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Biomedical subjects

A Van Zundert

Publications and source records attributed to A Van Zundert.

17 recordsLinked to original sources
PubMed2000

The combined spinal-epidural technique.

Epidural and spinal blocks are well-accepted regional techniques, but they have several disadvantages. The CSE technique can reduce or eliminate the risks of these disadvantages. CSE block combines the rapidity, density, and reliability of the subarachnoid block with the flexibility of continuous epidural block to extend duration of analgesia. The CSE technique is used routinely at many institutions, particularly for major orthopedic surgery and in obstetrics. It has been used in tens of thousands of patients without any reports of major problems. Although at first sight the CSE technique appears to be more complicated than epidural or spinal block alone, intrathecal drug administration and siting of the epidural catheter are both enhanced by the combined, single-space, needle-through-needle method. Concerns about the epidural catheter entering the theca via the small puncture hole are now considered to be unfounded, but as with all epidural catheter techniques, vigilant monitoring of the patient during and after any injection is paramount. CSE is an effective way to reduce the total drug dosage required for anesthesia or analgesia. The intrathecal injection achieves rapid onset with minimal doses of local anesthetics and opioids, and the block can be prolonged with low-dose epidural maintenance administration. In addition, the sequential CSE method can be used to extend the dermatomal block with minimal additional drugs or even saline. Reduction in total drug dosage has made truly selective blockade possible. Many studies have confirmed that low-dose CSE with local anesthetic and opioid, or low-dose epidural block alone, will provide effective analgesia with minimal motor and proprioceptive block. Such neurologic selective blockade has made it possible for most patients to walk and bear down normally in labor or postoperatively. There remains concern about the risk of infection being increased when the CSE technique is used in place of epidural block alone. Despite a recent flurry of reports of meningitis with CSE procedures, there is no evidence the CSE block is more hazardous than epidural or subarachnoid block alone. Arguably, the single-space, needle-through-needle CSE technique will continue to improve with new needle designs and other advances to improve further the success rate and reduce complications, such as neurotrauma, PDPH, and infection. Over the past decade it has become clear that the CSE technique is a significant advance in regional blockade.

Analgesia, Epidural↗
PubMed1992

Ten ml bupivacaine 0.125% with 12.5 micrograms epinephrine is a reliable epidural test dose to detect inadvertent intravascular injection in obstetric patients. A double-blind study.

A double-blind study was designed in order to determine the specificity and sensitivity of an epidural test dose to detect inadvertent intravenous injection in obstetric patients undergoing epidural analgesia. Forty unselected obstetric patients were given an intravenous injection of 10 ml bupivacaine 0.125% with 12.5 micrograms epinephrine (test dose) or 10 ml normal physiologic saline. The maternal heart rate was monitored by the direct ECG mode of a fetal monitor and registered simultaneously with the tocogram. The primary investigator was blinded to the solution he injected into an antecubital vein. After the injection was given, he recorded his judgment of which solution he had administered. Eight other anesthesiologists made similar judgments on the basis of the recordings plus various levels of additional information (presence or absence of epidural analgesia, time of injection, subjective signs and symptoms). In contrast to the primary investigator, the blood pressure values were not given to them. For the primary investigator, the specificity of the test dose was 100% and the sensitivity 97.5%. The judgments of the 8 other anesthesiologists resulted in an excellent specificity (99.1%) and a good sensitivity (91.9% with information on time of injection and subjective signs and symptoms). The better performance of the primary investigator is probably due to the availability of blood pressure data.

Analgesia, Epidural↗
PubMed1987

Plasma concentrations of epidural bupivacaine in mother and newborn: 0.125% versus 0.375%.

