Repeat epidural analgesia and unilateral block

The use of epidural analgesia has become so widespread in recent years that many women are now requesting repeat epidural analgesia for their second or subsequent labour. This study examines the incidence of problems at insertion and of inadequate block in 71 multiparae having second epidurals compared with 150 primiparae having their first epidural. Unilateral block occurred in 6.66% of primiparae and 18.3% of multiparae (P) <0.02). There was no association between difficulty of insertion of catheter, blood in needle/catheter or paraesthesia and unilateral blockade. Epidurals were inserted at a greater dilatation (P <0.05 and there was a shorter time to delivery (P < 0.01) in the multiparous group. We conclude that unilateral block is thus more common in women receiving repeat epidurals.     

Epidural analgesia for a parturient with herpes gestationis

A 23-yr-old parturient with herpes gestationis spontaneously delivered a normal healthy infant under epidural analgesia. She received five injections of bupivacaine 0.5 per cent over a ten-hour period. There was no infection at the lumbar region, even though her body was covered with vesicles and bullae including the face and neck. Eight months after delivery the patient still has a vesicular eruption which occurs mainly during her menses.     

Time course in thoracic epidural pressure measurement

The purpose of this study was to measure thoracic epidural pressure at the time of insertion of an epidural needle. The pressure was measured using a closed pressure measurement system after insertion of a Tuohy needle at the T_7–8 intervertebral level. This system is unique because it has a pressure transducer equipped with a device which regulates flow through the transducer and prevents the heparinized saline in the system from being evacuated into the epidural space due to sudden pressure change. As reported previously, high negative epidural pressures, up to −60 mmHg, were observed at the moment of epidural puncture. However, the pressure became positive in about 30 sec in 12 of the 13 patients, and stabilized at +3.7 ± 3.2 mmHg (mean ± SD) within 90 sec. Similar results were observed when the procedure was repeated within a few minutes to the same patients. This suggests that negative epidural pressures at the moment of epidural puncture are artifacts induced by tenting of the durai membrane. Subsequent adaptation of the surrounding tissue results in restoration of the normal positive epidural pressure. L’objectif de cette étude consiste à mesurer la pression epidurale thoracique au moment de l’insertion d’une aiguille épidurale. Grace à un système fermé, on mesure la pression épidurale à l’insertion d’une aiguille Tuohy au niveau intervertébral D₇–D₈. Ce système unique contient un transducteur depression équipé d’un dispositif qui régularise le flux à travers le transducteur et prévient l’évacuation de la solution héparinée dans l’espace épidural lors d’un changement subit de pression. Comme on l’a déjà rapporté, des pressions négatives élevées allant jusqu’à −60 mmHg sont observées au moment de la ponction épidurale. Cependant, la pression redevient positive chez 12 des 13 patients et se stabilise en 90 sec à +3,7 ±3,2 mmHg (moyenne ± SD). Des résultats identiques sont observés quand on répète la manoeuvre quelques minutes plus tard chez les mêmes patients. Ceci suggère que la pression négative produite au moment de la ponction épidurale est un artéfact causé par la dépression de la dure-mère par l’aiguille. L’adaptation subséquente du tissus environnant rétablit la pression épidurale normale.     

Early respiratory depression during Caesarean section following epidural meperidine

A case of respiratory depression which occurred following administration of epidural meperidine during Caesarean section is described. Epidural meperidine, 75 mg (10 mg.ml-1) was given after delivery of the infant to provide postoperative analgesia. Oxygen desaturation (SaO2 90%) and a decrease in respiratory rate (4.min-1) were noted 30 min after epidural meperidine was administered. Naloxone, 0.1 mg, was given iv which resulted in prompt improvement in both respiratory rate and oxygen saturation. Vascular absorption of meperidine from the epidural venous plexus is the most probable explanation for this case of early respiratory depression. We recommend a maximum bolus dose of 50 mg of epidural meperidine for pain management after Caesarean section. It is also important to monitor oxygen saturation continuously during the intraoperative period, and to monitor the patient closely in the recovery room for at least one hour for evidence of respiratory depression.     

