Hyeon Jeong Yang

Effect of preoperative warming during cesarean section under spinal anesthesia

Background Postoperative hypothermia and shivering is a frequent event in patients during cesarean section under spinal anesthesia. We assessed the effect of preoperative warming during cesarean delivery under spinal anesthesia for prevention of hypothermia and shivering. Methods Forty five patients undergoing elective cesarean section were randomly assigned to three groups. Group F received warmed intravenous fluid (40℃). Group A patients were actively warmed by forced air-warming. Group C was the control group. Forced air-warming and warmed fluid was maintained for the 15 min preceding spinal anesthesia. Core temperature (tympanic membrane) and the skin temperature of arm and thigh were measured and shivering was graded simultaneously. Results The core temperature at 45 min decreased less in Groups F and A than Group C (-0.5℃ ± 0.3℃ vs -0.6℃ ± 0.4℃ vs -0.9℃ ± 0.4℃, respectively; P = 0.004). The arm temperature at 15 min and 30 min exhibited a greater increase in Group A than Group F and Group C (P = 0.001 and P = 0.012, respectively). Leg temperature increased similarly among the three groups. The incidence of shivering was significantly less in Group A and Group F than Group C (20%, 13.3%, and 53.3%, respectively; P = 0.035). Conclusions Preoperative forced air-warming and warmed fluid prevents hypothermia and shivering in patients undergoing elective cesarean delivery with spinal anesthesia.

Comparison of fentanyl and sufentanil added to 0.5% hyperbaric bupivacaine for spinal anesthesia in patients undergoing cesarean section.

Background Subarachnoid block is widely used for cesarean section due to the rapid induction, the complete analgesia, the low failure rate and the prevention of aspiration pneumonia. The addition of intrathecal opioids to local anesthetics seems to improve the quality of analgesia & prolong the duration of analgesia. Therefore we compared the effects of fentanyl 20 µg and sufentanil 2.5 µg, which were added to intrathecal hyperbaric bupivacaine. Methods Seventy two healthy term parturients were randomly divided into three groups: Group C (control), Group F (fentanyl 20 µg) and Group S (sufentanil 2.5 µg). In every group, 0.5% heavy bupivacaine was added according to the adjusted dose regimen by Harten et al. We observed the maximal level of the sensory block and motor block, the quality of intraoperative analgesia, the duration of effective analgesia and the side effects. Results There were significant differences between the control and the fentanyl 20 µg and sufentanil 2.5 µg groups for the degree of muscle relaxation, the quality of intraoperative analgesia, the maximal sedation level and the duration of effective analgesia. The frequencies of side effects such as nausea and pruritis in the opioid groups were higher than those in the control group. But there were no differences between fentanyl 20 µg and sufentanil 2.5 µg for the frequencies of nausea and pruritis. Conclusions The addition of fentanyl 20 µg or sufentanil 2.5 µg for spinal anesthesia provides adequate intraoperative analgesia without significant adverse effects on the mother and neonate.

Bupivacaine and ropivacaine suppress glycine- and glutamate-induced ion currents in acutely dissociated rat hippocampal neurons.

Bupivacaine and ropivacaine are local surgical anesthetics with great efficacy in post-operative pain relief and labor analgesia. In the present study, the effects of bupivacaine and ropivacaine on ion currents induced by glycine and glutamate in acutely dissociated hippocampal CA1 neurons of rats were investigated via a nystatin-perforated patch clamping method at a clamped voltage. The magnitude of the glycine-induced ion currents was decreased reversibly and in a time-dependent manner by continuous application of 0.1 mg/ml of either bupivacaine or ropivacaine. The magnitude of the glutamate-induced ion currents was also suppressed time-dependently by continuous application of either bupivacaine or ropivacaine. The inhibitory action of bupivacaine and ropivacaine on currents induced by glycine and glutamate could be one of the mechanisms behind the actions of these anesthetics.

Amniotic fluid embolism that took place during an emergent Cesarean section -A case report-

Amniotic fluid embolism (AFE) is a rare but fatal obstetric emergency, characterized by sudden cardiovascular collapse, dyspnea or respiratory arrest and altered mentality, disseminated intravascular coagulation (DIC). It can lead to severe maternal morbidity and mortality, but the prediction of its occurrence and treatment are very difficult. We experienced a case of AFE during emergent Cesarean section in a 40+6 weeks healthy pregnant woman, age 33. Sudden dyspnea, hypotension, signs of pulmonary edema and DIC were developed during Cesarean section, and cardiac arrest followed after these events. The course of these events was so rapid and catastrophic, which was consistent with AFE. Thus, we report this case precisely and review pathophysiology, diagnosis, treatment of AFE by referring to up-to-date literatures.

