Spread of spinal anaesthesia for caesarean section in singleton and twin pregnancies

We have compared the spread of spinal anaesthesia in parturients with singleton and those with twin pregnancies. Fifty-five unpremedicated patients with uncomplicated pregnancy scheduled for Caesarean section were allocated to two groups: group I = 35 singleton mothers; group II = 20 with twin pregnancy. Both groups received spinal anaesthesia with hyperbaric bupivacaine 10 mg (2 ml of 0.5%). Mean birthweight was 3290 (SD 452) g and 5008 (495) g in groups I and II (combined birthweights), respectively. We found a statistically significant difference in onset and maximal cephalad spread of spinal anaesthesia (group I median T5, range T8-T4; group II T3, range T6-T2). The mechanisms of higher cephalad spread of spinal anaesthesia in parturients may be a decrease in cerebrospinal fluid volume secondary to shunting of blood from the obstructed inferior vena cava to the extradural venous plexus and increased nerve sensitivity to local anaesthetics because of increased concentrations of progesterone. The twin pregnancy group had heavier, larger uteri and greater daily production of progesterone.     

Duration of spinal anaesthesia is determined by the partition coefficient of local anaesthetic

We have compared the duration of motor block produced by four local anaesthetics administered into a chronically implanted subarachnoid catheter in rabbits. Each group (n = 6) received four different doses of amethocaine, bupivacaine, lignocaine or procaine, and the duration of the resulting motor block was assessed. Dose-response curves were plotted for each drug. As a measure of activity of the anaesthetics, we used the dose of each drug required to produce block of 60-min duration (D60 min) and the correlation between D60 min and different drug properties was examined. An inverse linear correlation (r = 0.995; P < 0.01) was observed between log D60 min and the log of the partition coefficient of the local anaesthetics. No correlation was found between the effect and degree of protein binding, pKa or molecular weight. These results suggest that, in spinal anaesthesia, the partition coefficient could be used as a predictor of the duration of anaesthetic action.     

Adverse effects and drug interactions associated with local and regional anaesthesia

Systemic and localised adverse effects of local anaesthetic drugs usually occur because of excessive dosage, rapid absorption or inadvertent intravascular injection. Small children are more prone than adults to methaemoglobinaemia, and the combination of sulfonamides and prilocaine, even when correctly administered, should be avoided in this age group. The incidence of true allergy to local anaesthetics is rare. All local anaesthetics can cause CNS toxicity and cardiovascular toxicity if their plasma concentrations are increased by accidental intravenous injection or an absolute overdose. Excitation of the CNS may be manifested by numbness of the tongue and perioral area, and restlessness, which may progress to seizures, respiratory failure and coma. Bupivacaine is the local anaesthetic most frequently associated with seizures. Treatment of CNS toxicity includes maintaining adequate ventilation and oxygenation, and controlling seizures with the administration of thiopental sodium or benzodiazepines. Cardiovascular toxicity generally begins after signs of CNS toxicity have occurred. Bupivacaine and etidocaine appear to be more cardiotoxic than most other commonly used local anaesthetics. Sudden onset of profound bradycardia and asystole during neuraxial blockade is of great concern and the mechanism(s) remains largely unknown. Treatment of cardiovascular toxicity depends on the severity of effects. Cardiac arrest caused by local anaesthetics should be treated with cardiopulmonary resuscitation procedures, but bupivacaine-induced dysrhythmias may be refractory to treatment. Many recent reports of permanent neurological complications involved patients who had received continuous spinal anaesthesia through a microcatheter. Injection of local anaesthetic through microcatheters and possibly small-gauge spinal needles results in poor CSF mixing and accumulation of high concentrations of local anaesthetic in the areas of the lumbosacral nerve roots. In contrast to bupivacaine, the hyperbaric lidocaine (lignocaine) formulation carries a substantial risk of neurotoxicity when given intrathecally. Drugs altering plasma cholinesterase activity have the potential to decrease hydrolysis of ester-type local anaesthetics. Drugs inhibiting hepatic microsomal enzymes, such as cimetidine, may allow the accumulation of unexpectedly high (possibly toxic) blood concentrations of lidocaine. Reduction of hepatic blood flow by drugs or hypotension will decrease the hepatic clearance of amide local anaesthetics. Special caution must be exercised in patients taking digoxin, calcium antagonists and/or beta-blockers.     

