Comparison of Patient-Controlled versus Continuous Epidural Analgesia in Adult Surgical Patients: A Systematic Review.

BACKGROUND: The advantages of PCEA over CEA have been demonstrated in obstetric patients. Whether a similar benefit applies to surgical patients is unclear. METHODS: Embase, PubMed, and Cochrane Library were searched, enabling a systematic review of studies comparing PCEA and CEA in adult surgical patients (PROSPERO: CRD42018106644). The study quality was assessed using the Cochrane risk-of-bias tool (RoB2). The primary outcome was pain scores on postoperative day one (POD1). Secondary outcomes were 24 or 48 h epidural or intravenous total analgesic dose, systemic analgesics, manual top-ups, side effects, and patient satisfaction. RESULTS: Six randomized controlled trials with high heterogeneity of study characteristics were identified with a moderate risk of bias. Two studies showed significantly reduced resting pain scores on POD1 in PCEA compared with CEA patients (36-44%, p < 0.05). Four studies found comparable pain scores between these groups. PCEA use reduced epidural medication (28% to 40% reduction, p < 0.01) in four studies. One study found a 23% reduction (p < 0.001) of top-ups in PCEA; intravenous morphine use by PCEA patients was reduced (0.16 vs. 3.45 mg per patient, p < 0.05) in one study. PCEA patients were more satisfied with analgesia (p < 0.001) in two studies. Nausea and vomiting were reduced in PCEA (p = 0.01). CONCLUSIONS: Regarding the reduction in pain scores, the effects of PCEA were not significant or clinically not relevant. However, regarding the amount of epidural drug use, the amount of required rescue systemic analgesics, patient satisfaction, and the number of required top-ups, PCEA had advantages over CEA in surgical patients.

Microbiological and scanning electron microscopic evaluation of epidural catheters.

BACKGROUND: Epidural catheters are frequently colonized by gram-positive bacteria. Although the incidence of associated epidural infections is low, their consequences can be devastating. We investigated bacterial growth on epidural catheters by quantitative bacterial culture and scanning electron microscopy (SEM) in order to explore the patterns of epidural catheter colonization. METHODS: 28 patients undergoing major abdominal surgery with thoracic epidurals (treatment ≥72 hours) were studied. Before the removal of the catheter, the skin surrounding the insertion site was swabbed. The entire catheter was divided into extracorporeal, subcutaneous, and tip segments. Skin swabs and catheter segments were quantitatively cultured, bacterial species were identified, and SEM was performed on four selected catheters. RESULTS: 27 of 28 catheters were included. The percentages of positive cultures were: skin swab 29.6%, extracorporeal segments 11.1%, subcutaneous segments 14.8%, and tip segments 33.3%. One patient was diagnosed with a catheter-associated infection. Staphylococcus epidermidis was cultured from the skin and the catheter extracorporeal, subcutaneous, and tip segments. SEM of this catheter showed bacteria-like and intraluminal host cell-like structures. SEM of two other catheters showed intraluminal fibrin networks in their tip segments. CONCLUSIONS: We present the first SEM pictures of an epidural catheter with a bacterial infection. Bacterial growth developed from the skin to the tip of this catheter, indicating the skin as a primary source of infection. By SEM, catheters with low levels of bacterial growth demonstrated an intraluminal fibrous network which possibly plays a role in catheter obstruction.

Face and construct validity of TU-Delft epidural simulator and the value of real-time visualization.

BACKGROUND AND OBJECTIVES: Learning epidural anesthesia traditionally involves bedside teaching. Visualization aids or a simulator can help in acquiring motor skills, increasing patient safety and steepening the learning curve. We evaluated the face and construct validity of the TU-Delft Epidural Simulator and the effect of needle visualization. METHODS: Sixty-eight anesthesiologists, anesthesia residents, and final-year medical students tested the epidural simulator. Participants performed six epidural simulations with and six without needle visualization. We tested face validity on a Likert scale questionnaire. We collected data with the simulator software (spinal taps, dura contacts, bone contacts, attempts, and time) and tested for correlation with the performer's experience (construct validity). A visualization aid was tested in a randomized crossover design. RESULTS: Face validity as rated by the participants was above average, with a mean of 3.7 (2.0-4.8) on a 5-point scale. Construct validity was indicated by significantly more spinal taps (0.4 [0-4) vs 0.07 [0-2], p=0.04) and more dura contacts (0.58 [0-6] vs 0.37 [0-3], p=0.002) by the inexperienced group compared with the expert group. The visualization aid improved performance by reducing the number of bone contacts and the number of attempts, and by decreasing the procedure time. Prior visualization training reduced the total procedure time from 279 s (69-574) to 180 s (53-605) (p=0.01) for the "blind" procedure. CONCLUSIONS: The TU-Delft Epidural Simulator is a useful tool for teaching motor skills during epidural needle placement. Prior use of a visualization tool improves performance even without visual support during consequent simulations.

