From the psychological point of view, regional anesthesia is something special because the patient experiences his operation consciously. This means that the anesthetist is required not only to guarantee a safe anesthetic, but also to recognize the special needs of the patients, to enter into them adequately, and thus to support the patient's own strategies for coping with his situation. The question arises as to what extent the anesthetist's behavior meets the patient's psychological requirements. For this reason, the conversation between patient and anesthetist was monitored during 17 operations under regional anesthesia and investigated by means of a quantitative speech analysis. It was shown that the anesthetist clearly predominated in the course of the conversation: particularly during the time when the patient was preparing himself for the operation, it was the anesthetist who actively framed the communication by numerous questions and conversational activities while the patient responsively remains passive. The anesthetist spoke simply and clearly to the patient. Prime consideration was given to explaining the anesthetic procedure and the operation. There were not many attempts by the physician to also deal with the patient's psychic state. On the while, communication was concerned with the quick and easy performance of anesthesia. This was also demonstrated by the fact that conversation between the anesthetist and the patient was nearly absent during the operation.
A 78-year-old female patient undergoing a hip operation received a catheter for continuous lumbar plexus blockade. The catheter was positioned without complications but its removal had apparently proved to be difficult. The catheter entered the operative site and its tip was coagulated by the coagulation forceps. There were no subsequent complications.
This randomized study was designed to determine the effects of isovolemic hemodilution and lumbar epidural anesthesia on plasma concentrations of bupivacaine in patients scheduled for endoprosthetic hip surgery. PATIENTS, MATERIALS AND METHODS. The patients were randomly assigned to two groups. In a hemodilution group (n = 15), which included patients undergoing lumbar epidural anesthesia following isovolemic hemodilution (15 ml/kg body weight), withdrawn blood was substituted by colloidal solution (hydroxyethyl starch solution 6%, 450/0.7; ratio of replacement 1:1). Controls were 15 patients who were not subjected to isovolemic hemodilution; epidural anesthesia only was performed. Both groups had identical fluid pretreatment (1000 ml Ringer's solution) before injection of the epidural bupivacaine dose (mean 14 ml, 0.75%); central venous blood samples were drawn at short intervals over 180 min. Both, the total plasma concentrations and the free bupivacaine fractions were determined by HPLC and ultrafiltration. RESULTS. Peak bupivacaine plasma levels (mean 1.30 microgram/ml) were found 10 min after application of the analgesic dose in the control patients. In contrast, in hemodiluted patients mean maximum plasma levels of bupivacaine were measured between the 20th and 30th min, with peak levels of only 0.75 microgram/ml plasma. The unbound bupivacaine levels were not significantly different in both groups over the entire measuring period despite the differing total bupivacaine concentrations. Therefore, protein binding of bupivacaine was about 6% lower in the hemodilution group, especially during the period shortly after injection. DISCUSSION. We conclude that isovolemic hemodilution leads to lower plasma bupivacaine concentrations after epidural anesthesia, probably due to an increased volume of distribution. Protein binding of bupivacaine is reduced by hemodilution; the free, non-protein-bound concentrations of local anesthetic were not associated with any systemic side effects in this study.
