UNLABELLED: N-methyl-D-aspartate (NMDA) antagonists administered before surgery will improve postoperative analgesia, presumably by inhibiting spinal sensitization processes. However, current clinical formulations of NMDA antagonists either enable only an oral application (i.e., dextromethorphan) or are associated with psychotropic side effects, as with the IV delivery of ketamine. Because of its noncompetitive NMDA receptor antagonist characteristics, amantadine may improve postoperative analgesia when administered before surgically induced trauma. In this prospective, randomized clinical study, we examined whether female patients undergoing elective abdominal hysterectomy experienced less postoperative pain when IV amantadine was applied in comparison with placebo before the start of surgery. Thirty patients were randomly assigned to receive 500 mL saline IV before the induction of standardized general anesthesia in Group 1 (Control group) or, in a double-blinded manner, 200 mg amantadine IV in 500 mL saline in Group 2 (Treatment group). Postoperative pain control was provided via IV patient-controlled analgesia with piritramide. During the first 48 h after tracheal extubation, pain perception was assessed by visual analog scales, and all analgesic requirements were documented. There were no significant differences between the two groups with respect to pain scores, postoperative analgesic requirements, and the incidence of side effects. Because of no differences in postoperative pain or opioid consumption, we conclude that a preoperative dose of 200 mg amantadine IV fails to enhance postoperative analgesia in patients undergoing elective abdominal hysterectomy. IMPLICATIONS: Because of no differences in postoperative pain or opioid consumption, we conclude that a preoperative dose of 200 mg amantadine IV fails to enhance postoperative analgesia in patients undergoing elective abdominal hysterectomy.

Aged↗

PubMed2001

Haemoglobin-based erythrocyte transfusion substitutes.

Concerns about the infectious and immunosuppressive risks of allogeneic blood products persist, and the increased disproportion of blood donation and consumption has reinforced the search for alternative erythrocyte transfusion strategies in recent years. With the absence of problems such as nephro-toxicity, increased colloid osmotic pressure and sudden renal clearance, modern haemoglobin based oxygen carriers (HBOC) have shown their effectiveness and tolerability in numerous animal and several clinical studies. HBOC can be infused without prior cross-matching and are now available as stable formulations with long shelf-life. Most clinical studies have been performed with human cross-linked haemoglobin (DCLHb) but all trials were stopped two years ago because of an increased mortality in two clinical trials in patients who received DCLHb after stroke and multiple injury shock. However, experimental trials in animals are in progress with DCLHb and recombinant human haemoglobin. In contrast, Phase III studies with polymerised bovine haemoglobin (HBOC-201) are finished or currently under evaluation showing that infusion of HBOC-201 can avoid or reduce allogeneic blood transfusion needs in specific peri-operative settings. As a consequence, HBOC-2001 was actually approved for treatment of peri-operative anaemia in elective adult surgical patients in South Africa. Other human or bovine haemoglobin solutions are currently being investigated in different clinical studies in cardiac surgery patients, sepsis and tumour patients. More recent investigations have shown that HBOC are not only simple erythrocyte transfusion substitutes but highly effective oxygen donators in terms of tissue oxygenation. HBOC open the door for a new therapeutic strategy: plasmatic oxygen delivery with physiological concentrations of inspired oxygen. In specific situations (e.g., ischaemia or arterial stenosis) HBOC have advantages over red blood cells because they can reach post-stenotic or poorly perfused tissues with the plasma stream, where erythrocytes are not able to pass. In addition to significant plasmatic oxygen transport, HBOC also enhance tissue oxygenation because of the facilitated oxygen release by HBOC and from remaining erythrocytes. Further studies will show, if the outcome of patients with impaired perfusion (e.g., stroke or myocardial infarction) can be improved by prophylactic or therapeutic application of HBOC. Whenever these formulations are globally launched, they will find differential indications as potent oxygen-delivering drugs in addition to the globally recognised goal of red cell substitutes in cases of bleeding.

Animals↗

PubMed2000

[Perioperative treatment of a patient with hereditary angioedema (HAE) in a case of a young patient with osteosynthesis from a femoral fracture].

The following case report describes hereditary angioedema (HAE) in a juvenile male patient presenting with femoral fracture. The clinical characteristics, pathophysiological changes, diagnostics and management of anaesthesia for patients with hereditary angioedema will be discussed. Hereditary angioedema (HAE) is a rare autosomal dominant disorder, which is caused by congenital deficiency of functional C1-inhibitor (C1-INH). Patients are suffering from episodic and painless edema of the skin (face and limbs) and mucous membranes of the respiratory and gastrointestinal tracts (the latter causing abdominal cramps due to edema of the intestine). Life-threatening airway obstruction may occur when patients develop laryngeal edema. It is important to differentiate HAE from the more frequent allergic angioedema because of differences in the pharmacological treatment of acute attacks of HAE. C1-INH-concentrate is effective in both treatment of acute attacks and prevention of edema, especially in children, juveniles and young women.

