Clemens Ortner, MD

Abstract

The intensity of physical activity which can be tolerated after lung transplantation and the tolerance to prolonged exercise at high altitude are poorly investigated. Lung ultrasound comet tails have been used in the diagnosis of interstitial pulmonary edema and high pulmonary altitude edema. The aim was to assess the number of lung ultrasound comet tails and to monitor changes in the optic nerve sheath diameter (ONSD) during a climb to the top of Mount Kilimanjaro in 10 lung transplant recipients and 10 healthy controls at three different altitude levels: 1360, 3505, 4900m. Lung transplant recipients showed a constant increase in comet tail scores with altitude, whereas control subjects only showed an increase at the highest measurement point. Differences between groups (transplant versus control) reached significance only after the first ascend: 0.9 (95% CI: -0.41; 2.21) vs. 0.1 (95% CI: -0.12; 0.32) (P=0.2; 1360m), 2.33 (95% CI: 0.64; 4.02) vs. 0.3 (95% CI: -0.18; 0.78) (P=0.04; 3505m), and 4.11 (95% CI: 0.13; 0.34) vs. 2.9 (95% CI: 0.49; 5.31) (P=0.15; 4900m); ONSD increased significantly in both groups from 3.53 (95% CI: 0.34; 0.66) at 1360m to 4.11 (95% CI: 0.36; 0.71) at 4900m (P<0.05). Lungs of transplant recipients are able to adapt to altitude and capable of performing prolonged exercise at high altitude after slow ascend.

View details for DOI 10.1111/tri.13307

View details for Web of Science ID 000447163400008

View details for PubMedID 29928768

Abstract

Pilot studies applying point-of-care ultrasound (POCUS) in preeclampsia indicate the presence of pulmonary interstitial edema, cerebral edema, and cardiac dysfunction. Laboratory markers of oncotic pressure (albumin) and cardiac dysfunction (brain natriuretic peptide [BNP]) may be abnormal, but the clinical application remains unclear. We investigated the prevalence of pulmonary interstitial syndrome (PIS), cardiac dysfunction, and increased optic nerve sheath diameter (ONSD) in late-onset preeclampsia with severe features. The primary aim was to examine the association between PIS or ONSD and maternal serum albumin level. The secondary aims were to explore the association between cardiac dysfunction and PIS, ONSD, BNP, and serum albumin level and between POCUS-derived parameters and a suspicious or pathological cardiotocograph.Ninety-five women were enrolled in this prospective observational cohort study. A POCUS examination of lungs, heart, and ONSD was performed. PIS was defined as a bilateral B-line pattern on lung ultrasound and diastolic dysfunction according to an algorithm of the American Society of Echocardiography. ONSD >5.8 mm was interpreted as compatible with raised intracranial pressure (>20 mm Hg). Serum BNP and albumin levels were also measured.PIS, diastolic dysfunction, systolic dysfunction, and raised left ventricular end-diastolic pressure (LVEDP) were present in 23 (24%), 31 (33%), 9 (10%), and 20 (25%) women, respectively. ONSD was increased in 27 (28%) women. Concerning the primary outcome, there was no association between albumin level and PIS (P = .4) or ONSD (P = .63). With respect to secondary outcomes, there was no association between albumin level and systolic dysfunction (P = .21) or raised LVEDP (P = .44). PIS was associated with diastolic dysfunction (P = .02) and raised LVEDP (P = .009; negative predictive value, 85%). BNP level was associated with systolic (P < .001) and diastolic dysfunction (P = .003) and LVEDP (P = .007). No association was found between POCUS abnormalities and a suspicious/pathological cardiotocograph (P = .07).PIS, diastolic dysfunction, and increased ONSD were common in preeclampsia with severe features. Cardiac ultrasound abnormalities may be more useful than albumin levels in predicting PIS. The absence of PIS may exclude raised LVEDP. The further clinical relevance of PIS and raised ONSD remains to be established. BNP level was associated with cardiac ultrasound abnormalities. Although this study was not designed to directly influence clinical management, the findings suggest that POCUS may serve as a useful adjunct to clinical examination for the obstetric anesthesiologist managing these complex patients.

