Pertti Pere

Preincisional paravertebral block reduces the prevalence of chronic pain after breast surgery.

We reported earlier that preincisional paravertebral block (PVB) provides significant immediate postoperative analgesia after breast cancer surgery. In the same patients (n = 60), a 1-yr follow-up was performed to find out whether PVB could also reduce the prevalence of postoperative chronic pain. The follow-up consisted of a 14-day symptom diary and telephone interviews 1, 6, and 12 mo after surgery. The 14-day consumption of analgesics was similar in the 30 PVB and the 30 control patients. However, 1 mo after surgery, the intensity of motion-related pain was lower (P = 0.005) in the PVB group. Six months after surgery, the prevalence of any pain symptoms (P = 0.029) was lower in the PVB group. Finally, at 12 mo after surgery, in addition to the prevalence of pain symptoms (P = 0.003) and the intensity of motion-related pain (P = 0.003), the intensity of pain at rest (P = 0.011) was lower in the PVB group. These findings were independent of whether or not axillary dissection had been performed. The incidence of neuropathic pain was low (two and three patients in the PVB and control groups, respectively). In addition to providing acute postoperative pain relief, preoperative PVB seems to reduce the prevalence of chronic pain 1 yr after breast cancer surgery.

Single-injection paravertebral block before general anesthesia enhances analgesia after breast cancer surgery with and without associated lymph node biopsy.

Paravertebral block (PVB) seems to decrease postoperative pain and postoperative nausea and vomiting (PONV) after breast surgery, but the studies have not been placebo controlled. We studied 60 patients scheduled for breast cancer surgery randomly given single-injection PVB at T3 with bupivacaine 5 mg/mL (1.5 mg/kg) or saline before general anesthesia. The patient and attending investigators were blinded; the PVB or the sham block was performed behind a curtain by an anesthesiologist not involved in the study. The patients given PVB with bupivacaine needed 40% less IV opioid medication (primary outcome variable) in the postanesthesia care unit, had a longer latency to the first opioid dose, and had less pain at rest after 24 h than the control patients (P < 0.01). They also had less PONV in the postanesthesia care unit (P < 0.05), were less sedated until 90 min (P < 0.05), and performed better in the digit symbol substitution test at 90 min and the ocular coordination test 60–120 min after surgery (P < 0.05). The average peak bupivacaine plasma concentration was 750 ng/mL. One patient had bilateral convulsions immediately after bupivacaine injection. We conclude that PVB before general anesthesia for breast cancer surgery reduced postoperative pain, opioid consumption, and occurrence of PONV and improved recovery from anesthesia.

Effect of continuous interscalene brachial plexus block on diaphragm motion and on ventilatory function

Interscalene block may cause phrenic nerve block and decreased diaphragmatic motion. We evaluated the effect of continuous interscalene block on ventilatory function and diaphragmatic motion. We studied ten patients scheduled for surgery or manipulation of the shoulder. Preoperatively, the patients underwent spirometry and double‐exposure chest radiography. They received an interscalene block with 0.75% bupivacaine. Thereafter, 0.25% bupivacaine was infused into the interscalene space for 24 h. Spirometry was repeated three times and double‐exposure radiography twice. The maximal inspiratory and expiratory pressures were measured repeatedly. Haemoglobin oxygen saturation (SPo2) was monitored with pulse oximetry. The block provided adequate anaesthesia for surgery or manipulation. All patients had a marked ipsilateral paresis of the diaphragm in the radiographs 3 h after the initial block. Twenty‐one hours later five patients had diaphragmatic motility comparable to the situation before the block. In the other five patients, the amplitude of diaphragmatic motility on the side of the block was only 4–37% of the values before the block. All patients had a clear reduction in forced vital capacity (FVC), forced expiratory volume in ls (FEV1) and peak expiratory flow (PEF) 3 and 8 h after the block without signs of dyspnoea. In conclusion, in all our patients interscalene block caused an ipsilateral hemidiaphragm paresis, which in five of ten patients persisted until the end of the continuous block.

Epidural analgesia diminished pain but did not otherwise improve enhanced recovery after laparoscopic sigmoidectomy: a prospective randomized study

BackgroundThe primary hypothesis for this study was that epidural analgesia reduces the use of opioids and thus advances bowel function and oral intake and shortens hospital stay after laparoscopic sigmoidectomy performed according to principles of enhanced recovery after surgery.MethodsFor this study, 60 patients with complicated diverticular disease were randomized to the epidural anesthesia group or the control group before surgery. Postoperative oxycodone consumption, pain, and recovery parameters were followed for 14xa0days.ResultsThe epidural group needed less oxycodone than the control group until 12xa0h postoperatively. They experienced significantly less pain related to coughing and motion until postoperative day 2. In the epidural group, fewer patients experienced significant pain, and the duration of postoperative pain was shorter. Postoperative oral intake, bowel function, hospital stay, and overall complication rate were similar in the two groups. However, the control group had more postoperative hematomas.ConclusionsEpidural analgesia significantly alleviates pain, reducing the need for opioids during the first 48xa0h after laparoscopic sigmoidectomy. However, epidural analgesia does not alter postoperative oral intake, mobilization, or length of hospital stay.

