A narrative review of peri-operative management of patients with thalassaemia.

In thalassaemic patients, multiple organ systems may be affected by the disease, blood transfusion, iron overload and chelating therapy. Patients may develop cardiomyopathy, pulmonary hypertension or heart failure requiring pre-operative echocardiography or cardiac catheterisation. Restrictive lung dysfunction is commonly encountered, especially in patients with splenomegaly. Haemoglobin level should be optimised pre-operatively and maintained at adequate levels with transfusion and blood-saving strategies. Susceptibility to infections should be managed with broad-spectrum antibiotics. Thromboembolic events due to hypercoagulability should be prevented by simple measures, such as graduated compression stockings, intermittent pneumatic compression and early mobilisation, and possibly anticoagulant drugs. When general anaesthesia is administered, the risk of difficult intubation due to oro-facial malformation should be considered. Cardiovascular depression due to negative inotropic and vasodilating effects of general anaesthesia should be minimised. Neuraxial techniques may also be challenging due to spinal skeletal abnormalities and extramedullary haemopoiesis. A multidisciplinary pre-operative approach, clinical optimisation and a carefully planned strategy are mandatory.

The effects of intrathecal and systemic adjuvants on subarachnoid block.

Various intrathecal and systemic adjuvants to local anaesthetics have been found to improve the quality and extend the duration of spinal block. Intrathecal opioids are the most frequently used; the lipophilic fentanyl and sufentanil enhance and moderately prolong the sensory block, whereas the hydrophilic morphine significantly prolongs spinal analgesia. Nausea/vomiting, pruritus, urinary retention and respiratory depression are possible side effects. Adrenergic agonists, such as adrenaline and phenylephrine may prolong the block due to vasoconstriction, while clonidine and dexmedetomidine accelerate the onset and prolong the duration of block and analgesia. Hypotension, sedation and respiratory depression have been reported with clonidine. Other intrathecal adjuvants, such as midazolam, ketamine and neostigmine may also improve the quality of block and prolong analgesia, but are not popular because of their adverse effects. Intrathecal magnesium sulphate mainly potentiates the analgesic action of intrathecal opioids, without significant side effects. A positive impact on spinal analgesia has also been suggested ­ from animal studies ­ for intrathecal calcium channel blockers, while the analgesic efficacy of intrathecal nonsteroidal anti-inflammatory drugs remains questionable. Several drugs may also affect the spinal block characteristics after systemic administration. Opioids enhance, alpha-2 agonists and ketamine prolong the block, magnesium sulphate reduces postoperative analgesic consumption and nimodipine may delay the regression of sensory block. Nitrous oxide inhalation has also been found to enhance the level of sensory spinal block. Even though opioids are the most popular adjuvants to spinal local anaesthetics, a variety of drugs given intrathecally or systemically, can accelerate, improve and extend the spinal block.

Current practice in obstetric anesthesia: a 2012 European survey.

BACKGROUND: New scientific findings are gradually implemented into daily clinical routine. The present questionnaire survey investigated the current practice in obstetric anesthesia in Europe. METHODS: A 19-point questionnaire on obstetric anesthesia practices, regarding the techniques, drugs, fluids, vasopressors and safety measures, was uploaded on the site of the European Society of Anaesthesiology (21/12/2011 to 21/12/2012). RESULTS: Three hundred and forty-one (341) completed questionnaires were analyzed. Single-shot subarachnoid anesthesia is preferred by 225 (66%) respondents in uncomplicated Cesarean deliveries and by 190 (55.7%) in preeclampsia. Most anaesthesiologists (N.=133, 39%) perform neuraxial techniques if platelet count exceeds 80000/mm3. In anticipated hemorrhage, general anesthesia is administered by 165 (48.4%) respondents. Anesthesia is induced with thiopental/succinylcholine by 193 (56.6%) survey participants, usually under cricoid pressure (N.=201, 58.8%). For prevention of the hypotension associated with regional anesthesia, coloading with 1L of crystalloid represents the most popular measure undertaken by 80 (40.2%) respondents, while vasopressors are not favored (N.=260, 76.2%). For hypotension treatment, ephedrine is preferred over phenylephrine by 124 (36.4%) versus 79 (23.2%) anesthesiologists. Supplemental oxygen is routinely administered to parturients receiving regional anesthesia by 176 (51.6%) respondents. The standard dose of oxytocin is 5IU, according to most answers (N.=160, 46.9%). CONCLUSION: Subarachnoid anesthesia is mostly favored among European anesthesiologists, while general anesthesia is reserved only for cases with anticipated hemorrhage. Fluid coloading and phenylephrine have gained popularity, in line with current knowledge. Conversely, cricoid pressure, standard supplemental oxygen and high oxytocin doses ­ though strongly questioned ­ are still advocated by most anaesthesiologists.

