Enhanced microbial safety of channel catfish (Ictalurus punctatus) fillet using recently invented medium molecular weight water-soluble chitosan coating.

Chitosan with higher molecular weight exhibited higher antimicrobial efficacy against foodborne pathogens. However, the poor water solubility of higher or medium molecular weight chitosan limits its applications. To overcome the challenge, our research team searched for simple preparation procedure for fast-dissolving medium molecular weight chitosan in water. Throughout the process, we were able to obtain a higher concentration of medium molecular weight water-soluble (MMWWS) chitosan (400 kDa). The MMWWS chitosan showed physicochemical properties that are suitable for edible coating. Antibacterial activities of 400-kDa chitosan coating prepared in acetic acid (1% v/v) or aspartic acid (1% or 3% w/v) were examined. The surface of catfish cubes was inoculated with six foodborne pathogens and then coated with chitosan solutions. The survival of each pathogen was evaluated during shelf life storage. Compared with the control, 3% w/v chitosan coating in aspartic acid solution exhibited the most effective antibacterial activities among other coating treatments, completely inhibiting Vibrio parahaemolyticus on the surface of catfish. The study suggested that chitosan dissolved in aspartic acid has the potential for use as an alternative antimicrobial coating for catfish fillet.

Effects of bilateral breast reduction on peak airway pressure and pulmonary function tests.

PURPOSE: Surgical reduction due to breast size is not carried out merely for anesthetic concerns but also for such complaints as breast pain belonging to breast and skeletal system, back pain, neck pain, and intertriginous rashes. This study aims to investigate the effect of bilateral breast reduction surgery on maximum inspiratory pressure (Ppeak) and pulmonary functions. This study aims to investigate the effect of bilateral breast reduction surgery on pulmonary function test. METHODS: The study included 50 patients who would undergo bilateral breast reduction. Patients were divided into two groups: group II were given positive end-expiratory pressure (PEEP), which was not administered to the group I. Patients were checked in terms of maximum inspiratory pressures (Ppeak) before surgery, after first and second breasts were removed, and after surgery. Pulmonary function tests were carried out on preoperative, postoperative second and 14th days. As RFT, forced vital capacity (FVC), FEV1 (forced expiratory volume at the first second of FVC), FEV1/FVC and PEF (peak expiratory flow rate) were measured. RESULTS: In both groups, demographic data were not found to statistically significant differences (P > 0.05). When compared both groups in terms of preoperative FVC and FEV1/FVC 14th day, a significant increase was found on the 14th day (P < 0.05). A significant difference was not established between groups in terms of Ppeak values (P > 0.05). Ppeak was found to be significantly higher in group I (22.28 ± 7.56) at the end of intubation compared with group II (19.04 ± 3.73) (P = 0.002, P < 0.05). Similarly, preoperative Ppeak was established to be 21.88 ± 7.51 in group I and it was significantly higher compared with group II (19.44 ± 4.08), (P = 0.002, P < 0.05). When compared Ppeak values at the end of intubation and before operation with entry values a statistically significant difference was not found in either group (P = 0.76, P > 0.05). CONCLUSIONS: Some researchers reported a positive correlation between FVC, FEV1/FVC, and PEF along with the excised tissue mass. We established a positive correlation between the excised tissue weight and FVC and FEV1/FVC and that PEEP application did not have an impact on Ppeak.

The effects of opioids, local anesthetics and adjuvants on isolated pregnant rat uterine muscles.

