Ultrasonographic needle tip tracking for in-plane infraclavicular brachialis plexus blocks: a randomized controlled volunteer study.

BACKGROUND: Onvision is a new technology for needle tip detection and tracking in ultrasound-guided regional anesthesia. The system consists of a piezoelectric sensor close to the needle tip and an electronic console integrated in the ultrasound system. The needle tip is visualized by a green circle on the ultrasound screen. The aim of the study was to investigate the effect of the new needle tip tracking technology on in-plane infraclavicular plexus blocks. METHODS: The study was a randomized, controlled, observer blinded cross-over trial in 26 healthy volunteers. Two specialists in anesthesiology performed an ultrasound-guided infraclavicular lateral sagittal brachial plexus block with and without needle tip tracking. Primary outcome was procedure time, measured from insertion of the needle until local anesthesia injection was completed. Secondary outcome measures included the number of hand movements and path lengths (assessed by hand motion analysis), block success rate, onset time and duration, discomfort experienced by the volunteers, and the anesthesiologists' confidence as to whether their block would be successful or not. RESULTS: Mean (SD) procedure time was 183.0 (56.1) s with and 206.8 (56.2) s without needle tip tracking (p=0.16). There were no significant differences in any of the secondary outcomes. Two volunteers' experienced Horner syndrome after blocks without needle tip tracking. No other adverse events occurred during the study. CONCLUSION: Our study on needle tip tracking for infraclavicular blocks did not reveal any significant differences between active needle tip tracking and the control procedures, neither for primary outcome nor secondary outcome measurements. TRIAL REGISTRATION NUMBER: NCT03631914.

The effect of needle tip tracking on procedural time of ultrasound-guided lumbar plexus block: a randomised controlled trial.

Technology that facilitates performance of deep peripheral nerve blocks is of clinical interest. The Onvision™ is a new device for ultrasonographic needle tip tracking that incorporates an ultrasound sensor on the needle tip that is then represented by a green circle on the ultrasound screen. The primary aim of this study was to investigate the effect of needle tip tracking on procedural time in the first human volunteer study. Secondary outcome measures included: number of hand movements; hand movement path length; block success rate; block onset time; block duration; discomfort experienced by the volunteers; and the anaesthetists' confidence as to whether their block would be successful. Two anaesthetists performed ultrasound-guided lumbar plexus blocks with an out-of-plane technique, with and without the use of needle tip tracking. In total, data from 25 volunteers were studied. Mean (SD) procedural time was 163 (103) s with needle tip tracking and 216 (117) s without (p = 0.10). Hand motion analysis showed that needle tip tracking was associated with a significant decrease in the mean (SD) number of intended needling hand movements (39 (29) vs. 59 (36); p = 0.03) and path lengths (3.2 (3.1) m vs. 5.5 (4.5) m; p = 0.03). No differences were found for any other secondary outcomes. The use of Onvision needle tip tracking did not reduce procedural time for out-of-plane ultrasound-guided lumbar plexus block but did reduce the number of hand movements and path lengths. This may indicate improved needle control but further studies are needed to confirm this finding.

Effects of Adrenaline on maternal and fetal fentanyl absorption in epidural analgesia: A randomized trial.

BACKGROUND: The combination of low-dose local anesthesia and lipophilic opioids such as fentanyl is established as a standard solution for labor epidural analgesia. Fentanyl increases efficacy, but may have negative effects on the neonate in terms of reduced neonatal neurologic and adaptive capacity scores and breast feeding. We hypothesized that addition of adrenaline 2 µg/mL to a solution of bupivacaine 1 mg/mL and fentanyl 2 µg/mL would reduce the systemic uptake of fentanyl, resulting in reduced serum fentanyl in the fetus at birth. METHODS: Forty-one nulliparous women requesting epidural analgesia were randomized to epidural analgesia with or without adrenaline. Blood samples were drawn from the mother with regular intervals, and at delivery. An umbilical vein blood sample (used as a proxy for fetal exposure) was drawn after clamping. RESULTS: There were no significant differences between the groups in fentanyl concentrations in the umbilical vein and maternal serum at birth. There was a significantly lower mean area under the maternal serum-concentration curve for the first 2 hours of treatment in the adrenaline group (mean difference 0.161 nmol h/L [0.034; 0.289], P = .015), implying slower systemic uptake in the adrenaline group initially. There were no significant differences in treatment duration, motor block, Apgar scores, umbilical pH and base excess, or mode of delivery. CONCLUSIONS: The addition of adrenaline to an epidural solution containing fentanyl lowered maternal systemic serum fentanyl concentration during the first 2 hours, but did not lower serum fentanyl concentration in the umbilical vein and mother at delivery.