View details for DOI 10.1213/ANE.0000000000003759

View details for PubMedID 30211771

Abstract

Pharmacokinetic data on drug administration during lactation are often inconsistent or missing. For legal reasons medicinal drug product information generally advises to interrupt breastfeeding for 24h after medication intake. However this is not standard of care in clinical practice as the mother should be instructed to initiate breastfeeding as soon as possible after giving birth. At the same time the medication exposure over the breast milk for the newborn should be minimized. Aim of this article is to summarize pharmacokinetic data and to give important clinical information on medications frequently administered during the lactation period. As ageneral rule amother can start breastfeeding following anesthesia as soon as she is able to get her baby latched on her breast.

View details for DOI 10.1007/s10354-018-0637-z

View details for PubMedID 29691694

Abstract

The following article contains information not only for the clinical working anaesthesiologist, but also for other specialists involved in obstetric affairs. Besides asynopsis of aGerman translation of the current "Practice Guidelines for Obstetric Anaesthesia 2016" [1], written by the American Society of Anesthesiologists, the authors provide personal information regarding major topics of obstetric anaesthesia including pre-anaesthesia patient evaluation, equipment and staff at the delivery room, use of general anaesthesia, peridural analgesia, spinal anaesthesia, combined spinal-epidural anaesthesia, single shot spinal anaesthesia, and programmed intermittent epidural bolus.

View details for DOI 10.1007/s10354-017-0584-0

View details for PubMedID 28744777

Abstract

To date the gold standard of treating labour pain is regional analgesia by application of epidural analgesia. When offering epidural analgesia, the programmed intermittent epidural bolus (PIEB) is more effective in terms of pain reduction, less motor blocks and higher satisfaction of the parturient compared to continuous application via perfusor pump. An upcoming alternative to epidural analgesia is remifentanil, ashort acting and potent opioid. Remifentanil, however, requires haemodynamic monitoring as cardiac and respiratory impairment has been described. Nitrous oxide has been used for decades in the Anglosphere but it is agreenhouse gas, and interactions with Vitamin B12are possible. Using novel extraction systems, nitrous oxide has become more attractive for treatment of the initial phase of labour pain in Central Europe. In order to provide the parturient with the best possible and with atailored pain concept an interdisciplinary approach with obstetricians, midwives and anaesthesiologists is required.

View details for DOI 10.1007/s10354-017-0571-5

View details for PubMedID 28577077

Abstract

The number of pregnant women with severe comorbidities is increasing. The aim of the present study was to analyze outcomes and determine trends in women who required peripartum admission to the intensive care unit (ICU).In this retrospective study, we identified all women who were admitted to the ICU between the second trimester of pregnancy and 6 weeks postpartum. Women with ICU admission between 2011 and 2014 were assigned to the study group, whereas those admitted between 1996 and 2003 were assigned to the historical group. Comorbidities, characteristics, outcomes, and treatment efforts were assessed. Descriptive analysis, Fisher's exact test, unpaired Student's t-test and one-way ANOVA were performed.We identified 238 cases, including 135 (56.7%) in the study group and 103 (43.3%) in the historical group. In 83 (34.9%) women, deterioration of the pre-existing medical condition was causal for ICU admission. Overall, preterm delivery and mean gestational age were 81.5% and 31.6 6.2weeks, respectively. In comparison to the historical group, women of the study group were older (p= 0.005), more frequently presented with multiple comorbidities (p= 0.003), pre-existing conditions (p< 0.001), and congenital heart disease (p= 0.012). Moreover, they had ashorter length of stay at the ICU than those of the historical group (p= 0.02).Peripartum ICU admissions are increasing in frequency. As maternal characteristics are changing, adequate risk stratification with multidisciplinary care are essential, and access to intermediate care units would be preferable for patients with short-term admission.

