A comparison of intravenous sugammadex and neostigmine + atropine reversal on time to consciousness during wake-up tests in spinal surgery

Objective

The effect of sugammadex on consciousness is not yet fully understood. This prospective, randomized, double-blind, multicenter study was performed to compare the effects of intravenous (IV) sugammadex and neostigmine + atropine reversals on time-to-consciousness during intraoperative wake-up tests in patients undergoing spinal surgery.

Subjects and Methods

A total of 66 American Society of Anesthesiologists I-II patients aged 10-25 years undergoing spinal surgery were recruited. In all patients, bispectral index (BIS), motor-evoked potential (MEP), somatosensory-evoked potentials (SSEP), and train-of-four (TOF) scores were monitored. Patients received the same total IV anesthesia protocol with a propofol-remifentanil mixture. Patients were randomly allocated into two groups. During wake-up test, when the TOF count reached 2 (T₂), either sugammadex 2 mg.kg^-1 in group S or neostigmine 0.04 mg.kg^-1 + atropine 0.01 mg.kg^-1 in group N were administered. BIS₉₀, SSEP₉₀, MEP₉₀ was recorded when TOF ratio reached 90, whereas time-to-consciousness (Time_cons) was recorded when the patient responded to verbal commands.

Results

BIS₉₀ (77.4 ± 4.7, 74.8 ± 3.7), SSEP₉₀(36 ± 9.9, 29.7 ± 8.5), and MEP₉₀ (465.3 ± 34.8, 431.3 ± 28.2) values were significantly greater in group S than in group N (P < 0.05 for each variables). Time_cons was significantly shorter with sugammadex than with the neostigmine + atropine combination (P < 0.05).

Conclusion

Using IV sugammadex 2 mg.kg^-1 reversal provides faster responses to verbal commands than neostigmine-atropine combination during the intraoperative wake-up test in patients undergoing spinal surgery because the time to consciousness was significantly shorter. This difference was thought to be related with faster return of neuromuscular transmission because the TOF ratio was >0.9 well before return of consciousness in both groups.

Comparison of intrathecal magnesium, fentanyl, or placebo combined with bupivacaine 0.5% for parturients undergoing elective cesarean delivery

BACKGROUND

Intrathecal (i.t.) administration of magnesium has been reported to potentiate opioid antinociception in rats and humans. In this prospective, randomized, double-blind, study, we investigated the sensory, motor, and analgesic block characteristics of i.t. magnesium 50 mg compared with fentanyl 25 microg and saline when added to 0.5% bupivacaine (10 mg).

METHODS

Ninety ASA I or II adult patients undergoing cesarean section were randomly allocated to receive 1.0 ml of 0.9% sodium chloride in group S, 50 mg of magnesium sulfate (1.0 ml) 5% in group M, or 25 microg of fentanyl (1.0 ml) in group F following 10 mg of bupivacaine 0.5% i.t. We recorded the following: onset and duration of sensory and motor block, maximal sensory block height, the time to reach the maximal dermatomal level of sensory block, and the duration of spinal anesthesia.

RESULTS

Magnesium did not shorten the onset time of sensory and motor blockade or prolong the duration of spinal anesthesia. The duration of sensory (P<0.032) and motor (P<0.002) blockade was significantly shorter in M and S groups than in the F group. The time to reach the maximal dermatomal level of sensory block was significantly shorter in the F group than in the S and M groups (P<0.002).

CONCLUSION

In patients undergoing cesarean section with spinal anesthesia, the addition of magnesium sulfate (50 mg) i.t. to 10 mg of spinal bupivacaine (0.5%) did not shorten the onset time of sensory and motor blockade or prolong the duration of spinal anesthesia, as seen with fentanyl.

The influence of epidural volume extension on spinal block with hyperbaric or plain bupivacaine for Caesarean delivery

BACKGROUND AND OBJECTIVE

Epidural volume extension via a combined spinal-epidural is the enhancement of a small-dose intrathecal block by an epidural injection of physiological saline solution. We evaluated the effect of epidural volume extension on the combined spinal-epidural technique of providing spinal anaesthesia for Caesarean section with hyperbaric or plain 0.5% bupivacaine.

