Bloqueio combinado raquiperidural versus bloqueio peridural contínuo para analgesia de parto em primigestas: resultados maternos e perinatais

OBJETIVOS: comparar a evolução materna e perinatal após a utilização da analgesia peridural contínua versus analgesia combinada raqui-peridural em parturientes primigestas. MÉTODOS: foi realizado ensaio clínico aleatorizado com 128 gestantes primigestas em trabalho de parto, divididas em dois grupos: analgesia peridural (APC) com 65 mulheres e grupo analgesia combinada raqui-peridural (ACRP) com 63, admitidas no pré-parto de duas maternidades na cidade de Jundiaí - SP. Foram estudadas as variáveis: tempo de latência de instalação da analgesia, intensidade da dor e tempo total decorrido até a dilatação completa, índice de Apgar no primeiro e quinto minutos, tempo de resolução do parto, grau de bloqueio motor, efeitos adversos como náuseas, vômitos, prurido, hipotensão arterial, e grau de satisfação materna. Foram critérios de inclusão: primigestas, estado físico ASA 1 e 2, feto único, apresentação cefálica, de termo, dilatação cervical de 3 a 6 cm e solicitação de analgesia pelo obstetra. Foram excluídas mulheres com morbidades, ruptura de membranas, anormalidades fetais e uso de opioides até quatro horas antes. Para a análise estatística utilizou-se o teste de Mann-Whitney para as variáveis contínuas não paramétricas e os testes exato de Fisher e χ2 de Pearson, para variáveis categóricas. RESULTADOS: não houve diferença entre os grupos para velocidade de dilatação cervical, tempo para resolução do parto, parâmetros hemodinâmicos maternos, vitalidade do recém-nascido, complementações analgésicas durante o trabalho de parto e modo de parto. Houve maior rapidez de instalação da analgesia no grupo da ACRP e menor bloqueio motor no grupo de APC. Não foram observadas diferenças em relação aos efeitos adversos como náuseas, vômitos, prurido e hipotensão, sendo hipotensão mais frequente no grupo APC (16,9 versus 6,3%) e náusea no grupo ACRP (6,3 versus 3,1%). CONCLUSÕES: as duas técnicas mostraram-se seguras e eficientes, porém a ACRP ofereceu analgesia mais rápida, com alívio precoce da dor. O bloqueio motor menos intenso no grupo APC proporcionou movimentação mais ativa no leito e colaboração mais efetiva das gestantes durante o período expulsivo. A grande maioria das mulheres referiu satisfação com a analgesia recebida. As doses de anestésicos locais e opioides utilizadas em ambas as técnicas analgésicas e as doses complementares, iguais nos dois grupos, não produziram efeitos adversos maternos significativos ou alteraram a vitalidade dos recém-nascidos.

Anaesthesia and Pain Management for Use in Orthopaedic Day Surgery

Day surgery has gained a large popularity during the last decades. In Finland, 57% of the elective procedures, and 50% at Turku University Hospital, were already conducted on day basis during 2012. The steady growth of day surgery is mostly due to an increased safety in perioperative care and cost-effectiveness. The development of surgical techniques and anaesthetic methods has advanced the modern day surgery and extended the repertory of the procedures for use in day surgery operations. Day surgery also offers certain benefits like reduced risk for hospital-related infections, stress and confusion. Patient satisfaction, regarding several issues, is high. Most concerns and complaints are related to postoperative pain, nausea and vomiting pain and nausea. Pain can hamper recovery and pain management is a crucial factor for hospital discharge. Appropriate pain treatment is effective, safe, easy and economical. A procedure-specific approach and an individually planned, multimodal analgesia should be the basis of modern pain management. The main aim of this thesis was to evaluate the effectiveness and safety of anaesthetic technique and methods in pain treatment of orthopaedic day case surgery, and following conclusions were made. Unilateral spinal block was achieved using hyperbaric bupivacaine with a small dose of clonidine but clonidine prolonged the block. Continuous subacromial bupivacaine was found to be safe but conferring only moderate efficacy in pain care after shoulder arthroscopy. Transdermal fentanyl, 12 g/h, as part of multimodal analgesia, offered a safe and easy option to pain management in this patient group. However, after forefoot surgery, it did not reduce pain any further. In general, pain scores in all patient groups were low and the need for rescue opioid moderate.