Adolescent↗

PubMed2000

Fast-track regional anaesthesia.

Regional anaesthesia plays an important role in day case surgery because it combines reliable effects with low risk and the possibility of local postoperative analgesia without systemic side-effects. Fast-track regional anaesthesia allows short-term postoperative surveillance or even bypassing the post-anaesthesia care unit. Peripheral nerve blocks provide long-lasting pain relief, and can accelerate timely discharge if a persisting motor block is accepted. Multiple peripheral nerve stimulation and injection techniques may help to realize differential blockades with a pronounced analgesic rather than a motor blocking effect. Nerve blocks with local anaesthetics in combination with alpha2-adrenoceptor agonists or non-steroidal anti-inflammatory drugs and short-acting parenteral opioids represent an effective multimodal concept for ambulatory surgery.

Journal Article↗

PubMed2000

Arificial Oxygen Carriers as Red Blood Cell Substitutes - Perfluorocarbons and Cell-Free Hemoglobin.

Forthcoming shortfall of blood products and persisting concerns about viral transmission and immunosuppressive side effects of allogeneic blood transfusion have reinforced the studies with alternative oxygen carriers in the last years. Modern perfluorochemicals and cell-free hemoglobin solutions can be applied without prior cross-matching and are now available as stable formulations with long shelf life. Both groups of oxygen carriers have shown their effectivity and tolerability in numerous animal studies. An emulsion of perflubron which has a 60% weight/volume relation is actually undergoing phase III studies with respect to its effectivity in augmented acute normovolemic hemodilution since it has been shown to reverse hemodynamic transfusion triggers. While clinical studies with human cross-linked hemoglobin (DCLHb) have been stopped last year because of the results of two clinical trials showing an increased mortality in patients with stroke and multiple injury shock being treated with DCLHb in comparison with saline, a phase III study with polymerized bovine hemoglobin HBOC-201 is actually being performed in noncardiac patients with perioperative bleeding. The objective of this multicenter study is to show that treatment with HBOC-201 can reduce or avoid allogeneic RBC transfusion. Besides its use in clinical transfusion protocols, artificial oxygen carriers have a unique potential to deliver oxygen to the tissues by plasmatic transport due to its different physiology of oxygenation when compared with conventional oxygenation provided by red blood cells. Future studies must show if these modern oxygen carriers are able to improve outcome of patients with impaired perfusion and organ oxygenation. Copyright 2000 S. Karger GmbH, Freiburg

Journal Article↗

PubMed1999

[Is spinal anesthesia for operations in the prone or jackknife position suitable?].

There is still controversy on the usefulness of spinal anesthesia for operations performed in the prone or jackknife position. There is about the risk of inadvertent increase of the sensomotory blockade with the patient in the prone position and the difficulty of managing consecutive cardiorespiratory complications or inducing general anesthesia in case of failures. This article reviews the current literature in terms of safety and effectiveness of spinal anesthesia for such operations. For lower-limb or perianal operations with limited extension and blood loss, performed in the prone position, spinal anesthesia seems to be a safe, effective and economic technique in patients without severe a cardiac history. Substantial knowledge about the onset time, fixation time, duration of sensomotory block and baricity of the applied local anesthetic is crucial in this setting. Obese patients are at risk for sudden extension of the block when turned into the prone position. Additional narcotics and sedatives should be avoided and continuous monitoring of hemodynamic and respiratory parameters, of the level of the blockade and vigilance of the patient is mandatory.

Anesthesia, Spinal↗

PubMed1999

[Intraoperative normothermia with partial warming of patients undergoing orthopedic procedures].

