Jyrson Guilherme Klamt

Dose-response study of intrathecal morphine versus intrathecal neostigmine, their combination, or placebo for postoperative analgesia in patients undergoing anterior and posterior vaginoplasty.

This study was designed to examine postoperative analgesia with intrathecal neostigmine in a randomized, blinded trial with morphine as the active control in patients undergoing anterior and posterior vaginoplasty.A secondary aim was to provide preliminary data on the interaction between these two drugs. The incidence of adverse effects was also assessed. Forty-eight patients were divided into eight groups (50 micro gram, 100 micro gram, and 200 micro gram morphine [M]; saline; 50 micro gram, 100 micro gram, and 200 micro gram neostigmine [N]; and 50 micro gram morphine + 50 micro gram neostigmine). Anesthesia was provided with a balanced technique. All patients stayed 24 h in the recovery room where adequacy of postoperative analgesia and side effects were assessed. Increasing doses of intrathecal morphine (50 micro gram, 100 micro gram, and 200 micro gram) and intrathecal neostigmine (50 micro gram, 100 micro gram, and 200 micro gram) showed a dose-dependent pattern of analgesia (P < 0.001). The M50 + N50 combination resulted in a better analgesic effect with fewer side effects than M50, N50, and control groups. These preliminary data suggest that spinal neostigmine produces analgesia for vaginoplasty surgery similar in duration to spinal morphine and that the combination of morphine and neostigmine may allow a reduction in the dose of each component for postoperative analgesia. (Anesth Analg 1996;82:1182-7)

Analgesic effect of subarachnoid neostigmine in two patients with cancer pain

&NA; Two patients suffering with severe pain due to metastatic abdominal neoplasm were selected to examine whether subarachnoid neostigmine provided effective pain relief. Neostigmine was injected through a catheter introduced into the subarachnoid space at L4–L5. Patients were monitored for changes in arterial blood pressure, cardiac and respiratory rates, body temperature, level of consciousness and neurologic change. Pain was classified by the patients on a verbal four‐grade scale, and analgesia was classified on a verbal three‐grade scale. Complete pain relief was obtained 2 h after neostigmine (0.2 mg) in one patient and 4 h after neostigmine (0.1 mg) in the second patient. Pain of mild intensity returned 20 and 22 h after drug administration, respectively. Gastrointestinal discomfort was observed in both cases, but nausea and vomiting occurred only in the patient treated with the highest dose of neostigmine. No significant change in the monitored parameters was observed, except for a 6‐h period of decreased blood pressure in the patient treated with the lower dose of neostigmine which required no specific treatment. The results obtained in these anecdotal cases indicate that subarachnoid neostigmine may provide analgesia in patients with pain arising from neoplasia, but further studies using controlled trials are needed before the drug is brought into clinical use.

Effects of intrathecal sufentanil on plasma oxytocin and cortisol concentrations in women during the first stage of labor.

Background and Objectives Intrathecal sufentanil provides analgesia comparable to epidural bupivacaine for the first stage of labor. Both epidural local anesthetics and intrathecal opioid reduce some parameters of the neuroendocrine response to labor pain and the reflex release of oxytocin in animals. In humans, epidural local anesthetics only reduce the spurt release of oxytocin. This study compared the effect of intrathecal sufentanil and epidural bupivacaine administration on the plasma concentration of oxytocin and cortisol in women with labor pain during the first stage of labor. Methods Thirty healthy parturients requesting analgesia were enrolled in this randomized and open-label study. Each patient was in spontaneous labor at greater than 5 cm cervical dilatation. Using a combined spinal and epidural technique, patients received either intrathecal sufentanil 10 μg (SUF = intrathecal sufentanil group) or epidural plain bupivacaine 0.25%, 12 mL (BUPIV = epidural bupivacaine group). Analgesia was assessed using a visual analog scale, and blood samples for oxytocin and cortisol plasma concentration measurements were collected immediately before analgesia and 15, 30, 60, and 90 minutes after induction of the analgesia. Plasma cortisol and oxytocin concentrations were determined by specific radioimmunoassay. The values were expressed as mean ± SEM. Results Intrathecal sufentanil provided faster and more complete analgesia within 15 and 30 minutes of its administration, compared with epidural bupivacaine. Plasma oxytocin concentrations were similar in the 2 groups before analgesia (7.24 ± 2.1 and 6.6 ± 3.1 pg/mL SUF and BUPIV, respectively). It decreased significantly in the SUF and increased in the BUPIV after analgesic administration. Cortisol concentrations were elevated in both groups before analgesia (51.6 ± 5.3 and 54.2 ± 4.8 μg/dL SUF and BUPIV, respectively). Both analgesic treatments significantly decreased the plasma cortisol levels. Conclusions Intrathecal sufentanil analgesia decreases plasma concentrations of oxytocin and cortisol in women with labor pain during the first stage of labor, but epidural bupivacaine only reduced the cortisol concentration.