Local anaesthetics, opioids and adjuvants are often used for managing labor pain. Some others of these agents are reported to cause alterations on uterine contractility during labor. However, there are controversies and the effects of some others are unknown. In the present study, we aimed to elucidate the effects of opioids such as alfentanyl, meperidine, remifentanyl; local anesthetics such as mepivacaine, ropivacaine, bupivacaine; and adjuvants such as clonidine and midazolam on isolated pregnant rat uterine muscle. Strips of longitudinal uterine smooth muscle obtained from rats pregnant for 18-21 days were suspended in 20 ml organ baths. Isometric tension was continuously measured with an isometric force transducer connected to a computer-based data acquisition system. The effects of cumulative concentrations of alfentanyl, meperidine, remifentanyl, mepivacaine, ropivacaine, bupivacaine, clonidine and midazolam (10(-8) - 10(-4) M, for all) on contractions induced by oxytocin (1 mU/ml) were studied. Alfentanyl (10(-5) M), meperidine (10(-5) M), remifentanyl (10(-4) M), bupivacaine (10(-4) M), ropivacaine (10(-4) M) and midazolam (3 x 10(-5) M) caused significant decreases in contractile responses of uterine strips to oxytocin. Contrastingly, mepivacaine increased (33.1% +/- 7.2%) oxytocin-induced contractions of uterine strips while clonidine exerted no significant effect. The sensitivity of myometrial preparations to tested local anesthetics or opioids did not differ significantly. The findings of the present study demonstrated that some local anesthetics, opioids and adjuvants caused significant and agent-specific alterations on contractility of the pregnant rat myometrium. Therefore, they seemed to have a potential to influence uterine contractility during clinical management of pain during labor. However, further research is needed to extrapolate these finding to clinical practice.

Pain relief for children after adenotonsillectomy.

Effective pain relief following adenotonsillectomy in children remains a challenge. This study evaluated the effects of intramuscular 0.5 mg/kg ketamine, 1 mg/kg tramadol or 1 mg/kg meperidine on post-operative pain and recovery in 45 children aged 1-7 years undergoing adenotonsillectomy. Anaesthesia was induced with thiopental or sevoflurane (with succinylcholine for intubation) and was maintained with sevoflurane in oxygen and nitrous oxide. Post-operative pain was scored blind using a modified Toddler-Preschooler Post-Operative Pain Scale 30, 60, 120 and 240 min after tracheal extubation. Post-operative agitation scores were also recorded. Mean post-operative pain score was significantly higher in the tramadol-treated group compared with the meperidine-treated group 120 min after extubation. At all other time-points after extubation, mean post-operative pain scores were similar for the three treatment groups. Ketamine was associated with a significantly higher mean agitation score compared with tramadol and meperidine. We conclude that the effects of ketamine, meperidine and tramadol on post-operative pain following adenotonsillectomy in children were similar.

Comparison of epidural and combined spinal-epidural analgesia in the management of labour without pain.

The effects of combined spinal-epidural analgesia (CSEA) and epidural analgesia (EA) were studied in 50 healthy parturients randomly allocated to receive bupivacaine plus fentanyl either epidurally, or intrathecally and epidurally. Significant differences from baseline values were seen in systolic blood pressure at all time-points except for 4 h in the EA group and at 3 and 4 h in the CSEA group. Significant differences from baseline values were seen in diastolic blood pressure at 1, 2, 3 and 4 h in the EA group, whereas no significant differences from baseline were seen in the CSEA group. Pain scores in both groups were significantly decreased compared with baseline and all scores, except at 2h, were significantly lower in the CSEA group compared with the EA group. The duration of labour and total amount of drugs used were significantly decreased and cervical dilatation was faster with CSEA compared with EA. In conclusion, CSEA was associated with more rapid onset of analgesia and faster progress in cervical dilatation compared with EA, and can be used safely for labour analgesia.

The effects of bupivacaine, ropivacaine and mepivacaine on the contractility of rat myometrium.

Local anesthetic agents are commonly used for obstetric anesthesia and analgesia. We determined the effects of bupivacaine, ropivacaine and mepivacaine on the contractility of isolated pregnant rat uterine muscle strips. Uterine specimens were obtained from 18- to 21-day pregnant Wistar rats (n = 28). Myometrial strips were obtained from the uterine horns after removing the fetuses and non-uterine tissue, incubated in organ baths and contractions stimulated with oxytocin. When contractions became regular, strips were exposed to increasing concentrations of the study drugs. Mepivacaine (n = 8), ropivacaine (n = 10) and bupivacaine (n = 10) were used at cumulative doses from 10(-8) to 10(-4) mol/L. Two of the local anesthetics, bupivacaine most, ropivacaine least, caused a dose-dependent inhibition of uterine contractility. In contrast, mepivacaine significantly increased uterine contractility. Bupivacaine, ropivacaine and mepivacaine were found to have no effect on frequency of uterine contractions. These results demonstrate that bupivacaine and ropivacaine may inhibit myometrium contractility.