Randomized controlled trial of intra-articular ketorolac on pain and inflammation after minor arthroscopic knee surgery.

BACKGROUND: Ketorolac is an effective non-steroidal anti-inflammatory drug, commonly used with local anaesthetics as part of local infiltration analgesia protocols following orthopaedic surgery. However, systemic uptake and drug action may be the major mechanism after local infiltration. The aims of this project were to study the effects of a small, systemically ineffective dose of ketorolac given intra-articularly for post-operative pain and also to study synovial inflammatory biomarkers. We investigated whether ketorolac affects pro-inflammatory biomarkers in an in vitro model, as well. METHODS: In this placebo-controlled, blind, randomized study, we analysed intra-articular ketorolac (5 mg) in ambulatory minor knee surgery patients with moderate or severe pain (n = 44). We assessed post-operative pain intensity (n = 44) and analysed microdialysis samples taken from knee synovial tissue every 20 min (n = 34). We also tested cyclooxygenase-independent effects of ketorolac in synovial cells stimulated by prostaglandin E2 and chondroitin sulphate in vitro. RESULTS: Intra-articular ketorolac (5 mg) administration did not reduce pain or synovial pro-inflammatory cytokines CXCL1, IL-8, and MCP-1, 0-120 min after knee arthroscopy. Female gender was a risk factor for moderate or severe pain (relative risk 1.45, 95% confidence interval 1.04-2.01). Paradoxically, ketorolac increased the release of CXCL1 and IL-8 in prostaglandin E2 and chondroitin sulphate-stimulated synovial cells in vitro. CONCLUSION: Ketorolac prescribed at a low dose intra-articularly does not produce any detectable analgesic effect after minor knee surgery.

Changes in pulmonary function during pregnancy: a longitudinal cohort study.

OBJECTIVE: To record any physiological changes in lung function during healthy pregnancies, and evaluate the influence of parity, pregestational overweight, and excessive weight gain. DESIGN: Longitudinal cohort study. SETTING: Antenatal clinic at Oslo University Hospital. POPULATION: One hundred healthy white women with singleton pregnancies. METHODS: The women were studied with repeated measures of lung function using spirometry at a gestational age of 14-16, 22-24, 30-32, and 36 weeks, and at 6 months postpartum. MAIN OUTCOME MEASURES: Forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), and peak expiratory flow (PEF), also expressed as a percentage of predicted values according to age and height: i.e. FVC%, FEV1%, and PEF%. RESULTS: Both FVC and FVC% increased significantly after 14-16 weeks of gestation (P=0.001), as was the case for both PEF and PEF% (P<0.001). FVC, FVC%, PEF, and PEF% in early and mid-pregnancy were significantly lower compared with the postpartum value (all P<0.05). Nulliparous women had an overall 4.4% lower value of FVC% than parous women (P=0.039). There were no differences in FVC, FEV1, or PEF dependent upon pregestational overweight or excessive weight gain. CONCLUSIONS: Forced vital capacity (FVC) increases significantly after 14-16 weeks of gestation. The FVC% is significantly higher in parous compared with primigravida women, suggesting that the changes in FVC occurring during pregnancy persist postpartum. PEF increases significantly during healthy pregnancies, and should be interpreted cautiously in pregnant women with impaired lung function.

Paratracheal placement of orotracheal tube: a complication when aborting percutaneous tracheotomy.