View details for DOI 10.1007/s00508-016-1161-z

View details for PubMedID 28101669

View details for PubMedCentralID PMC5599431

Abstract

The intensity of post-egg retrieval pain is underestimated, with few studies examining postprocedural pain and predictors to identify women at risk for severe pain. We evaluated the influence of preprocedural hormonal levels, ovarian factors, and mechanical temporal summation (mTS) as predictors for post-egg retrieval pain in women undergoing in vitro fertilization.Eighteen women scheduled for ultrasound-guided egg retrieval under standardized anesthesia and postprocedural analgesia were enrolled. Preprocedural mTS, questionnaires, clinical data related to anesthesia and the procedure itself, postprocedural pain scores, and pain medication for breakthrough pain were recorded. Statistical analysis included Pearson product-moment correlations, Mann-Whitney U tests, and multiple linear regressions.Average peak post-egg retrieval pain during the first 24 hours was 5.01.6 on a numerical response scale (0=no pain, 10=worst pain imaginable). Peak post-egg retrieval pain was correlated with basal antimullerian hormone (AMH) (r=0.549, P=0.018), preprocedural peak estradiol (r=0.582, P=0.011), total number of follicles (r=0.517, P=0.028), and number of retrieved eggs (r=0.510, P=0.031). Ovarian hyperstimulation syndrome (n=4) was associated with higher basal AMH (P=0.004), higher peak pain scores (P=0.049), but not with peak estradiol (P=0.13). The mTS did not correlate with peak postprocedural pain (r=0.266, P=0.286), or peak estradiol level (r=0.090, P=0.899).Peak post-egg retrieval pain intensity was higher than anticipated. Our results suggest that post-egg retrieval pain can be predicted by baseline AMH, high peak estradiol, and ovarian hyperstimulation syndrome. Further studies to evaluate intraprocedural and postprocedural pain in this population are needed, as well as clinical trials to assess postprocedural analgesia in women presenting with high hormonal levels.

View details for DOI 10.1097/AJP.0000000000000251

View details for Web of Science ID 000373827200006

View details for PubMedID 25968448

Abstract

The influence of common disturbances seen in preeclampsia, such as changes in strong ions and weak acids (particularly albumin) on acid-base status, has not been fully elucidated. The aims of this study were to provide a comprehensive acid-base analysis in severe preeclampsia and to identify potential new biological predictors of disease severity.Fifty women with severe preeclampsia, 25 healthy non-pregnant- and 46 healthy pregnant controls (26-40 weeks' gestation), were enrolled in this prospective case-control study. Acid-base analysis was performed by applying the physicochemical approach of Stewart and Gilfix.Mean [sd] base excess was similar in preeclamptic- and healthy pregnant women (-3.3 [2.3], and -2.8 [1.5] mEq/L respectively). In preeclampsia, there were greater offsetting contributions to the base excess, in the form of hyperchloraemia (BE(Cl) -2 [2.3] vs -0.4 [2.3] mEq/L, P<0.001) and hypoalbuminaemia (BE(Alb) 3.6 [1] vs 2.1 [0.8] mEq/L, P<0.001). In preeclampsia, hypoalbuminaemic metabolic alkalosis was associated with a non-reassuring/abnormal fetal heart tracing (P<0.001). Quantitative analysis in healthy pregnancy revealed respiratory and hypoalbuminaemic alkalosis that was metabolically offset by acidosis, secondary to unmeasured anions and dilution.While the overall base excess in severe preeclampsia is similar to that in healthy pregnancy, preeclampsia is associated with a greater imbalance offsetting hypoalbuminaemic alkalosis and hyperchloraemic acidosis. Rather than the absolute value of base excess, the magnitude of these opposing contributors may be a better indicator of the severity of this disease. Hypoalbuminaemic alkalosis may also be a predictor of fetal compromise.clinicaltrials.gov: NCT 02164370.

