiratory failure is non-treatable with mechanical ventilation and can be treated with veno-venous extracorporeal membrane oxygenators (VV-ECMO). It can also be used as a bridge to lung transplantation or recovery of lung function. This patient group can suffer from chronic pain, which is further exacerbated by painful procedures required as part of treatment. Pregabalin is licensed for chronic neuropathic pain and generalized anxiety disorder. Thus far, it has not been tried in routine analgesia protocols for pain relief of patients on VV-ECMO.

Case Series

We included nine patients aged 17-54 years on VV-ECMO awaiting lung transplantation. Exclusion criteria were acute kidney injury and chronic kidney disease. All patients had morphine patient-control analgesia. In addition, pregabalin 50 mg twice daily was initiated in all patients with dose escalation as required. Pain scores and quality of sleep were evaluated daily. All patients experienced significant pain relief, demonstrated by reduced pain scores after treatment commencement. The mean visual analogue scale score was reduced significantly from 6 ± 2 to 3 ± 1. A significant increase in good-quality sleep duration was recorded from 5 ± 1.7 hours per day before to 8 ± 2.1 hours per day after pregabalin treatment. All patients except for two reported reduced anxiety levels of at least 2 ± 1 scale improvement (p <0.05).

Conclusions

Pregabalin is an efficient analgesic with accompanying anxiolytic effects in this group of patients with unique characteristics such as high analgesia requirements and exacerbated psychological and emotional stress. HIPPOKRATIA 2023, 27 (1):22-24.

Positioning accuracy for lung stereotactic body radiotherapy patients determined by on-treatment cone-beam CT imaging

Stereotactic body radiotherapy for early stage non-small cell lung cancer is an emerging treatment option in the UK. Since relatively few high-dose ablative fractions are delivered to a small target volume, the consequences of a geometric miss are potentially severe. This paper presents the results of treatment delivery set-up data collected using Elekta Synergy (Elekta, Crawley, UK) cone-beam CT imaging for 17 patients immobilised using the Bodyfix system (Medical Intelligence, Schwabmuenchen, Germany). Images were acquired on the linear accelerator at initial patient treatment set-up, following any position correction adjustments, and post-treatment. These were matched to the localisation CT scan using the Elekta XVI software. In total, 71 fractions were analysed for patient set-up errors. The mean vector error at initial set-up was calculated as 5.3 ± 2.7 mm, which was significantly reduced to 1.4 ± 0.7 mm following image guided correction. Post-treatment the corresponding value was 2.1 ± 1.2 mm. The use of the Bodyfix abdominal compression plate on 5 patients to reduce the range of tumour excursion during respiration produced mean longitudinal set-up corrections of -4.4 ± 4.5 mm compared with -0.7 ± 2.6 mm without compression for the remaining 12 patients. The use of abdominal compression led to a greater variation in set-up errors and a shift in the mean value.

Optimal clinical implementation of the siemens virtual wedge

Installation of a modern high-energy Siemens Primus linear accelerator at the Northern Centre for Cancer Treatment (NCCT) provided the opportunity to investigate the optimal clinical implementation of the Siemens virtual wedge filter. Previously published work has concentrated on the production of virtual wedge angles at 15 degrees, 30 degrees, 45 degrees, and 60 degrees as replacements for the Siemens hard wedges of the same nominal angles. However, treatment plan optimization of the dose distribution can be achieved with the Primus, as its control software permits the selection of any virtual wedge angle from 15 degrees to 60 degrees in increments of 1 degrees. The same result can also be produced from a combination of open and 60 degrees wedged fields. Helax-TMS models both of these modes of virtual wedge delivery by the wedge angle and the wedge fraction methods respectively. This paper describes results of timing studies in the planning of optimized patient dose distributions by both methods and in the subsequent treatment delivery procedures. Employment of the wedge fraction method results in the delivery of small numbers of monitor units to the beam's central axis; therefore, wedge profile stability and delivered dose with low numbers of monitor units were also investigated. The wedge fraction was proven to be the most efficient method when the time taken for both planning and treatment delivery were taken into consideration, and is now used exclusively for virtual wedge treatment delivery in Newcastle. It has also been shown that there are no unfavorable dosimetric consequences from its practical implementation.

Behavior of the Siemens Virtual Wedge following an interruption to beam delivery

Investigations were made into the beam profile shape and dose delivered by the Siemens Virtual Wedge trade mark under standard operational conditions compared with those following delivery interruption on two Siemens Primus linear accelerators (Type 7445 and 8067) running different versions of control software (7.2 and 7.0, respectively). The shape of the Virtual Wedge trade mark profiles was found to be unaffected by beam delivery interruption. An increase in the dose delivered to the central axis was found when delivery was interrupted and subsequently resumed using information recorded in a recall data file on one of the accelerators. This dose increase was attributed to a difference in delivered monitor units recorded in the recall data file compared to those displayed on the linear accelerator control console.

The UK national study of magnetic resonance imaging as a method of screening for breast cancer (MARIBS)

The UK national study of magnetic resonance imaging as a method of screening for breast cancer (MARIBS) is in progress. The study design, accrual to date, and related research projects are described. Revised accrual rates and expected recruitment are given. 15 cancers have been detected to date, from a total of 1236 screening measurements. This event rate and the tumour grades reported are compared with recent reports from other studies in women at high risk of breast cancer.

Case report: rhabdomyolysis following grand mal seizures presenting as a delayed and increasingly dense nephrogram

Rhabdomyolysis as a result of major trauma is a well recognized cause of acute renal failure. Non-traumatic rhabdomyolysis causing transient renal impairment may occur following generalized convulsions. We present a case in which rhabdomyolysis following epilepsy was first indicated at urography by a delayed and increasingly dense persistent nephrogram.