Central venous plasma concentrations of bupivacaine were determined in two groups of 15 parturients each who were given epidural analgesia for labor and vaginal delivery. One group received 10 ml of 0.125% bupivacaine plus epinephrine 1:800,000, the other group received 7 ml of 0.375% bupivacaine plus epinephrine 1:800,000. Plasma concentrations of bupivacaine in the umbilical venous (UV) and the umbilical arterial (UA) blood of their babies were also determined. The mean UA, UV, and maternal central venous (MV) plasma concentrations of bupivacaine differed significantly between the two groups: in patients given 0.375% bupivacaine UA values were 63% higher (P less than 0.01), UV values were 57% higher (P less than 0.01), and the MV values were 34% higher (P less than 0.05) than in patients given 0.125% bupivacaine. The measured plasma concentrations speak in favor of the less concentrated solution of bupivacaine in epidural analgesia for obstetrics. Seven milliliters of bupivacaine 0.375% is suitable for epidural analgesia in obstetrics but a low concentration-low dose technique, using 10 ml of bupivacaine 0.125% plus epinephrine 1:800,000 is safer. It provides good analgesia with minimal or no motor block and is associated with low maternal and neonatal plasma concentrations of bupivacaine, well below toxic levels and, to our knowledge, lower than in any other study.

Anesthesia, Epidural↗
PubMed1986

Extradural analgesia and retinal haemorrhage in the newborn.

The incidence and severity of retinal haemorrhage were examined in 976 babies born by vaginal delivery. The influence of the method of analgesia, instrumental delivery and parity was studied. The mothers of 638 infants received extradural analgesia, while the other 338 received either narcotics or no analgesia. Extradural analgesia did not lead to a higher incidence of retinal haemorrhage, even though the number of vacuum extractions was doubled. With increasing parity, the total frequency and the frequency of severe retinal haemorrhage decreased (P less than 0.001). Severe retinal haemorrhage was not seen in any baby of whom the mother was para 4 or more.

Anesthesia, Epidural↗
PubMed1986

Motor blockade during epidural anesthesia.

The effects of lumbar epidural anesthesia (LEA) on a previously described test of function of the rectus abdominalis muscle (the RAM-test) were compared with the effects of LEA on the Bromage test of muscle power in the hips and legs in 20 women having elective cesarean sections under LEA using 0.5% bupivacaine with epinephrine 1:200,000. The results showed no statistically significant correlation between the two tests. We conclude that zones of differential somatic motor blockade are present during LEA and that in obstetrics the RAM-test is the more appropriate test for evaluating the effects of LEA on somatic motor function. Use of the RAM-test is suggested in situations where one is interested in motor function of the abdominal wall muscles under LEA.

Abdominal Muscles↗
PubMed1985

Penile dorsal nerve block for penile surgery.

As pain is better prevented than relieved, 46 patients scheduled for phimosis operations, had for their pain control a penile dorsal nerve block: 37 children with additional inhalation anesthesia intraoperatively and 9 adults without any further analgesia. The technique used is described in detail. No untoward effects were recorded. It is concluded that penile dorsal nerve block offers such a simple, effective and reliable method of analgesia intra- and postoperatively that it should be an integral part of the anesthetic management of penile surgery.

Adolescent↗
PubMedDate not supplied

Combined spinal-epidural technique.

BACKGROUND: For the past 16 years the combined spinal-epidural (CSE) technique has been extensively researched and developed to the point where it is now in widespread use. Along with the use of low-dose mixtures of local anesthetics and opioids, and the introduction of fine-gauge pencil-point needles, CSE is being increasingly recognized as another important addition to the armamentarium of the anesthesiologist. METHOD: One hundred and forty-two publications focusing on the CSE technique, or on questions concerning CSE-related issues, were reviewed. Out of 33 double-blind or controlled studies, 23 directly investigated the CSE technique. Fifty-four prospective studies and letters made directly relevant points on advantages or problems with CSE. Twenty-one book chapters, reviews and editorials were included, 11 of them concerning the use of CSE technique. RESULTS: All CSE techniques which may be used for surgical anesthesia, for analgesia in labor or for postoperative pain management are described. Indications, advantages, disadvantages, and the various methods for performing CSE procedures, including sequential CSE block, are described and reviewed, along with the equipment currently available for their administration. CONCLUSION: The CSE technique offers many potential advantages over continuous epidural or subarachnoid methods alone, including a reduction in drug dosage, the ability to eliminate motor blockade and to achieve highly selective sensory blockade and optimize analgesia. These features hold great promise for minimizing the hazards and side effects of traditional epidural and subarachnoid techniques. Controversial fears, risks, and pitfalls of the CSE technique and of continuous epidural and subarachnoid methods are debated and discussed.