Steroid anaesthesia (Althesin - CT 1341) and dorsal horn cell activities in feline spinal cord

The effects of steroid anaesthesia (Althesin -CT 1341) on dorsal horn cells (laminae 4 and 5) were studied by extracellular recordings in the spinal cat. I.v. administration of Althesin (0.2 ml/kg) strongly depressed the spontaneous and evoked activities of both types of cells. No differences were found between cells activated by noxious or innocuous stimuli. These results emphasize the fact that the transmission of afferent messages is depressed by various anaesthetics at the level of the first synapses in the CNS. The depressive effects on lamina 5 cells could explain in part the analgesic effects of Althesin.     

The risks of anesthesia in obstetric interventions

In obstetric anaesthesia, general anaesthesia combined with endotracheal intubation, spinal anaesthesia and peridural anaesthesia is used. The main risks of general anaesthesia are: difficult intubation, aspiration of acid gastric content in non-fasting patients, depression of the fetus with narcotics and the occurrence of awareness of the mother. The main dangers of spinal anaesthesia are: hypotension of the mother leading to reduced utero-placentar blood flow due to sympathetic block, post-spinal headache and vomiting. The specific risks of peridural anaesthesia are: maternal hypotension, the possibility of inadvertent intravenous injection of local anaesthetics leading to cardiac and cerebral intoxication, inadvertent intrathecal application of local anaesthetics followed by total spinal block which requires reanimation and inadvertent dura perforation followed by long-lasting headache. Most anaesthesia-related maternal deaths by far occur during Caesarean section performed under general anaesthesia, but at present there is no clear evidence that the anaesthetic risk of spinal or peridural anaesthesia, on the one hand, is lower than that one of general anaesthesia, on the other.     

Maternal and uteroplacental haemodynamic state in pre-eclamptic patients during spinal anaesthesia for Caesarean section

We have studied the effects of crystalloid (Ringer's acetate 1 litre) preloading and subsequent spinal anaesthesia in 12 pre-eclamptic parturient patients undergoing elective Caesarean section. Maternal placental uterine artery circulation was measured using a pulsed colour Doppler technique with simultaneous measurement of maternal haemodynamic state. Despite preloading, mean maternal systolic arterial pressure (SAP) decreased significantly and marked maternal hypotension (SAP < 80% of baseline value) was recorded in two patients after induction of spinal anaesthesia. Mean central venous pressure increased significantly after preload, but decreased to baseline shortly after induction of spinal anaesthesia. Mean pulsatility index (PI) in the uterine artery did not change during preload or spinal block. In one patient, uterine artery PI increased significantly when SAP decreased to 71% of the baseline value, 14 min after induction of spinal anaesthesia. These results suggest that preload with crystalloid solution does not prevent maternal hypotension in pre-eclamptic patients, and that changes in uterine artery velocity waveforms were minor when SAP was 80% or more of baseline during spinal anaesthesia. These changes did not appear to have any major effect on the clinical condition of the neonate, as assessed by Apgar score and umbilical artery pH values.     

Epidural anaesthesia and spinal haematoma

PURPOSE: Haematoma formation in the spinal canal due to epidural anaesthesia is a very rare but serious complication. This paper presents a comprehensive review of case reports. SOURCE: Sampling of case reports over a 10 yr period, medline-research (1966-1995) and cross-check with former reviews. FINDINGS: Fifty-one confirmed spinal haematomas associated with epidural anaesthesia were found. Most were related to the insertion of a catheter, a procedure that was graded as difficult or traumatic in 21 patients. Other risk factors were: fibrinolytic therapy (n = 2), previously unknown spinal pathology (n = 2), low molecular weight heparin (n = 2), aspirin or other NSAID (n = 3), epidural catheter inserted during general anaesthesia (n = 3), thrombocytopenia (n = 5), ankylosing spondylitis (n = 5), preexisting coagulopathy (n = 14), and intravenous heparin therapy (n = 18). CONCLUSION: Coagulopathies or anticoagulant therapy (e.g., full heparinization) were the predominant risk factors, where-as low-dose heparin thromboprophylaxis or NSAID treatment was rarely associated with spinal bleeding complications. Ankylosing spondylitis was identified as a new, previously unreported risk factor. Analysis of reported clinical practice suggests an incidence of haematoma of 1:190,000 epidurals.     

