Lars Berggren

Organization of acute pain services: a low-cost model

&NA; It is being increasingly recognized that the solution to the problem of inadequate postoperative pain relief lies not so much in development of new techniques but in development of a formal organization for better use of existing techniques. Acute Pain Services (APS) are being increasingly established to provide good quality postoperative analgesia. In the United States such 24‐h services usually consist of anesthesiologists, residents, specially trained nurses and pharmacists. However, less than 30% of US surgical population has access to APS. Furthermore, only patients selected by surgeons receive the benefits of these services. Additionally, the economic costs of such services are high (≥

A systematic review of the peripheral analgesic effects of intraarticular morphine.

200/ patient). Less expensive alternatives have to be developed if the aim is to improve the quality of postoperative analgesia for every patient after any type of surgery. Sophisticated analgesia techniques such as epidural and patient‐controlled analgesia (PCA) are neither necessary nor realistic for the majority of patients. Our nurse‐based anesthesiologist‐supervised model is based on the concept that postoperative pain relief can be greatly improved by provision of in‐service training for surgical nursing staff, optimal use of systemic opioids and use of regional analgesia techniques and PCA in selected patients, Regular recording of each patients pain intensity by VAS every 3 h and recording of treatment efficacy on a bedside vital‐sign chart are the cornerstones of this model. A VAS greater than 3 is promptly treated. Surgeon and ward nurse participation are crucial in this organization. An Acute Pain Nurse (APN) makes daily rounds of all surgery departments. Her duties include referral of problem patients to the anesthesiologist. At our hospital about 18,000–20,000 surgical procedures are performed each year; our low‐cost (

A meta-analysis of the efficacy of wound catheters for post-operative pain management.

3–4/patient) organization is designed to benefit all of these patients. This organization has been functioning satisfactorily for 3 years, and it can be easily modified for non‐surgical wards.

Effect of auditory evoked potential-guided anaesthesia on consumption of anaesthetics and early postoperative cognitive dysfunction: a randomised controlled trial.

The analgesic effects of intraarticular morphine are controversial. To systematically evaluate the effects, we performed a review of the literature and a metaanalysis of the peripheral effects of morphine injected intraarticularly. Research databases were searched to identify articles in which peripheral analgesic effects of morphine were studied in patients undergoing arthroscopic knee procedures under local, regional, or general anesthesia. The review was performed on three issues: does morphine injected intraarticularly produce analgesia, is it a dose-dependent effect, and, if so, is the effect systemic or mediated via peripheral opioid receptors? Visual analog score (VAS) and analgesic consumption were studied during the early phase (0–2 h), intermediate phase (2–6 h), and late phase (6–24 h) postoperatively after injection of morphine intraarticularly. Metaanalysis of these effect variables was performed by the weighted-analysis technique, and the essential homogeneity assumption was tested by the &khgr;2 test. Forty-five articles could be identified in which the effects of morphine were studied in a prospective, randomized manner, and 32 of these studies included a placebo control. Pooled analyses of data from 19 studies suitable for metaanalysis showed an improvement in analgesia after morphine compared with placebo in the order of 12–17 mm on the VAS during all three phases of treatment. Studies with high quality scores showed somewhat smaller improvements. Total analgesic consumption could not be analyzed statistically, but the number of studies showing decreased analgesic consumption or no differences between groups was identical (six and six). No clear dose-response effect was seen when VAS was used as a measure of pain, but it was seen when area under the curve was used as a measure of pain. A systemic effect of peripherally-injected morphine was not possible to exclude because of the very limited data available. We conclude from this metaanalysis that intraarticularly administered morphine has a definite but mild analgesic effect. It may be dose dependent, and a systemic effect cannot be completely excluded.

Intra-peritoneal microdialysis and intra-abdominal pressure after endovascular repair of ruptured aortic aneurysms.