Percutaneous dilatational tracheotomies (PT) are commonly performed in the ICU. The procedure carries the risk of complications, among them severe events as loss of airway or pneumothorax. In this case report we describe complications related to a PT procedure in the ICU. The procedure was performed with a single dilator kit, and by visual guidance of a bronchoscope. Because of difficulties with the insertion of the tracheal cannula, the procedure was aborted, and the endotracheal tube (ET) reinserted. After placement of the ET, subcutaneous emphysema emerged. Upon digital exploration in the tracheotomy incision the tube was found to exit from the trachea, the tube-tip being situated para-tracheally. The tube position was corrected using a finger in the incision, and the patient could again be ventilated. Poor visual conditions may occur during PT because of bleeding. Importantly, there is a risk for the ET to exit an incision in the trachea when reintubating during a PT procedure, or after decannulation. This can be prevented using digital occlusion of the tracheal opening.

Haemodynamic effects of oxytocin in women with severe preeclampsia.

BACKGROUND: Several previous publications demonstrate the significant haemodynamic effects of oxytocin in healthy pregnant women, but there is only one publication of the oxytocin effects in women with severe preeclampsia. We investigated the haemodynamic effects of oxytocin in women with severe preeclampsia using invasive haemodynamic monitoring. METHODS: Eighteen women with severe preeclampsia were included in this observational study. All women had continuous invasive haemodynamic monitoring during spinal anaesthesia for caesarean section using the LiDCOplus monitor. Preeclamptic patients were given intravenous boluses of 5IU oxytocin following delivery. RESULTS: Following an intravenous bolus of 5IU oxytocin all patients had an increase in heart rate, a decrease in systemic vascular resistance and a decrease in blood pressure. Five patients had a decrease in cardiac output due to an inability to increase stroke volume. CONCLUSIONS: The haemodynamic effects of oxytocin in women with severe preeclampsia may be less predictable compared to findings in healthy pregnant women, suggesting that oxytocin should be given with caution in women with severe preeclampsia.

Regional anaesthesia for a Caesarean section in women with cardiac disease: a prospective study.

BACKGROUND: We conducted a prospective observational survey of pregnant women with cardiac disease. The aim was to analyse and present the mode of delivery, outcome, and haemodynamic changes during a caesarean section under regional anaesthesia in women with cardiac disease. METHODS: All pregnant women with a cardiovascular diagnosis, except hypertension, were included in the registry. Based on the cardiac diagnoses, and on the New York Heart Association classification, a multidisciplinary group made recommendations for each patient and decided on the mode of delivery. The data from continuous, invasive haemodynamic monitoring in intermediate- and high-risk patients under regional anaesthesia for a caesarean section were analysed and presented. RESULTS: The hospital had approximately 9000 deliveries in the period from November 2003 to April 2008. A total of 113 pregnancies in 107 women were included. Thirty-two (28.3%) pregnancies were classified into the high-risk category. Of 103 deliveries, caesarean sections were performed in 59 (52.2%) cases, with regional anaesthesia in 51 patients (18 emergencies), general anaesthesia in eight patients (five emergencies), and a planned vaginal delivery in 44 patients. There was no mortality among the mothers or the babies during the hospital stay or 6 months postpartum. Pre-operative cardiovascular stability during the caesarean section was maintained by volume and phenylephrine infusion guided by invasive monitoring of haemodynamic variables. CONCLUSION: Our study suggests that pregnant women with cardiac disease may safely deliver the baby by a caesarean section under regional anaesthesia. According to our findings, haemodynamic stability can be obtained by titrated regional anaesthesia, intravenous (i.v.) volume, phenylephrine infusion, and small repeated doses of i.v. oxytocin guided by invasive monitoring.

Haemodynamic effects of repeated doses of oxytocin during Caesarean delivery in healthy parturients.