Impact of anaesthetic drugs and adjuvants on ECG markers of torsadogenicity.

Drug-induced prolongation of cardiac repolarization may trigger malignant ventricular arrhythmias, such as torsade de pointes. The duration of QT interval, QT corrected for heart rate (QTc), JT interval, QT dispersion (QTd), QT variability index, and transmular dispersion of repolarization (TDR) are ECG markers of torsadogenicity. All volatiles, especially isoflurane and desflurane, have been found to prolong QTc and QTcd, while sevoflurane has probably no effects on TDR. Among i.v. anaesthetics, propofol seems superior due to its minimal effects on QTc and TDR; moreover, a decrease in QTc and QTcd has been demonstrated in many studies. Regarding opioids, fentanyl, alfentanil, and remifentanil produce no effects on QTc, while sufentanil, at high doses, may induce QT prolongation. Succinylcholine, but not the non-depolarizing neuromuscular blockers, produces QTc prolongation which can be attenuated by opioids and ß-blockers. Reversal of neuromuscular block with anticholinesterase-anticholinergic combinations has been associated with significant QTc prolongation, while such an effect has not been demonstrated for sugammadex, even at high doses. Local anaesthetics have probably no intrinsic action on duration of repolarization; nevertheless, an extensive subarachnoid sympathetic block may increase the duration of QTc. On the contrary, thoracic epidural anaesthesia has been associated with a decrease in both QTc and TDR. Among adjuvants, midazolam seems to have no effect on QTc and TDR, while commonly used antiemetics, such as droperidol, domperidone, and most 5-HT3 antagonists, produce significant QT prolongation. The effects of anaesthetic drugs and techniques on electrocardiographic torsadogenic markers should be considered in the perioperative management of patients with preexisting repolarization abnormalities.

Maternal and umbilical cord oxygen content and acid-base balance in relation to general, epidural or subarachnoid anesthesia for term elective cesarean section.

PURPOSE: To compare maternal and neonatal oxygenation and acid-base status after elective cesarean section (CS) under different anesthetic techniques. MATERIALS AND METHODS: Three hundred and eighty parturients undergoing elective cesarean section were randomly assigned to receive general (GA, n =140), epidural (EA, n = 117) or subarachnoid anesthesia (SA, n =123). Blood gases, oxygen content, and acid-base status parameters were measured in maternal artery and umbilical cord vessels. Neonatal Apgar scores were also recorded. RESULTS: Umbilical artery pH, HCO3-, and actual base excess (ABE) were significantly higher in the GA compared to SA group (p < 0.001, p < 0.05, andp < 0.05, respectively). Umbilical vein ABE was lower in the SA compared to GA and EA groups (p < 0.05). Oxygen content in maternal artery was higher in the GA and EA groups compared to the SA group (p < 0.05). Neonatal oxygen content in both cord vessels was higher in the GA group compared to EA and SA groups (p < 0.05). Umbilical venous-arterial difference of PO2, oxygen content, and Apgar scores did not differ significantly among groups. CONCLUSION: Neonatal oxygenation and acid-base status values were better preserved when GA was administered for elective CS compared to regional modalities. Apgar scores and neonatal outcomes were not affected by the anesthetic technique.