Local anesthetics (LA) are injected via catheters placed in surgical wounds for post‐operative analgesia. The primary aim of this systematic review was to assess whether LA reduce pain intensity when injected via wound catheters. A literature search was performed from Medline via PubMed, EMBASE and the Cochrane database from 1966 until November 2009. The search strategy included the following key words: pain, postoperative, catheters and local anesthetics. Two co‐authors independently read every article that was initially included and extracted data into a pre‐defined study record form. A total of 753 studies primarily fit the search criteria and 163 were initially extracted. Of these, 32 studies were included in the meta‐analysis. Wound catheters provided no significant analgesia at rest or on activity, except in patients undergoing gynecological and obstetric surgery at 48 h (P=0.03). The overall morphine consumption was lower (≈13 mg) during 0–24 h (P<0.001) in these patients. No significant differences in side effects were found, except for a lower risk of wound breakdown (P=0.048) and a shorter length of hospital stay (P=0.04) in patients receiving LA. A statistically significant heterogeneity was seen between the studies in most end‐points. LA injected via wound catheters did not reduce pain intensity, except at 48 h in a subgroup of patients undergoing obstetric and gynecological surgery. Rescue analgesic consumption was also lower in this group at 0–24 h. The magnitude of these effects was small and compounded by pronounced heterogeneity.

Salvage of an acutely ruptured thoracic aortic aneurysm during CPR.

Background Post-operative cognitive dysfunction (POCD) after non-cardiac surgery is a well known problem in some categories of patients. This study aims to evaluate the influence of auditory evoked potential (AEP)-guided anaesthesia on the requirement for anaesthetic drugs and their influence on POCD. Methods Four hundred and fifty patients aged between 18 and 92 years scheduled for ophthalmic surgery under general anaesthesia were assigned randomly to one of two groups. In group A (AEP group), the depth of anaesthesia (DoA) was aimed at an AEP index (AAI) between 15 and 25. In group C (control group), DoA was guided by clinical signs. Hypotension was treated with fluids and vasopressors using a standardised algorithm. A mini-mental test and the Cognitive Failure Questionnaire were used to evaluate cognitive function. Results Anaesthetic drug requirements were significantly lower in group A than in group C: propofol 92.5 ± 26.5 vs. 103.8 ± 39.5 mg (P = <0.001) and desflurane end-tidal concentration 2.5 ± 0.58 vs. 3.3 ± 0.79% (P < 0.001). In group A, 36 patients (16%) received additional fluids and vasopressors compared to 65 patients (29%) in group C (P < 0.01). AAI values differed significantly between the groups: 18 (11–21) in group A vs. 12 (10–19) in group C (P < 0.001). The number of patients with POCD was 16 in group C compared to two in group A (P < 0.001) at day 1 post-operation. Conclusion AEP monitoring allows dose reduction of anaesthetic agents, leading to better cardiovascular stability and decreased requirements for intra-operative fluids and vasopressors. Cognitive decline seen following minor ophthalmic surgery, even when anaesthesia is assessed clinically, is short-lived with no long-term sequelae.

Perioperative management in order to minimise postoperative delirium and postoperative cognitive dysfunction: Results from a Swedish web-based survey

OBJECTIVES This study aims to evaluate intra-peritoneal (ip) microdialysis after endovascular aortic repair (EVAR) of ruptured abdominal aortic aneurysm (rAAA) in patients developing intra-abdominal hypertension (IAH), requiring abdominal decompression. DESIGN Prospective study. MATERIAL AND METHODS A total of 16 patients with rAAA treated with an emergency EVAR were followed up hourly for intra-abdominal pressure (IAP), urine production and ip lactate, pyruvate, glycerol and glucose by microdialysis, analysed only at the end of the study. Abdominal decompression was performed on clinical criteria, and decompressed (D) and non-decompressed (ND) patients were compared. RESULTS The ip lactate/pyruvate (l/p) ratio was higher in the D group than in the ND group during the first five postoperative hours (mean 20 vs. 12), p = 0.005 and at 1 h prior to decompression compared to the fifth hour in the ND group (24 vs. 13), p = 0.016. Glycerol levels were higher in the D group during the first postoperative hours (mean 274.6 vs. 121.7 μM), p = 0.022. The IAP was higher only at 1 h prior to decompression in the D group compared to the ND group at the fifth hour (mean 19 vs. 14 mmHg). CONCLUSIONS Ip l/p ratio and glycerol levels are elevated immediately postoperatively in patients developing IAH leading to organ failure and subsequent abdominal decompression.