Epidural sufentanil does not attenuate the central haemodynamic effects of Caesarean section performed under epidural anaesthesia

The effect of sufentanil 30 μg added to the epidural local anaesthetic solutions used for anaesthesia during elective Caesarean section on central haemodynamic variables was studied. Haemodynamic measurements made by thoracic electrical bioimpedance (TEB) monitoring were compared in 21 healthy parturients undergoing Caesarean section under epidural anaesthesia with and without the addition of epidural sufentanil. The patients were randomized to control (Group C) and study (Group S) groups. Following iv prehydration, an epidural catheter was placed at the L_2?3 or L_3?4 interspace. After a negative test dose, in a double-blinded protocol, patients in Group S received sufentanil 30 μg (0.6 ml) in 4.4 ml lidocaine carbonate 2% with 5 μg · ml^?1 epinephrine and those in Group C received 5 ml lidocaine carbonate 2% with epinephrine. Lidocaine carbonate 2% with 5 μg · ml^?1 epinephrine was then titrated to establish an anaesthetic level of T₄. Haemodynamic variables (heart rate, mean arterial blood pressure, cardiac index, ejection fraction and end-diastolic index) were measured non-invasively, continuously throughout the perioperative period. There were no differences noted in haemodynamic measurements between the groups at any time perioperatively. However, differences occurred within the groups when compared with baseline values. Heart rate was increased in both groups intraoperatively. Cardiac index was increased throughout the intraoperative period in Group S but was less frequently elevated in Group C. Ejection fraction was increased throughout the perioperative period in Group S but not in Group C. End-diastolic index increased following iv preloading in both groups and returned to baseline with induction of epidural block. Maternal haemodynamic measurements as assessed by TEB monitoring, during Caesarean section, were not altered by the addition of 30 μg sufentanil to carbonated lidocaine for lumbar epidural anaesthesia.     

A comparative study of patient-controlled epidural fentanyl and single dose epidural morphine for post-caesarean analgesia

In a prospective, randomized, double-blinded study, 23 patients who had undergone Caesarean delivery under epidural anaesthesia were assessed to evaluate the effectiveness of patientcontrolled epidural analgesia (PCEA) with fentanyl compared with a single dose of epidural morphine for postoperative analgesia. Group A (n = 11) received epidural fentanyl 100 μg intraoperatively, then self-administered a maximum of two epidural fentanyl boluses 50 μg (10 μg · ml^?1) with a lockout period of five minutes for a maximum of two doses per hour. Group B (n = 11) received a single bolus of epidural morphine 3 mg (0.5 mg · ml^?1) intraoperatively and received the same instructions as Group A but had their PCA devices filled with 0.9% NaCl. Patients were assessed up to 24 hr for pain, satisfaction with pain relief, nausea and pruritus using visual analogue scales (VAS). The treatments for inadequate analgesia, nausea and pruritus as well as time to first independent ambulation were recorded. The ventilatory response to carbon dioxide challenge was measured at four and eight hours. Pain relief, satisfaction with pain relief, and the use of supplemental analgesics were similar in both groups. The mean 24 hr dose of epidural fentanyl used by group A patients was 680 μg. Pruritus was less common in Group A patients at the 8 and 24 hr observation periods (P < 0.0125). Both groups experienced the same degree of nausea and clinically unimportant respiratory depression. We conclude that PCEA with fentanyl provides analgesia equal to a single dose of epidural morphine and may be suitable for patients who have experienced considerable pruritus after epidural morphine adminstration.     

Exacerbation of postdural puncture headache after epidural blood patch

The purpose of this report is to describe a new complication of epidural blood patch for inadvertent dural puncture. A dural tap in an obstetric patient was managed initially with a prophylactic blood patch via the epidural catheter. Despite this, 48 hr later, she developed post-dural puncture headache, neck, and shoulder pain, and was given a second epidural blood patch. This was followed by an immediate and severe exacerbation of her symptoms, which later resolved after the administration of diclofenac. There were no further sequelae. Although severe complications of epidural blood patch are rare, they are alarming. Exacerbation of the original symptoms of post-dural puncture headache caused by, or following, epidural blood patching has not previously been reported.     