Unilateral spinal anaesthesia with hyperbaric bupivacaine

BACKGROUND: The dosage of local anaesthetic and the time the patient must be kept in the lateral decubitus position for a unilateral spinal anaesthesia is not known. The aim of this study was to determine the ideal dosage of hyperbaric bupivacaine and the time required for the lateral decubitus position for a unilateral spinal block. METHODS: Ninety patients who were scheduled to receive spinal block for surgery in the lower extremity were randomised into 9 groups (n = 10). The spinal block was performed through the L4-L5 intervertebral space with the patient in the lateral decubitus position. Patients in groups Ia, Ib, Ic; IIa, IIb, IIc; IIIa, IIIb, IIIc received 1.5 ml of 0.5%, 2 ml of 0.5%, and 2.5 ml of 0.5% hyperbaric bupivacaine solutions, respectively. The patients were turned to the supine position for 5 min after the injection in groups Ia, IIa, IIIa, 10 min after the injection in groups Ib, IIb, IIIb, and 15 min after the injection in groups Ic, IIc, IIIc. The onset and regression of sensory and motor block were checked and compared between the dependent and non-dependent sides in each group. RESULTS: The rate of block progression of the non-dependent side was higher in the groups receiving 2.5 ml 0.5% hyperbaric bupivacaine solution than in the other groups; at the same time the level of block was higher and the duration of block was longer. The incidence of hypotension was 10-20% in these groups. In the 2 ml 0.5% hyperbaric bupivacaine solution groups, a satisfactory block level and duration of anaesthesia for surgery was obtained. The rate of block progression to non-dependent side in the groups receiving 1.5 ml of 0.5% hyperbaric bupivacaine solution was lower than the other groups, but the duration of block was shorter and the level of block was lower than the other groups. CONCLUSION: For unilateral spinal anaesthesia in lower extremity operations, 2ml 0.5% hyperbaric bupivacaine solution for operations above the knee and 1.5 ml 0.5% hyperbaric bupivacaine solution for operations below the knee and keeping the patients for 10 min in the lateral decubitus position were found to be appropriate.     

Liver function tests following anaesthesia

Liver function tests were performed in 41 patients who required repeated anaesthetics for genito-urinary surgery, and who had received multiple halothane anaesthetics in the past, first following anaesthesia using halothane and then following an anaesthetic without halothane. There was a smaller frequency of disturbance of liver function after halothane than after the non-halothane anaesthetic. There was no obvious relationship between the number of anaesthetics, or the total duration of anaesthesia, and the disturbance of liver function tests.     

Comparison of continuous spinal anaesthesia using a 32-gauge catheter with anaesthesia using a single-dose 24-gauge atraumatic needle in young patients

One hundred and twenty-eight ASA I-III patients less than 40 yr of age, undergoing orthopaedic or trauma lower limb surgery, were allocated randomly to receive either continuous spinal anaesthesia (CSA) using a 32-gauge polyimide microcatheter with a permanent stylet (Rusch/TFX Medical, Duluth, GA, USA) or single-dose spinal anaesthesia (SDSA) with a 24-gauge x 103-mm Sprotte spinal needle (Pajunk, Germany). Plain bupivacaine (0.5%) was used as the local anaesthetic. The initial doses were 1 ml (5 mg) of CSA and 3 ml (15 mg) of SDSA, while the re-injection doses were 1 ml (5 mg) in the CSA group. SDSA was quicker to perform: mean 4.4 (SD 1.6) min compared with 6.2 (2.6) min for CSA (P < 0.01). Times to onset and surgical anaesthesia were also significantly greater in the CSA group (P < 0.01). The quality of the block was better in the SDSA group (P < 0.05), but was associated with greater haemodynamic instability (P < 0.05). The segmental level of analgesia was significantly lower in the CSA group (median T10 (range T12-T8)) than in the SDSA group (T9 (T11-T5)) (P < 0.05). There were no significant differences in the incidence of postoperative complications, with two mild spinal headaches in both groups. We conclude that CSA using a microcatheter in young patients is difficult to perform and affords no advantages over SDSA with a small gauge atraumatic needle.     