BACKGROUND: The haemodynamic effects of oxytocin 5 u have been described previously, but still some authors attribute these effects to the delivery itself. We studied the haemodynamic effects of two repeated doses of oxytocin i.v. in 20 healthy women during spinal anaesthesia for Caesarean delivery. METHODS: Data were obtained from a randomized controlled study of 80 pregnant women undergoing an elective Caesarean section. All women had an arterial line inserted, and LidCOPlus was used for measuring cardiac output (CO), stroke volume (SV), and systemic vascular resistance (SVR). RESULTS: Twenty women required a second bolus of oxytocin 5 u. Both the first and the second doses produced clinically and statistically significant haemodynamic changes, but the haemodynamic changes induced by the second dose were smaller than after the first dose. The mean maximal change in CO after the first and second doses were 94% (CI 70-117) and 42% (CI 33-52), respectively (P<0.0001), and for systolic arterial pressure 31% (CI 27-35) and 23% (CI 20-27), respectively (P=0.003). CONCLUSIONS: An initial bolus of oxytocin 5 u produced prominent haemodynamic changes, whereas a second bolus produced smaller changes. This could be due to desensitization of endothelial oxytocin receptors.

Assessment of pain.

UNLABELLED: Valid and reliable assessment of pain is essential for both clinical trials and effective pain management. The nature of pain makes objective measurement impossible. Acute pain can be reliably assessed, both at rest (important for comfort) and during movement (important for function and risk of postoperative complications), with one-dimensional tools such as numeric rating scales or visual analogue scales. Both these are more powerful in detecting changes in pain intensity than a verbal categorical rating scale. In acute pain trials, assessment of baseline pain must ensure sufficient pain intensity for the trial to detect meaningful treatment effects. Chronic pain assessment and its impact on physical, emotional, and social functions require multidimensional qualitative tools and health-related quality of life instruments. Several disease- and patient-specific functional scales are useful, such as the Western Ontario and MacMaster Universities for osteoarthritis, and several neuropathic pain screening tools. The Initiative on METHODS: Measurement, and Pain Assessment in Clinical Trials recommendations for outcome measurements of chronic pain trials are also useful for routine assessment. Cancer pain assessment is complicated by a number of other bodily and mental symptoms such as fatigue and depression, all affecting quality of life. It is noteworthy that quality of life reported by chronic pain patients can be as much affected as that of terminal cancer patients. Any assessment of pain must take into account other factors, such as cognitive impairment or dementia, and assessment tools validated in the specific patient groups being studied.

Pain and disability 1 year after knee arthroscopic procedures.

BACKGROUND: Persistent chronic pain after surgery is a major health care problem. Its prevalence after knee arthroscopy is unknown. We conducted a follow-up of knee arthroscopy patients. The aims were to estimate the prevalence of pain at rest and during activity 1 year after knee arthroscopy. METHODS: One hundred patients with moderate or severe acute pain after knee arthroscopy were included in one of two randomized-controlled pain trials. A questionnaire was mailed to all the patients 1 year after inclusion. RESULTS: The prevalence of pain at rest 1 year after surgery [numeric rating scale (NRS) 0-10 grade >/=1] was 30% (95% CI 17-47) in women and 29% (95% CI 17-46) in men. Four of 33 female (10%) and three of 34 male patients (9%) experienced pain intensities at rest of NRS>4, and the number of patients who had experienced NRS>4 during activities were 7 (21%) and 4 (11%), respectively. Age above 50 years was positively correlated to persistent pain. The number of patients who reported a reduced activity of daily living (ADL) due to pain (NRS>4) was 14 of 33 (42%, 95% CI 28-56%) in female and five of 34 (15%, 95% CI 5-25%) in male patients (P=0.03). Age above 50 years was positively correlated to impaired ADL function due to knee pain. CONCLUSIONS: Persistent pain after knee arthroscopy may be a significant health care problem. Age and female gender are independent risk factors for pain and disability 1 year after surgery.

Monitoring urinary bladder volume and detecting post-operative urinary retention in children with an ultrasound scanner.