Effects of Dexmedetomidine-Fentanyl Infusion on Blood Pressure and Heart Rate during Cardiac Surgery in Children

Background. The purpose of this study was to access the effects of dexmedetomidine-fentanyl infusion on blood pressure (BP) and heart rate (HR) before surgical stimulation, on their changes to skin incision, and on isoflurane requirement during cardiac surgery in children. Methods. This study had a prospective, randomized, and open-label design. Thirty-two children aged 1 month to 10 years undergoing surgery for repair congenital heart disease (CHD) with CPB were randomly allocated into two groups: group MDZ received midazolam 0.2 mg·kg−1·h−1 and group DEX received dexmedetomidine 1 μg·kg−1·h−1 during the first hour followed by half of these rates of infusions thereafter. Both group received fentanyl 10 μg·kg−1, midazolam 0.2 mg·kg−1 and vecuronium 0.2 mg·kg−1 for induction. These same doses of fentanyl and vecuronium were infused during the first hour then reduced to half. The infusions started after induction and maintained until the end of surgery. Isoflurane was given briefly to control hyperdynamic response to skin incision and sternotomy. Results. In both groups, systolic blood pressure (sBP) and heart rate (HR) decreased significantly after one hour of infusion of the anesthetic solutions, but there were significantly less increase in diastolic blood pressure, sBP, and HR, and less patients required isoflurane supplementation to skin incision in the patients of the DEX group. Discussion. Dexmedetomidine infusion without a bolus appears to be an effective adjunct to fentanyl anesthesia in control of hemodynamic responses to surgery for repair of CHD in children.

Labor analgesia in a patient with paroxysmal nocturnal hemoglobinuria with thrombocytopenia

Background and Objectives Paroxysmal nocturnal hemoglobinuria (PNH) is a form of acquired hemolytic anemia in which a defect of glycophosphoinositol anchor proteins in the cell membrane of bone marrow stem cells leads to activation of the complement system and consequent destruction of defective cells. The characteristics of this disease are an increased frequency of thrombotic events, anemia, and thrombocytopenia. Methods We report a case of a pregnant patient with PNH with thrombocytopenia who delivered vaginally after receiving epidural labor analgesia. Prophylaxis of thromboembolism was performed with heparin 1 hour after the removal of the epidural catheter, and repeated at 12-hour intervals. Sensory changes or motor changes and pain were monitored every 10 minutes for 8 hours after delivery. Results During analgesia, the patient reported complete pain relief. Delivery and the immediate postpartum period were without any untoward events. Conclusions Four major factors influenced the anesthetic conduct used for the present patient: (1) the risk of an acute hemolytic crisis, (2) the need to perform prophylaxis for thromboembolism, (3) the need to reduce labor stress, and (4) minimizing the risk of missing an epidural hematoma. We also present a survey of the literature about PNH and discuss the anesthetic conduct in this patient.

