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H C Niesel

Publications and source records attributed to H C Niesel.

At least 19 recordsLinked to original sources
PubMed1993

[Ropivacaine 1% versus bupivacaine 0.75% without a vasoconstrictor. A comparative study of epidural anesthesia in orthopedic surgery].

The long-acting local anaesthetic agent ropivacaine, S(-)-1-propyl-2',6'-pipecoloxylidid, is characterised by lower lipid solubility and lower cardiotoxicity compared with bupivacaine. This study was designed to evaluate its clinical efficacy and motor blocking properties when using lower volumes and higher concentrations of both plain substances. METHODS. In a randomised, double-blind study plain ropivacaine (ro) 1% (150 mg) and bupivacaine (bu) 0.75% (112.5 mg) were compared in 44 patients. In the lateral position, epidural anaesthesia was performed at L2/3 or L3/4 using the loss-of-resistance technique. A test dose of 3 ml was given followed by 12 ml (total volume 15 ml). Sensory blockade was registered by the pin-prick method after 2 min at 5-min intervals up to maximal levels and after the operation at 30-min intervals. Simultaneously, the motor block was determined by means of the Bromage scale. Results are given as median values. RESULTS. The onset of analgesia was 6.0 min for both substances (L2), the time to level L5 16.0 and 17.0 min, respectively. The median maximum upper level of sensory analgesia was achieved after 24.5 min with ro (Th 5) and after 21.0 min (Th 7) with bu. The maximum durations (regression to L2) were 321.5 (ro) and 266.0 min (bu) (P < 0.05). Times for 2-segment regression were comparable at 177.5 and 176.0 min, respectively, and for 4-segment regression at 201.3 and 222.0 min. Twenty-one of the 22 patients developed a first-degree motor block (latency 15 and 12 min); 16 patients in the ro group developed a second-degree block, as did 14 in the bu group (latency 24 and 22 min). Third-degree motor block was recorded in 3 patients (latency 45 and 38 min). The duration of first-degree motor block was 233 min and 207 min, of second-degree block 150 and 155 min, and third-degree block 135 min in both groups. The mean arterial pressures and heart rates did not differ. The diastolic pressures were lower after bu (-8.3%) than after ro (-0.4%) at 30 min. No major side effects were observed. Theodrenaline and/or dihydroergotamine (1:10 diluted) was administered to 38.6% of the patients; 34.1% received atropine for the treatment of bradycardias (decrease > or = 12%) and hypotension of more than 20%. No significant differences were found in frequency of analgesia (pin-prick) between both groups. One of 22 patients in the ro group and 6 of 22 in the bu group required additional analgesics or general anaesthesia. The difference is not statistically significant, but is of clinical relevance. With 2 patients after ro and 4 patients after bu the relaxation was insufficient for good operating conditions. CONCLUSION. Ropivacaine 1% produced a longer duration of analgesia and better clinical efficacy than bupivacaine 0.75%. The clinical difference in motor blockade was not statistically significant. The Bromage scale is not representative for a substance with good analgesic effects and moderate motor blocking properties, as has been shown in sophisticated studies on ropivacaine motor blockade.

Adolescent↗
PubMed1992

Plasma prilocaine and mepivacaine concentrations after combined lumbosacral plexus block.

In a pharmacokinetic study of combined sciatic/3-in-1 block for lower limb surgery, the two moderate-acting local anaesthetics prilocaine and mepivacaine were compared. The mean maximum venous plasma concentrations of mepivacaine were more than twice as high as when prilocaine was used as anaesthetic (5.1 micrograms/ml vs. 2.37 micrograms/ml). When used in combination with the former, ornipressin did not reduce plasma concentrations of mepivacaine to values which were below the threshold for toxic symptoms (5-6 mg/ml). The peak plasma concentrations exceeded the threshold of 5 micrograms/ml in four of the nine patients of the mepivacaine group (maximum value 7.21 mg/ml) and in two of the nine patients of the mepivacaine+ornipressin group (maximum value 8.61 micrograms/ml).

Adult↗
PubMed1992

Prilocaine in lumbosacral plexus block--general efficacy and comparison of nerve stimulation amplitude.