The effect of remifentanil for reducing myoclonus during induction of anesthesia with etomidate

BACKGROUND Myoclonic movement is a common problem during induction of anesthesia with etomidate. We investigated the influences of pretreatment with remifentanil on etomidate induced myoclonus. METHODS Ninety ASA class I patients were divided randomly into three groups. Group NS received normal saline 2 ml as placebo (n = 30), group R0.5 and group R1.0 were pretreated with remifentanil 0.5 microgram/kg (n = 30) or 1.0 microgram/kg (n = 30) 1 minute before induction with etomidate 0.3 mg/kg. Orotracheal intubation was performed after administration of rocuronium 0.5 mg/kg. We assessed the incidence, onset, duration and intensity of myoclonus. Mean arterial pressure (MAP), heart rate (HR) and bispectral index (BIS) were recorded during induction. RESULTS Twenty five patients developed myoclonus in group NS (83.3%), 3 patients in group R0.5 developed myoclonus (10%), as did 5 patients in group R1.0 (16.7%). Moderate to severe myoclonus of grade 3 and 4 were found 66.7% of patients in group NS, whereas no patients in both remifentanil pretreated groups developed this grade of myoclonus. The duration of myoclonus was reduced significantly in the remifentanil groups: 93.8 +/- 59.5 sec in group NS, 49.3 +/- 34.9 sec in group R0.5, 36.0 +/- 27.0 sec in group R1.0 (P < 0.05). HR was decreased by pretreatment with remifentanil prior to induction, while MAP and HR were decreased after induction with etomidate (P < 0.05). BIS changes were not different among the three groups. The dose dependent differences between the two remifentanil doses were not noticed. CONCLUSIONS Pretreatment with remifentanil significantly reduced the incidence, duration and intensity of etomidate induced myoclonus.

Meralgia paresthetica affecting parturient women who underwent cesarean section -A case report-

Meralgia paresthetica is commonly caused by a focal entrapment of lateral femoral cuteneous nerve while it passes the inguinal ligament. Common symptoms are paresthesias and numbness of the upper lateral thigh area. Pregnancy, tight cloths, obesity, position of surgery and the tumor in the retroperitoneal space could be causes of meralgia paresthetica. A 29-year-old female patient underwent an emergency cesarean section under spinal anesthesia without any problems. But two days after surgery, the patient complained numbness and paresthesia in anterolateral thigh area. Various neurological examinations and L-spine MRI images were all normal, but the symptoms persisted for a few days. Then, electromyogram and nerve conduction velocity test of the trunk and both legs were performed. Test results showed left lateral cutaneous nerve injury and meralgia paresthetica was diagnosed. Conservative treatment was implemented and the patient was free of symptoms after 1 month follow-up.

Inadequate spinal anesthesia in a parturient with Marfan's syndrome due to dural ectasia

Marfan syndrome (MFS) is a rare hereditary connective tissue disorder that affects the cardiovascular, musculoskeletal, and ocular systems. Pregnancy further increases the potential for cardiovascular risks due to increases in blood volume, heart rate and stroke volume. The choice of anesthetic technique is very important in patients with MFS. Dural ectasia (DE) in MFS patients may result in failure of spinal anesthesia. We reported a patient without typical symptoms related to DE who experienced spinal anesthesia failure. A-29-year-old female (weight, 58 kg; height, 161 cm) with known MFS was admitted for cesarean delivery at 37 + 6 weeks of gestational age. She had valve sparing aortic root replacement surgery due to aortic root aneurysm and was diagnosed with MFS 6 years ago. Preoperative echocardiography revealed a left ventricular ejection fraction of 68% with moderate aortic regurgitation (G2-3), trivial tricuspid regurgitation and intact aortic root graft. Aortic regurgitation had increased since the previous study conducted 6 months earlier. The patient was medicated with atenolol during pregnancy. Elective cesarean section was scheduled and routine monitoring devices were applied in the operating room. The left radial artery was cannulated for continuous monitoring of arterial pressure. The initial blood pressure was 140/73 mmHg, heart rate was 74 beats /min, and peripheral oxygen saturation was 100% at room air. Combined spinal-epidural (CSE) anesthesia was administered. The epidural space was found using a loss of resistance technique at the first attempt. Clear cerebrospinal fluid (CSF) was obtained on spinal needle insertion. There was no paresthesia. Eight mg of 0.5% hyperbaric bupivacaine and 10 ug of fentanyl was injected intrathecally. An epidural catheter was inserted without resistance and advanced 5 cm upward. The levels of sensory block were tested by alcohol swabs and pinprick tests. Ten minutes following the intrathecal injection, the patient had only limited lower limb analgesia. The epidural injection was titrated over the next 20 min, and 8 ml of 2% lidocaine and 8 ml of 0.75% ropivacaine were required to achieve T4 sensory block. The remainder of the procedure was uneventful. Ephedrine 4 mg IV was administered twice to maintain systolic blood pressure above 100 mm Hg and the patient was sedated with midazolam after delivery. The patients postoperative vital signs were stable with a blood pressure of 111/54 mmHg, a heart rate of 68 beats/min, and an oxygen saturation of 98%. The postoperative pain was managed with patient-controlled epidural analgesia. She had an uneventful postoperative course and was discharged 4 days later. DE is defined as 1) an enlarged neural canal along the spinal column, usually in the lower lumbar and sacral regions; 2) a thinning of the cortex of the pedicles and lamina of the vertebra; 3) a widening of the neural foramina; or 4) an anterior meningocele [1]. A more recent definition of DE is a widening of the dural sac or spinal nerve root sleeves. The most common clinical symptoms include low backpain, headache, weakness, and loss of sensation above and below the affected limb, bowel and bladder dysfunction, occasional rectal pain and pain in the genital area [2]. The incidence of DE in MFS patients reportedly ranges from 63% to 92% [3]. The associated increase in CSF volume due to DE, and the erratic spread of spinal anesthetic is thought to increase rate of spinal anesthesia failure in the MFS parturient [2]. A thorough reevaluation of patient DE symptoms was done before anesthesia. Our patient had no common clinical symptoms of DE, hence we expected success in spinal anesthesia. CSE anesthesia was performed in order to provide postoperative pain control, as well as epidural anesthesia in case of spinal anesthesia failure. Contrary to our expectations, spinal anesthesia failed to produce a block adequate for surgical procedure. Foran et al. [4] characterized DE in MFS patients and reported that such patients are usually asymptomatic. The severity of DE can only be radiologically evaluated by computed tomography or MRI, by assessing dural sac diameter, nerve root sleeve diameter, and lumbar pedicle width [3]. Despite lack of symptoms associated with DE the presence of DE could not be ruled out. The prevalence of DE is high among MFS patients, hence probable DE in the study patient resulted in failure of spinal anesthesia [3]. Baghirzada et al. [5] reported 2 cases of regional anesthesia in parturients with MFS with conflicting spinal anesthesia results. The success of spinal anesthesia differed based on the severity of the DE. Unless a patient undergoes radiologic examination for the presence and severity of DE before surgery, it is not possible to predict the success of spinal anesthesia in MFS patients. Epidural anesthesia provides a gradual titration of local anesthetics that ensures adequate post-operative pain control while minimizing potential hypotension caused by local anestheticinduced sympathectomy. Epidural anesthesia provides more stable hemodynamics in MFS patients with cardiovascular complications. We recommend the CSE technique or epidural anesthesia for MFS patients regardless of the presence of DE related symptoms, due to its high incidence among MFS patients and often asymptomatic occurrence.