Intradermal anaesthesia: comparison of several compounds

OBJECTIVE: To compare the efficacy of different local anaesthetics to produce intradermal anaesthesia for venous cannulation and the discomfort associated with skin infiltration. DESIGN: Randomized, double blind study. SETTING: Induction room of a university hospital. PATIENTS: Convenience sample of 600 patients (18-65 years; ASA I-II) scheduled for elective surgery. INTERVENTIONS: Patients received one of six preparations: 0.9% saline, 1% prilocaine (Xylonest), 1% lidocaine (Xylocain), 1% mepivacaine-1 (Meaverin), 1% mepivacaine-2 (Scandicain), 1% procaine (Novocain). A skin wheal was raised on the dorsum of the hand by injecting 0.1 ml intradermally and 0.1 ml subcutaneously via a 27-g hypodermic needle. 60 seconds later an 18-g intravenous cannula was passed through that skin wheal into a vein. MEASUREMENTS: A visual analog scale (VAS) for pain (0 = no pain/10 = most pain imaginable) was used to assess pain elicited by raising the skin wheal and inserting the cannula. MAIN RESULTS: With regard to analgesic potency all five local anaesthetics were comparable (mean VAS-score 1.7-2.09) and effective when compared to 0.9% saline (mean VAS-score 4.2; P < 0.001). Infiltration pain was least with mepivacaine-1 (mean VAS-score 1.0; P < 0.001) and highest with procaine (mean VAS score 2.7; P < 0.001). CONCLUSIONS: Of the local anaesthetics tested, Mepivacaine-1 is the drug of choice for skin infiltration as its injection elicits least discomfort.     

Pituitary apoplexy after spinal anaesthesia

We report the case of a previously healthy 51-yr-old male who underwent an uneventful total hip replacement under spinal anaesthesia. His immediate postoperative course was complicated by the development of a severe frontal headache. Initial conservative treatment included oral analgesics and an epidural blood patch. The headache persisted and was followed by progressive vision loss and a right partial third nerve palsy. The patient was almost blind at the time of transfer to our neurosurgical unit. Relevant investigations revealed marked hyponatraemia (serum sodium concentration 122 mmol litre-1) and second-degree heart block (Mobitz I). A CT scan showed a pituitary tumour and confirmed the clinical diagnosis of pituitary apoplexy. Urgent craniotomy was scheduled and a large necrotic pituitary adenoma was excised. The postoperative course was uneventful with return of near normal vision at the time of discharge. Clinicians should consider this diagnosis when focal neurological deficits occur with post-dural puncture headache.     

The beginnings of anesthesia

In the nineteenth century, introduction of the first inhaled general anaesthetic (Long, 1842) induced a further search for new types of anaesthesia: carbon dioxide, petroleum ether, derivatives of ethylene, acetone, methyl dichloride, and the study of a new technique-hypnosis. Only chloroform, ether, nitrous oxide were used. Towards the end of the century, ether became the mainstay of inhaled anaesthetics. The other routes of administering anaesthetics (rectal, venous, spinal, local) appeared around 1860.     

Caudal clonidine and bupivacaine for combined epidural and general anaesthesia in children

BACKGROUND: Clonidine produces analgesia by actions on alpha 2-adrenoceptors and enhances both sensory and motor blockade from epidural injection of local anaesthetics. Low-dose clonidine has been used so far for caudal injection in children. Our aim was to study the perioperative effects of high-dose caudal clonidine when added to low concentration of bupivacaine for combined epidural and general anaesthesia in children. METHODS: After induction of general anaesthesia caudal block was performed either with 1 ml.kg-1 bupivacaine 0.175% with the addition of clonidine 5 micrograms.kg-1 (n = 20), or with 1 ml.kg-1 bupivacaine 0.175% (n = 20). The intraoperative anaesthetic requirements, the perioperative haemodynamic effects, respiratory rate, sedation score, postoperative pain scores and side effects were assessed by a blinded observer. A patient-controlled analgesia system was used for postoperative pain relief. The quality of postoperative pain relief was assessed using Smiley's pain analogue scale. RESULTS: Intraoperative haemodynamic responses did not differ between the groups. However, during emergence from general anaesthesia children in the clonidine group had significantly lower heart rates and blood pressure compared to children in the control group. In addition, heart rates and blood pressures were also lower in the clonidine group in the early postoperative period (P < 0.05). Postoperative analgesia was significantly better in the clonidine group as evidenced by the total number of requests (3 vs 12, P < 0.05) and the total amount of tramadol (20.5 mg vs 72.8 mg, P < 0.05) administered. The duration of the caudal analgesia was significantly longer in the clonidine group (20.9 +/- 7.4 h vs 14.4 +/- 10.9 h, P < 0.05). CONCLUSION: Our results suggest that caudal clonidine 5 micrograms.kg-1 enhances and prolongs caudal blockade with bupivacaine (1.175% in children. It also blocks sympathoadrenergic responses during emergence from anaesthesia. Sedation and cardiovascular effects are observed up to 3 h into the postoperative period.     