The significance of the threshold amperage of peripheral nerve stimulation (PNS) for the efficacy and latency of sciatic block is shown in a controlled randomized study of stimulation amplitude. In all cases the block was complete within a short time when the threshold amperage was 0.3 mA or less. Incomplete motor and sensory blocks occurred with higher stimulation amplitudes of 0.5 and 1.0 mA. In view of these results a prospective study of the clinical efficacy of 852 combined sciatic/3-in-1 blocks using prilocaine, and performed by means of peripheral nerve stimulation was carried out. No CNS or cardiovascular complications, no problems resulting from methaemoglobinaemia and, above all, no nervous lesions were observed. The limiting factor for surgery of the lower limb with this method of anaesthesia is the tolerance of the femoral tourniquet which depends mainly on the efficacy of the 3-in-1 block. Ninety-one per cent of the combined blockades were primarily successful when there was no tourniquet at all, and 87% when the tourniquet was placed on the lower leg. In the course of surgery with a femoral pneumatic tourniquet, only 55% of the blocks did not require supplement when 20 ml of 1% prilocaine was used for the 3-in-1 block, while 72% and 74% were efficacious with 30 ml and 35 ml, respectively. The efficacy of the sciatic block proved to be extremely high (> 95%), its success depending on the dosage of the local anaesthetic and correct execution of the peripheral nerve stimulation.

Adult↗
PubMed1991

[Epidural blockade for analgesia and treatment of acute pancreatitis].

The effect of a fractional epidural blockade on acute pancreatitis was investigated in a prospective study. PATIENTS AND METHODS. Thoracic (20 patients) or lumbar (six patients) epidural blockade was carried out in 26 patients with severe abdominal conditions comprising sub-ileus in 100%, pancreatic edema indicated by sonography/computer tomography in 57.8%, and necrosis of the pancreas in 34.6%. RESULTS. On average, 3.4 (1-6) injections with single doses of 6-20 ml 0.25% bupivacaine were injected per day. In four patients, morphine (up to 4 mg per 24 h) was added to the local anesthetic. The duration of treatment was between 1 and 15 days. After 10.5% of the injections, the systolic pressure decreased by more than 20%, and after 12.8% of the injections the blood pressure decreased by more than 30%. Hypotension of more than 30% was treated with 0.3 to 0.5 ml theodrenaline (Akrinor) and/or 0.1 to 0.2 mg dihydro-ergotamine (Dihydergot). General analgesics had to be administered in addition on 21.8% of the treatment days and intensive care treatment (artificial ventilation) on 32% of the treatment days. The duration of epidural analgesia varied between 1 and 15 days depending on the intensity of symptoms (pain, ileus). Within 4 days, the enzyme activity of the lipase fell from 8120 to 427 IU, and that of alpha amylase fell from 1401 to 143 IU. In 3 patients laparotomy (for drainage) was performed. An ERCP was carried out in 16 patients. Cardiopulmonary failure necessitated artificial ventilation over a period of 1-15 days in 6 patients; the epidural blockade was continued during the artificial ventilation. Cholecystectomy was carried out as an interval operation in 6 patients. No neurological complications were observed. All patients survived and were discharged from hospital.

Acute Disease↗
PubMed1991

[Dose limits for local anesthetics. Recommendations based on toxicologic and pharmacokinetic data].

Since Heinrich Braun added adrenaline to cocaine (and later also to procaine) in 1903 to allow clinical use of this local anesthetic, "limiting dosages" for local anesthetics have been "recommended" with no reference to the technique of administration, on the assumption that adrenaline will lower the toxicity of the local anesthetic used. However, the limiting dosages determined up to now do not take account of important pharmacokinetic and toxicological data: (1) The dependence of blood levels measured on the technique of regional anesthesia and (2) the raised toxicity of a local anesthetic solution containing adrenaline following inadvertent intravascular (intravenous) injection. A maximum dose recommendation that differs according to the technique of local anesthesia is suggested for (A) subcutaneous injection, (B) injection in regions of high absorption, (C) single injection (perineural, e.g. plexus), (D) protracted injection (catheter, combined techniques), (E) injection into vasoactive regions (near to the spinal cord, spinal, epidural, sympathetic). This sequential categorization also underscores the need for selection of appropriate techniques as well as for concomitant monitoring referred to the technique of administration and to the expected and the possible plasma level curve.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthetics, Local↗
PubMed1991

[Can choice of medications and adjuvants reduce risks of local anesthetic complications?].

Local anesthetic agents in high concentrations may cause local irritation by ischemia especially after the use of adrenaline whereas felypressin has no tissue-irritating properties. Adrenaline but not felypressin increases the intravenous systemic toxicity. Noradrenaline has to be avoided as a vasoconstrictor. An aspiration test before injection will decrease the risk of inadvertent intravenous injection.

Adjuvants, Anesthesia↗
PubMed1990

[Ropivacaine--a new local anesthetic with specific properties].