Sucrose ingestion causes opioid analgesia

The intake of saccharin solutions for relatively long periods of time causes analgesia in rats, as measured in the hot-plate test, an experimental procedure involving supraspinal components. In order to investigate the effects of sweet substance intake on pain modulation using a different model, male albino Wistar rats weighing 180-200 g received either tap water or sucrose solutions (250 g/l) for 1 day or 14 days as their only source of liquid. Each rat consumed an average of 15.6 g sucrose/day. Their tail withdrawal latencies in the tail-flick test (probably a spinal reflex) were measured immediately before and after this treatment. An analgesia index was calculated from the withdrawal latencies before and after treatment. The indexes (mean ± SEM, N = 12) for the groups receiving tap water for 1 day or 14 days, and sucrose solution for 1 day or 14 days were 0.09 ± 0.04, 0.10 ± 0.05, 0.15 ± 0.08 and 0.49 ± 0.07, respectively. One-way ANOVA indicated a significant difference (F(3,47) = 9.521, P<0.001) and the Tukey multiple comparison test (P<0.05) showed that the analgesia index of the 14-day sucrose-treated animals differed from all other groups. Naloxone-treated rats (N = 7) receiving sucrose exhibited an analgesia index of 0.20 ± 0.10 while rats receiving only sucrose (N = 7) had an index of 0.68 ± 0.11 (t = 0.254, 10 degrees of freedom, P<0.03). This result indicates that the analgesic effect of sucrose depends on the time during which the solution is consumed and extends the analgesic effects of sweet substance intake, such as saccharin, to a model other than the hot-plate test, with similar results. Endogenous opioids may be involved in the central regulation of the sweet substance-produced analgesia.

The effects of positive end-expiratory pressure on respiratory system mechanics and hemodynamics in postoperative cardiac surgery patients

We prospectively evaluated the effects of positive end-expiratory pressure (PEEP) on the respiratory mechanical properties and hemodynamics of 10 postoperative adult cardiac patients undergoing mechanical ventilation while still anesthetized and paralyzed. The respiratory mechanics was evaluated by the inflation inspiratory occlusion method and hemodynamics by conventional methods. Each patient was randomized to a different level of PEEP (5, 10 and 15 cmH2O), while zero end-expiratory pressure (ZEEP) was established as control. PEEP of 15-min duration was applied at 20-min intervals. The frequency dependence of resistance and the viscoelastic properties and elastance of the respiratory system were evaluated together with hemodynamic and respiratory indexes. We observed a significant decrease in total airway resistance (13.12 ± 0.79 cmH2O l-1 s-1 at ZEEP, 11.94 ± 0.55 cmH2O l-1 s-1 (P<0.0197) at 5 cmH2O of PEEP, 11.42 ± 0.71 cmH2O l-1 s-1 (P<0.0255) at 10 cmH2O of PEEP, and 10.32 ± 0.57 cmH2O l-1 s-1 (P<0.0002) at 15 cmH2O of PEEP). The elastance (Ers; cmH2O/l) was not significantly modified by PEEP from zero (23.49 ± 1.21) to 5 cmH2O (21.89 ± 0.70). However, a significant decrease (P<0.0003) at 10 cmH2O PEEP (18.86 ± 1.13), as well as (P<0.0001) at 15 cmH2O (18.41 ± 0.82) was observed after PEEP application. Volume dependence of viscoelastic properties showed a slight but not significant tendency to increase with PEEP. The significant decreases in cardiac index (l min-1 m-2) due to PEEP increments (3.90 ± 0.22 at ZEEP, 3.43 ± 0.17 (P<0.0260) at 5 cmH2O of PEEP, 3.31 ± 0.22 (P<0.0260) at 10 cmH2O of PEEP, and 3.10 ± 0.22 (P<0.0113) at 15 cmH2O of PEEP) were compensated for by an increase in arterial oxygen content owing to shunt fraction reduction (%) from 22.26 ± 2.28 at ZEEP to 11.66 ± 1.24 at PEEP of 15 cmH2O (P<0.0007). We conclude that increments in PEEP resulted in a reduction of both airway resistance and respiratory elastance. These results could reflect improvement in respiratory mechanics. However, due to possible hemodynamic instability, PEEP should be carefully applied to postoperative cardiac patients.