Toe skin temperature as a guide to epidural anaesthesia dosing

To determine the time for additional epidural anaesthesia, skin temperature of the big toe was evaluated in 50 patients undergoing mastectomy. Epidural catheters were placed at or near the T_5?6 intervertebral space and 12 ml, lidocaine 1.5% with 1:200,000 epinephrine were injected. When the skin temperature, which had increased following epidural anaesthesia, decreased by 0.3° C without an increase of systolic arterial blood pressure (ABP) of more than 20%, 8 ml lidocaine 1.5% were injected. If the skin temperature increased, the monitor was judged to have been useful. When ABP increased > 20% without a decrease of skin temperature, the monitor was judged not to have been useful. Monitoring of toe skin temperature was useful in 39 patients (78%) in estimating the time for the first additional dose of epidural anaesthetic. First, second and third intervals between injection were 96.5 ± 21.0 (n = 39), 69.7 ± 14.2 (n = 35) and 50.1 ± 12.2 min (n = 7), respectively. We conclude that, when epidural puncture is performed at upper thoracic levels, toe skin temperature can be a useful monitor to judge the time for additional anaesthetic.     

Post-caesarean section analgesia: a comparison of epidural butorphanol and morphine

Epidural butorphanol 1, 2 and 4 mg were compared with morphine, 5 mg, for postoperative analgesia in 92 consenting, healthy, term parturients who had undergone Caesarean section under epidural lidocaine anaesthesia in a randomized double-blind study. Postoperative pain was assessed using a visual analogue scale and recorded with heart rate, blood pressure and respiratory rate. The demographic characteristics, and the incidences of primary and repeat Caesarean sections, were not different among the four treatment groups. At 15, 30, 45 and 60 min after treatment the median pain scores following butorphanol were similar and lower than those following morphine (P less than 0.05). Calculated median percentage pain relief values for butorphanol were higher than morphine at each of these times (P less than 0.05). At 90 min and 2 hr the pain scores and pain relief values were similar. Beyond 45 min the number of patients requesting supplemental medication and dropping out of the study increased progressively in both the butorphanol and morphine treated patients. The attrition profiles for butorphanol were different from morphine (P less than 0.01). The median time in the study was greater than 24 hr for morphine, and 3, 2.5 and 4 hr for butorphanol, 1, 2 or 4 mg, respectively. No patient developed a clinically important change in heart rate or blood pressure, and none experienced a decrease in respiratory rate below 12 breaths.min-1. One of 69 patients (1.4 per cent) who received butorphanol developed pruritus compared with ten (43 per cent) of 23 patients who received morphine. The global assessments of the adequacy of analgesia were indistinguishable between morphine and butorphanol. Epidural butorphanol provides safe, effective postoperative analgesia, has a prompt onset, and a limited duration.     

Bupivacaine 0.1% does not improve postoperative epidural fentanyl analgesia after abdominal or thoracic surgery

Epidural infusions of fentanyl, in a 10 micrograms.ml-1 concentration, combined with bupivacaine 0.1% were compared with epidural infusions of fentanyl alone for postoperative analgesia following abdominal or thoracic surgery. There were no detectable differences between the two groups in analgesia (mean visual analogue scale pain scores ranging between 15-35 mm), average infusion rates of 7-9 ml.hr-1, and serum fentanyl concentrations which reached 1-2 ng.ml-1. There was no difference in postoperative pulmonary function (pH, PaCO2, SaO2), or bowel function (time to flatus or po fluids). The incidence of side-effects including somnolence, nausea and vomiting, pruritus and postural hypotension was also similar. Of the patients receiving fentanyl and bupivacaine 0.1%, three developed a transient unilateral sensory loss to pinprick and ice, and two of these patients had unilateral leg weakness equal to a Bromage 1 score. The addition of bupivacaine 0.1% does not improve epidural infusions of fentanyl using a 10 micrograms.ml-1 concentration following abdominal or thoracic surgery.     

Epidural anaesthesia for labour and Caesarean section in a parturient with a single ventricle and transposition of the great arteries

We describe a case of a 29-year-old parturient with a single ventricle and transposition of the great arteries who had lumbar epidural analgesia/anaesthesia with a local anaesthetic for labour, emergency Caesarean section and postoperative pain. Her outcome and that of her baby was successful. The anaesthetic techniques used in other parturients with similar congenital cardiac anomalies are reviewed.     

