Post-surgical pain syndromes: a review for the non-pain specialist

Purpose

This is a selective narrative review of the latest information about the epidemiology, impact, and prevention of chronic post-surgical pain (CPSP), intended primarily for those without a special interest in pain medicine.

Principal findings

Chronic post-surgical pain is an important problem in terms of personal impact. It has staggering economic implications, exerts powerful negative effects on the quality of life of many of those it afflicts, and places a significant burden on chronic pain treatment services in general. It is well known that surgery at certain body sites is apt to cause CPSP, but emerging evidence shows a strong correlation between CPSP and demographic (young age, obesity, and female sex) and psychological characteristics (anxiety, depression, stress, and catastrophizing). Severe acute pain is a strong risk factor for CPSP, and this adds yet more weight to the argument that acute pain should be controlled effectively. In specific circumstances, CPSP can be reduced by regional anesthetic techniques, infiltration of local anesthetic, or preoperative use of gabapentin. The ability of other known interrupters of afferent nociceptive transmission—commonly used to reduce CPSP when administered at the time of surgery—is currently unproven, as is the hypothesis that the use of remifentanil during surgery worsens CPSP.

Conclusions

Reduction of CPSP is a worthy long-term outcome for anesthesia providers to consider as they plan the perioperative care of their patients. More evidence is needed about the effect of currently used analgesics and other perioperative techniques on CPSP.     

Perceived professional support and the use of blocking behaviours by hospice nurses

A prospective study of the impact of training 41 hospice nurses in assessment skills was used to test hypotheses that blocking behaviours would be used more when patients disclosed feelings and used less when nurses perceived that they had satisfactory professional support Each nurse was asked to assess a patient's current problems before and after feedback training and 8 months later Audiotape recordings of these interviews were rated by trained raters They determined the frequency of nurses' responses which had the function of blocking patient disclosure and the emotional level of patient disclosure Before each patient assessment each nurse was interviewed and questionnaires administered to measure her perceptions of the support she received Blocking behaviours were most evident when patients disclosed their feelings (Kendalls r=0 36, P < 0 001) In interviews containing most patient disclosure of feeling, blocking was significantly less (r= - 0 24, P < 0 5) when the nurse felt that practical help would be available if needed and when the nurse felt that her direct supervisor was concerned about the nurse's own welfare (r= -0 37, P < 0 005)     

A novel multiple frequency stimulation method for steady state VEP based brain computer interfaces

The objective is to increase the number of selections in brain computer interfaces (BCI) by recording and analyzing the steady state visual evoked potential response to dual stimulation. A BCI translates the VEP signals into user commands. The frequency band from which stimulation frequency can be selected is limited for SSVEP. This paper discusses a method to increase the number of commands by using a suitable combination of frequencies for stimulation. A biopotential amplifier based on the driven right leg circuit (DRL) is used to record 60 s epochs of the SSVEP (O(z)-A(1)) on 15 subjects using simultaneous overlapped stimulation (6, 7, 12, 13 and 14 Hzs and corresponding half frequencies). The power spectrum of each recording is obtained by frequency domain averaging of 400 ms SSVEPs and the spectral peaks were normalized. The spectral peaks of the combination frequencies of stimulation are predominant compared to individual stimulating frequencies. This method increases the number of selections by using a limited number of stimulating frequencies in BCI. For example, six selections are possible by generating only three frequencies.     

Validation of AAST EGS Grade for Acute Pancreatitis

Background

The AAST recently developed an emergency general surgery (EGS) disease grading system to measure anatomic severity. We aimed to validate this grading system for acute pancreatitis and compare cross sectional imaging-based AAST EGS grade and compare with several clinical prediction models. We hypothesize that increased AAST EGS grade would be associated with important physiological and clinical outcomes and is comparable to other severity grading methods.

Methods

Single institution retrospective review of adult patients admitted with acute pancreatitis during 10/2014–1/2016 was performed. Patients without imaging were excluded. Imaging, operative, and pathological AAST grades were assigned by two reviewers. Summary and univariate analyses were performed. AUROC analysis was performed comparing AAST EGS grade with other severity scoring systems.