BACKGROUND: Post-operative urinary retention (PUR) is associated with a risk of over-distension and permanent detrusor damage. The prevention of PUR by routine catheterization may increase the risk of urinary tract infection. Post-operative monitoring of the bladder volume is a reliable method in adults, but has not been evaluated for reliability in children. METHODS: Forty-eight patients who, according to current clinical guidelines, required urinary bladder emptying were scanned before catheterization using the Bladderscan. Volumes estimated with ultrasound were compared with volumes measured after emptying the bladder with a catheter. Bladder emptying was controlled by concomitant fluoroscopy in 20 children. RESULTS: The mean difference between the ultrasound estimates and the catheter-emptied urine volumes was 4 ml [standard deviation (SD) = 25 ml] in 26 children above the age of 3 years and -18 ml (SD = 19 ml) in 22 younger children. In the subpopulation in whom complete bladder emptying could be confirmed by fluoroscopy (14 children; median age, 3 years; range, 1-11 years), the mean difference between the ultrasound estimates and the catheter-emptied volumes was -11 ml (SD = 24 ml). CONCLUSIONS: This study confirms agreement between the ultrasound scanner estimates of urinary bladder volume and the urine volume measured by emptying the bladder. Reliability was good in children above the age of 3 years. The volume was underestimated in younger children. Thus, routine monitoring of urinary bladder volume with an ultrasound scanner is a non-invasive, pain-free and reliable way of preventing over-distension of the urinary bladder in children after surgery and other procedures under general anaesthesia.

Effective pain relief from intra-articular saline with or without morphine 2 mg in patients with moderate-to-severe pain after knee arthroscopy: a randomized, double-blind controlled clinical study.

BACKGROUND: Intra-articular (IA) morphine has given good and prolonged pain relief in some studies when given at the end of arthroscopic procedures in the knee joint. However, similar studies have not been able to document any local analgesic effect of morphine. A large number of the negative studies have not demonstrated any assay sensitivity. We have documented that around 40% of patients have only very mild or no pain after arthroscopic procedures in the knee joint. This obviously is a confounding factor, reducing assay sensitivity when all patients are included in IA morphine studies. METHOD: By leaving a soft catheter IA in 57 patients and including only patients who developed moderate-to-severe pain within 1 h after an arthroscopic procedure in the knee joint under general anaesthesia, we included 40 patients. These patients had a mean pre-treatment baseline pain of about 50/100 on a 100-mm visual analogue scale (VAS) for pain intensity. A randomized, double-blind controlled comparison of saline 10 ml with or without morphine 2 mg followed. Test drugs were administered through the IA catheter. Pain intensity and pain relief, consumption of rescue analgesics and global evaluation of effect and adverse effects were measured up to 36 h thereafter. RESULTS: Pain intensity decreased from about 50 to about 10-15/100 in both groups and the sum of pain intensity differences at 2 and 22 h was not significantly different between the two groups. Global evaluation of effects and adverse effects, as well as consumption of rescue analgesics during 36 h after arthroscopic procedures, were also similar in the two groups. CONCLUSIONS: Only 70% of 57 patients had pain of moderate-to-severe intensity within 1 h after an arthroscopic procedure of the knee joint under general anaesthesia. IA injection of saline 10 ml and saline 10 ml with morphine 2 mg were both associated with pain relief. These findings may have implications for interpretations of a majority of published studies on IA morphine.

Detecting postoperative urinary retention with an ultrasound scanner.

BACKGROUND: Retention of urine is a common postoperative problem associated with risk of overdistention and permanent detrusor damage. Prevention of urinary retention by insertion of indwelling catheter may increase the risk of urinary infection. We have performed a reliability test of an ultrasound scanner, implemented in the postoperative monitoring equipment. METHODS: Patients were monitored after different types of surgery under spinal anesthesia with an ultrasound scanner in the postanesthesia care unit (PACU). PATIENTS: Patients who according to current guidelines required a urinary bladder catheter, were scanned before a catheter was inserted and urine volume was measured. These two urine volumes were compared and analyzed for agreement. RESULTS: Nineteen female and 17 male patients were included. The mean difference between ultrasound estimates and catheter urine volume measurements was - 21.5 mL, and limits of agreement, calculated as a 95% confidence interval, were - 147 and + 104 mL. This means that the urine volume estimated by ultrasound was on average 21.5 mL smaller than the urine volume when the bladder was emptied. CONCLUSION: This study confirms a good agreement between the ultrasound scanner estimates of urinary bladder volume and urine volume measured after emptying the bladder. Nurses in the PACU could operate the ultrasound scanner after a brief instruction and training period. Considering the potentially serious long-term consequences of undiagnosed postoperative urinary retention, introducing this equipment for routine monitoring of urinary bladder volume should be considered.