Acute subdural haematoma after accidental dural puncture during epidural anaesthesia.

A case is reported of acute intracranial subdural haematoma following accidental dural puncture during epidural anaesthesia. A 36-year-old primigravida with a gestation of 37 weeks and 3 days underwent caesarean section for which epidural anaesthesia was initially planned. An 18-gauge Tuohy needle was inserted into the L3-4 interspace but accidental dural puncture occurred. The needle was removed and general anaesthesia was initiated for surgery. On the second day post partum, the patient described a headache in both occipital area and neck that was relieved by lying down. On the seventh post-partum day she suffered tonic-clonic convulsions and underwent computerised tomography (CT). Despite different analgesic treatments and a normal CT, the patient suffered severe headaches in the following days. Magnetic resonance imaging revealed a 4-mm subdural hematoma in the right frontal area. The persisting headache decreased on day 12 and disappeared on day 14. The patient was discharged from hospital on day 15. The presence of post dural puncture headache complicated by atypical neurological deterioration following epidural anaesthesia should prompt the anaesthetist to consider the existence of intracranial complications and to seek immediate clinical and radiological diagnosis.

Prediction of difficult tracheal intubation in Turkish patients: a multi-center methodological study.

BACKGROUND AND OBJECTIVE: Preoperative evaluation is important in the detection of patients at risk for difficult airway management. It is still unclear whether true prediction is possible and which variables should be chosen for evaluation. The aim of this prospective, multi-centre study was to investigate the incidence of difficult intubation, the sensitivity and positive predictive values of clinical screening tests and whether combining two or more of these tests will improve the prediction of difficult intubation in Turkish patients. METHODS: Seven study sites from six regions in Turkey participated in this study. One thousand six hundred and seventy-four ASA physical status I-III patients, scheduled to undergo elective surgery under general anaesthesia, were included. RESULTS: The incidence of difficult intubation was 4.8% and increased with age (P < 0.05). The incidence of difficult intubation was significantly higher in patients who had a Mallampati III or IV score, a decreased average thyromental and sternomental distance, decreased mouth opening, or decreased protrusion of the mandible (P < 0.05). Mouth opening and Mallampati III-IV were found to be the most sensitive criteria when used alone (43% and 35%, respectively). Combination of tests did not improve these results. CONCLUSIONS: There is still no individual test or a combination of tests that predict difficult intubations accurately. Tests with higher specificity despite low positive predictive value are needed.

Intrathecal fentanyl added to hyperbaric ropivacaine for transurethral resection of the prostate.

BACKGROUND: Our purpose was to evaluate the effect of intrathecal fentanyl 25 microg added to 18 mg of 6 mg ml(-1) hyperbaric ropivacaine on the characteristics of subarachnoid block and postoperative pain relief in patients undergoing TURP surgery. METHODS: The patients were randomly assigned into two groups: Group S (saline group, n=16) received 3 ml of 18 mg hyperbaric ropivacaine + 0.5 ml saline--in total, a 3.5-ml volume intrathecally; and Group F (fentanyl group, n=15) received 3 ml of 18 mg hyperbaric ropivacaine + 0.5 ml of 25 microg fentanyl--in total, a 3.5-ml volume intrathecally. In both groups the onset and recovery times of the sensory block, degree and recovery times of the motor block and side-effects were recorded and statistically compared. RESULTS: There was no significant difference between the groups in achieving the highest level of sensory block, and in the times taken to reach the peak level. Regression to L1 was significantly prolonged in the fentanyl group compared with the saline group (P=0.004). Times to the first feeling of pain and the first analgesic requirement were significantly prolonged in the fentanyl group compared with the saline group (P=0.011 and P=0.016, respectively). The frequency of pruritus was significantly higher in the fentanyl group compared with the saline group (P=0.022). CONCLUSION: Addition of fentanyl 25 microg to hyperbaric ropivacaine 18 mg for spinal anesthesia in patients undergoing TURP may significantly improve the quality and prolong the duration of analgesia, without causing a substantial increase in the frequency of major side-effects.