Results

There were 297 patients with a mean (±SD) age of 55?±?17 years; 60% were male. Gallstone pancreatitis was the most common etiology (28%). The overall complication, mortality, and ICU admission rates were 51, 1.3, and 25%, respectively. The AAST EGS imaging grade was comparable to other severity scoring systems that required multifactorial data for readmission, mortality, and length of stay.

Conclusions

The AAST EGS grade for acute pancreatitis demonstrates initial validity; patients with increasing AAST EGS grade demonstrated longer hospital and ICU stays, and increased rates of readmission. AAST EGS grades assigned using cross sectional imaging findings were comparable to other severity scoring systems. Further studies should determine the generalizability of the AAST system.Level of Evidence: IVStudy Type: Single institutional retrospective review

     

Antral resection versus antral preservation during laparoscopic sleeve gastrectomy for severe obesity: Systematic review and meta-analysis

Although laparoscopic sleeve gastrectomy is an established operation for severe obesity, there is controversy regarding the extent to which the antrum is excised. The objective of this systematic review was to investigate the effect on perioperative complications and medium-term outcomes of antral resecting versus antral preserving sleeve gastrectomy. MEDLINE, EMBASE, and Cochrane databases were searched from 1946 to April 2017. Eligible studies compared antral resection (staple line commencing 2–3 cm from pylorus) with antral preservation (>5 cm from pylorus) in patients undergoing primary sleeve gastrectomy for obesity. Meta-analyses were performed with a random-effects model, and risk of bias within and across studies was assessed using validated scoring systems. Eight studies (619 participants) were included: 6 randomized controlled trials and 2 cohort studies. Overall follow-up was 94% for the specified outcomes of each study. Mean percentage excess weight loss was 62% at 12 months (7 studies; 574 patients) and 67% at 24 months (4 studies; 412 patients). Antral resection was associated with significant improvement in percentage excess weight loss at 24-month follow-up (mean 70% versus 61%; standardized mean difference .95; confidence interval .35–1.58, P<.005), an effect that remained significant when cohort studies were excluded. There was no difference in incidence of perioperative bleeding, leak, or de novo gastroesophageal reflux disease. According to the available evidence, antral resection is associated with better medium-term weight loss compared with antral preservation, without increased risk of surgical complications. Further randomized clinical trials are indicated to confirm this finding.     

Obesity surgery makes patients healthier and more functional: real world results from the United Kingdom National Bariatric Surgery Registry

Background

The National Bariatric Surgery Registry (NBSR) is the largest bespoke database in the field in the United Kingdom.

Comparison of adductor canal block and IPACK block (interspace between the popliteal artery and the capsule of the posterior knee) with adductor canal block alone after total knee arthroplasty: a prospective control trial on pain and knee function in immediate postoperative period

Background

Adductor canal block (ACB) is a peripheral nerve blockade technique that provides good pain control in patients undergoing total knee arthroplasty which however does not relieve posterior knee pain. The recent technique of an ultrasound-guided local anesthetic infiltration of the interspace between popliteal artery and the capsule of posterior knee (IPACK) has shown promising results in providing significant posterior knee analgesia without affecting the motor nerves.

Materials and methods

A prospective study was conducted from September 2016 to March 2017 in a total of 120 patients undergoing unilateral total knee arthroplasty. The initial 60 consecutive patients received ACB?+?IPACK (Group 1, n?=?60), and the subsequent 60 patients received ACB alone (Group 2, n?=?60). All patients were evaluated with VAS score for pain recorded at 8 h, postoperative day (POD) 1 and POD 2 after the surgery. The secondary outcome measures assessed were the range of movement (ROM) and ambulation distance.

Results

VAS score showed significantly (p?<?0.005) better values in ACB?+?IPACK group compared to the ACB group. The mean ROM of knee and ambulation distance also showed significantly better values in ACB?+?IPACK group compared to the ACB group.

Conclusion

ACB?+?IPACK is a promising technique that offers improved pain management in the immediate postoperative period without affecting the motor function around the knee joint resulting in better ROM and ambulation compared to ACB alone.