View details for DOI 10.1093/bja/aev221

View details for Web of Science ID 000358808100018

View details for PubMedID 26170350

Abstract

The PhysioDoloris analgesia monitor assesses nociception effects on the autonomic nervous system by analyzing changes in heart rate variability (HRV). This non-invasive device analyses ECG signals and determines the analgesia nociception index (ANI), allowing for quantitative assessment of the analgesia/nociception balance in anesthetized patients. Ketamine, an analgesic adjuvant with sympathomimetic properties, has been shown to improve perioperative pain management. The purpose of this pilot study was to evaluate whether low-dose ketamine, due to its intrinsic effect on the sino-atrial node, affects HRV and, therefore, interferes with ANI measurements. This pilot study included 20 women undergoing abdominal hysterectomies. Anesthesia and analgesia were maintained with sevoflurane and fentanyl respectively, in a standardized manner. Five minutes after intubation, 0.5 g kg(-1) of intravenous (i.v.) ketamine was administered. ANI, bispectral index (BIS), heart rate and blood pressure were recorded from the induction of anesthesia until 5 min after skin incision. There was not any significant decrease in mean (SD) ANI values after intubation (2.1120.11, p=0.35) or i.v. ketamine administration (1.3115.26, p=0.28). The mean (SD) reduction in ANI values after skin incision was statistically significant (13.6515.44, p=0.01), which is consistent with increased nociception. A single i.v. bolus of 0.5 g kg(-1) ketamine did not influence the ANI values of 20 women under standardized general anesthesia conditions and absent noxious stimulation. These results suggest that the ANI derived from the PhysioDoloris analgesia monitor is feasible under such clinical conditions.

View details for DOI 10.1007/s10877-014-9600-8

View details for Web of Science ID 000352742400012

View details for PubMedID 25062948

Abstract

Osteogenesis imperfecta is a congenital disorder resulting in multiple fractures and extremely short stature, usually necessitating cesarean delivery. Identical twins with severe osteogenesis imperfecta each of whom underwent a cesarean delivery with different anesthetic modalities are presented. A review of the literature and anesthetic options for cesarean delivery and postoperative analgesia for women with osteogenesis imperfecta are discussed.

View details for DOI 10.1016/j.ijoa.2014.07.006

View details for Web of Science ID 000349725800012

View details for PubMedID 25433579

Abstract

The incidence of chronic pain after cesarean delivery (CD) has been estimated to range between 0.3% and 18%. This wide range may be explained by differing study methodologies. Furthermore, a comprehensive characterization of pain quality is lacking. The aim of this study was to evaluate persistent pain in a healthy obstetric population undergoing planned CD and to provide a comprehensive description of pain quality.Three hundred eighty-one women with no pain history undergoing CD were included in this prospective, observational cohort study. Spinal anesthesia was standardized, and postoperative pain was recorded at 24 hours. In each woman, pain was assessed at 8 weeks, and 6 and 12 months using questionnaires of pain intensity and interference. Pain quality was assessed using the Short-Form McGill Pain Questionnaire-Revised.The incidence of persistent pain at 8 weeks was 11% (95% confidence interval, 8%-14%), with pain reported as being mild and interfering with common daily activities by 32% of women. At 6 and 12 months, the incidence was 3% (95% confidence interval, 2%-6%) and 0.6% (95% confidence interval, 0%-2%) respectively, with pain rarely interfering with daily activities. However, 22% of women described other surgery-related symptoms at 12 months.The incidence of chronic pain at 12 months after planned CD is low (0.6%) and if present symptoms are mostly mild and not interfering with common daily activities. Using Short-Form McGill Pain Questionnaire-Revised, this study provides a comprehensive evaluation of pain quality that can be used as a basis in future post-CD pain trials.