Influence on number of top-ups after implementing patient controlled epidural analgesia: A cohort study.

Postoperative epidural analgesia often needs rate readjustment using top-ups. Patient-controlled epidural analgesia (PCEA) is said to reduce the requirement of epidural top-ups when compared to continuous epidural analgesia (CEA). We compared CEA and PCEA in major thoracic and abdominal surgery, in a cohort study. The primary endpoint was the required number of epidural top-ups. Secondary endpoints were pain scores, side effects and workload differences. We analysed 199 patients with CEA and 187 with PCEA. Both groups had similar pain scores. The total number of top-ups was 75 in 57 patients (CEA) versus 20 top-ups in 18 patients (PCEA). (p = 0.0001) Sedation tended to occur more frequently in patients with CEA versus PCEA, 5.5% vs 1.6% (p = 0.05). Implementation of PCEA led to a decreased number of top-ups, fewer side-effects and decreased use of the postoperative care unit.

Serum levels of bupivacaine after pre-peritoneal bolus vs. epidural bolus injection for analgesia in abdominal surgery: A safety study within a randomized controlled trial.

BACKGROUND: Continuous wound infiltration (CWI) has become increasingly popular in recent years as an alternative to epidural analgesia. As catheters are not placed until the end of surgery, more intraoperative opioid analgesics might be needed. We, therefore, added a single pre-peritoneal bolus of bupivacaine at the start of laparotomy, similar to the bolus given with epidural analgesia. METHODS: This was a comparative study within a randomized controlled trial (NTR4948). Patients undergoing hepato-pancreato-biliary surgery received either a pre-peritoneal bolus of 30ml bupivacaine 0.25%, or an epidural bolus of 10ml bupivacaine 0.25% at the start of laparotomy. In a subgroup of patients, we sampled blood and determined bupivacaine serum levels 20, 40, 60 and 80 minutes after bolus injection. We assumed toxicity of bupivacaine to be >1000 ng/ml. RESULTS: A total of 20 patients participated in this sub-study. All plasma levels measured as well as the upper limit of the predicted 99% confidence intervals per time point were well below the toxicity limit. In a mixed linear-effect model both groups did not differ statistically significant (p = 0.131). The intra-operative use of opioids was higher with CWI as compared to epidural (86 (SD 73) µg sufentanil vs. 50 (SD 32). CONCLUSIONS: In this exploratory study, the pre-peritoneal bolus using bupivacaine resulted in serum bupivacaine concentrations well below the commonly accepted toxic threshold. With CWI more additional analgesics are needed intraoperatively as compared to epidural analgesia, although this is compensated by a reduction in use of vasopressors with CWI. TRIAL REGISTRATION: Netherlands Trial Register NTR4948.

Intraoperative Fluid Restriction in Pancreatic Surgery: A Double Blinded Randomised Controlled Trial.

BACKGROUND: Perioperative fluid restriction in a variety of operations has shown improvement of: complications, recovery of gastrointestinal function and length of stay (LOS). We investigated effects of crystalloid fluid restriction in pancreatic surgery. Our hypothesis: enhanced recovery of gastrointestinal function. METHODS: In this double-blinded randomized trial, patients scheduled to undergo pancreatoduodenectomy (PD) were randomized: standard (S:10ml/kg/hr) or restricted (R:5ml/kg/hr) fluid protocols. PRIMARY ENDPOINT: gastric emptying scintigraphically assessed on postoperative day 7. RESULTS: In 66 randomized patients, complications and 6-year survival were analyzed. 54 patients were analyzed in intention to treat: 24 S-group and 30 R-group. 32 patients actually underwent a PD and 16 patients had a palliative gastrojejunostomy bypass operation in the full protocol analysis. The median gastric emptying time (T½) was 104 minutes (S-group, 95% confidence interval: 74-369) versus 159 minutes (R-group, 95% confidence interval: 61-204) (P = 0.893, NS). Delayed gastric emptying occurred in 10 patients in the S-group and in 13 patients in the R-group (45% and 50%, P = 0.779, NS). The primary outcome parameter, gastric emptying time, did not show a statistically significant difference between groups. CONCLUSION: A fluid regimen of 10ml/kg/hr or 5ml/kg/hr during pancreatic surgery did not lead to statistically significant differences in gastric emptying. A larger study would be needed to draw definite conclusions about fluid restriction in pancreatic surgery. TRIAL REGISTRATION: ISRCTN62621488.