Acid-base state of cerebrospinal fluid during pregnancy and its effect on spread of spinal anaesthesia

To assess the possible relationship between changes in acid-base state of cerebrospinal fluid (CSF) and enhanced spread of spinal anaesthesia during pregnancy, we have measured CSF pH, carbon dioxide tension (PCO2) and HCO3- values in 73 women undergoing spinal anaesthesia with hyperbaric amethocaine 8 mg. Patients were allocated to one of four groups according to gestational period: non-pregnant group (n = 13), first trimester group (8-13 weeks, n = 19), second trimester group (14-26 weeks, n = 11) and third trimester group (27-39 weeks, n = 30). The pH of the CSF was greater in the second and third trimester groups than in the non-pregnant group. CSF PCO2 decreased by 0.53-0.8 kPa throughout pregnancy. CSF HCO3- was decreased throughout pregnancy. Overall, no clinically significant correlation was found between maximum cephalad spread of analgesia and CSF pH, PCO2 or HCO3-. We conclude that pregnancy-induced changes in acid-base state of CSF have little effect on the spread of spinal anaesthesia, although there is a clinically different spread of spinal anaesthesia between non-pregnant and pregnant states.     

General anaesthesia for surgery can influence circulating melatonin during daylight hours

BACKGROUND: Both melatonin and anaesthetics have been shown to affect sleep and behaviour. The effect of general anaesthesia on circulatory melatonin has not been reported, but anaesthetic-related alterations in hormone profiles are known. We hypothesize that differences in recovery from anaesthesia may be associated with differences in circulatory melatonin levels because of melatonin's sedative effect in humans. METHODS: The influences of general anaesthesia and surgery on circulating melatonin, prolactin, and cortisol concentration were investigated in 32 female patients scheduled for elective gynaecological surgery to study differences in hormone profiles and responses during anaesthesia and the recovery period. Patients were randomly assigned to one of two groups. General anaesthesia was induced with either thiopentone/fentanyl (Group 1: n = 16) or propofol/fentanyl (Group 2: n = 16). Maintenance of anaesthesia was achieved with either isoflurane (0.8-1.0 vol%)/fentanyl (Group 1) or propofol (6 mg.kg-1.h-1)/fentanyl (Group 2) with a N2O/O2 flow ratio of 2:1 in both groups. During anaesthesia, patients' eyes were carefully taped shut to prevent light effects. Blood samples were taken before and after premedication, immediately before induction of anaesthesia, every 15 min during anaesthesia, and hourly in the recovery room for 8 h. The control group consisted of 6 healthy women who were not subjected to surgery, but who were in a similar environment, including light conditions, as the study groups. RESULTS: Isoflurane and propofol anaesthesia as well as darkness elicited elevated plasma melatonin levels that persisted in the recovery period in patients anaesthetized with isoflurane, but gradually decreased during the recovery of patients anaesthetized with propofol. Circulating prolactin and cortisol values were also elevated during anaesthesia and had similar decreases during the recovery period. CONCLUSION: Higher plasma levels of melatonin during the recovery period following isoflurane anaesthesia may, in part, explain increased sedation in these patients compared with patients who received propofol anaesthesia. However, the relationship between recovery from anaesthesia and plasma melatonin levels may not be simple and straightforward.     

Spinal anaesthesia and spina-bifida occulta

We describe a patient with unexpected spina bifida who underwent spinal anaesthesia for trans-urethral resection of prostate and developed serious neurological signs. An unexpected spinal tumour was removed two weeks later. This report demonstrates that not all neurological problems associated with spinal anaesthesia should be blamed on the technique.     