In a prospective randomized clinical investigation, we examined the influence of continuous thoracic epidural analgesia (TEA) on pulmonary function and pathologic chest X-ray findings. METHODS. One hundred sixteen patients having resection and/or anastomosis of the colon participated in this study; 57 were randomly assigned to the epidural group, whereas 59 were given systemic analgesia. Both groups were comparable with regard to ASA classification and pre-existing disease, as well as operative procedures and surgeons. Bupivacaine 0.75% was given to the TEA patients pre- and intraoperatively (epidural catheter T8/9), and postoperatively they received bupivacaine 0.25% continuously by motor pump for 3 days. We aimed to reach an analgesic spread from T5 to L2. In order to maintain sufficient analgesia, we had to increase the dosage from 19.2 mg/h on the evening of the operative day to 22.2 mg on the 3rd postoperative day. However, under these conditions the number of blocked segments decreased from 9.3 postoperatively to 6.6 on the 3rd postoperative day. Balanced anesthesia (isoflurane plus fentanyl) was given to the control group. Postoperatively, these patients received systemic analgesia on request (piritramide i.m., tramadol, or a simple analgesic). Vital capacity and pain score (10-point nominal analog score) were evaluated at 1, 8, 24, 36, 48, 60 and 72 h postoperatively. Blood gas analyses were taken at 1, 8, 24, 48 and 72 h, and chest X-rays were performed on the 1st, 3rd, and 8th postoperative days. Statistically significant results are indicated by "*" (P less than 0.05) and "*" (P less than 0.005) and "***" (P less than 0.001). The standard deviations were shown in cases of statistical significance. RESULTS. There were significantly lower pain scores by 1.0-2.2 points at 1, 8, 24 and 36 h postoperatively in the TEA group. Fourteen patients in group I required adjustments of the postoperative pain treatment regime: 6 had a unilateral epidural block; in 4 the catheter was withdrawn involuntarily. Up to the 2nd postoperative day, patients in the control group received systemic analgesics significantly more often. The vital capacity (percentage of preoperative value) was significantly higher in the TEA group than in the control group after 1 h (58.5% vs 51.7%) and 8 h (63.9% vs 56.7%). From the 1st postoperative day on there was no difference between both groups with regard to arterial blood gases, there was no difference in pCO2 between both groups 1 h postoperatively; it was, however, significantly lower in patients receiving bupivacaine at 8, 24, 48 and 72 h. There was no difference in pO2 at any time. The number of pathologic chest X-ray findings showed no difference between both groups. Looking especially for infiltrates, dystelectasis, atelectasis, and congestion, we also could not demonstrate any difference between the groups. (ABSTRACT TRUNCATED AT 400 WORDS)
Perioperative antiarrhythmic therapy with lidocaine (bolus dosage 100 mg followed by infusion of 200 mg/h) was performed in 24 patients; 12 of them simultaneously received an intravenous injection of 10 mg midazolam with the bolus of lidocaine (group I: with midazolam; group II: without midazolam). Central venous blood samples were collected over a period of 1 h (1, 3, 5, 10, 20, 30, and 60 min after the bolus) to evaluate unbound and total (protein-bound + unbound) plasma concentrations of lidocaine, thus calculating plasma protein binding. One minute after intravenous administration of lidocaine peak plasma concentrations occurred: in group I 5.38 +/- 1.99 micrograms/ml (mean +/- SD), in group II 5.25 +/- 1.90. Up to 60 min there was only a gradual decrease in plasma concentrations in both groups. There was no significant difference between the two groups (group I: mean free concentration 0.67-0.80 micrograms/ml; mean total concentration 4.84-5.38 micrograms/ml; mean plasma protein binding 83%-86%; group II: 0.69-0.89 micrograms/ml; 4.62-5.25 micrograms/ml; 82%-85%). We draw the conclusion that midazolam administration is safe in patients undergoing antiarrhythmic therapy or regional anesthesia with lidocaine.
In 1988, questionnaires were sent to 1225 departments of anesthesiology to evaluate the practice of postoperative epidural analgesia (EA) in the Federal Republic of Germany. The following problems were investigated. To what extent are anesthesiologists concerned with postoperative pain therapy? Does EA play a major role in this, in particular outside the intensive care setting? Who is allowed to administer epidural injections: anesthesiologists, other physicians or nurses? What kind of monitoring is used? What agents are used for epidural injections and what problems and complications have arisen? In all, 461 (38%) evaluable forms were returned. Most anesthesiologists said they were responsible for postoperative pain control. In 75.3% of the responding departments EA was used as a method of postoperative pain therapy, while in 24.7% the catheter was removed immediately after the operation, in most cases for fear of complications resulting from insufficient monitoring. In clinical practice, however, EA was the only major alternative to routine intermittent injections of opioids as needed. Some departments reported that they restricted postoperative EA to patients in the intensive care unit or in the recovery room because adequate monitoring was not feasible on the ordinary wards. EA was administered in 62.4% on ordinary wards. But in only 25.7% were trained nurses allowed to give epidural injections. Most responding departments (77%) preferred epidural use of opioids during intensive care, in most cases morphine or buprenorphine in combination with low-dose local anesthetics, and 66.7% also favored epidural opioids on ordinary wards.