Endogenous opiate analgesia induced by tonic immobility in guinea pigs

A function of the endogenous analgesic system is to prevent recuperative behaviors generated by tissue damage, thus preventing the emission of species-specific defensive behaviors. Activation of intrinsic nociception is fundamental for the maintenance of the behavioral strategy adopted. Tonic immobility (TI) is an inborn defensive behavior characterized by a temporary state of profound and reversible motor inhibition elicited by some forms of physical restraint. We studied the effect of TI behavior on nociception produced by the formalin and hot-plate tests in guinea pigs. The induction of TI produced a significant decrease in the number of flinches (18 ± 6 and 2 ± 1 in phases 1 and 2) and lickings (6 ± 2 and 1 ± 1 in phases 1 and 2) in the formalin test when compared with control (75 ± 13 and 22 ± 6 flinches in phases 1 and 2; 28 ± 7 and 17 ± 7 lickings in phases 1 and 2). In the hot-plate test our results also showed antinociceptive effects of TI, with an increase in the index of analgesia 30 and 45 min after the induction of TI (0.67 ± 0.1 and 0.53 ± 0.13, respectively) when compared with control (-0.10 ± 0.08 at 30 min and -0.09 ± 0.09 at 45 min). These effects were reversed by pretreatment with naloxone (1 mg/kg, ip), suggesting that the hypoalgesia observed after induction of TI behavior, as evaluated by the algesimetric formalin and hot-plate tests, is due to activation of endogenous analgesic mechanisms involving opioid synapses.

Presurgical ketoprofen, but not morphine, dipyrone, diclofenac or tenoxicam, preempts post-incisional mechanical allodynia in rats

The treatment of pain before it initiates may prevent the persistent pain-induced changes in the central nervous system that amplify pain long after the initial stimulus. The effects of pre- or postoperative intraperitoneal administration of morphine (2 to 8 mg/kg), dipyrone (40 and 80 mg/kg), diclofenac (2 to 8 mg/kg), ketoprofen (10 and 20 mg/kg), and tenoxicam (10 and 20 mg/kg) were studied in a rat model of post-incisional pain. Groups of 5 to 8 male Wistar rats (140-160 g) were used to test each drug dose. An incision was made on the plantar surface of a hind paw and the changes in the withdrawal threshold to mechanical stimulation were evaluated with Von Frey filaments at 1, 2, 6 and 24 h after the surgery. Tenoxicam was given 12 or 6 h preoperatively, whereas the remaining drugs were given 2 h or 30 min preoperatively. Postoperative drugs were all given 5 min after surgery. No drug abolished allodynia when injected before or after surgery, but thresholds were significantly higher than in control during up to 2 h following ketoprofen, 6 h following diclofenac, and 24 h following morphine, dipyrone or tenoxicam when drugs were injected postoperatively. Significant differences between pre- and postoperative treatments were obtained only with ketoprofen administered 30 min before surgery. Preoperative (2 h) intraplantar, but not intrathecal, ketoprofen reduced the post-incisional pain for up to 24 h after surgery. It is concluded that stimuli generated in the inflamed tissue, rather than changes in the central nervous system are relevant for the persistence of pain in the model of post-incisional pain.

Evaluation of piroxicam-β-cyclodextrin as a preemptive analgesic in functional endoscopic sinus surgery

The preemptive analgesic efficacy and adverse effects of preoperatively administered piroxicam-β-cyclodextrin for post-endoscopic sinus surgery pain was determined in a prospective, double-blind, randomized, clinical study. Seventy-five American Society of Anesthesiologists status I-II patients, aged 18-65 years, were divided into three groups with similar demographic characteristics: group 1 received 20 mg piroxicam-β-cyclodextrin, group 2 received 40 mg piroxicam-β-cyclodextrin and group 3 received placebo orally before induction of general anesthesia. A blinded observer recorded the incidence and severity of pain at admission to the post-anesthesia care unit (PACU), at 15, 30, and 45 min in the PACU, and 1, 2, 4, 6, and 24 h postoperatively. All patients received patient-controlled morphine analgesia during the postoperative period and consumption was recorded for 24 h. During the PACU period, mean visual analogue scale values were significantly lower in groups 1 and 2 compared to group 3 (P < 0.05). During the postoperative period, morphine consumption was 3.03 ± 2.54, 2.7 ± 2.8, and 5.56 ± 3.12 mg for each group, respectively (P < 0.05). As a side effect, bleeding was observed in groups 1 and 3, nausea and vomiting in all groups, and edema only in group 3. However, no significant differences were detected in any of the parameters analyzed, which also included epigastric pain, constipation/diarrhea and headache. Similar hematological test results were obtained for all groups. Preemptive administration of piroxicam-β-cyclodextrin effectively reduced analgesic consumption, and 40 mg of the drug was more effective than 20 mg piroxicam-β-cyclodextrin without side effects during the postoperative period.