View details for DOI 10.1097/AAP.0000000000000158

View details for Web of Science ID 000344933500007

View details for PubMedID 25304476

Abstract

The percentage of women undergoing cesarean delivery under general anesthesia has significantly decreased, which limits training opportunities for its safe administration. The purpose of this study was to evaluate how effective simulation-based training was in the learning and long-term retention of skills to perform general anesthesia for an emergent cesarean delivery.During an eight-week obstetric anesthesia rotation, 24 residents attended lectures and simulation-based training to perform general anesthesia for emergent cesarean delivery. Performance assessments using a validated weighted scaling system were made during the first (pre-test) and fifth weeks (post-test) of training, and eight months later (post-retention test). Resident's competency level (weighted score) and errors were assessed at each testing session. Six obstetric anesthesia attending physicians, unfamiliar with the simulation scenario, generated a mean attendings' performance score. The results were compared.At one week of training, residents' performance was significantly below mean attendings' performance score (pre-test: 13522 vs. 15911, P=0.013). At five weeks, residents' performance was similar to mean attendings' performance score (post-test: 15921) and remained at that level at eight months (post-retention test: 16416). Of the important obstetric-specific tasks, left uterine displacement was missed by 46% of residents at eight months.Following lectures and simulation-enhanced training, anesthesia residents reached and retained for up to eight months a competency level in a simulator comparable to that of obstetric anesthesia attending physicians. Errors in performance and missed tasks may be used to improve residency training and continuing medical education.

View details for DOI 10.1016/j.ijoa.2014.04.008

View details for Web of Science ID 000345203200008

View details for PubMedID 25066817

Abstract

With over four million deliveries annually in the United States alone and a constant increase in cesarean delivery rate, childbirth is likely to have a huge impact on the occurrence of acute and possibly chronic postpartum pain. Recent awareness that chronic pain may occur after childbirth has prompted clinicians and researchers to investigate this topic. Current evidence points towards a relatively low incidence of chronic pain after cesarean delivery, with rates ranging between 1% and 18%. To provide a potential mechanistic explanation for the relatively low occurrence of chronic pain after cesarean delivery compared with that after other types of surgery, it has been proposed that endogenous secretion of oxytocin may confer specific protection. Clinical interventions to reduce the incidence and severity of chronic post-surgical pain have not been consistently effective. Likely explanations are that the drugs that have been investigated were truly ineffective or that the effect was too modest because with a low incidence of chronic pain, studies were likely to be underpowered and failed to demonstrate an effect. In addition, since not all women require preventive therapies, preoperative testing that may identify women vulnerable to pain may be highly beneficial. Further research is needed to identify valid models that predict persistent pain to allow targeted interventions to women most likely to benefit from more tailored anti-hyperalgesic therapies.

View details for DOI 10.1016/j.ijoa.2013.01.008

View details for Web of Science ID 000318137700009

View details for PubMedID 23477888

Abstract

Over 1.4 million Caesarean deliveries are performed annually in the United States, out of which 30% are elective repeat procedures. Post-operative hyperalgesia is associated with an increased risk for persistent post-surgical pain; however, there are no data on whether residual scar hyperalgesia (SHA) from a previous Caesarean delivery (CD) persists until the next delivery. We hypothesized that residual SHA may be present in a substantial proportion of women and is associated with increased post-operative pain.One hundred and sixty-three women scheduled for a repeat CD under spinal anaesthesia were enrolled into the study. Mechanical temporal summation (mTS) and SHA index were measured preoperatively. SHA was considered present when the index was >0. Post-operative pain scores at 12, 24 and 48h and wound hyperalgesia (WHA) at 48h were recorded.SHA was present in 67 women 41% with a median SHA index of 0.42 (Q (25) =0.25; Q (75) =1.1, range 0.03-4.25). Women with SHA had overall higher post-operative pain scores and SHA was correlated with preoperative mTS (r=0.164, p<0.05), post-operative pain severity (r=0.25, p<0.002) and WHA at 48h (r=0.608, p<0.001). Severe pain (visual analogue pain scale-S487, n=20) was predicted with a sensitivity and specificity of 60% and 62%, respectively. Positive predictive value was 18% and negative predictive value was 92%.Preoperative SHA is present in 41% of women scheduled for repeat CD and is associated with increased mTS and post-operative pain. Screening for preoperative SHA may predict women at risk for increased post-operative pain, and guide post-operative analgesia to include anti-hyperalgesic drugs.