The impact of spinal anaesthesia for caesarean delivery on coagulation assessed by thromboelastography.

BACKGROUND: Pregnancy and puerperium are associated with a hypercoagulable state. The aim of the study was to assess the impact of spinal anaesthesia on coagulation using thromboelastography in healthy term pregnant women undergoing elective caesarean delivery. METHODS: Thromboelastography was performed on 60 women undergoing elective caesarean delivery under spinal anaesthesia. As spinal anaesthesia has different effects on upper and lower extremity vasculature, venous blood samples were collected from both hand and foot, before and one hour after spinal injection. RESULTS: In the hand samples, R and K values decreased significantly from before to one hour after spinal injection (5.7±1.9 min versus 3.6±1.3 min, P<0.001 and 2.1±0.9 min versus 1.5±0.4 min, P<0.001, respectively). At the same times, significant increases in the alpha angle (58.6±9.1 degrees versus 65.6±7.5 degrees, P<0.001), MA (85.1±4.6 mm versus 87.0±3.8 mm, P<0.001) and CI (2.6±2.1 versus 4.9±1.5, P<0.001) were seen. No significant changes were found in thromboelastography parameters in samples collected from foot veins before and one hour after spinal injection, with the exception of the alpha angle (62.1±11.5 versus 66.5±8.8 degrees, P<0.012). CONCLUSION: In women undergoing caesarean delivery under spinal anaesthesia, enhanced coagulation thromboelastography parameters were observed in blood collected from hand veins. No changes were detected in the majority of parameters collected from the foot. Spinal anaesthesia has different effects on coagulation parameters in the hand and foot in pregnant women undergoing caesarean delivery.

Transcranial Doppler monitoring of middle cerebral flow velocity in a patient with a ventriculoperitoneal shunt undergoing laparoscopy.

Laparoscopic surgery is possibly associated with a risk of intracranial pressure (ICP) increase due to pneumoperitoneum in patients with ventriculoperitoneal shunts (VPS). Invasive techniques for shunt pressure monitoring are not routinely used because of the possible complications. Transcranial Doppler (TCD) is a non-invasive, safe method which gives accurate information about blood-flow velocities in basal cerebral arteries and indirectly about the ICP. Moreover it is inexpensive and simple in use. We report the use of TCD for middle cerebral flow velocity monitoring in a patient with a VPS who underwent laparoscopic surgery. In the case we present, during 60 min of pneumoperitoneum, TCD showed a sustained, but not clinically significant increase of the Pulsatility Index, with a recorded maximum change of 31 %. We consider that the use of TCD may increase the safety of laparoscopic procedures in patients with preexisting VPS.

Perioperative management of hereditary arrhythmogenic syndromes.

Patients with inherited cardiac channel disorders are at high risk of perioperative lethal arrhythmias. Preoperative control of symptoms and a multidisciplinary approach are required for a well-planned management. Good haemodynamic monitoring, adequate anaesthesia and analgesia, perioperative maintenance of normocarbia, normothermia, and normovolaemia are important. In congenital long QT syndrome, torsades de pointes should be prevented with magnesium sulphate infusion and avoidance of drugs such as droperidol, succinylcholine, ketamine, and ondansetron. Propofol and epidural anaesthesia represent safe choices, while caution is needed with volatile agents. In Brugada syndrome, ß-blockers, α-agonists, and cholinergic drugs should be avoided, while isoproterenol reverses the ECG changes. Propofol, thiopental, and volatiles have been used uneventfully. In congenital sick sinus syndrome, severe bradycardia resistant to atropine may require isoproterenol or epinephrine. Anaesthetics with vagolytic properties are preferable, while propofol and vecuronium should be given with caution due to risk of inducing bradyarrhythmias. Neuraxial anaesthesia should produce the least autonomic imbalance. Arrhythmogenic right ventricular dysplasia/cardiomyopathy induces ventricular tachyarrhythmias, which should be treated with ß-blockers. Generally, ß-adrenergic stimulation and catecholamine release should be avoided. Halothane and pancuronium are contraindicated, while large doses of local anaesthetics and epinephrine should be avoided in neuraxial blocks. In catecholaminergic polymorphic ventricular tachycardia, ß-blocker treatment should be continued perioperatively. Catecholamine release and ß-agonists, such as isoproterenol, should be avoided. Propofol and remifentanil are probably safe, while halothane and pancuronium are contraindicated. Regional anaesthesia, without epinephrine, is relatively safe. In suspicious cardiac deaths, postmortem examination and familial screening are recommended.

