Summary

Background: In this prospective, randomized, double-blind, controlled study, we investigated the sensory, motor and analgesic block characteristics of S(+) ketamine, fentanyl and saline given intrathecally (IT) in addition to 0.5% plain bupivacaine (10 mg) for spinal analgesia. Methods: Ninety ASA I or II adult patients undergoing Caesarean section were randomly allocated to receive 1.0 mL of 0.9% saline in Group S (n = 30), 0.05 mg kg−1 of S(+) ketamine (1.0 mL) in Group K (n =30) or 25 μg (1.0 mL) of fentanyl in Group F (n =30) following 10 mg of plain bupivacaine 0.5% IT. We recorded onset and duration of sensory and motor block, time to reach the maximal dermatomal level of sensory block and duration of spinal analgesia. Results: The onset time of sensory and motor block was significantly shorter in Groups K and F than in Group S (P < 0.014). Their duration was significantly longer in Group F than in Groups K and S (P < 0.009). The time to reach the maximal dermatomal level of sensory block was significantly shorter in Groups K and F than in Group S (P < 0.001). The duration of spinal analgesia was significantly longer in Group F than in Groups K and S (P < 0.001). Conclusion: In patients undergoing Caesarean section with spinal analgesia, the addition of S(+) ketamine (0.05 mg kg−1) IT to 10 mg of spinal plain bupivacaine (0.5%) led to rapid onset of both sensory and motor blockade and enhanced the segmental spread of spinal block without prolonging the duration of spinal analgesia, whereas fentanyl provided prolonged analgesia.

Patients receiving anticoagulants offer a challenge to anaesthesiologists. The issue of spinal haematoma following central neuraxial block in such patients is a contentious issue. Although rare, with an estimated incidence of <1 : 150 000 for epidural blocks and 1 : 220 000 for spinal anaesthetics in patients with normal coagulation status, this is an emergency situation with a potentially grave prognosis. The review presents cases of spinal haematomata that have occurred in the last 5 years, both spontaneously and after central neuraxial blockade. Of the 60 cases reported in the literature, 33% occurred following central neuraxial block and, of these, 55% were associated with concomitant use of anticoagulants. The pharmacology of the newer and older anticoagulants is also described. The variety of risk factors and diverse recommendations that have been described in these patients are reviewed.

Background and objective In recent studies, ultrasonic diagnostic imaging has proved useful in the screening of the trajectory of the epidural needle. With regard to possible side-effects of spinal and epidural anaesthesia caused by vessel injury, we aimed to evaluate the usability of Colour Doppler imaging for the depiction of interspinous vessels in prepuncture examination.

Methods Ultrasonic examination of the L¾ interspace area was performed in 20 volunteers. Using a 4-MHz and a 7-MHz probe with B-mode and Colour Doppler imaging, respectively, we compared four settings for the quality of vessel depiction in the puncture area. Overall resolution was evaluated according to the distinction of landmarks. Vascular structures were identified by pulsation (B-mode) or blood flow (Doppler).

Results Colour Doppler imaging of the L3/4 interspace was unachievable using the 7-MHz transducer. Vessel detection was possible in 50% of the B-mode images and in all of the 4-MHz Doppler images. Vessels were perceptible from a diameter of 0.5 mm. Veins were the predominantly visible structures. Overall vessel visibility was best using 4-MHz Colour Doppler.

Conclusions Prepuncture Doppler imaging can provide the epiduralist with information regarding the position of vessels in the needle trajectory. This might help to reduce complications in regional anaesthesia.

This study was designed to determine the efficacy of oral etilefrine in preventing hypotension induced by spinal anaesthesia. Forty patients, ASA grade I or II, aged 23–60 years, scheduled for orthopaedic surgery involving the lower extremity under spinal anaesthesia were studied. The patients were randomly allocated to one of two groups; the etilefrine group (n=20) received oral etilefrine 15mg (30 drops), 60 min before the subarachnoid lock, and the control group (,n=20) received no etilefrine. Patients were given 0.5% isobaric bupivacaine intrathecally. Hypotension was defined as a 30% decrease from base-line for systolic arterial pressure and mean arterial pressure or systolic value <90mmHg, and was treated with intravenous boluses of etilefrine 2 mg. The overall incidence of spinal anaesthesia induced hypotension was 25%, ranging from 20% in the etilefrine group to 30% in the control group. The fall in systolic arterial pressure and mean arterial pressure was significantly greater in the control group than in the etilefrine group (P < 0.05). The patients in the etilefrine group received less etilefrine supplement than those in control group and no subject in the etilefrine group required repeat etilefrine doses, while in the control group five patients received multiple etilefrine doses (P < 0.05). The mean heart rate remained fairly stable throughout the study periods. We conclude that oral etilefrine, given 60 min before surgery, reduces the fall in blood pressure during spinal anaesthesia.