AAI-guided anaesthesia is associated with lower incidence of 24-h MMSE < 25 and may impact the IL-6 response

Purpose: To report the successful endovascular treatment of a ruptured thoracic aortic aneurysm during cardiopulmonary resuscitation. Case Report: A 72-year-old woman with a type B aortic dissection treated conservatively for 8 years was referred for rupture of a 16-cm aneurysm of the descending thoracic aorta. During transfer to the operating room, the patient suffered cardiac arrest; cardiopulmonary resuscitation (CPR) was initiated. A few minutes later during CPR, the surgical procedure began with a cutdown of the right femoral artery and insertion of a guidewire and an aortic occlusion balloon, which was inflated at the origin of the left subclavian artery (LSA). Blood pressure was immediately measurable. By only partially deflating the occluding balloon, a thoracic stent-graft was advanced above it and deployed at the origin of the LSA while rapidly deflating and retracting the occluding balloon. Three stent-grafts were required to cover 27 cm of the descending aorta. The patient was partly ventilator dependent for 3 months due to a massive pleural hematoma that was not evacuated. At the 10-month follow-up, the patient is fully recovered without any sign of respiratory dysfunction or any other sequela. CT scans reveal that the massive hematoma is almost completely resolved. Conclusions: This case illustrates that optimal collaboration between anesthesiologists, interventional radiologists, and vascular surgeons with appropriate resources can significantly expand the possibilities of emergent treatment in the face of aortic rupture.

Does depth of anesthesia influence postoperative cognitive dysfunction or inflammatory response following major ENT surgery

Cognitive side-effects such as emergence agitation (EA), postoperative delirium (POD) and postoperative cognitive dysfunction (POCD) are not infrequently complicating the postoperative care especially in elderly and fragile patients. The aim of the present survey was to gain insight regarding concern and interest in prevention and treatment strategies for postoperative delirium and dysfunction, and the use of EEG-based depth-of-anaesthesia monitoring possibly reducing the risk for cognitive side effects among anaesthesia personnel. Methods A web-based validated questionnaire was sent to all Swedish anaesthesiologists and nurse anaesthetists during summer 2013. The questionnaire consisted of 3 sections, subjective preferences, routines and practices related to the perioperative handling of EA, POD, POCD. Results The response rate was 52%. Cardiovascular/pulmonary risks where assessed as importance by 98, 97% of responders while 69% considered the risk of neurocognitive side-effects important. When asked explicitly around cognitive side-effects 89%, 37% and 44% assessed awareness, POC and POD respectively of importance. EEG-based depth-of-anaesthesia monitors were used in 50% of hospitals. The responders were not convinced about the benefits of such monitors even in at-risk patients. Structured protocols for the management of postoperative cognitive side-effects were available only in few hospitals. Conclusion Swedish anaesthesia personnel are concerned about the risk of postoperative cognitive side-effects but are more concerned about cardiovascular/pulmonary risks, pain, PONV and the rare event of awareness. Most respondents were not convinced about the use of depth-of-anaesthesia monitors. There is a need to improve knowledge around risk factors, prevention and management of postoperative cognitive side effects.

Routines for reducing the occurrence of emergence agitation during awakening in children, a national survey

INTRODUCTION Trauma stress and neuro-inflammation caused by surgery/anaesthesia releases cytokines. This study analysed impact of Auditory Evoked Potential Index (AAI) depth-of-anaesthesia titration on the early plasma IL-6 release after eye surgery under general anaesthesia. METHOD This is a subgroup analysis of a prospective randomized study on the effect of auditory evoked potential guided anaesthesia for eye surgery. Plasma IL-6 levels taken before, 5 and 24 h after end of surgery from 450 patients undergoing elective ophthalmic surgery under desflurane anaesthesia were analysed. Minimal mental state examination (MMSE) was also tested at 24-h. RESULTS IL- 6 increased significantly at both 5 and further at 24 h after surgery (3.2, 4.5 and 5.1 base-line, 5 and 24-h respectively), the IL-6 increase showed different patterns between the 2 groups; IL-6 was significantly increased in the control group of patients between preoperative baseline and 24 h after surgery (p = 0.008) also between 5 h and 24 h, (p = 0.006) after surgery while the AAI-group had only minor non-significant changes. The 18 patients that showed a 24-h MMSE score less than 25 had a significant higher 24-h IL-6 compared to the 390 patients with a MMSE score > 24 (p = 0.002). CONCLUSION The IL-6 increase after surgery was less pronounced in patients where anaesthesia was titrated by AAI compared to anaesthesia adjusted on clinical signs only. IL-6 were also found to be higher in patients with a MMSE < 25 at 24-h. Further studies are warranted evaluating the role of depth of anaesthesia monitoring on the risk for early cognitive impairment and neuro-inflammation. TRIAL REGISTRATION Clinicaltrials.gov identifier: NA/study were conducted between January 2005-April 2008.