Perioperative management of a parturient with hyponatraemia due to carbamazepine therapy.

We describe the perioperative management of an epileptic parturient who developed hyponatraemia due to carbamazepine therapy. Caesarean delivery was performed under combined spinal-epidural anaesthesia with a good outcome for both mother and neonate. The diagnostic and therapeutic approach, anaesthetic implications and maternal and neonatal risks for a patient with hyponatraemia complicating carbamazepine therapy are discussed.

The effects of mild hypothermia on coagulation tests and haemodynamic variables in anaesthetized rabbits / Efectos de la hipotermia leve sobre las pruebas de coagulación y las variables hemodinámicas en conejos anestesiados

OBJECTIVE: Hypothermia has been associated with coagulation defects. The purpose of this experimental study was to investigate the effect of mild hypothermia on clinically used coagulation tests and on haemodynamic variables. METHODS: Νine New Zealand rabbits were subjected to mild core hypothermia by administration of general anaesthesia and exposure to room temperature of 22°C for 60 minutes. Blood samples were obtained at normothermia and mild hypothermia for measurement of prothrombin time, activated partial thromboplastin time, fibrinogen levels, platelet count and haemoglobin concentration. Hypothermic values were compared to the normothermic values. Additionally, the progressive temperature drop and haemodynamic changes (blood pressure, heart rate) were recorded. RESULTS: Core temperature decreased significantly over time changing from 39.4 ± 0.27 to 36.6 ± 0.28°C (p = 0.0001). Prothrombin time and activated partial thromboplastin time decreased at hypothermia, but the changes were not statistically significant (p = 0.203 and p = 0.109, respectively). Platelet count, fibrinogen levels and haemoglobin concentration decreased significantly (p = 0.0001, p = 0.03 and p = 0.027) but remained within normal limits. Mean arterial pressure and heart rate declined significantly over time (p = 0.0001 and p = 0.0001, respectively). CONCLUSION: The results of this study suggest that short term mild hypothermia may affect the coagulation mechanism to a clinically nonsignificant extent, while haemodynamic responses are significantly suppressed.

OBJETIVO: La hipotermia ha sido asociada con defectos de coagulación. El propósito de este estudio experimental fue investigar el efecto de la hipotermia leve sobre las pruebas de coagulación de uso clínico, así como sobre las variables hemodinámicas. MÉTODOS: Nueve conejos de Nueva Zelanda fueron sometidos a hipotermia central leve mediante la administración de anestesia general y exposición a una temperatura ambiente de 22°C durante 60 minutos. Se obtuvieron muestras de sangre en condiciones de normotermia e hipotermia leve para medir el tiempo de protrombina, el tiempo de tromboplastina parcial activada, los niveles de fibrinógeno, el conteo de plaquetas, y la concentración de hemoglobina. Se compararon los valores hipotérmicos con los valores normotérmicos. Además, se registraron la caída progresiva de la temperatura y los cambios hemodinámicos (presión sanguínea, frecuencia cardíaca). RESULTADOS: La temperatura corporal central disminuyó significativamente con el tiempo, cambiando de 39.4 ± 0.27 a 36.6 ± 0.28°C (p = 0.0001). El tiempo de protrombina y el tiempo de tromboplastina parcial activado disminuyeron en la hipotermia, pero los cambios no fueron estadísticamente significativos (p = 0.203 y p = 0.109, respectivamente). El conteo de plaquetas, los niveles de fibrinógeno y la concentración de la hemoglobina disminuyeron significativamente (p = 0.0001, p = 0.03 y p = 0.027) pero permanecieron dentro de los límites normales. La presión arterial promedio y la frecuencia cardíaca disminuyeron significativamente con el tiempo (p = 0.0001 y p = 0.0001, respectivamente). CONCLUSIÓN: Los resultados de este estudio sugieren que la hipotermia leve a corto plazo puede afectar el mecanismo de la coagulación hasta un punto clínicamente no significativo, mientras que respuestas hemodinámicas se suprimen significativamente.