Anesthesia, Epidural↗
PubMedDate not supplied

Clonidine added to bupivacaine-epinephrine-sufentanil improves epidural analgesia during childbirth.

BACKGROUND AND OBJECTIVES: A double-blind study was conducted to assess the efficacy and the side effects of a low dose of clonidine added to an epidural injection of bupivacaine and epinephrine, with or without sufentanil. METHODS: One hundred healthy parturients (ASA 1) were randomly allocated into four groups according to the type of epidural analgesia administered. The bupivacaine/epinephrine (BE) group received a 10-mL standard injection of bupivacaine (B) 1.25 mg/mL and epinephrine (E) 1.25 microg/mL. In the bupivacaine/epinephrine/sufentanil (BES) group, 7.5 microg sufentanil (S) was added to the BE mixture. For the bupivacaine/ epinephrine/clonidine (BEC) group, 50 microg clonidine (C) was added to the BE mixture, whereas for the bupivacaine/epinephrine/sufentanil/clonidine (BESC) group, both sufentanil and clonidine were added to BE. Fetal heart rate was monitored by continuous cardiotocography. Duration of analgesia, method of delivery, and neonatal outcome (measured using APGAR score, peripheral oxygen saturation, and neurologic adaptive capacity score) and side effects of clonidine were observed. The parturients were routinely asked for their global appreciation of the epidural analgesia technique by visual analog score, 2 hours postpartum. RESULTS: The overall quality and duration of analgesia were superior in the BESC group compared with the other groups, as was the global appreciation by the parturient. The frequency of side effects in the clonidine groups was comparable, with the exception of hypotension and sedation. Hypotension was easily treated by fluids or ephedrine and caused no fetal distress. The level of sedation was mild, and all parturients aroused immediately after verbal commands. CONCLUSION: The addition of a low dose of clonidine to an epidural injection of bupivacaine with epinephrine and sufentanil provides better analgesia during labor, while keeping the side effects minimal and of minor clinical importance.

Adrenergic Agonists↗
PubMedDate not supplied

Atraucan: a new needle for spinal anesthesia.

BACKGROUND AND OBJECTIVES: Atraucan 26-gauge spinal needles have a tip designed to make a small linear cut (as opposed to a V-shaped cut) in the dura mater. The cut is shorter than the outside diameter of the needle and is dilated as the needle passes through the dura. The needle is used with a 20-gauge introducer. In vitro, it causes less leakage of cerebrospinal fluid than Quincke 26-gauge or Sprotte 24-gauge needles. This study was designed to test the ease of use and any damage caused to the needle tip during lumbar dural puncture. METHODS: This was a multicenter trial (six centers in five countries) involving 362 patients undergoing spinal anesthesia. A detailed questionnaire was filled in for every patient by the anesthesiologist. All the needles were returned to the factory and examined microscopically for damage. RESULTS: Lumbar dural puncture was successful in all but one patient. Spinal anesthesia was satisfactory for the planned surgery in 97%. Microscopy of the needle tips showed only a minor degree (0.01-0.19 mm) of bending in 14%, and none of the tips had a "hook." Postdural puncture headache (PDPH) occurred in nine patients (2.5%), all but one of whom (a 15-year-old male) were females under 55 years of age. CONCLUSIONS: The Atraucan needle is easy to use and has a high success rate in identifying the subarachnoid space. Lumbar dural puncture causes minimal damage to the tip. The incidence of PDPH is low, but a larger comparative study needs to be performed.

Adolescent↗