View details for DOI 10.1002/j.1532-2149.2012.00171.x

View details for Web of Science ID 000312300800014

View details for PubMedID 22689634

Abstract

The transversus abdominis plane (TAP) block is an established technique to manage post-cesarean delivery pain. Transversus abdominis plane blocks with a local anesthetic only offer no analgesic benefits compared with intrathecal morphine. Adjuvants to extend TAP block duration and possibly reduce wound hyperalgesia, known to be a risk factor for chronic pain, have not been studied. We hypothesized that a TAP block with clonidine will affect postsurgical wound hyperalgesia and improve pain outcomes.Ninety women were randomly assigned to receive 1 of 3 TAP blocks after cesarean delivery: saline (placebo), bupivacaine (BupTAP), or bupivacaine + clonidine (CloTAP). The primary outcome was wound hyperalgesia index at 48 hours. Secondary outcomes included pain scores, analgesic consumption, and pain descriptors up to 12 months.Wound hyperalgesia index at 48 hours (median [25th-75th percentiles]) was 1.07 (0.48-3.26) in the placebo group, 1.27 (0.59-2.95) in the BupTAP group, and 0.74 (0.09-2.25) in the CloTAP group (P = 0.48). Morphine request in the postanesthesia care unit was significantly higher in the placebo group compared with the other TAP groups (P = 0.01). Postoperative pain scores and requests for breakthrough medication at 48 hours (30% in the placebo group, 24% in the BupTAP group, and 12% in the CloTAP group, P = 0.25) or chronic pain descriptors reported up to 12 months did not differ significantly among groups.Adding clonidine to a TAP block with bupivacaine did not affect wound hyperalgesia index and it did not improve short-term or long-term pain scores in women undergoing elective cesarean delivery. Further studies are warranted to determine the benefits of antihyperalgesic adjuvants in TAP solutions for specific individuals at risk for chronic pain.

View details for DOI 10.1097/AAP.0b013e318259ce35

View details for Web of Science ID 000308673000010

View details for PubMedID 22683707

Abstract

Combining tramadol with paracetamol is an established analgesic treatment strategy. However, dosing and differential effects on peripheral and central hyperalgesia are still to be determined. After Ethics Committee approval, 32 volunteers have been included in this 2 phased, double blinded, placebo controlled, cross-over study. A defined small skin area was irradiated with a UVB source inducing hyperalgesia. Twenty-four hours after irradiation, heat pain-, cold pain threshold (HPPT, CPPT), mechanical pain sensitivity to pin prick (MPS) in the area of pin prick hyperalgesia (AsH) and MPS in the sunburn were determined. In phase I, measurements have been repeated 30min after receiving cumulative 0.3, 0.6 and 1mg/kg of intravenous (i.v.) tramadol or active placebo. Only at 1mg/kg tramadol and solely for MPS in the sunburn a reduction to placebo could be demonstrated (p=0.024). Accordingly in phase II, the trial has been repeated using 1mg/kg tramadol and paracetamol or placebo in a cumulative i.v. dose of 330, 660 and 990mg. Now the addition of 330mg paracetamol to tramadol reduced thermal hyperalgesia by 1.15C (CI 0.55; 1.76). This effect, however, did not increase with higher doses. Tramadol showed week anti-hyperalgesia reducing CPPT, MPS and AsH compared to baseline measurements (p<0.05). Paracetamol also reduced secondary hyperalgesia, but no combination effect with tramadol could be shown. We conclude, in inflammatory hyperalgesia tramadol alone exerts only weak anti-hyperalgesia. Even adding a small dose paracetamol enhances thermal anti-hyperalgesia.