The effects of mild hypothermia on coagulation tests and haemodynamic variables in anaesthetized rabbits.

OBJECTIVE: Hypothermia has been associated with coagulation defects. The purpose of this experimental study was to investigate the effect of mild hypothermia on clinically used coagulation tests and on haemodynamic variables. METHODS: Nine New Zealand rabbits were subjected to mild core hypothermia by administration of general anaesthesia and exposure to room temperature of 22 degrees C for 60 minutes. Blood samples were obtained at normothermia and mild hypothermia for measurement of prothrombin time, activated partial thromboplastin time, fibrinogen levels, platelet count and haemoglobin concentration. Hypothermic values were compared to the normothermic values. Additionally, the progressive temperature drop and haemodynamic changes (blood pressure, heart rate) were recorded. RESULTS: Core temperature decreased significantly over time changing from 39.4 +/- 0.27 to 36.6 +/- 0.28 degrees C (p = 0.0001). Prothrombin time and activated partial thromboplastin time increased [corrected] at hypothermia, but the changes were not statistically significant (p = 0.203 and p = 0.109, respectively). Platelet count, fibrinogen levels and haemoglobin concentration decreased significantly (p = 0.0001, p = 0.03 and p = 0.027) but remained within normal limits. Mean arterial pressure and heart rate declined significantly over time (p = 0.0001 and p = 0.0001, respectively). CONCLUSION: The results of this study suggest that short term mild hypothermia may affect the coagulation mechanism to a clinically nonsignificant extent, while haemodynamic responses are significantly suppressed.

Anaesthesia preference, neuraxial vs general, and outcome after caesarean section.

We investigated parturients' preference for neuraxial vs general anaesthesia, while they have experienced both techniques in the past. A total of 102 parturients who underwent elective caesarean section under general or neuraxial anaesthesia at different times completed a questionnaire comparing the two techniques. According to our results, 98% vs 51% (p < 0.001) of the women saw the baby and 51% vs 29% (p = 0.003) ambulated in the neuraxial and general anaesthesia groups, respectively, within the first 24 h postoperatively. Neuraxial anaesthesia was associated with less pain assessed by the Verbal Analogue Scale (VAS) (54 ± 21 vs 72 ± 20 p < 0.001), fewer days of hospital stay (4 ± 0.5 vs 5 ± 1.5, p = 0.001) and higher satisfaction scores (77 ± 18 vs 52 ± 24, p = 0.001) vs general anaesthesia. Finally, 80% of the women would choose neuraxial anaesthesia for a future caesarean section.

Compartment syndrome as a complication of the lithotomy position / El síndrome de compartimiento como complicación de la posición de litotomía

Compartment syndrome is a rare but serious complication of surgical procedures performed in the lithotomy position. Preventive measures include careful placement of the patient's legs and limited elevation. Early diagnosis is based on vigilance and close postoperative follow-up, especially after prolonged surgery. Finally, postoperative analgesia does not delay the diagnosis, if the patient's needs are assessed carefully.

El síndrome de compartimiento es una complicación rara pero seria de los procedimientos quirúrgicos realizados en posición de litotomía. Las medidas preventivas incluyen colocación cuidadosa de las piernas de la paciente y elevación limitada. El diagnóstico temprano se basa en la vigilancia y el seguimiento cercano post-operatorio, especialmente luego de una cirugía prolongada. Finalmente, la analgesia post-operatoria no demora el diagnóstico, si las necesidades de la paciente son evaluadas con cuidado.