Monitoring intraoperative awareness. Vegetative signs, isolated forearm technique, electroencephalogram, and acute evoked potentials

Several methods have been developed to quantify central anaesthetic effects and monitor awareness during general anaesthesia. The most important of these are the PRST score, calculated from changes in blood pressure, heart rate, sweating, and tear production, the isolated forearm technique, where the patient is allowed to move during surgery, the processed electroencephalogram (EEG) and the derived parameters median frequency (MF) and spectral-edge frequency (SEF), and mid-latency auditory evoked potentials (MLAEP). In clinical practice, the application of individual doses of anaesthetics is generally guided by autonomic vegetative clinical signs such as changes in blood pressure, heart rate, sweating, and tear production, quantified as the PRST score. Unfortunately, these parameters are not very reliable with regard to predicting the suppression of consciousness and awareness, especially when high-dose opioids are used in patients with cardiovascular medications and a variety of accompanying diseases. The PRST score probably indicates mainly the autonomic responses to painful stimuli, and seems to be useful in guiding the individual use of analgesics. The isolated forearm technique is a useful test of the patient's responsiveness during general anaesthesia, and thus an instrument for investigating the incidence of awareness during different anaesthetic regimens and when muscle relaxants are employed. A disadvantage is that it can only be used for 20 to 30 min because of pressure-induced nerve blocks or lesions. It can not be employed when long-term relaxation is necessary and consciousness and awareness are to be monitored continuously. The processed EEG and the derived parameters MF and SEF are important scientific tools to quantify central effects of many anaesthetics and opioid analgesics that allow the development of pharmacodynamic-pharmacokinetic models of anaesthetic action. MF has proven to be useful in monitoring closed-loop feedback of intravenous drug administration. Unfortunately, until now there have been no clinical studies that document the usefulness of MF or SEF with regard to predicting intraoperative arousal or awareness. To the contrary, some experimental data failed to predict imminent arousal and response to surgical incision or verbal commands by MF or SEF. Therefore, the EEG seems to be of limited value for monitoring awareness, consciousness, or memory formation during anaesthesia. MLAEP are suppressed in a dose-dependent fashion by many general anaesthetics and correlate with wakefulness, awareness, and explicit and implicit memory during anaesthesia and seem to be a promising method of monitoring awareness during anaesthesia. Nevertheless, future studies will have to determine threshold values for the different MLAEP parameters for intraoperative awareness and explicit and implicit recall of intraoperatively presented information for the different commonly used anaesthetics. Only then will it be possible to determine the usefulness of the method in clinical practice.     

Prevention of hypotension during spinal anaesthesia for caesarean section: ephedrine infusion versus fluid preload

We compared the efficacy of prophylactic ephedrine infusion over fluid preloading in prevention of maternal hypotension during spinal anaesthesia for Caesarean section. Forty-six women undergoing elective Caesarean section at term were allocated randomly to receive either intravenous fluid preloading with Hartmann's solution 20 ml.kg-1 (fluid group) or prophylactic intravenous ephedrine 0.25 mg.kg-1 (ephedrine group). Moderate hypotension was defined as > or = 20% reduction in systolic blood pressure and severe hypotension as > or = 30% reduction in systolic blood pressure. Maternal uterine circulation was measured using Doppler ultrasound in 11 parturients before and after spinal anaesthesia. There was a lower incidence of severe hypotension in the ephedrine group compared with the fluid group (35% vs. 65%, p = 0.04), although the incidence of moderate hypotension was similar. Mean umbilical venous pH was higher in the ephedrine group than in the fluid group (7.33 vs. 7.29, p = 0.02) and the number of patients shivering was lower in the ephedrine group (2 vs. 9, p = 0.02). No difference was found between pre- and postspinal uterine artery pulsatility indices in either group. We conclude that prophylactic ephedrine infusion alone is at least as good as fluid preload alone in combating the hypotension associated with spinal anaesthesia for Caesarean section.     

Anesthesia and delivery]

Close collaboration of an informed anaesthetist with the obstetrician, and respect of the security protocols in every anaesthesia must guarantee the well-being of pregnant women. The development of loco-regional anaesthesia for use in labour analgesia and caesarean section has reduced the indications and the mortality related to general anaesthesia. In the last 30 years, analgesia and control of loco-regional anaesthesia effects have been greatly improved. Loco-regional anaesthesia protocols are now safe for the mother and various. Epidural anaesthesia using low concentrations of local anaesthetics allows parturient ambulation. Intrathecal anaesthesia, with combined spinal-epidural technique, is mostly used for caesarean-section and for the early and late labour.