C. Power

The Analgesic Efficacy of Transversus Abdominis Plane Block After Abdominal Surgery: A Prospective Randomized Controlled Trial

BACKGROUND:The transversus abdominis plane (TAP) block is a novel approach for blocking the abdominal wall neural afferents via the bilateral lumbar triangles of Petit. We evaluated its analgesic efficacy in patients during the first 24 postoperative hours after abdominal surgery, in a randomized, controlled, double-blind clinical trial. METHODS:Thirty-two adults undergoing large bowel resection via a midline abdominal incision were randomized to receive standard care, including patient-controlled morphine analgesia and regular nonsteroidal antiinflammatory drugs and acetaminophen (n = 16), or to undergo TAP block (n = 16) in addition to standard care (n = 16). After induction of anesthesia, 20 mL of 0.375% levobupivacaine was deposited into the transversus abdominis neuro-fascial plane via the bilateral lumbar triangles of Petit. Each patient was assessed by a blinded investigator in the postanesthesia care unit and at 2, 4, 6, and 24 h postoperatively. RESULTS:The TAP block reduced visual analog scale pain scores (TAP versus control, mean ± sd) on emergence (1 ± 1.4 vs 6.6 ± 2.8, P < 0.05), and at all postoperative time points, including at 24 h (1.7 ± 1.7 vs 3.1 ± 1.5, P < 0.05). Morphine requirements in the first 24 postoperative hours were also reduced (21.9 ± 8.9 mg vs 80.4 ± 19.2 mg, P < 0.05). There were no complications attributable to the TAP block. All TAP patients reported high levels of satisfaction with their postoperative analgesic regimen. CONCLUSIONS:The TAP block provided highly effective postoperative analgesia in the first 24 postoperative hours after major abdominal surgery.

Transversus abdominis plane block: a cadaveric and radiological evaluation.

Background and Objectives: The abdominal wall is a significant source of pain after abdominal surgery. Anterior abdominal wall analgesia may assist in improving postoperative analgesia. We have recently described a novel approach to block the abdominal wall neural afferents via the bilateral lumbar triangles of Petit, which we have termed a transversus abdominis plane block. The clinical efficacy of the transversus abdominis plane block has recently been demonstrated in a randomized controlled clinical trial of adults undergoing abdominal surgery. Methods: After institutional review board approval, anatomic studies were conducted to determine the deposition and spread of methylene blue injected into the transversus abdominis plane via the triangles of Petit. Computerized tomographic and magnetic resonance imaging studies were then conducted in volunteers to ascertain the deposition and time course of spread of solution within the transversus abdominis fascial plane in vivo. Results: Cadaveric studies demonstrated that the injection of methylene blue via the triangle of Petit using the “double pop” technique results in reliable deposition into the transversus abdominis plane. In volunteers, the injection of local anesthetic and contrast produced a reliable sensory block, and demonstrated deposition throughout the transversus abdominis plane. The sensory block produced by lidocaine 0.5% extended from T7 to L1, and receded over 4 to 6 hours, and this finding was supported by magnetic resonance imaging studies that showed a gradual reduction in contrast in the transversus abdominis plane over time. Conclusions: These findings define the anatomic characteristics of the transversus abdominis plane block, and underline the clinical potential of this novel block.

The association between chronic low back pain and sleep: a systematic review.

ObjectivesChronic low back pain (CLBP) adversely affects many quality of life components, and is reported to impair sleep. The aim of this review was to determine the association between CLBP and sleep. MethodsThis review comprised 3 phases: an electronic database search (PubMed, Cinahl Plus, EMBASE, PsychInfo, Pedro, and Cochrane Library) identified potential articles; these were screened for inclusion criteria by 2 independent reviewers; extraction of data from accepted articles; and rating of internal validity by 2 independent reviewers and strength of the evidence using valid and reliable scales. ResultsThe search generated 17 articles that fulfilled the inclusion criteria (quantitative n=14 and qualitative n=3). CLBP was found to relate to several dimensions of sleep including: sleep disturbance and duration (n=15), sleep affecting day-time function (n=5), sleep quality (n=4), sleep satisfaction and distress (n=4), sleep efficiency (n=4), ability to fall asleep (n=3), and activity during sleep (n=3). Consistent evidence found that CLBP was associated with greater sleep disturbance; reduced sleep duration and sleep quality; increased time taken to fall asleep; poor day-time function; and greater sleep dissatisfaction and distress. Inconsistent evidence was found that sleep efficiency and activity were adversely associated with CLBP. DiscussionMany dimensions of sleep are adversely associated with CLBP. Management strategies for CLBP need to address these to maximize quality of life in this patient cohort.

Measurement of Pain: A Comparison of the Visual Analogue with a Nonvisual Analogue Scale

Because of difficulties encountered with patient compliance using the standard visual analogue scale, a new nonvisual analogue scale has been devised for pain measurement. The new scale was found to give values for pain that correlated well with values given using the visual scale and was found to be more easily understood. The scale was considered to be simpler and more reliable than the visual scale heretofore in use.

Immunological/physiological relationships in asthma: potential regulation by lung macrophages

There is now a consensus that T-cell-mediated inflammation and eosinophil activation in the bronchial wall contribute to the pathogenesis of asthma. However, the relationship between these immunopathological mechanisms and the observed physiological aberrations remain unclear. Here, Len Poulter and colleagues identify the links between T-cell-mediated inflammation and bronchial hyperresponsiveness, and propose a hypothesis for asthma pathogenesis in which the combination of immunological and physiological abnormalities may result in the promotion of disease. Furthermore, they suggest that an integral factor in the prevention of this process is the regulation of bronchial T-cell reactivity by a population of immunosuppressive macrophages.