Implications of extubation failure and prolonged mechanical ventilation in the postoperative period following elective intracranial surgery

Patients undergoing neurosurgery are predisposed to a variety of complications related to mechanical ventilation (MV). There is an increased incidence of extubation failure, pneumonia, and prolonged MV among such patients. The aim of the present study was to assess the influence of extubation failure and prolonged MV on the following variables: postoperative pulmonary complications (PPC), mortality, reoperation, tracheostomy, and duration of postoperative hospitalization following elective intra-cranial surgery. The study involved a prospective observational cohort of 317 patients submitted to elective intracranial surgery for tumors, aneurysms and arteriovenous malformation. Preoperative assessment was performed and patients were followed up for the determination of extubation failure and prolonged MV (>48 h) until discharge from the hospital or death. The occurrence of PPC, incidence of death, the need for reoperation and tracheostomy, and the length of hospitalization were assessed during the postoperative period. Twenty-six patients (8.2%) experienced extubation failure and 30 (9.5%) needed prolonged MV after surgery. Multivariate analysis showed that extubation failure was significant for the occurrence of death (OR = 8.05 [1.88; 34.36]), PPC (OR = 11.18 [2.27; 55.02]) and tracheostomy (OR = 7.8 [1.12; 55.07]). Prolonged MV was significant only for the occurrence of PPC (OR = 4.87 [1.3; 18.18]). Elective intracranial surgery patients who experienced extubation failure or required prolonged MV had a higher incidence of PPC, reoperation and tracheostomy and required a longer period of time in the ICU. Level of consciousness and extubation failure were associated with death and PPC. Patients who required prolonged MV had a higher incidence of extubation failure.

Percutaneous sciatic nerve block with tramadol induces analgesia and motor blockade in two animal pain models

Local anesthetic efficacy of tramadol has been reported following intradermal application. Our aim was to investigate the effect of perineural tramadol as the sole analgesic in two pain models. Male Wistar rats (280-380 g; N = 5/group) were used in these experiments. A neurostimulation-guided sciatic nerve block was performed and 2% lidocaine or tramadol (1.25 and 5 mg) was perineurally injected in two different animal pain models. In the flinching behavior test, the number of flinches was evaluated and in the plantar incision model, mechanical and heat thresholds were measured. Motor effects of lidocaine and tramadol were quantified and a motor block score elaborated. Tramadol, 1.25 mg, completely blocked the first and reduced the second phase of the flinching behavior test. In the plantar incision model, tramadol (1.25 mg) increased both paw withdrawal latency in response to radiant heat (8.3 ± 1.1, 12.7 ± 1.8, 8.4 ± 0.8, and 11.1 ± 3.3 s) and mechanical threshold in response to von Frey filaments (459 ± 82.8, 447.5 ± 91.7, 320.1 ± 120, 126.43 ± 92.8 mN) at 5, 15, 30, and 60 min, respectively. Sham block or contralateral sciatic nerve block did not differ from perineural saline injection throughout the study in either model. The effect of tramadol was not antagonized by intraperitoneal naloxone. High dose tramadol (5 mg) blocked motor function as well as 2% lidocaine. In conclusion, tramadol blocks nociception and motor function in vivo similar to local anesthetics.

Relationship between deep venous thrombosis and inflammatory cytokines in postoperative patients with malignant abdominal tumors