OBJECTIVE: This study investigates if warming of the upper or lower half of the body preserves normothermia in patients undergoing major orthopaedic surgery. Additionally, we compared the intraoperative tympanic membrane and urinary bladder temperatures of these patients. METHODS: Fifty-four patients undergoing major orthopaedic operations were observed. In all patients general anaesthesia was induced with fentanyl, etomidate, and atracurium and was maintained with isoflurane and nitrous oxide. Thirty patients were randomly allocated to maintain normal body temperatures (WarmTouch 5000. Mallinckrodt Medical, level IV, 41-42 degrees C), whereas 24 patients were not actively warmed. Warming of the patients was performed by complete body heating preoperatively and warming of the upper (n = 19) or lower (= 11) half of the body intraoperatively. Core temperature was recorded from the tympanic membrane. The urinary bladder temperature was measured by a special urinary catheter. RESULTS: Without active warming of the patients the core temperature decreased 1.6 degrees C during surgery. Core temperature remained constant in all actively heated patients, regardless of upper or lower body heating. Hypothermia of the unwarmed patients was detected by both, tympanic membrane measurement and--with a short delay--the urinary bladder temperature probe. CONCLUSION: This data suggests that active warming of the upper or lower half of the body during major orthopaedic surgery can preserve normothermia in all patients. During these surgical procedures the urinary bladder temperature was able to represent reliable core temperatures.

Anesthesia, General↗

PubMed1999

[Recent developments in obstetric regional anesthesia. A review of experiences at the Eppendorf University Hospital].

OBJECTIVES: The study investigates changes of anaesthesia practice in obstetric patients of a University Hospital over a six years' period. METHODS: Between 1993 and 1998 data of 7476 deliveries were collected by the perinatal documentation system of the Obstetric Department and by computerized anaesthesia protocols of the Department of Anesthesiology. Since combined spinal-epidural anaesthesia with sufentanil was introduced in 1997, all patients with subarachnoid techniques were prospectively examined between 1997 and 1998. RESULTS: While the total number of deliveries decreased over the years, the number of patients undergoing anaesthetic treatment increased continuously. In parallel, the number of patients with regional anaesthesia increased between 1993 and 1998 from 14.3% to 34.8%. The cesarean delivery rate increased from 23.7% to 28.7% with an increasing number of patients receiving regional anaesthesia for cesarean section (1993: 25.3% vs. 1998: 62.1%). The number of emergency cesarean deliveries performed in regional anaesthesia increased to 19.3% in 1998. The number of neonates with an umbilical artery pH below 7.2 decreased from 18% in 1993 to 11% in 1998. The success rate of regional anaesthesia increased from 88.2% in 1993 to 97.5% in 1998. Combined spinal-epidural anaesthesia provided greater pain reduction when compared with epidural anesthesia (VAS -81 +/- 12 vs. -68 +/- 18). Early vasopressor administration resulted in a decrease of hypotension from 40% to 14% in spinal and from 21% to 13% in combined spinal-epidural anaesthesia. The incidence of postdural puncture headache after subarachnoid anaesthesia was 2.4%. DISCUSSION: Epidural and subarachnoid application of sufentanil appears to enhance the success rate of obstetric regional anaesthesia. Subarachnoid techniques such as spinal or combined spinal-epidural anaesthesia showed a high effectiveness, low incidence of side effects and high degree of patients' satisfaction.

Anesthesia, Conduction↗

PubMed1999

[Symptomatic tachyarrhythmia in patients with a cardiac pacemaker in emergency situations].

Symptomatic tachyarrhythmia in the presence of a cardiac pacemaker is challenging in preclinical emergency situations. This article presents a case report and a diagnostic and therapeutic concept for prehospital treatment of such cases. The usefulness of extracorporeal magnet application which is recommended in the literature and the possibilities of antiarrhythmic therapy will be critically discussed.

Aged↗

PubMed1999

Patients' vs nurses' assessments of postoperative pain and anxiety during patient- or nurse-controlled analgesia.

We have compared patients' and nurses' assessments of postoperative pain and anxiety after different analgesic treatments. Sixty orthopaedic patients were allocated randomly to receive i.v. piritramide (either nurse-controlled or patient-controlled) or subarachnoid bupivacaine (nurse-controlled or patient-controlled). Patients and nurses assessed pain and anxiety using a visual analogue scale (VAS; 1-100 mm). Pain and anxiety ratings of patients and nurses were significantly correlated (Spearman's r > or = 0.69; P < 0.001). In general, patients' pain scores were higher than nurses' scores (patients' median VAS = 34 (range 1-76) mm; nurses VAS 21 (1-59) mm) and for all groups except the patient-controlled subarachnoid bupivacaine group, where they were significantly higher (P < 0.01). Discrepancy in pain estimates between patients and nurses increased with the level of pain. The relationship between patients' and nurses' anxiety scores was less clearly defined and did not depend on the level of anxiety.

Adolescent↗

PubMed1999

Wound infiltration and drain lavage with ropivacaine after major shoulder surgery.