Uso do azul de metileno no tratamento de choque anafilático durante anestesia: relato de caso

BACKGROUND AND OBJECTIVES The risk of perioperative anaphylaxis should always be considered. The incidence of anesthetic allergic reactions is controversial, varying from 1/3,000 to 1/20,000, with mortality range between 3 and 9%. This report describes the use of methylene blue as coadjuvant drug to treat anaphylaxis refractory to conventional therapy. CASE REPORT A 53-year-old male patient was submitted to inguinal hernia correction under spinal anesthesia. After receiving 1.5 g intravenous dipirone at surgery completion, he immediately developed bronchospasm, cyanosis, decreased SpO2 and SBP, culminating with cardiac arrest. Resuscitation was started with external cardiac massage followed by tracheal intubation, as well as 1 mg epinephrine and 1 mg atropine injections. Heart rate returned (150 bpm) with no palpable pulse though. Additional 1 mg epinephrine and 1 g hydrocortisone were administered with central pulse recovery (8 minutes). Although receiving dopamine (20 microg.kg-1.min-1), patient remained hypotensive (60 mmHg) until 80 minutes. Intravenous 100 mg methylene blue was then administered with increased SBP to 85 and 105 mmHg after the second dose. Dopamine dose was tapered from 10 to 7, 5 and finally 2 microg.kg-1.min-1. CONCLUSIONS Histamine is the major anaphylaxis mediator. Inducing nitric oxide (NO) production, it consequently increases guanylate cyclase, which promotes arteriolar vasodilation by increasing cyclic GMP. Methylene blue may be helpful in such situations because it inhibits guanylate cyclase and consequently vasodilation, resulting in hemodynamic improvement.

High-dose aprotinin does not affect troponin I, N-Terminal pro-B-type natriuretic peptid and renal function in children submitted to surgical correction with extracorporeal circulation

OBJECTIVE To evaluate if the use of hemostatic high-dose aprotinin seems influence to myocardial, renal and metabolic functions in children submitted to surgical correction with extracorporeal circulation (ECC). Material and Methods A prospective randomized study was conducted on children aged 30 days to 4 years submitted to correction of acyanogenic congenital heart disease with ECC and divided into two groups: Control (n=9) and Aprotinin (n=10). In the Aprotinin Group the drug was administered before and during ECC and the myocardial and multiorgan dysfunctions were analyzed on the basis of clinical and biochemical markers. Differences were considered to be significant when P<0.05. RESULTS The groups were similar regarding demographic and intraoperative variables, except for a greater hemodilution in the Aprotinin Group. The drug had no benefit regarding time of mechanical pulmonary ventilation, permanence in the pediatric postoperative intensive care unit (ICU) and length of hospitalization, or regarding the use of inotropic drugs and renal function. The partial arterial oxygen pressure/inspired oxygen fraction ratio (PaO2/FiO2) was significantly reduced 24h after surgery in the Control Group. Blood loss was similar for both groups. Cardiac troponin I (cTnI), creatine kinase MB fraction (CKMB), serum glutamic-oxaloacetic transaminase (SGOT) and the aminoterminal fraction of natriuretic peptide type B (NT-proBNP) did not differ significantly between groups. Post-ECC blood lactate concentration and metabolic acidosis was more intense in the Aprotinin Group. There were no complications with the use of aprotinin. CONCLUSION High-dose aprotinin did not significant influence in serum markers troponin I, NT-proBNP and renal function, but did associated with hemodilution, blood lactate concentration and metabolic acidosis more intense.

Hemodynamic Effects of the Combination of Dexmedetomidine-Fentanyl versus Midazolam-Fentanyl in Children Undergoing Cardiac Surgery with Cardiopulmonary Bypass