Deep venous thrombosis (DVT) is a common surgical complication in cancer patients and evidence that inflammation plays a role in the occurrence of DVT is increasing. We studied a population of cancer patients with abdominal malignancies with the aim of investigating whether the levels of circulating inflammatory cytokines were associated with postoperative DVT, and to determine the levels in DVT diagnoses. The serum levels of C-reactive protein (CRP), interleukins (IL)-6 and IL-10, nuclear transcription factor-κB (NF-κB) and E-selectin (E-Sel) were determined in 120 individuals, who were divided into 3 groups: healthy controls, patients with and patients without DVT after surgery for an abdominal malignancy. Data were analyzed by ANOVA, Dunnet's T3 test, chi-square test, and univariate and multivariate logistic regression as needed. The CRP, IL-6, NF-κB, and E-Sel levels in patients with DVT were significantly higher than those in the other groups (P<0.05). The IL-10 level was higher in patients with DVT than in controls but lower than in patients without DVT. Univariate analysis revealed that CRP, IL-6, NF-κB, and E-Sel were statistically associated with the risk of DVT (OR=1.98, P=0.002; OR=1.17, P=0.000; OR=1.03, P=0.042; and OR=1.38, P=0.003; respectively), whereas IL-10 had a protective effect (OR=0.94, P=0.011). Multivariate analysis showed that E-Sel was an independent risk factor (OR=1.41, P=0.000). Thus, this study indicated that an increased serum level of E-Sel was associated with increased DVT risk in postoperative patients with abdominal malignancy, indicating that E-Sel may be a useful predictor of diagnosis of DVT.

Dexamethasone and sodium carboxymethyl cellulose prevent postoperative intraperitoneal adhesions in rats

We aimed to evaluate the effects of the barrier agent sodium carboxymethyl cellulose (SCMC) with and without dexamethasone for the prevention of postoperative adhesion formation in a rat model of postoperative peritoneal adhesion. A total of 160 three-month old male and female Wistar rats underwent a laparotomy, and adhesions were induced by ileocecal abrasion. Rats were randomly assigned to 4 groups (n=40 each): group A, untreated; group B, treated with SCMC only; group C1, treated with SCMC + 3 mg dexamethasone, and group C2, treated with SCMC + 8 mg dexamethasone. After 12 days, adhesion formation and histopathological changes were compared. In groups A, B, C1, and C2, the mortality rates were 10, 5, 5, and 5%, respectively. In groups C1 and C2, the adhesions were filmy and easy to dissect and were milder compared with those in groups A and B. The total adhesion score in group C1 (3.38±0.49) was significantly lower than that of group B (6.01±0.57; P<0.01) or group A (8.01±0.67; P<0.05). There was no significant difference in adhesion formation between groups C1 and C2. Compared with groups A and B, groups C1 and C2 exhibited milder histopathological changes. SCMC in combination with dexamethasone can prevent adhesion formation and is a better barrier agent than SCMC alone. The safety and feasibility of SCMC in combination with dexamethasone to prevent adhesion formation after abdominal surgery warrants further clinical study.

Negative emotions affect postoperative scores for evaluating functional knee recovery and quality of life after total knee replacement

This study aimed to determine whether psychological factors affect health-related quality of life (HRQL) and recovery of knee function in total knee replacement (TKR) patients. A total of 119 TKR patients (male: 38; female: 81) completed the Beck Anxiety Inventory (BAI), Beck Depression Inventory (BDI), State Trait Anxiety Inventory (STAI), Eysenck Personality Questionnaire-revised (EPQR-S), Knee Society Score (KSS), and HRQL (SF-36). At 1 and 6 months after surgery, anxiety, depression, and KSS scores in TKR patients were significantly better compared with those preoperatively (P<0.05). SF-36 scores at the sixth month after surgery were significantly improved compared with preoperative scores (P<0.001). Preoperative Physical Component Summary Scale (PCS) and Mental Component Summary Scale (MCS) scores were negatively associated with extraversion (E score) (B=-0.986 and -0.967, respectively, both P<0.05). Postoperative PCS and State Anxiety Inventory (SAI) scores were negatively associated with neuroticism (N score; B=-0.137 and -0.991, respectively, both P<0.05). Postoperative MCS, SAI, Trait Anxiety Inventory (TAI), and BAI scores were also negatively associated with the N score (B=-0.367, -0.107, -0.281, and -0.851, respectively, all P<0.05). The KSS function score at the sixth month after surgery was negatively associated with TAI and N scores (B=-0.315 and -0.532, respectively, both P<0.05), but positively associated with the E score (B=0.215, P<0.05). The postoperative KSS joint score was positively associated with postoperative PCS (B=0.356, P<0.05). In conclusion, for TKR patients, the scores used for evaluating recovery of knee function and HRQL after 6 months are inversely associated with the presence of negative emotions.

Recherche sur les effets de l'analgésie périopératoire optimale (RAPO) sur la douleur et la fonction après chirurgie de la main

Essai cinique randomisé