Epidural morphine for analgesia after Caesarean section: a report of 4880 patients

This retrospective study was undertaken to assess the efficacy and safety of epidural morphine in providing analgesia following Caesarean section under epidural anaesthesia. The morphine was administered as a single bolus, following delivery, in doses ranging from 2 to 5 mg. The charts of 4880 Caesarean sections, performed on 4500 patients, were reviewed. The duration of analgesia and the occurrence of any symptoms which might be side-effects of the epidural morphine were recorded. The duration of analgesia was 22.9 +/- 10.1 hr and was not correlated with the dose of epidural morphine. Eleven per cent of the patients required no supplemental analgesia during the first 48 hr. Twelve patients (0.25 per cent) had respiratory rates less than 10 breaths per minute, on at least one occasion. No serious sequelae resulted from these periods of bradypnoea. Pruritus occurred in 58 per cent of patients, nausea and vomiting in 39.9 per cent and dizziness in ten per cent. Herpes simplex labialis was recorded in 3.5 per cent of patients. Epidural morphine is thus confirmed as an effective analgesic technique post-Caesarean section with 3 mg being the optimal dose. Even in this young healthy patient population, clinically detectable respiratory depression occurs so clinical respiratory monitoring is indicated.     

Successful treatment of chronic pancreatitis pain with interpleural analgesia

Interpleural analgesia has recently been shown to be effective in the management of various chronic pain syndromes. We have used interpleural analgesia successfully in 11 patients with severe chronic pancreatitis of 24-38 months' duration. Daily injections of 30 ml of 0.5 per cent bupivacaine with epinephrine 5 mu.ml-1, were given through a percutaneously inserted pleural catheter over a five- to ten-day period. Patients have remained pain-free during follow up which ranges from 24 to 40 weeks. This method of providing analgesia for the patient suffering from the pain of chronic pancreatitis is simple, safe, effective and can be provided on an outpatient basis.     

Lumbar and thoracic epidural analgesia via the caudal approach for postoperative pain relief in infants and children

Thirty infants scheduled for a variety of gastrointestinal, genitourinary and thoracic surgical procedures were selected for insertion of lumbar or thoracic epidural catheters via the caudal approach using either an Intracath or a Burron continuous brachial plexus kit. The catheters were inserted with ease by residents in training and no catheter-related complications were encountered. Lidocaine 0.5 per cent with 1:200,000 epinephrine was then injected to assure proper placement of the catheter before narcotics were administered. Postoperative analgesia was adequate in all patients using preservative-free morphine 0.05 mg.kg-1. The mean dosing interval was 15 hr and no episodes of nausea, vomiting, hypotension or histamine release were noted. Urinary retention occurred in two infants and one infant became apnoeic three hours after epidural morphine administration but responded to naloxone and pulmonary ventilation with bag and mask. In conclusion, epidural catheters placed via the caudal approach are a safe and effective means of providing postoperative pain control in infants using preservative-free morphine. However, the use of epidural narcotics in infants less than two years of age is restricted to those who will receive intensive care unit monitoring postoperatively so that if apnoea occurs, rapid intervention can be taken by skilled nursing personnel.     

Patient-controlled analgesia (PCA) using fentanyl in a parturient with a platelet function abnormality

A term parturient with documented platelet dysfunction presented to the case room for induction of labour. Since this bleeding abnormality contraindicated the use of lumbar epidural analgesia (LEA), we elected to use an iv fentanyl patientcontrolled analgesia (PCA) technique for pain relief during labour. The patient received a 50 μg fentanyl loading dose after which 20 μg boluses of fentanyl were self-administered every three minutes as required. The patient received a total of 400 μg of fentanyl over the 3 1/2 hr of active labour. Mother and neonate tolerated the fentanyl without sequelae. If facilities to monitor the neonate and mother are present, this method of analgesia is useful in those patients where LEA is contraindicated. Au terme d’une grossesse, une patiente porteuse d’une dysfonction plaquettaire devait avoir une induction de travail au bloc obstétrical. Ecartant l’usage d’une epidurale à cause des risques de saignement, nous avons employé du fentanyl en autoanalgésie (PCA) pour soulager les douleurs du travail. Après une dose initiate de50 μg, la patiente s’injectait des doses de 20 μg de fentanyl iv aux 3 minutes prn. Elle utilisa un total de 400 μg de fentanyl au cours des 3,5 heures que dura le travail. La mère et le nouveau-né tolérèrent fort bien ce mode d’analgésie. L’autoanalgésie offre done une alternative au bloc épidural lorsque ce dernier est contre-indiqué toutefois, nous recommandons de monitorer la mére et le nouveau-né pendant quelques heures.     