UNLABELLED: Subcutaneous infiltration and wound lavage with ropivacaine is an alternative to opioids after major shoulder surgery. However, the efficacy and potential toxicity of this method remain unclear. We therefore evaluated plasma ropivacaine concentrations after shoulder infiltration and wound lavage. We subsequently quantified the efficacy of two ropivacaine concentrations. Patients undergoing major shoulder surgery were anesthetized with alfentanil and propofol. The initial patients (n = 18) received ropivacaine 7.5 mg/mL and ropivacaine plasma concentrations were measured in 15-min intervals. The subsequent 45 patients were randomly assigned to: 1) isotonic saline, 2) 3.75 mg/mL ropivacaine, or 3) 7.5 mg/mL ropivacaine. Ten milliliters of each solution was administered subcutaneously and 20 mL was injected into the wound drain which was clamped for 10 min. Supplemental postoperative pain relief was provided by patient-controlled anesthesia using the opioid piritramid (3.5-mg boluses, 6-min lock-out). Postoperative pain scores were recorded on a 100-mm visual analog scale for 4 h in the initial patients and for 10 h in the second part of the study. Unbound ropivacaine plasma concentrations peaked after 15 min at 0.08+/-0.09 microg/mL; the maximum was 0.30 microg/mL, compared with a toxic threshold of 0.6 microg/mL. In the second part of the study, pain scores were significantly lower after 3.75 mg/mL (20+/-15 mm) or 7.5 mg/mL (10+/-9 mm) ropivacaine than saline (35+/-10 mm). Piritramid requirements differed significantly in the three groups, being highest with saline and lowest with ropivacaine 7.5 mg/mL. We conclude that wound infiltration and lavage with 30 mL ropivacaine 7.5 mg/mL after major shoulder surgery resulted in very low pain scores and opioid requirement. IMPLICATIONS: Wound infiltration and lavage with 30 mL ropivacaine 7.5 mg/mL after major shoulder surgery resulted in very low pain scores and opioid requirement.

Amides↗

PubMed1999

Postoperative pain facilitates nonthermoregulatory tremor.

BACKGROUND: Spontaneous tremor is relatively common in normothermic patients after operation and has been attributed to many causes. The hypothesis that nonthermoregulatory shivering-like tremor is facilitated by postoperative pain was tested. In addition, the effects of intravenous lidocaine on nonthermoregulatory tremor were evaluated. METHODS: Patients undergoing knee surgery were anesthetized with 2 microg/kg intravenous fentanyl and 0.2 mg/kg etomidate. Anesthesia was maintained with 1.7 +/- 0.8% (mean +/- SD) isoflurane. Intraoperative forced-air heating maintained normothermia The initial 44 patients were randomly allocated to receive an intra-articular injection of 20 ml saline (n = 23) or lidocaine, 1.5% (n = 21). The subsequent 30 patients were randomly allocated to receive an intravenous bolus of 250 microg/kg lidocaine followed by an infusion of 13 microg x kg(-1) x h(-1) lidocaine or an equivalent volume of saline when shivering was observed. Patient-controlled analgesia was provided for all patients: 3.5 mg piritramide, with a lockout interval of 5 min, for an unlimited total dose. Shivering was graded by a blinded investigator using a four-point scale. Pain was assessed by a 100-mm visual analog scale (0 = no pain and 100 = worst pain). The arteriovenous shunt status was evaluated with forearm-minus-fingertip skin-temperature gradients. RESULTS: Morphometric characteristics and hemodynamic responses were similar in the four groups. Core and mean skin temperature remained constant or increased slightly compared with preoperative values, and postoperative skin-temperature gradients were negative (indicating vasodilation) in nearly all patients. After intra-articular injection of saline, pain scores for the first postoperative hour averaged 46 +/- 32 mm (mean +/- SD), and 10 of the 23 (43%) patients shivered. In contrast, the pain scores of patients who received intra-articular lidocaine were significantly reduced to 5 +/- 9 mm and shivering was absent in this group (P < 0.05). In the second portion of the study, neither intravenous lidocaine nor saline reduced the magnitude or duration of nonthermoregulatory tremor or the patients' pain scores. CONCLUSIONS: Intra-articular, but not intravenous, lidocaine reduced surgical pain and prevented nonthermoregulatory shivering. Therefore, these data indicate that postoperative pain facilitates nonthermoregulatory shivering.

Adult↗

PubMed1999

Histology and ultrastructure of liver and kidney following blood exchange with ultrapurified, polymerised bovine hemoglobin in comparison with hydroxyethyl starch.