BACKGROUND AND OBJECTIVES To evaluate the efficacy of the combined infusion of dexmedetomidine and fentanyl on the hemodynamic response during cardiac surgery with cardiopulmonary bypass (CPB) in children. METHODS Thirty-two children, ages 1 month to 10 years, scheduled for cardiac surgery with cardiopulmonary bypass were randomly divided in two groups: the MDZ Group received midazolam 0.2 mg.kg(-1).h(-1), while the DEX group received dexmedetomidine 1 microg.kg(-1).h(-1) during one hour followed be a reduction by half in the rate of infusion in both groups. Both groups received fentanyl 10 microg.kg(-1), midazolam 0.2 mg.h(-1), and vecuronium 0.2 mg.kg(-1) for anesthesia induction. The same doses of fentanyl and vecuronium used during induction were infused during the first hour after induction, followed by a reduction to half. Infusions were initiated immediately after induction and maintained until the end of the surgery. Isoflurane was administered for a short time to control the hyperdynamic response to incision and sternotomy. RESULTS In both groups, systolic blood pressure and heart rate reduced significantly after one hour of anesthetic infusion, but the increase in systolic and diastolic pressure and heart rate to skin incision were significantly lower in the DEX Group. A significantly lower number of patients demanded supplementation with isoflurane in the DEX Group. After CPB, patients in both groups had similar hemodynamic responses. CONCLUSIONS Infusion of dexmedetomidine without bolus seems to be an effective adjuvant to fentanyl on the promotion of sedation and control of hemodynamic responses during surgery for congenital cardiopathies in children.

Assessment of aprotinin in the reduction of inflammatory systemic response in children undergoing surgery with cardiopulmonary bypass

OBJECTIVE To evaluate if the hemostatic high-dose aprotinin seems to reduce the inflammatory process after extracorporeal circulation (ECC) in children. METHODS A prospective randomized study was conducted on children aged 30 days to 4 years submitted to correction of acyanogenic congenital heart disease with ECC and divided into two groups: Control (n=9) and Aprotinin (n=10). In the Aprotinin Group the drug was administered before and during ECC and the systemic inflammatory response and hemostatic and multiorgan dysfunctions were analyzed on the basis of clinical and biochemical markers. Differences were considered to be significant when P<0.05. RESULTS The groups were similar regarding demographic and intraoperative variables, except for a greater hemodilution in the Aprotinin Group. The drug had no benefit regarding time of mechanical pulmonary ventilation, permanence in the postoperative ICU and length of CONCLUSION In this series, hemostatic high-dose aprotinin did not minimize the clinical manifestations or serum markers of the inflammatory systemic response.

Anesthesia for cesarean section in a patient with familiar hypertrophic cardiomyopathy: case report

BACKGROUND AND OBJECTIVES Familiar Hypertrophic cardiomyopathy (FHC) is a rare hereditary cardiac disorder characterized by hypertrophy of the ventricular septum and variable degrees of subvalvular aortic stenosis. In this disease, the increase in myocardial contractility and reduction in peripheral vascular resistance can aggravate left ventricular outlet obstruction, leading to arrhythmias and cardiac ischemia. The objective of this report was to discuss the anesthetic management of cesarean section in a patient with FHC. CASE REPORT A patient in the 33rd week of pregnancy and prior diagnosis of FHC presented, on the 24-hour Holter monitor, 22 episodes of non-sustained ventricular tachycardia (NSVT) and 2 episodes of sustained ventricular tachycardia (SVT). She complained of episodes of palpitation, dyspnea, and chest pain of short duration. The patient was medicated with atenolol, with control of symptoms and cardiac arrhythmias. Within 38 weeks and 5 days of gestation, the patient underwent elective cesarean section. Besides the usual monitoring, analysis of the ST segment and invasive blood pressure were also instituted. Anesthesia consisted of combined spinal-epidural technique with subarachnoidal administration of 5 microg of sufentanil followed by the administration of increasing doses of 0.375% bupivacaine until it reached the level of T6 (total of 16 mL). Metaraminol was used as a vasopressor. Perioperative maternal hypotension or other complications were not observed. CONCLUSIONS General anesthesia is often used for cesarean sections in patients with FHC. Spinal-epidural anesthesia with slow installation of the blockade was a safe alternative. In those patients, one should avoid an increase in myocardial contractility and, if necessary, a a-agonist should be used to treat maternal hypotension.