Ropivacaine is the (S)-enantiomer of 1-propyl-2',6'-pipecoloxylidide. In terms of its physicochemical properties, it is a long-acting local anesthetic (molecular weight of the base 274, pKa 8.07, protein-binding 92%). It shows a selective action on A delta and C fibers. This may be attributable to its relatively low partition coefficient (6.1 in n-heptane). The subcutaneous and intravenous acute toxicity (LD50) is lower than that of other long-acting local anesthetics. Because of its vasoconstrictor potency, its use as a vasoconstrictor-free solution is of particular interest.

Amides↗
PubMed1990

[Fundamentals and requirements of peripheral electric nerve stimulation. A contribution to the improvement of safety standards in regional anesthesia].

The use of a nerve stimulator allows an injection cannula to be located without the cooperation of the patient. Regional anesthesia thus becomes safer because the basic condition "no paresthesia, no anesthesia" becomes irrelevant. In accordance with the basic electrophysiological conditions, a stimulator should have the following properties: (1) adjustable constant current at resistances of 0.5-10 kOhm; (2) monophasic square-wave initial impulse; (3) impulse duration selectable (0.1 ms + 1 ms, and exactly adjustable; (4) impulse amplitude (0-5 mA) exactly adjusted, unequivocal scale graduation or current indicator, in particular in the range of 0.05-1.0 mA; (5) impulse frequency 1-2 (-3) Hz; (6) alarm at high impedance and check on electrical circuit; (7) battery test (indication of battery voltage); (8) unequivocal assignment of load end; (9) high-quality connecting cable and plug; and availability of (10) instructions for use with relevant parameters (tolerated variations, steady-state characteristic curves, etc.).

Anesthesia, Conduction↗
PubMed1990

[The function of peripheral nerve stimulators in the implementation of nerve and plexus blocks].

A selection of nine instruments supplied by eight different manufacturers for carrying out peripheral nerve stimulation were checked for their suitability, safety and ease of operation, and were compared and contrasted with reference to a spectrum of characteristics that appear desirable in theoretical and practical terms. Measurements at Ohm's resistance showed that in the clinically relevant range of impulse amplitudes (0.1-1.0 mA) the quality of adjustment of the instruments varied widely. The actual electrical impulse delivered by some of the instruments deviated so widely from the adjusted theoretical value that they must be regarded as unsuitable. The duration of the impulse corresponded to the manufacturer's specifications for only two instruments. Four instruments did not generate a monophasic square-wave signal despite assertions to the contrary in the instructions for use, and one instrument did generate such a signal although a "special biphasic asymmetrical" impulse is described by the manufacturer. Impulse-like overshooting at the beginning of the signal, oscillations into the positive range at the end of the signal and fall in current during the course of the signal were the form variants indicating technically inadequate design in the other instruments. Resistance to the square-wave current impulse engendered by the complex body resistance (impedance), a good approximation to the mathematical e-function to be expected, could be demonstrated for the rising signal flank, whereas the signal curve in the lower part of the descending flank was flatter than expected owing to polarization effects in the body tissue. The characteristic voltage and time values calculated for the signal curves are shown in tables.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation Studies as Topic↗
PubMed1990

[Ropivacaine for peridural anesthesia. Studies on the dose-response relationship in orthopedic surgery].

In an open, nonrandomized dose response study, the efficacy of 0.75% ropivacaine (plain) for epidural analgesia was evaluated during 46 orthopedic surgical procedures (18 total hip replacements, 10 knee prostheses, 3 forefoot operations, 14 arthrotomies or osteotomies). Group 1 received 15 ml (112.5 mg); group 2 20 ml (150 mg); and group 3 25 ml (187.5 mg). The times to initial onset (6.7-7.9 min) and to the maximum level of sensory analgesia (25.7, 27.1, and 30.7 min) hardly differed. The mean maximum level of sensory analgesia increased from T6 (group 1), to T5 (group 2) and T3 (group 3), with an absolute maximum level of C3 (statistically not significant). Times for two-segment regression increased from 146 min and 169 to 192 min, for regression of analgesia to T10 from 193 and 189 to 246 min and to T12 from 220 min and 244 to 296 min (significant). The mean maximum durations were 239(+/- 54), 267(+/- 49.8) and 355(+/- 59.2) min. The degree of motor blockade varied with the volume. Motor block grade I was recorded in 100% of cases, and motor block grade II in 64% of patients in group 1, in 73% in group 2, and in 100% in group 3. Motor block grade III was only seen in 7.1% in group 1, 20% in group 2, and 47% in group 3. The duration was 102 min, 133 min and 188 min for grade I, 158 min, 199 min and 263 min for grade III when this occurred. MAP, HF and RPP varied by a maximum of -8.3%, -11.5% and -17.6% from the initial value.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[The single intercostal block--surgical and therapeutic indications].