Intra-articular morphine for pain relief after knee arthroscopy.

BACKGROUND: Peripheral opioid analgesia is well documented. But the clinical usefulness of intra-articular morphine after surgery is uncertain. The aim of the present study was to evaluate the analgesic effects of intra-articular morphine after knee arthroscopy. METHODS: In this parallel-group, double-blind study, 90 patients were randomised to receive either morphine 1 mg, morphine 2 mg or placebo in 5 ml saline intra-articularly at the end of arthroscopic knee surgery. Anaesthetic technique was local infiltration and intra-articular injection of lidocaine. Analgesic efficacy was evaluated by a global pain score, pain intensity (visual analogue scale), and analgesic requirements (paracetamol) during the first 48 h postoperatively. RESULTS: No significant differences between the groups were found for any of the efficacy variables. A majority of the patients had mild pain throughout the study, thus possibly compromising study sensitivity. In a subgroup with more intense pain early after arthroscopy, intra-articular morphine 2 mg reduced pain intensity (P < 0.05) and analgesic requirements (P < 0.05) compared with placebo. CONCLUSION: Postoperative analgesic effect of intra-articular morphine was found only in a subgroup of patients with higher pain intensity in the immediate postanaesthetic period. Possible reasons for our overall negative findings include low study sensitivity due to weak pain stimulus, lack of inflammation that may be a prerequisite for peripheral opioid analgesia, and the local anaesthetic, which impedes local inflammatory reaction and expression of peripheral opioid receptors. These factors may also explain the conflicting results in other studies.

[Serious streptococcal infections of the head and neck region]. / Alvorlige streptokokkinfeksjoner i øre-nese-halsområdet.

This article describes the four cases of serious infections caused by Streptococcus pyogenes in the head and neck. Three patients presented with invasive infections of the soft tissues in the neck and one with epiglottitis. Two patients fulfilled the criteria for toxic streptococcal shock syndrome. The incidence of severe streptococcal disease is increasing in Norway, which emphasizes the importance of an aggressive attitude when diagnosing and treating atypical throat infections.

[Central venous catheter. Better routine for placing of catheters]. / Sentralt venekateter. Bedret rutine for kateterplassering.

Malposition of a central venous catheter is a major cause of serious complications such as perforation and cardiac tamponade. To prevent such complications it is necessary to confirm that the catheter tip is in the correct position. Intravascular electrocardiography is a reliable way of ensuring that the catheter tip is placed above the right atrium. With a minimum of extra equipment and training, we have tested the electrocardiography technique applied to our standard central venous catheter equipment (Secalon Seldy and Hydrocath). Our experience is that this technique makes catheter tip placement distal to the right atrium more easy to achieve.

Coding guidelines for ICD-9 section on mental disorders and reliability of chart clinical diagnoses.

A major innovation of the ICD-10 draft is provision of diagnostic guidelines. This is assumed to be appropriate for use in clinical situations. In Norway a similar approach was adopted when ICD-9 was introduced as the official classification system in 1987. This was done in order to avoid national diagnostic bias and increase diagnostic reliability. A comparison with the DSM-III criteria was included in the diagnostic guidelines. The effectiveness of this approach was investigated by comparing the chart ICD-9 diagnoses of 104 psychiatric in- and outpatients from 2 teaching hospitals with the diagnoses obtained by using case record rating forms (criterion diagnosis). According to the criterion diagnoses, the base rate of chart diagnoses of schizophrenia and manic-depressive psychosis was too low, and the base rate of reactive psychosis too high. Several chart diagnoses proved to have low reliability, particularly reactive psychosis, paranoid psychosis, depressive neurosis and personality disorders. The study suggests that the provision of extensive diagnostic guidelines does not necessarily alter previous diagnostic practice. Reasons for these findings and the implications for the ICD-10 diagnostic criteria and diagnostic guidelines are discussed.