Continuous regional anaesthesia in infants

Physiological immaturity of the respiratory musculature and central respiratory control centres leads to an increased risk of apnoea and respiratory complications following general anaesthesia in neonates. Regional anaesthetic techniques may obviate the need for general anaesthesia and lessen the risks of perioperative morbidity. Although these techniques have been described in infants, previous reports have dealt with singleshot techniques for brief surgical procedures (< 60 min). Experience with prolonged operative cases using regional anaesthesia via indwelling catheters in infants is limited. We present our experience with four infants in whom either caudal epidural or spinal anaesthesia was administered via indwelling catheters for operative procedures that lasted 90 to 180 min. We believe this technique is an alternative to general anaesthesia in these patients. A cause de l’immaturité physiologique de sa musculature et de son centre respiratoires, le nouveau-né est plus sujet à l’apnée et aux complications après une anesthésie générale. L’anesthésie régionale peut remplacer en partie l’anesthésie générale et diminuer ainsi la morbidité périopératoire. Les techniques régionales sont bien décrites pour l’enfant mais elles sont utilisées en doses uniques pour des interventions brèves (< 60 min). L’expérience d’interventions sous régionale avec des cathéters en place est limitée. Nous présentons ici notre expérience avec quatre enfants auxquels on a administré une caudale ou une rachianesthésie continue pour des interventions de 90 à 180 min. Nous croyons que ces techniques sont des alternatives valables à l’anesthésie générale chez ces patients.     

Anaesthetic management of a complex morbidly obese parturient

A case is presented of a morbidly obese parturient who had multiple medical problems. She had angina and was receiving nitrate therapy, had insulin-dependent diabetes mellitus, hypertension, asthma and benign intracranial hypertension (pseudotumour cerebri). Lumbar epidural analgesia was chosen for labour and delivery and resulted in an uneventful outcome.     

Fluid through the epidural needle does not reduce complications of epidural catheter insertion

Epidural catheter insertion may be associated with blood vessel trauma or nerve root irritation. The purpose of this study was to assess whether the injection of small amounts of fluid through the Tuohy needle prior to catheter insertion reduced the incidence of these and other minor complications. Two hundred patients in labour, requesting epidural analgesia, were randomly assigned to one of three groups: Group I--the catheter was inserted without previous injection of fluid; Group II--3 ml, 1.5 per cent lidocaine hydrochloride was injected through the needle prior to catheter insertion; Group III--3 ml, saline was injected prior to catheter insertion. There were no differences among the groups in the incidence of blood vessel trauma or paraesthesiae. We conclude that there is no advantage in injecting of fluid routinely into the epidural space prior to catheter insertion.     

Uterine and umbilical blood flow velocity during epidural anaesthesia for Caesarean section

The purpose of this study was to use colour Doppler to determine the effect of epidural anaesthesia on the uterine and umbilical blood flow velocities. After determining the precision of the technique, Doppler insonation of the uterine and umbilical arteries was performed in consenting non-labouring patients requesting epidural anaesthesia for Caesarean section. Patients in Group I were normal and those in Group II were at high risk for uteroplacental blood flow abnormalities. The pulsatility indexes (PI) of both uterine and umbilical arteries were compared at the following times: control, after fluid and after anaesthesia using repeated measure analysis of variance. In Group I (n = 30) the PI increased from 0.72 to 0.82 in the left uterine artery and from 0.71 to 0.85 in the right uterine artery (P < 0.05). In Group II (n = 10) the PI increased from 0.67 to 0.85 in the left uterine artery (NS) and from 0.98 to 1.38 in the right uterine artery (P < 0.05). There was no change in the PI in the umbilical artery. We conclude that the PI of the uterine arteries increases after epidural anaesthesia with lidocaine, epinephrine and fentanyl but there is no change in the umbilical PI. While these changes do not appear to be clinically important in the low-risk population, further studies are required to determine the impact on fetuses at high risk for in utero hypoxaemia.     

Transforaminal escape of a lumbar epidural catheter

A patient is presented whose lumbar epidural catheter was found to lie in the paravertebral tissues during a right radical nephrectomy. The catheter had been placed with the patient awake and the procedure performed in a routine fashion without difficulty or indication of catheter malposition. Four ml of 2% CO2 lidocaine were initially injected as a test dose without any demonstrable effect. After the induction of general anaesthesia, fentanyl 100 mu and 0.25% bupivacaine 10 ml were injected slowly into the catheter. Previous studies suggest that transforaminal escape of an epidural catheter occurs after 1-6% of insertions. It may occur without nerve root symptoms during catheter placement. The authors recommend that epidural catheters be introduced whilst the patients are awake and an effective block demonstrated before induction of general anaesthesia.