In a prospective clinical study the follow-up course of 630 lumbar single-shot and continuous epidural anesthetics in young patients (average age 24.5 years) with 20-25 ml prilocaine 2% (epinephrine concentration 1:200,000) and 0.1 mg fentanyl was examined critically. The patients were interviewed postoperatively about this method of anesthesia. In 89% of cases the patients had been found suitable for surgery without any additional medication; 9% of the patients needed 0.1-0.15 mg fentanyl and 2.5-5 mg midazolam i.v. Only in 10/630 cases was supplementary anesthesia needed. During anesthesia a drop in blood pressure by 30% or more of the original value was recorded in 1.4% of patients; 5 patients had obvious simultaneous bradycardia. Nausea and vomiting were observed in 2.5% of cases; in 6 patients the level of peridural anesthesia was as high as T4-5. Postoperatively, 19% of the patients complained of discomfort in the area of the lumbar vertebral column. It subsided significantly 2 days after surgery; in 5.6% of cases patients had micturition disorder needing treatment. In 93% of cases the patients considered the method of anesthesia quite acceptable; in the same circumstances 96.5% said they would prefer epidural block to general anesthesia. The main reasons for this were the possibility of observing the surgical operation (26.8%) and the likelihood of speedy recovery on the same day (24.3%). Epidural block is preferred to any form of general anesthesia according to the experience we have gained in these young patients without essential concomitant diseases and with exact consideration to the contraindications for all operations distal of segments T9 and T10.
A 72-year-old female patient was scheduled for abdominal surgery with epidural block in combination with general anesthesia. An 18 G epidural catheter was inserted through an 18 G Tuohy needle between T12 and L1 using the midline approach and the 'loss of resistance' technique. A test dose of 13 ml bupivacaine 0.25% showed no effect and a bolus of 12 ml bupivacaine 0.25% was added 8 min later. Bilateral analgesia between S5 and C4 developed over the following 17 min but was not accompanied by any cardiovascular or respiratory depression. The patient became sleepy and was finally intubated after the administration of thiopentone 175 mg and pancuronium 6 mg. There were no objections to surgery, so the hemicolectomy was continued as planned. Intraoperatively the systolic blood pressure dropped twice, to a minimum of 105 mm Hg, coinciding with eventration of the intestine, but this was reversed immediately on administration of a vasoconstrictor. Extubation of the patient was possible 90 min later on the termination of surgery, when the level of anesthesia had reached T2. A spinal X-ray with radiopaque dye showed a typical intrathecal distribution. Most remarkable in this case is the stability of the cardiovascular function which in our opinion is related to the 0.25% solution. Serious complications of an inadvertent dural puncture can be avoided or alleviated with this concentration if the epidural block is to be combined with general anesthesia.
In a prospective study, 184 patients were studied after orthopedic operations with regard to analgesic requirements, analgesic effectiveness, and appearance of postoperative complications. In four groups, 0.0375, 0.075, 0.1 or 0.15 mg morphine was given in combination with 0.5% hyperbaric bupivacaine for perioperative analgesia. The patients' ages ranged between 13 and 90 years (means = 62.97). One hundred sixteen patients did not need any analgesics in the first 24 h. The effect of the spinal opiate was found to be pleasant, especially by patients who received a total hip prosthesis: in this group the average duration of analgesia was more than 24 h in 77.9% and 14.5 h in 22.1% of patients. The need for additional postoperative analgesia was seen earliest in the patients who received a knee prosthesis of the sledge type (P less than 0.05). The overall consumption of the analgesic piritramid was clearly reduced and amounted to 7.7 mg on the day of operation, 8.4 mg on the 1st day, 6.0 mg on the 2nd day, and 3.6 mg on the 3rd day after surgery. The degree of postoperative analgesia was the same in all four groups (P greater than 0.05). Blood gas analyses, respiratory rate, blood pressure, heart rate, oxygen saturation, and laboratory parameters were also examined. The application of small doses of opiate close to the spinal cord produced a good and long-lasting reduction of pain with few opiate side effects. In the spinal anesthetics with larger doses of morphine, side effects were rare and hardly different from those accompanying spinal anesthesia without morphine addition. There were no serious complications noted during the opiate anesthesia.(ABSTRACT TRUNCATED AT 250 WORDS)
Up to now, mandibular nerve blocks have been carried out without knowing the exact blood concentrations resulting from the use of the local anesthetics. Due to the high vascularity a rapid increase in serum local anesthetic levels is to be expected. Due to analytical problems, the literature provides controversial statements about the pharmacokinetics of articaine which is generally used for this block. The given half-life periods following intramuscular application range from 39 min [8] to 31 h [6]. For this reason, mandibular nerve blocks with 2 ml 4% articaine with 1:200,000 epinephrine were carried out in 10 awake patients and 10 patients during intubation anesthesia. RESULTS. Blood samples from peripheral veins showed an average maximum concentration of 2.1 +/- 1.3 mg/l after 12.5 +/- 2.5 min. After 8 h the value had fallen below the minimum detection limit of 0.05 mg/l. In the present study, a half-life of approximately 20 min was determined for articaine after conduction anesthesia. This local anesthetic holds an exceptional position because as an amide-type local anesthetic it contains an additional ester group that is hydrolytically metabolized in the blood. The concentration of the resulting metabolite reaches a maximum value of 2.6 +/- 1.6 mg/l after 40 to 50 min. CONCLUSIONS. Compared to other amide-type local anesthetics, whose terminal plasma half-life varies between 1 and 3.6 h [5], the value of 20 min found for articaine is very low. This is in part due to its structure, as the ester group is rapidly metabolized by plasma esterases. Because of its rapid breakdown articaine is very suitable for use in oral surgery. The HPLC method represents an uncomplicated analytical technique for the determination of local anesthetics levels in blood and other body fluids.