An 86-year-old man on whom a transurethral resection of prostate was performed under spinal anaesthesia developed profound bradycardia and hypotension with disturbance of consciousness during transfer to the recovery room. Initial treatment with atropine produced rapid improvement in cardiovascular and cerebral function. A further hypotensive episode (without bradycardia) occurred approximately 1 h later but responded rapidly to methoxamine. The patient made a full recovery during an overnight stay on the High Dependency Unit. Possible mechanisms for this event are discussed, with the proposal that the concomitant administration of captopril and the relative unavailability of Angiotensin II may have significantly contributed to the problem.

Gamma hydroxybutyric acid, a central inhibitory neurotransmitter and a cerebral metabolite of gamma-aminobutyric acid, is present in high concentrations in the mammalian hypothalamus and basal ganglia. Its sodium salt gamma hydroxybutyrate has been effectively used as an intravenous anaesthetic agent, and as an oral sedative, and in the management of the alcohol withdrawal syndrome. In an animal model, using 72 Wistar strain rats allocated to one of six groups of 12 animals each, with implanted lumbar intrathecal catheters, we examined whether gamma hydroxybutyrate, 20% 40 μL (32 mg kg−1) administered alone or combined with fentanyl, gamma hydroxybutyrate 20% 20 μL (16 mg kg−1), fentanyl 0.005% 20 μL (4 mg kg−1) as an intrathecal bolus, provides intra-operative anaesthesia, comparable with that produced by intrathecal lignocaine. We demonstrated that gamma hydroxybutyrate, given by an intrathecal bolus in the rat model, produced reversible segmental antinociception, together with muscular relaxation of the abdominal wall and rear limbs. This is accompanied by moderate sedation without haemodynamic or respiratory depression. This agent may thus be promising for use as a spinal anaesthetic drug.

Gamma-hydroxybutyrate (GHB) may well be developed as an alternative for optional sedation during spinal anaesthesia. As in the case of propofol (PRO), GHB has good sedative properties associated with cardiovascular and respiratory stability. When used as a narcotic agent, recovery times are variable (e.g. > 30 min); in contrast, sedative dosages, as used in intensive care patients (e.g. 10–20 mg kg−1 h−1), result in adequate clinical recovery. The goal of the present study was to compare the clinical properties of GHB and PRO after continuous administration during spinal anaesthesia (SPA). Thirty patients (ASA I and II) received either GHB (n=15) or PRO (n=15) at random. Patients refusing sedation (n=15) received 0.9% saline (control). At eight defined time points, haemodynamic (BP, HR), respiratory (RR, RMV, Pao2, Spo2, Peto2, Petco2, ̇Vo2, ̇Vco2) and endocrinological parameters (plasma concentrations of noradrenaline and adrenaline) as well as the clinical side-effects were assessed simultaneously. With both sedatives, the desired level of sedation was achieved. Recovery times ranged between 1.7±0.9 min with PRO and 6.1±4.9 min with GHB. GHB provided stable haemodynamic conditions without clinically relevant respiratory depression. In contrast, PRO caused a decrease in mean arterial pressue (MAP) of 15%, whereas respiratory minute volume was decreased by 53% (with periods of apnoea, Spo2<90%). ̇Vo2 and ̇Vco2 correlated with respiratory minute volume (GHB, PRO, control). Plasma noradrenaline and adrenaline concentrations remained nearly constant in the GHB and control groups and declined during sedation with PRO. Both GHB and PRO are suitable for optional sedation during spinal anaesthesia. Control and recovery are acceptable for clinical purposes. It seems that GHB and PRO have similar haemodynamic, respiratory and endocrinological characteristics. Therefore, GHB may serve as an alternative for the established management of continuous sedation during SPA with PRO.

The medical literature sometimes reports neurological complications after spinal or epidural anaesthesia. In a few cases, the onset of symptoms can be a sign of a pre-existing disease without a primary connection with regional anaesthesia. In the following case report, the patient complained of paraesthesias in both legs after a failed spinal anaesthesia, even though the needle had been placed intrathecally. Only neurological examination and nuclear magnetic resonance imaging revealed the presence of syringomyelia.

A report is made of respiratory complications which occurred following the insertion of Palacos bone cement during Howse total hip replacement under spinal anaesthesia in a 78-year-old female patient. Persistent cough and tachypnoea developed 30 s after the insertion of bone cement into the acetabulum and femur and persisted for 2–3 min producing considerable passive movement of the pelvis and femur. The probable cause, disadvantages and prevention of these complications are discussed.