METHODS

Patients (n = 240) with height >163 cm received 9 mg and patients <163 cm received 8 mg of bupivacaine. Each study drug was combined with 20 mug fentanyl. Using the combined spinal-epidural technique, Group A (n = 60) received hyperbaric bupivacaine, and Group B (n = 60) received hyperbaric bupivacaine and 10 mL saline epidurally 5 min after subarachnoid injection. Group C (n = 60) received plain bupivacaine and Group D (n = 60) received plain bupivacaine and 10 mL saline epidurally 5 min after subarachnoid injection. An anaesthetist blinded to the anaesthetic solution injected examined the level of analgesia by the pinprick method and motor block with the modified Bromage scale for 30 min after subarachnoid injection, during the intraoperative period and subsequently every 15 min for 135 min during the recovery period.

RESULTS

Time to reach a sensory block at T4 was significantly shorter in Groups C and D than in Groups A (P = 0.003 and 0.017) and B (P = 0.006 and 0.048), respectively. During the intraoperative period, sensory block levels were significantly higher in Group C than in Group A. Recovery was similar in all groups; only onset was faster in Groups C and D.

CONCLUSION

There was no effect of epidural volume extension on the profile of spinal anaesthesia with the combined spinal-epidural technique for Caesarean section using hyperbaric or plain bupivacaine.

Remifentanil-induced mechanical responses and membrane potential changes in human umbilical arteries

BACKGROUND

The aim of this study was to evaluate the characteristic features of the mechanical responses and membrane potential changes induced by remifentanil in human umbilical arteries (HUAs). The ionic mechanisms underlying the electrophysiological responses were pharmacologically assessed using two K(+) channel blockers.

METHODS

Thirty-eight HUAs were obtained. Contraction-relaxation, membrane potential changes and electrical responses of the HUAs were recorded.

RESULTS

Remifentanil produced concentration-dependent relaxation in both endothelium-intact and endothelium-denuded HUA rings. Remifentanil produced a significantly greater relaxation response in intact than in denuded HUA rings. In endothelium-intact rings, pre-treatment with L-nitroarginine [N(w)-NITRO-(L)-ARGININE (L-NO-ARG)] or indomethacin decreased the degree of remifentanil-induced relaxation. Remifentanil (10(-9)-10(-6) mol/l) produced a transient concentration-dependent membrane hyperpolarization, which was not decreased by pre-treatment with L-NO-ARG or indomethacin. It also produced a small concentration-dependent hyperpolarization in the presence of charybdotoxin or tetraethylammonium.

CONCLUSION

In both endothelium-intact and endothelium-denuded HUAs, remifentanil induces concentration-dependent vasorelaxation and simultaneously releases nitric oxide, prostaglandins and possibly an endothelium-derived hyperpolarizing factor. In addition, it produces hyperpolarization in a dose-dependent manner. Hyperpolarization induced by remifentanil involves the activation of Ca(2+)-dependent and Ca(2+)-independent potassium channels regulated by intracellular Ca(2+).

A double-blind comparison of intrathecal S(+) ketamine and fentanyl combined with bupivacaine 0.5% for Caesarean delivery

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 microg (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.

The effect of adding intrathecal magnesium sulphate to bupivacaine-fentanyl spinal anaesthesia

BACKGROUND

The addition of intrathecal (IT) magnesium to spinal fentanyl prolongs the duration of spinal analgesia for vaginal delivery. In this prospective, randomized, double-blind, controlled study, we investigated the effect of adding IT magnesium sulphate to bupivacaine-fentanyl spinal anaesthesia.

METHODS

One hundred and two ASA I or II adult patients undergoing lower extremity surgery were recruited. They were randomly allocated to receive 1.0 ml of preservative-free 0.9% sodium chloride (group S) or 50 mg of magnesium sulphate 5% (1.0 ml) (group M) following 10 mg of bupivacaine 0.5% plus 25 microg of fentanyl intrathecally. We recorded the following: onset and duration of sensory block, the highest level of sensory block, the time to reach the highest dermatomal level of sensory block and to complete motor block recovery and the duration of spinal anaesthesia.