Pharmacokinetics of ropivacaine in uremic and nonuremic patients after axillary brachial plexus block

Reports on the efficacy and pharmacokinetics of local anesthetics in uremic patients have been controversial. Our study involved 29 uremic and 28 nonuremic patients. We performed axillary block with ropivacaine 300 mg (50 mL). Venous blood samples were drawn for 24 h for assay of total and unbound plasma ropivacaine, 3-hydroxyropivacaine, pipecoloxylidide (PPX), and serum alpha(1)-acid glycoprotein (AAG). Block quality was similar in both groups. No toxicity occurred. Plasma clearance of ropivacaine was smaller and the area under the concentration-time curve of ropivacaine, 3-hydroxyropivacaine, and PPX larger in the uremic patients. The plasma concentration of PPX increased until 24 h in uremic patients whose AAG concentrations were also larger throughout the study. The free fraction of ropivacaine in plasma was smaller in the uremic group when measured 60 min and 12 h after the block, but the unbound concentration of ropivacaine was larger in the uremic group at 12 h. Enhanced absorption of ropivacaine into circulation, increased binding to AAG, and probably reduced urinary excretion of the metabolites lead to larger total plasma concentrations of ropivacaine and its main metabolites in uremic patients.

Cumulation of bupivacaine, desbutylbupivacaine and 4‐hydroxybupivacaine during and after continuous interscalene brachial plexus block

Desbutylbupivacaine (DBB) and 4‐hydroxybupivacaine (4‐OHB) are major metabolites of bupivacaine. They may cumulate during continuous infusion blocks. In the present study, all patients received an interscalene brachial plexus block with 20–28 ml of 0.75% bupivacaine plus adrenaline. A catheter was introduced into the interscalene space, and an infusion of 0.25% bupivacaine (5–9 ml/h) was started and continued with ten patients for 24 h and with another ten for 48 h. An infiltration block of the suprascapular and intercostobrachial nerves was performed using 0.5% bupivacaine. Before surgery, light general anaesthesia was induced. For measurement of plasma concentrations of bupivacaine, DBB and 4‐OHB blood samples were taken before the block and 30 min, 3 h, 24 h and 48 h after the blocks as well as 30 min, 1 h, 2 h, 4 h and 6 h after the termination of the infusions. The highest plasma concentrations of bupivacaine, mean 1.84 μg/ml, were measured 30 min after the block. There was a slight but statistically significant rise in the bupivacaine concentrations between 24 and 48 h. The bupivacaine concentration decreased by 54% and 45%, on average, during the first 6 h following the 24‐ and 48‐h infusions, respectively. On average, the highest DBB concentrations were measured 2 h after the 24‐h infusion (0.31 ± 0.18 μg/ml) and 30 min after the 48‐h infusion (0.33 ± 0.13 μg/ml). The highest 4‐OHB concentrations were measured 1 h (0.18 ± 0.09 μg/ml) and 30 min (0.20 ± 0.05 μg/ml) after the 24‐ and 48‐h infusions, respectively. The increase of the 4‐OHB concentration between 24 and 48 h was statistically significant (P<0.005). The use of a large initial bupivacaine dose (150–210 mg) followed by a continuous infusion of 12.5–22.5 mg/h for 24 and 48 h, resulted in marked cumulation of bupivacaine and the two metabolites in the plasma. No toxic symptoms or potentially toxic concentrations were observed.

Poor Antibacterial Effect of Ropivacaine Comparison with Bupivacaine

ROPIVACAINE (1-propyl-29,69-pipecoloxylidide) is a long-acting aminoamide local anesthetic that has been introduced into clinical use in the last few years, largely as a replacement for bupivacaine. Bupivacaine has been reported to possess a significant antibacterial effect. Because data regarding ropivacaine are not available, we compared the antibacterial effects of clinically appropriate concentrations of ropivacaine and bupivacaine in a laboratory setting.

Randomised comparison of hyperbaric articaine and hyperbaric low-dose bupivacaine along with fentanyl in spinal anaesthesia for day-case inguinal herniorrhaphy.