Compartment syndrome as a complication of the lithotomy position.

Compartment syndrome is a rare but serious complication of surgical procedures performed in the lithotomy position. Preventive measures include careful placement of the patient's legs and limited elevation. Early diagnosis is based on vigilance and close postoperative follow-up, especially after prolonged surgery. Finally, postoperative analgesia does not delay the diagnosis, if the patient's needs are assessed carefully.

General versus neuraxial anaesthesia for caesarean section: impact on the duration of hospital stay.

We investigated retrospectively the duration of hospital stay of 1,619 women who received general (GA) (n = 582) or neuraxial anaesthesia (combined spinal-epidural [CSEA] (n = 614), epidural [EA] (n = 423)) for caesarean delivery over the years 2002-2005. Hospital stay was also analysed for the different obstetricians involved. Overall duration of hospital stay differed between 2002 and 2005 (p < 0.0001) but not between CSEA and EA (p = 0.460). Overall duration of hospital stay differed between neuraxial and GA group (p < 0.001). Duration of hospital stay of the GA group showed a progressive decrease between 2002 and 2005 (p = 0.002). Duration of hospital stay after neuraxial anaesthesia differed between 2002 and 2005 (p = 0.013) and among different surgeons (p < 0.001). Discharge rates from the hospital were shorter after neuraxial anaesthesia versus GA for the 3rd and 4th postoperative days (p < 0.001 and p < 0.001, respectively). Neuraxial anaesthesia for caesarean section seems to be associated with shorter duration of hospital stay than GA.

Melatonin premedication does not enhance induction of anaesthesia with sevoflurane as assessed by bispectral index monitoring.

INTRODUCTION: Exogenous melatonin has sedating and hypnotic actions. The present prospective double-blind randomised study investigated the effect of melatonin premedication on the induction of anaesthesia with sevoflurane. METHODS: 71 women of reproductive age, scheduled for a hysteroscopy, were randomised into the melatonin or the control group. 30 minutes before the induction of anaesthesia, patients in the melatonin and control groups sublingually received 9 mg of melatonin or placebo, respectively. In the operating room, patients were attached to a standard monitor and bispectral index (BIS) monitor. Anaesthesia was induced with 8 percent sevoflurane in oxygen via an anaesthetic system primed with 8 percent sevoflurane. BIS values were recorded every 30 seconds, during the first 300 seconds of sevoflurane administration. Inspired and expired sevoflurane concentrations, heart rate and oxygen saturation were also recorded at the same time intervals. Noninvasive blood pressure was recorded before and after the completion of measurements. RESULTS: BIS values (p-value is 0.725, F is 0.125, degrees of freedom [df] 1), inspired (p-value is 0.468, F is 0.535, df 1) and expired (p-value is 0.388, F is 0.756, df 1) sevoflurane concentrations, heart rate (p-values is 0.516, F is 0.427, df 1) and oxygen saturation (p-value is 0.401, F is 0.717, df 1), did not differ between the two groups, at any time point of measurement. Systolic blood pressure before (p-value is 0.131, t 1.530, df 67) and after measurement (p-value is 0.8288, t 0.218, df 54) as well as diastolic blood pressure before (p-value is 0.370, t 0.902, df 67) and after measurement (p-value is 0.764, t 0.302, df 54) did not differ between the two groups. CONCLUSION: Melatonin premedication under the present study design failed to enhance the induction of anaesthesia with sevoflurane.

A randomized study of maternal serum cytokine levels following cesarean section under general or neuraxial anesthesia.