RESULTS

Magnesium caused a delay in the onset of both sensory and motor blockade. The highest level of sensory block was significantly lower in group M than in group S at 5, 10 and 15 min (P < 0.001). The median time to reach the highest dermatomal level of sensory block was 17 min in group M and 13 min in group S (P < 0.05). The mean degree of motor block was also lower in group M at 5, 10 and 15 min (P < 0.001). The median duration of spinal anaesthesia was longer in group M (P < 0.001).

CONCLUSION

In patients undergoing lower extremity surgery, the addition of IT magnesium sulphate (50 mg) to spinal anaesthesia induced by bupivacaine and fentanyl significantly delayed the onset of both sensory and motor blockade, but also prolonged the period of anaesthesia without additional side-effects.

A comparative study of continuous positive airway pressure (CPAP) and intermittent positive pressure ventilation (IPPV) in patients with flail chest

INTRODUCTION

The role of non-invasive positive pressure ventilation delivered through a face mask in patients with flail chest is uncertain. We conducted a prospective, randomised study of continuous positive airway pressure (CPAP) given via a face mask to spontaneously breathing patients compared with intermittent positive pressure ventilation (IPPV) with endotracheal intubation (ETI) in 52 patients with flail chest who required mechanical ventilation.

METHOD

The 52 mechanically ventilated patients were randomly divided into two treatment groups: the ET group (n = 27) received mechanical ventilation with ETI, whereas patients in the CPAP group (n = 25) received CPAP via a face mask with patient controlled analgesia (PCA). Major complications, arterial blood gas levels, length of intensive care unit (ICU) stay and ICU survival rate were recorded.

RESULTS

Nosocomial infection was diagnosed in 10 of 21 patients in the ET group, but only in 4 of 22 in the CPAP group (p = 0.001). Mean PO(2) was significantly higher in the ET group in the first 2 days (p<0.05). There were no significant differences in length of ICU stay between groups. Twenty CPAP patients survived, but only 14 of 21 intubated patients who received IPPV (p<0.01).

CONCLUSION

Non-invasive CPAP with PCA led to lower mortality and a lower nosocomial infection rate, but similar oxygenation and length of ICU stay. The study supports the application of CPAP at least as a first line of treatment for flail chest caused by blunt thoracic trauma.

The effect of pre-anaesthetic administration of intravenous dexmedetomidine on postoperative pain in patients receiving patient-controlled morphine

BACKGROUND AND OBJECTIVE

This prospective, randomized, double-blind, controlled study was designed to test the effect of pre-anaesthetic administration of dexmedetomidine, given as a single intravenous (i.v.) dose, on postoperative pain scores and morphine consumption in patients receiving patient-controlled morphine after abdominal surgery.

METHODS

Sixty patients were randomly allocated to receive dexmedetomidine (1 microg kg(-1)) or saline 10 min before induction of anaesthesia. Twenty minutes before the end of surgery, all patients received a standardized (0.1 mg kg(-1)) loading dose of morphine. They were then allowed to use a patient-controlled analgesia (PCA) device giving bolus doses of morphine (0.02 mg kg(-1)). Pain, discomfort and sedation scores; cumulative morphine consumption; time to extubation; time to recovery; and any side-effects were recorded after recovery and at 1, 2, 6, 12 and 24 h after the start of PCA.

RESULTS

The mean time to extubation at the end of anaesthesia and recovery time were similar in both groups. There were no significant differences between groups with regard to mean pain, discomfort, sedation and nausea scores. Cumulative morphine consumption was significantly lower in the dexmedetomidine group at 6, 12 and 24 h (P < 0.05). The incidence of side-effects did not differ between the groups.

CONCLUSIONS

A single i.v. dose of dexmedetomidine (1 microg kg(-1)) given 10 min before induction of anaesthesia significantly reduced postoperative morphine consumption at identical pain scores compared to control, but had no effect on postoperative recovery time.

Comparative study of the antiemetic efficacy of ondansetron, propofol and midazolam in the early postoperative period

BACKGROUND AND OBJECTIVE

To compare the antiemetic efficacy of ondansetron with two different hypnotic drugs (propofol 15 mg, midazolam 1 and 2 mg) for the treatment of established postoperative nausea and vomiting (PONV).