The need for a national strategy for chronic pain management in Ireland.

BackgroundChronic pain is defined as pain on a daily basis for more than six months.1 It affects 13% of the Irish population.2 Despite its prevalence and the impact on patient’s quality of life there is no national strategy for this problem.AimTo determine the need for a national strategy for chronic pain in Ireland.MethodsThe cost of low back pain (LBP) (common chronic pain condition), the level of education and research and current chronic pain clinic resources were investigated.ResultsThe cost of LBP in Ireland is enormous: disability payments from the Department of Social and Family Affairs amounted to €348 million and insurance payments cost €10.5 million.The number of teaching hours timetabled for pain education in the schools of Medicine, Physiotherapy Dentistry, Nursing and Psychology in Ireland’s six universities varied significantly (e.g. 11.5-72 hrs in nursing). Research grants awarded from state organisations were limited to one over a four-year period. No current chronic pain clinics comply with recommended International Association for the Study of Pain (IASP) guidelines.3ConclusionA national strategy is needed to reduce costs, standardise teaching and increase pain clinic resources to maximise patient care.

The impact of spinal cord stimulation on physical function and sleep quality in individuals with failed back surgery syndrome: A systematic review

The aim of this review was to determine the impact of spinal cord stimulation (SCS) on physical function and sleep quality in individuals with failed back surgery syndrome (FBSS). This review comprised three phases: an electronic database search (PubMed, Cinahl Plus, EMBASE, PsychInfo, Pedro, Cochrane Library) identified potential papers; these were screened for inclusion criteria, with extraction of data from accepted papers and rating of internal validity by two independent reviewers using the Effective Public Health Practice Project quality assessment tool, a tool designed to assess non‐RCTs (randomized controlled trials) as well as RCTs. Strength of the evidence was rated using the Agency for Health Care Policy and Research guidelines. The search generated 13 quantitative papers that fulfilled the inclusion criteria; all 13 studies investigated the impact of SCS on physical function, and nine studies investigated the impact of SCS on sleep quality. Consistent evidence (level C) found that SCS positively affected physical function, with improvements in participation in activities of daily living, leisure, social and work‐related activities. Similarly, consistent evidence (level C) found improvements in sleep quality following SCS. Improvements in sleep quantity, a reduction in awakenings and a decrease in sleep medication use were also noted (level D). The impact of SCS on cognitive function, i.e., memory and concentration, was also assessed using the same search strategy, no papers fulfilled the inclusion criteria for this study. Spinal cord stimulation effectively addressed many physical function and sleep problems associated with FBSS; however, there is a need for further high‐quality objective investigations to support this.

T cell dominated inflammatory reactions in the bronchioles of asymptomatic asthmatics are also present in the nasal mucosa.

Endobronchial and nasal mucosa biopsies were obtained from 5 patients with clinically-stable, diagnosed asthma (ATS criteria). A comparison was made of the presence and distribution of immunocompetent lymphocytes and macrophages within each sample. The distribution of immunocompetent cells within the nasal biopsies of the asthmatic patients reflected a very similar inflammatory infiltrate to that seen in the bronchial biopsies. Significantly raised numbers of T lymphocytes, CD45RO + lymphocytes, RFD1 + macrophage-like cells and RFD7 + macrophages were seen in both the nasal mucosa and the bronchial biopsies. Increases in HLA-DR expression were also seen in the nasal mucosa biopsies from asthmatics although the increases over normal did not reach statistical significance. It is concluded that inflammation present in the nasal mucosa of asymptomatic asthmatics exhibits cellular characteristics also seen in endobronchial biopsies. This observation offers the possibility that mucosal biopsy may be an alternative and less invasive approach for studying the cells involved in the bronchial inflammatory reaction that possibly predisposes asthmatics to bronchial hyper-responsiveness.

Acute superior vena caval syndrome with airway obstruction following elective mediastinoscopy

A 47‐year‐old female patient had a subclinical superior vena caval syndrome which developed into the ‘full blown’ acute condition when she was placed into the left lateral position after mediastinoscopy. She developed airway obstruction requiring urgent re‐intubation and subsequent admission to the intensive care unit. This subclinical condition might have been suspected pre‐operatively if closer attention had been paid to the history, physical examination and review of the computerised axial tomography scan: she had a history of intermittent dyspnoea, wheeze and cough which was worse on waking and improved as the day progressed, she had a positive Pembertons sign and the computerised axial tomography scan showed that the lesion was encroaching on the superior vena cava.

Five-year experience of critical incidents associated with patient-controlled analgesia in an Irish University Hospital

BackgroundPatient-controlled analgesia (PCA) is a common and effective means of managing post-operative pain. We sought to identify factors that may lead to critical incidents (CIs) in patient safety when using PCA in our institution.MethodsAn observational study of prospectively collected data of patients who received PCA from 2002 to 2006 was performed. All CIs were documented and analysed by staff members of the acute pain service (APS). Cause analysis of CIs was undertaken to determine if measures can be instituted to prevent recurrence of similar events.ResultsOver eight thousand patients (8,240) received PCA. Twenty-seven CIs were identified. Eighteen were due to programming errors. Other CIs included co-administration of opioids and oversedation.ConclusionIn our institution, the largest contributory factor to CIs with PCAs was programming error. Strategies to minimize this problem include better education and surveillance.