View details for DOI 10.1016/j.ejpain.2011.08.007

View details for Web of Science ID 000305947000011

View details for PubMedID 22396084

Abstract

We present five cases of women who received ultrasound-guided transversus abdominis plane catheters for post-cesarean delivery analgesia. Pain relief was maintained with repeated boluses of local anesthetic combined with oral acetaminophen and ibuprofen unless contraindicated. We conclude that repeated dosing through transversus abdominis plane catheters may be offered to women as an alternative or adjuvant to intrathecal morphine. Larger studies to evaluate the safety and further refinements of this novel procedure are warranted.

View details for DOI 10.1016/j.ijoa.2011.10.007

View details for Web of Science ID 000303619600013

View details for PubMedID 22153133

Abstract

Emergent placement of a chest tube is a potentially life-saving procedure, but rate of misplacement and organ injury is up to 30%. In principle, chest tube insertion can be performed by using Trocar or Non-trocar techniques. If using trocar technique, two different chest tubes (equipped with sharp or blunt tip) are currently commercially available. This study was performed to detect any difference with respect to time until tube insertion, to success and to misplacement rate.Twenty emergency physicians performed five tube thoracostomies using both blunt and sharp tipped tube kits in 100 fresh human cadavers (100 thoracostomies with each kit). Time until tube insertion served as primary outcome. Complications and success rate were examined by pathological dissection and served as further outcomes parameters.Difference in mean time until tube insertion (63 s vs. 59 s) was statistically not significant. In both groups, time for insertion decreased from the 1st to the 5th attempt and showed dependency on the cadaver's BMI and on the individual physician. Success rate differed between both groups (92% using blunt vs. 86% using sharp tipped kits) and injuries and misplacements occurred significantly more frequently using chest tubes with sharp tips (p = 0.04).Data suggest that chest drain insertion with trocars is associated with a 6-14% operator-related complication rate. No difference in average time could be found. However, misplacements and organ injuries occurred more frequently using sharp tips. Consequently, if using a trocar technique, the use of blunt tipped kits is recommended.

View details for DOI 10.1186/1757-7241-20-10

View details for Web of Science ID 000302259600001

View details for PubMedID 22300972

View details for PubMedCentralID PMC3395864

View details for DOI 10.1111/j.1600-0412.2011.01191.x

View details for Web of Science ID 000293151900020

View details for PubMedID 21615357

View details for DOI 10.1213/ANE.0b013e31821f154f

View details for Web of Science ID 000293064500047

View details for PubMedID 21788333

Abstract

Combining ropivacaine with sufentanil for intrathecal (i.t.) analgesia in labor is well recognized, but information on dosing is limited. This study aimed to determine the ED 50 of i.t. ropivacaine and to assess the effect of adding defined low doses of sufentanil.This was a two-phase, double-blind, randomized and prospective study. One hundred and fifteen parturients receiving combined spinal epidural analgesia were allocated to one of four groups to receive ropivacaine or sufentanil alone or in combination. In phase one, sufentanil dose-response was calculated using logistic regression. In phase two, ED 50 of ropivacaine and of the combination with a fixed dosage of sufentanil at ED 20 and ED 40 was evaluated using the technique of up-down sequential allocation. Analgesic effectiveness was assessed 15 min after injection using a 100 mm visual analog scale, with <10 mm lasting for 45 min defined as effective. Furthermore, side effects and duration were recorded.The ED 50 of i.t. ropivacaine was 4.6 mg [95% confidence intervals (95% CI) 4.28, 5.31]. Adding sufentanil at ED 20 significantly decreased the ED 50 of i.t. ropivacaine to 2.1 mg (95%CI 1.75, 2.5) (P<0.005); at ED 40, the reduction was similar (P<0.005). Combining sufentanil with ropivacaine resulted in a dose-independent prolongation of analgesia. Besides pruritus, which was well tolerated, there were no differences in side effects.Adding sufentanil at ED 20 results in a more than 50% dose-sparing effect of ropivacaine and considerably prolongs analgesia. Increasing dosage implicates no clinical benefit.

View details for DOI 10.1111/j.1399-6576.2010.02254.x

View details for Web of Science ID 000280616700011

View details for PubMedID 20546210