BACKGROUND: Cytokines are significant mediators of the immune response to surgery and also play a role in parturition. The aim of the study was to investigate the impact of the anesthetic technique for cesarean section on plasma levels of cytokines IL-6 and TNF-alpha. METHODS: Thirty-five parturients scheduled for elective cesarean section were randomly assigned to general (n=18) or neuraxial (n=17) anesthesia. The general anesthesia group received thiopental 4 mg/kg, succinylcholine 1-1.5 mg/kg and 1% end-tidal concentration of sevoflurane in nitrous oxide and 50% oxygen. The neuraxial anesthesia group received intrathecal 0.5% levobupivacaine 1.8-2.2 mL and epidural fentanyl 1 microg/kg. Blood samples were taken for IL-6 and TNF-alpha immediately after positioning the parturient on the operating table, after uterine incision and before the umbilical cord clamping and 24h after surgery (T(1), T(2) and T(3) respectively). RESULTS: The two groups did not differ in IL-6 (P=0.15) or TNF-alpha (P=0.73) serum concentrations at any time point. In the general and neuraxial anesthesia groups, IL-6 serum concentrations were significantly higher in the third blood sample, T(3) (12.2+/-5.0 and 15.2+/-4.3 pg/mL), than in T(1) (0.41+/-0.38 and 0.29+/-0.10 pg/mL) and T(2) (0.37+/-0.47 and 0.24+/-0.05) respectively (P<0.001). Within each group, serum TNF-alpha concentrations did not differ significantly over time (P=0.44). CONCLUSIONS: Under the present study design anesthetic technique did not affect IL-6 or TNF-alpha concentrations in parturients undergoing elective cesarean section. Serum IL-6 levels increased 24 h postoperatively independently of anesthetic technique.

Acute postoperative pain predicts chronic pain and long-term analgesic requirements after breast surgery for cancer.

Postoperative pain and analgesic requirements may be associated with chronic pain. The aim of the study was to investigate this association. We studied 98 patients who had cancer breast surgery and served as controls in four previous studies, receiving placebo. We compared the pain and analgesic requirements 0-9 h and 1-6 days postoperatively: a) between patients with chronic pain 3 months postoperatively versus patients without and b) between those patients who consumed analgesics at home versus those who did not. Patients with chronic pain had experienced higher intensity pain at rest the first 9 postoperative hours (VAS-rest p = 0.033). Patients requiring analgesics at home had consumed postoperatively more opioids (p = 0.005) and more paracetamol (p = 0.037). These patients had experienced pain of higher intensity the first 9 postoperative hours (VAS-rest p = 0.022, VAS-movement p = 0.009) as well as during the six postoperative days (VAS-rest p = 0.013, VAS-movement p = 0.001). Higher intensities of acute postoperative pain are associated with chronic pain development. Higher analgesic needs and higher acute postoperatively pain intensity are associated with long-term analgesic consumption.

Local application of halothane, isoflurane or sevoflurane increases the response to an electrical stimulus in humans.

UNLABELLED: Volatile anesthetics may interfere with pain perception. This study investigates the effect of halothane, isoflurane and sevoflurane when applied locally, to the response of an electrical stimulus. METHODS: In this randomized control double-blind crossover study 70 volunteers were studied. In experiment 1 (30 subjects), equipotent liquid volumes of halothane 1 ml, isoflurane 1.5 ml and sevoflurane 2.7 ml were randomly applied on one forearm for 30 minutes. The other forearm received water. Both forearms were exposed to an electrical stimulus. The experiment was repeated the following day in a reverse fashion. In experiments 2 (20 subjects) and 3 (20 subjects) the response to the same stimulus was tested after local application of 2, 4, and 6 ml of halothane or 5 ml of sevoflurane respectively. RESULTS: Low doses of the three anesthetics were associated with an increased response to the electrical stimulus (F = 8.940, df = 1,174, P = 0.003). Higher doses of halothane and sevoflurane had no effect on the response (F = 2.358, df = 1,114, P = 0.127 and t = 0.840, df = 19, P = 0.411 respectively). CONCLUSIONS: Low liquid volumes of volatile anesthetics, when applied locally to the skin enhanced the response to an electrical stimulus but higher volumes had no effect.