One disadvantage of perivascular axillary block using a catheter technique is delayed temporal development of the blockade. Some clinical studies have concluded that pH-adjusted solutions of local anesthetics produce a more rapid onset of blockade. Alkalinization of mepivacaine for brachial block produced conflicting results. In the present study, we attempted to define the effect of alkalinization of mepivacaine 1% on clinical efficacy, onset, and regression in patients undergoing upper extremity surgery with axillary block using the catheter technique. METHODS. Sixty consecutive adult patients (ASA I-II) scheduled for upper extremity surgery under axillary block, were randomly assigned to one of two groups. In a double-blind fashion, 30 patients received 40 ml 1% mepivacaine, the pH of which had been raised to 7.25 by adding 4 ml 8.4% NaHCO3, and 30 received 40 ml commercially prepared 1% mepivacaine hydrochloride solution containing 4 ml 0.9% NaCl (pH 6.0). All patients received axillary block using the catheter technique. After placement of the block, a blinded observer tested sensory and motor blockade after 2 min, 5 min and then every 5 min for 30 min in each of the terminal nerves of the brachial plexus. Sensory blockade was determined by pinprick and graded in accordance with the scale proposed by Hollmèn: 0: Normal sensation of pinprick. 1: pinprick felt as sharp-pointed but weaker compared with the same area in the other upper extremity. 2: Pinprick recognized as touch with a blunt object. 3: No perception of touch. The gradation of motor blockade was 0: normal muscular function; 1: slight depression in muscular function compared with preanesthetic strength; 2: very weak action persisting in muscles; and 3: complete block. The results for each group were compared at every time interval. Duration of blockade was compared by evaluating the rate of regression within the first 2 h after placement of the block in each group. Mepivacaine plasma levels were measured by HPLC in 10 patients of each group prior to injection and 5, 10, 15, 20, 30, 60, and 120 min thereafter. Statistical comparison was made using the chi 2 and t tests. Differences were considered statistically significant when P-values were less than 0.05. RESULTS. The bicarbonate and saline groups were similar with respect to age, height, weight, and sex distribution. Significantly more patients in the bicarbonate group showed onset of motor blockade (grade 1) after 2 min with respect in the axillary, musculocutaneous, radial, and median nerves as well as onset of sensory blockade in the same nerves with a significant difference in blockade of the radial nerve. (ABSTRACT TRUNCATED AT 400 WORDS)
Acute paraplegia caused by an epidural hematoma developed in a patient following the removal of an epidural catheter. This catheter had been used for 3 days for postoperative pain relief with no apparent complications. Heparin (10,000 units/day) had been infused for thrombosis prophylaxis and was associated with a normal activated partial thromboplastin time (aPTT) for the first two postoperative days. However, test results from blood drawn prior to catheter removal revealed, in retrospect, an unexpected prolongation of the aPTT (75 s) and PT (56%, Quick's method). An epidural hematoma extending from T12 to L4 was evacuated during emergency laminectomy and neurologic deficits resolved completely over the next days. Thus, the removal of an epidural catheter has the potential for inducing formation of an epidural hematoma. Accordingly, it may be safest to leave epidural catheters in place if test results demonstrate a bleeding diathesis or if a potential for bleeding is suspected on clinical grounds.