Background and objective Low-dose mixture of hyperbaric bupivacaine and fentanyl is commonly used in day-case spinal anaesthesia. Using hyperbaric articaine, the onset may be faster and duration more predictable than with bupivacaine–fentanyl. We compared these two spinal anaesthetics for inguinal herniorrhaphy. Methods Adult patients were randomised to spinal anaesthesia with hyperbaric articaine 84u200amg (group A, nu200a=u200a40) or hyperbaric bupivacaine 7u200amg along with fentanyl 10u200a&mgr;g (group B+F, nu200a=u200a40). A blinded observer tested the block characteristics. Aiming at sensory block spread to T10 dermatome, the operating table was tilted head-end up or down 10° (once or twice), as required. Postoperative telephone interviews were performed. Results All patients in group A had a sensory block to T10 in a median time of 4 (range 2–20)u200amin. In group B+F, the median onset time of T10 analgesia was 10 (2–30)u200amin (Pu200a<u200a0.001), but T10 analgesia was not reached in seven of 40 B+F patients. A head-up tilt was needed in 37 of 40 group A patients to prevent from too extensive cephalad spread of block, and 34 of 40 group B+F patients needed a head-down tilt to enhance cephalad spread of analgesia. To treat hypotension, 6.4u200amg of ephedrine was required, on average, in group A and 1.8u200amg in group B+F (Pu200a=u200a0.01). Median time to recovery from sensory block was significantly shorter in group A (2.5u200ah) than in group B+F (3u200ah; Pu200a=u200a0.002). General anaesthesia was needed in three patients (group A, two patients: sensory block too short; group B+F, one patient: sensory block too limited). Conclusion Hyperbaric articaine leads to faster onset of block and faster recovery than bupivacaine along with fentanyl. Hypotension is more common with articaine. The onset and extension of the spinal block are unpredictable when using these techniques.

Changes in heart rate variability in elderly patients undergoing major noncardiac surgery under spinal or general anesthesia.

BACKGROUND AND OBJECTIVESnHeart rate variability (HRV), widely used as an indicator of activity of the autonomic nervous system, has been reported to decrease during and after both spinal and general anesthesia in patients without cardiovascular disease. We evaluated the changes in HRV bands in 40 patients with a high risk of ischemic heart disease.nnnMETHODSnThe patients were randomly assigned to receive either spinal (SA) or general anesthesia (GA) for elective total hip arthroplasty or peripheral vascular surgery. Anesthetic techniques and perioperative fluid administration were standardized. Holter monitoring was started preoperatively and continued until the third postoperative day. Three HRV frequency bands were analyzed.nnnRESULTSnA significant decrease was seen in very low frequency (VLF) and low frequency (LF) bands during GA but not during SA. Also the LF/high frequency (HF) ratio decreased during GA but not during SA. A decrease in all HRV frequency bands was seen after both types of anesthesia. None of the frequency bands returned back to the preoperative level during the 3-day trial. Postoperatively circadian variation was found only in the VLF band after SA.nnnCONCLUSIONSnThe sympathovagal balance (LF/HF) is more stable during SA than during GA in patients with a high risk of ischemic heart disease. The postoperative decrease in HRV bands, however, is independent of the anesthetic technique.

Ketorolac is not nephrotoxic in connection with sevoflurane anesthesia in patients undergoing breast surgery.

Ketorolac, which may cause renal vasoconstriction by cyclooxygenase inhibition, is often administered to patients anesthetized with sevoflurane that is metabolized to inorganic fluoride (F-), another potential nephrotoxin. We assessed this possible interaction using urine N-acetyl-&bgr;-D-glucosaminidase indexed to urinary creatinine (U-NAG/crea) as a marker of proximal tubular, &bgr;2-microglobulin as a tubular, urine oxygen tension (PuO2) as a medullary, and erythropoietin as a marker of tubulointerstitial damage. Thirty women (ASA physical status I-II) undergoing breast surgery were included in our double-blinded study. They were allocated into two groups receiving either ketorolac 30 mg IM (Group K) or saline (Group C) at the time of premedication, at the end of, and 6 h after anesthesia maintained with sevoflurane. Urine output, U-NAG/crea, PuO2, serum creatinine, urea, and F- were assessed. Blood loss was larger in Group K (465 ± 286 mL vs 240 ± 149 mL, mean ± sd, P < 0.05). The MAC-doses of sevoflurane were similar. U-NAG/crea increased during the first 2 h of anesthesia and serum F- peaked 2 h after the anesthesia without differences between the groups. There were no statistically significant changes in PuO2, erythropoietin, &bgr;2-microglobulin, serum creatinine, urea, or urine output during anesthesia or the recovery period in either group. Our results indicate that the kidneys are not affected by ketorolac administered in connection with sevoflurane anesthesia.