Since the first paravertebral blockade was carried out by Sellheim in 1905, this method has proved effective for the isolated blockade of spinal nerves. The efficacy of preoperative intercostal blockade (ICB) in combination with neuroleptanalgesia (NLA) or Pentothal-pentazocine-N2O anesthesia (Pe-Pz) was studied (unilateral analgesia for cholecystectomy). Group 1: NLA; group 2: NLA with ICB; group 3: Pe-Pz; group 4: Pe-Pz with ICB. The analgesic requirement differed significantly between groups 1 (0.33 mg fentanyl) and 2 (0.15 mg fentanyl) and groups 3 (63.5 mg pentazocine) and 4 (31.5 mg pentazocine). There were also significant differences in circulatory responses. The maximum deviation from the initial value at the beginning of the operation in group 1 compared to group 2 was pulse rate + 28.7% vs + 2.4%, mean arterial pressure (Part) + 24.6% vs + 3.1%, and systolic pressure (Psyst) + 33% vs +/- 0%; group 3 compared to group 4: pulse rate + 16.4% vs + 3.2%, Part + 24.5% vs 0.0%, and Psyst + 26.5% vs + 196. The times of action of ICB extended from 7.54 h to 11.33 h for partial analgeisa, time to the first dose of analgesic from 12.3 h to 16.9 h (etidocaine 0.5% and 1% respectively without and with epinephrine). The mean blood levels after 100 mg bupivacaine-CO2 rose to 1.16 micrograms/ml after 5 min and reached a maximum after 15 min (1.29 micrograms/ml) as compared to 0.98 micrograms/ml after addition of ornithine-vasopressin. These values are very much higher than those after the use of bupivacaine-HCl solution. Etidocaine and bupivacaine-HCl have comparable durations of analgesia. Toxicologically, both substances can be applied safely with consideration of all pharmacological data for ICB. Of a total of 3,485 intercostal blockades, 2,775 were applied perioperatively (pre- and postoperatively); 265 were carried out for trauma patients (rib fractures) and 445 for therapeutic indications (herpes zoster neuralgia, tumor pain, costovertebral pain). In 8 blocks 10% ammonium sulfate, in 4 blocks absolute alcohol, and in 19 blocks 5% phenol were used for neurolysis. In 2 cases a marginal pneumothorax was seen, which was resorbed spontaneously (0.06%). Altogether 16,270 single intercostal nerves were blocked. Single-session intercostal blockade can be combined as unilateral analgesia with general anesthesia. This combination is characterized by stable circulatory conditions with avoidance of hypertensive reactions. The long-lasting analgesia allows early mobilization and physiotherapy both postoperatively and posttraumatically in patients with unilateral thoracic and abdominal pain.(ABSTRACT TRUNCATED AT 400 WORDS)

Bupivacaine↗
PubMed1988

[Influence of minimum current for peripheral nerve stimulation on the latency and success rate of sciatic blockade].

UNLABELLED: The efficacy of conduction anesthesia depends to a great extent on accurate application of the local anesthetic solution (LA) in close proximity to the nerve trunk. The problem with most peripheral nerve stimulators available in the past was that they did not provide a small enough electrical stimulus. Correct positioning of the needle could not be guaranteed if muscle contractions occurred. New current-controlled stimulators have recently been developed with low currents from 0.1 mA upwards. We studied the intensity of stimulus currents eliciting just-visible muscle contractions in the lower leg (m. triceps surae) to see how this influenced the latency and success rate of sciatic nerve block. METHOD: In a randomized study, 35 patients (18-68 years, ASA I and II) undergoing elective surgery were investigated. The block was performed by posterior approach using 30 ml 1% prilocaine. The stimulator was switched on with a frequency of 1 impulse/s and a stimulus current of 1 mA when the insulated needle was at a depth of 4 cm. In group 1 (n = 5) LA was injected when the first visible muscle contractions occurred at a current of 1.0 mA, but vanished if the current was diminished. In group 2 (n = 10) the needle was placed if a minimum current of 0.5 mA just triggered a muscular response. In group 3 (n = 10) the threshold current was 0.3 mA and in group 4 (n = 10) 0.1 mA. In all cases direct contact between the needle tip and the nerve was avoided.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1982

[Regional anesthesia in abdominal surgery].

Spinal and peridural anesthesia are most useful in lower abdominal operations. For upper laparotomies needing analgesia, good relaxation and quiet ventilation, intercostal block and peridural anesthesia with light general anesthesia are suitable techniques to avoid hypertension and metabolic responses (hyperglycemia, cortisol). During the postoperative period, regional blocks improve lung function and bowel motility, and afford early ambulation.

Abdomen↗