In the few case reports of hearing loss following spinal anesthesia, complete recovery of the hearing impairment has always been described. In nine cases with hearing loss following not only spinal anesthesia but also myelography and dural puncture, the hearing of three patients did not recover or only partly returned. Two cases went to court for malpractice. Their suits could be dismissed because it appears likely that this rare complication arises only in persons with a wholly or partially unobliterated aquaeductus cochleae due to loss of perilymphatic fluid into the cerebrospinal space. Hearing loss was seen in eight of nine patients in lower frequencies around 30-40 dB. In six patients there was impairment on both sides. Recovery of normal hearing occurred in six of the nine patients. Transient hearing loss may occur more often than is generally assumed, and the symptom may remain unnoticed when a severe post-dural puncture syndrome with headache, dizziness, and nausea dominates the attention of the patient. Not all cases of hearing loss proved to be fully reversible, but the individual risk for this complication is not predictable. The use of fine-gauge needles may reduce the leakage of cerebrospinal fluid through the dural puncture and thus lower the incidence.
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)
Continuous epidural anesthesia (CEA) is generally accepted as a routine method of regional anesthesia while there has been only limited application of continuous spinal anesthesia (CSA), due mainly to a lack of adequate spinal catheters. With the introduction of a new, ultra-thin spinal catheter (32 G) inserted via a thin puncture needle, some of the complications reported after CSA can be eliminated. We studied CSA versus CEA in lower-extremity operations.
In regional anesthesia the onset of analgesia is usually determined by stimulating the skin with sharp or cold objects: when sensations of sharp pain or cold are lost, all nociceptive afferents are regarded as blocked. Sharp pain and cold are mediated by thin, myelinated axons whereas the majority of nociceptor axons are unmyelinated. In peripheral nerve blocks unmyelinated fibers are blocked first, followed by those mediating sharp pain and cold. In spinal and epidural blocks the levels of anesthesia to sharp pain and cold correspond within 1-2 segments. Although pinprick seems to be a simple test for analgesia, it involves the risk of infection and is disliked by the patient. As the stimulus is spatially discontinuous, coarse testing may simulate analgesia. An ideal stimulus for testing analgesia should be noninvasive, give distinct sensations, not frighten the patient, and allow spatially continuous examination of larger skin areas. A stimulus that meets these conditions is cold applied to the skin by a metal roller (Fig. 1). If the roller is kept at room temperature (20 degrees-24 degrees C), it gives a strong cold sensation when it is slowly rolled (5-10 cm/s) over the warm skin (usually 30 degrees-35 degrees C on the trunk). With this noninvasive device, the levels of anesthesia to cold can be determined rapidly, with high precision, and without frightening the patient.
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 subileus 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.
We report a patient who was given continuous epidural anesthesia due to painful contractions during delivery of a child after intrauterine fetal death. Placement of the catheter and repeated reinjections were carried out without problems, however, during withdrawal of the catheter it could only be pulled 1-2 cm until there was enormous resistance. An X-ray film showed knotting of the catheter in the epidural space. Firm pulling finally allowed complete withdrawal of the catheter. Insertion of the catheter too far into the epidural space initially must be considered as a possible cause. As this complication rarely occurs, we consider this case worth reporting.
We present a 71-year-old male in whom an epidural abscess developed within a short temporal interval after an epidural anesthetic. Due to different locations of the abscess and the site of the epidural puncture, the diagnosis was quite problematic. The initial symptoms consisted of pain in the shoulder-neck region, elevated temperature, and leucocytosis 1 week after the puncture was performed. The further course presented a picture of high spinal paralysis with respiratory insufficiency and massive cardiovascular problems. Magnetic resonance imaging of the cervical spine confirmed the suspected diagnosis of an epidural abscess (Fig. 1). Due to the reduced general condition of the patient, an operation was initially not possible. After the patient's condition had stabilized under antibiotic therapy with penicillin G, vancomycin, and gentamycin, exploration of the abscess area was performed. Histologic studies showed granulomatous tissue resulting from the previous inflammation. During the subsequent course of the disease, the clinical symptoms did not regress significantly. The patient required prolonged mechanical ventilation and died of recurrent bronchopulmonary infections after 5 months of intensive care treatment. The probable pathogenesis of the abscess as well as the diagnostic and therapeutic aspects are discussed in summary.