METHODS

Four-hundred-and-fifty-three patients scheduled for elective gynaecological or abdominal surgery were enrolled. One-hundred-and-twenty patients (26%) experienced postoperative emesis, and when nausea scores reached 2 or greater on a five-point scale, they were randomized to receive intravenously: propofol 15 mg (1.5 mL) in Group P, midazolam 1 mg in Group M1, midazolam 2 mg in Group M2 and ondansetron 4 mg in Group O.

RESULTS

Four patients (13.3%) in Group P, 13 patients (43.3%) in Group M1, five patients (16.6%) in Group M2 and one patient (3.3%) in Group O required a second dose of the study drug. After administration of the study drugs, nausea scores were significantly lower in all groups than before these drugs were given. No patient had a sedation score over 3 (the patients remained awake and/or responded to verbal contact). The sedative effects of midazolam and propofol lasted for a much shorter time than the antiemetic effects of these drugs.

CONCLUSIONS

Propofol and midazolam used in subhypnotic doses were as effective as ondansetron in treating PONV in patients undergoing abdominal or gynaecological surgery without untoward sedative or cardiovascular effects.

Comparative study of the antiemetic efficacy of ondansetron, propofol and midazolam in the early postoperative period

BACKGROUND AND OBJECTIVE

To compare the antiemetic efficacy of ondansetron with two different hypnotic drugs (propofol 15 mg, midazolam 1 and 2 mg) for the treatment of established postoperative nausea and vomiting (PONV).

METHODS

Four-hundred-and-fifty-three patients scheduled for elective gynaecological or abdominal surgery were enrolled. One-hundred-and-twenty patients (26%) experienced postoperative emesis, and when nausea scores reached 2 or greater on a five-point scale, they were randomized to receive intravenously: propofol 15 mg (1.5 mL) in Group P, midazolam 1 mg in Group M1, midazolam 2 mg in Group M2 and ondansetron 4 mg in Group O.

RESULTS

Four patients (13.3%) in Group P, 13 patients (43.3%) in Group M1, five patients (16.6%) in Group M2 and one patient (3.3%) in Group O required a second dose of the study drug. After administration of the study drugs, nausea scores were significantly lower in all groups than before these drugs were given. No patient had a sedation score over 3 (the patients remained awake and/or responded to verbal contact). The sedative effects of midazolam and propofol lasted for a much shorter time than the antiemetic effects of these drugs.

CONCLUSIONS

Propofol and midazolam used in subhypnotic doses were as effective as ondansetron in treating PONV in patients undergoing abdominal or gynaecological surgery without untoward sedative or cardiovascular effects.

Pre-emptive analgesic efficacy of tramadol compared with morphine after major abdominal surgery

BACKGROUND

Studies of pre-emptive analgesia in humans have shown conflicting results. This prospective, randomized, double-blind, controlled study was designed to test the hypothesis that a reduction in postoperative morphine consumption can be achieved by tramadol administered after induction of anaesthesia.

METHODS

Ninety patients were allocated randomly to receive i.v. tramadol (1 mg kg(-1)) (Group T), morphine (0.1 mg kg(-1)) (Group M) or saline 2 ml (Group S) after induction of anaesthesia. At peritoneal closure, a standardized (0.1 mg kg(-1)) morphine loading dose was given to all patients for postoperative pain management. Patients were allowed to use a patient-controlled analgesia (PCA) device giving bolus doses of morphine 0.025 mg kg(-1). Discomfort, sedation, pain scores, cumulative morphine consumption, and side-effects were recorded at 1, 2, 6, 12 and 24 h after the start of PCA.

RESULTS

There were no significant differences between groups in mean pain, discomfort, and sedation scores at any study period. Cumulative morphine consumption was significantly lower in Group M at 12 and 24 h after starting the PCA than in Group S. In Group T, it was lower only after 24 h (28% less in Group M and 17% less in Group T; P<0.017). There were no significant differences in morphine consumption between Groups T and M.

CONCLUSIONS

Tramadol (1 mg kg(-1)), administered after induction of anaesthesia, offered equivalent postoperative pain relief, and similar recovery times and postoperative PCA morphine consumption compared with giving morphine 0.1 mg kg(-1). These results also suggest that presurgical exposure to systemic opioid analgesia may not result in clinically significant benefits .