Effects of hyperbaric spinal ropivacaine for caesarean section: with or without fentanyl.

BACKGROUND AND OBJECTIVE: Adding various opioids to the local anaesthetic solution administrated intrathecally improves the analgesic potency of spinal analgesia. The purpose of this study was to evaluate the efficacy and safety of intrathecal fentanyl 10 microg added to 15 mg hyperbaric ropivacaine in patients undergoing caesarean section under spinal anaesthesia. METHODS: Thirty-seven healthy, full-term parturients were randomly assigned into two groups: Group S (saline group, n=17) received 15 mg hyperbaric ropivacaine in 2.5 mL + 0.5 mL saline; Group F (fentanyl group, n=20) received 15 mg hyperbaric ropivacaine in 2.5 mL + 10 microg fentanyl in 0.5 mL, intrathecally. Characteristics of spinal block, intraoperative quality of spinal anaesthesia, time to first feeling of pain (complete analgesia), time to first request of analgesics postoperatively (effective analgesia), side-effects and fetal outcomes were evaluated. RESULTS: Regression of sensory block to L5 was significantly prolonged in the fentanyl group compared with the saline group (P = 0.001). Time to the first feeling of pain (130.6 +/- 15.8 min vs. 154.3 +/- 31.1 min; P = 0.008) and the first analgesic requirement (161.2 +/- 32.6 min vs. 213.0 +/- 29.3 min; P < 0.001) were significantly shorter in the saline group compared with the fentanyl group. Side-effects, umbilical arterial and venous blood gases did not differ between the groups. Apgar scores were similar in both groups and no infants had an Apgar score < or =7 at 5 min. CONCLUSIONS: The addition of fentanyl 10 microg, to hyperbaric ropivacaine 15 mg, for spinal anaesthesia increased the duration of analgesia in the early postoperative period in patients undergoing caesarean delivery.

Effects of intravenous anesthetic agents on pregnant myometrium.

Emergent or elective surgical procedures under general anesthesia may be required during pregnancy for some patients. For this reason, effects of anesthetics on uterine contractions are important. General anesthesia is not limited to the administration of inhalation agents, since induction and maintenance of anesthesia usually involve intravenous administration of different anesthetic agents. The effects of these agents on uterine contractions and blood flow are very important. The unexpected relaxation or contraction of myometrium can be harmful to fetus and continuing pregnancy. Our aim in this study is to investigate the effects of intravenous anesthetic agents on uterine contractions. In our study, we examined the effects of ketamine, propofol and midazolam on contractions of isolated pregnant rat myometrium. We observed that exposure to propofol, ketamine and midazolam at the concentrations of 10(-5)-10(-4) M decreased spontaneous contractile activity in myometrial strips isolated from pregnant rats. There was statistically significant difference between the control and all strips exposed to propofol, ketamine and midazolam in the contraction amplitude and integrated area under the contraction curve.

Analgesic effects of intrathecal neostigmine in perianal surgery.