Because of their oxygen binding capacity, cell-free hemoglobin solutions are promising blood substitutes. However, their clinical use has so far been limited by toxic side effects on liver and kidney until ultrapurification and chemical modifications have been established in the production process of hemoglobin-based oxygen carriers. The present study has been designed to examine structural changes of liver and kidney by light and electron microscopy after complete isovolemic blood exchange with a new ultrapurified bovine hemoglobin solution (UPBH-2) in eight beagle dogs. The results have been compared with a sham-operated control and eight animals having undergone blood exchange with hydroxyethyl starch (HES), a clinically used colloidal volume substitute. In the kidney, no changes were observed after blood exchange with UPBH-2 as compared with the sham control. These findings indicate sufficient tissue oxygenation and lack of renal toxicity. In contrast, histological signs of severe proximal tubular damage, eg, wide lumina, cytoplasmic protrusions, brush-border defects, and tubular necroses, were seen after blood exchange with HES. These changes are consistent with hypoxic tissue damage. In the liver, a slight increase in the number of single cell necroses was observed after UPBH-2 treatment as well as after blood exchange with HES. At the ultrastructural level, partial loss of microvilli and cytoplasmic protrusions of hepatocytes as well as swelling of endothelial cells were present in both groups, but slightly more pronounced in the UPBH-2 group. In all UPBH-2-treated animals, a marked diminution of glycogen-granula in hepatocytes was observed indicating an influence of UPBH-2 upon glycogen metabolism. Whereas the alterations of hepatocytes after nearly complete blood exchange with HES can be interpreted as a consequence of tissue hypoxia, the ultrastructural changes after UPBH-2 treatment cannot be attributed to hypoxic conditions, because improved tissue oxygenation has been demonstrated during treatment with UPBH-2. Hepatocyte damage was very discrete and comparable with the alterations observed after HES treatment. Hence, major hepatotoxicity can be excluded. The absence of significant adverse effects on the ultrastructural integrity of the kidney indicates that UPBH-2, owing to ultrapurification and polymerization, is an oxygen-carrying hemoglobin without acute renal toxicity.

Animals↗

PubMed1998

[Bovine hemoglobin. HBOC-201 causes a reduction of the oxygen partial pressure in poststenotic skeletal muscle].

UNLABELLED: We investigated the effects of ultrapurified polymerized bovine hemoglobin (HBOC-201) on skeletal muscle tissue oxygen tension when applied before establishment of a nearly complete arterial stenosis. METHODS: Twelve foxhounds were anaesthetized IV and mechanically ventilated with 30% oxygen in air. Catheters were inserted into the right femoral artery and vein for measurements of haemodynamic parameters and blood-gas sampling. Arterial blood flow of the left popliteal artery was measured by an electromagnetic flow probe. Skeletal muscle tissue oxygen tension (tpo2) was measured in the left gastrocnemic muscle using a stepwise-driven polarographic needle probe, creating histograms from 200 single tpO2 measurements. Following isovolaemic haemodilution with Ringer's solution to a target haematocrit of 20%, the animals were randomly assigned to receive either 200 ml of predonated fresh blood (group 1) or 200 ml of HBOC-201 (MW 32,000-500,000; Hb 13 +/- 1 g-dl-1, group 2). After a 15-min stabilization period, a 95% artificial stenosis of the left popliteal artery was established. While animals of group 1 received two applications of 200 ml 6% hetastarch (HES, 200,000; 0.5), animals of group 2 received 200 ml Ringer's solution 45 and 75 min after establishment of the arterial stenosis, respectively. Variables were measured at baseline, after haemodilution and application of the respective compound, and 30, 60 and 90 min after establishment of the stenosis. RESULTS: Demographic data, muscle temperature and arterial blood gases did not differ between groups. With the exception of a higher mean pulmonary artery pressure in HBOC-201-treated animals, haemodynamics did not differ between groups. In both groups oxygen delivery and oxygen consumption of the muscle decreased in parallel to the decreasing blood flow during arterial stenosis. In contrast, oxygen extraction ratio increased after infusion of HBOC-201 and remained unchanged during stenosis (P < 0.05). In group 1, the tpO2 decreased during stenosis when compared to baseline (P < 0.001) and remained decreased after administration of HES. In contrast, administration of 200 ml of HBOC-201 before establishment of the arterial stenosis sustained the tpO2 values at nearly baseline levels during stenosis. Skeletal muscle tissue oxygen tension was higher after HBOC-201 infusion during stenosis when compared to HES infusion (P < 0.001). CONCLUSION: These data suggest that haemoglobin solutions can reach poststenotic tissues. The increased oxygen extraction after application of HBOC-201 is associated with improved skeletal muscle oxygen tension during severe arterial stenosis.

Animals↗