Anesthetic management for emergent Cesarean section in a patient with toxic epidermal necrolysis -A case report-

Toxic epidermal necrolysis (TEN) is rare but serious cutaneous reaction with significant mortality and long-term morbidity. Various etiologies, particularly numerous medications and infectious agents have been implicated. It is characterized as inflammatory bullous lesions of the skin and mucous membrane and can develop serious complications such as pneumonia, pneumothorax, sepsis and renal failure. In general, patients with TEN are managed as severe second-degree burn patients with preventing excessive fluid deficit and infections. In this case, we aimed to present anesthetic management of a 26-year-old pregnant woman with TEN who received general anesthesia during emergent cesarean section.

The relationship between symphysis-fundal height and intravenous ephedrine dose in spinal anesthesia for elective cesarean section.

Background A decreased lumbosacral subarachnoidal space volume is a major factor in the cephalad intrathecal spread of local anesthetics in term parturients and their subarachnoidal space is decreased due to the compressive effect of huge uteri. Therefore, they show a higher level of sensory block and hypotensive episodes. The purpose of this study is to investigate whether the symphysis-fundal height (SFH) correlates with the highest sensory level and the amount of ephedrine administered under spinal anesthesia. Methods Fifty-two uncomplicated parturients who consented to spinal anesthesia for elective cesarean section were studied. The SFH of all parturients had been measured just before the spinal anesthesia administered by one person. Hyperbaric bupivacaine with fentanyl 20 µg, was administered for spinal anesthesia. The amount of 0.5% bupivacaine was adjusted according to the patients height and weight. The level of sensory block and the amounts of ephedrine to treat hypotension, nausea and vomiting were assessed. Linear regression and correlation analysis were applied to analyze the data. Results According to the results of correlation analysis, there was no significant correlation between the level of sensory block and SFH. There were statistically significant positive correlations between the amount of ephedrine administered due to hypotension and SFH. Conclusions In term parturients choosing elective cesarean section, the SFH is not correlated with the sensory level of spinal anesthesia, but is correlated with the amount of ephedrine administered during spinal anesthesia.

Anesthetic management for cesarean section in a patient with Budd-Chiari syndrome - A case report -

Budd-Chiari syndrome (BCS) represents a spectrum of disease states resulting in hepatic venous outflow occlusion. Prothrombotic disorders, such as protein S deficiency may cause thrombosis of the portal and hepatic veins. We report the management of a 30-year-old BCS primigravida with protein S deficiency and destroyed lung by the pulmonary tuberculosis scheduled for Cesarean section. Moreover, patients lungs were destroyed by the pulmonary tuberculosis. Spinal anesthesia was selected for the anesthetic management. The patient recovered without any complication and discharged from hospital on the fifth postoperative day.