BACKGROUND AND OBJECTIVE: In recent human and animal studies, intrathecal administration of various doses of neostigmine produces analgesia without neurotoxicity. The aim was to examine the effects of intrathecal neostigmine and bupivacaine in patients undergoing perianal surgery under spinal anaesthesia. METHODS: The patients were randomly allocated into three groups of 15: Group 1 (controls) received hyperbaric bupivacaine 10 mg + dextrose 5%, 1 mL, to a total volume of 3 mL; Group 2 received hyperbaric bupivacaine 10 mg + neostigmine 25 microg in dextrose 5%, 1 mL, to a total volume of 3 mL; and Group 3 received hyperbaric bupivacaine 10 mg + neostigmine 50 microg in dextrose 5%, 1 mL, to a total volume of 3 mL. RESULTS: The onset of sensory block was significantly earlier for Group 2 and 3 patients compared with Group 1 patients (P < 0.05). The full time to recovery of motor block and sensory block was significantly longer in Group 3 compared with Group 1 (P < 0.05). In Group 3, the average time until the first dose of tramadol was longer than Group 1 (P < 0.05). The incidence rate of nausea and vomiting was significantly higher in Groups 2 and 3 than in Group 1 (P < 0.05). CONCLUSIONS: The use of intrathecal neostigmine as an analgesic drug in perianal surgery is unsatisfactory because of prolonged motor blockade and nausea.

The analgesic and sedative effects of intrathecal midazolam in perianal surgery.

BACKGROUND AND OBJECTIVE: Our purpose was to evaluate the analgesic and sedative effects of intrathecal midazolam when added to spinal bupivacaine in patients undergoing perianal surgery under spinal anaesthesia. METHODS: Forty-four patients were randomly allocated into two equal groups: Group I (B) received hyperbaric bupivacaine 0.5% 2 mL + saline 0.9% 1 mL in a total volume of 3 mL intrathecally; Group II (BM) received hyperbaric bupivacaine 0.5% 2 mL + 1 mL of 2mg preservative-free midazolam in a total volume of 3 mL intrathecally. In both groups, the onset and recovery times of sensory block, the degree and recovery times of motor block as well as the sedation and visual analogue pain scores were recorded, and statistically compared. RESULTS: In Group BM, the postoperative visual analogue pain scores were significantly lower at the first 4 h (P < 0.05), the average time until the first dose of additional analgesic requirement was significantly longer (P < 0.05), and sedation scales were significantly higher (P < 0.05), compared to Group B. There were no statistically significant differences in the onset and the full recovery times of sensory and motor blocks in the two groups. CONCLUSION: The use of intrathecal midazolam combined with intrathecal bupivacaine produces a more effective and longer analgesia with a mild sedative effect in perianal surgery.

Postoperative retention of urine in general surgical patients.

OBJECTIVE: To find out the incidence of retention of urine after various general surgical operations, and to assess the effects of applying a bag filled with warm water (40-45 degrees C), and encouraging early mobilisation onreducing the necessity for catheterisation. DESIGN: Open study. SETTING: Cumhuriyet University Hospital, Sivas, Turkey. SUBJECTS: 577 consecutive patients who had no history of urinary problems and had not already been catheterised, and who underwent general surgical operations between April 1989 and December 1991. MAIN OUTCOME MEASURE: Ability to pass urine spontaneously. RESULTS: 64 of 272 men (24%) and 47 of 305 women (15%) developed retention of urine (p = 0.02), and 15 and 11, respectively, required catheterisation. Patients were most likely to develop retention after repair of incisional hernia (13/32, 38%), midline laparotomy (19/82, 23%), and subcostal incisions (30/142, 21%), but there were no significant differences among these. Significantly more patients whose operations had lasted 60 minutes or more, and who had opiate analgesia, required catheterisation (5/232 compared with 21/345, p = 0.04, and 11/120 compared with 15 out of 457, p = 0.01, respectively). 85 of the 111 patients who went into retention (77%) were able to pass urine spontaneously after application of a bag containing warm water to the suprapubic region, and walking about. The mean period of catheterisation was 12 hours (range 4-76), and all patients but one passed urine spontaneously when the catheter was removed. Only two of the 26 patients who were catheterised developed microbiologically confirmed urinary tract infections. CONCLUSION: Retention of urine is a common complication after general surgical operations, but the necessity for catheterisation can be kept to a minimum by simple and inexpensive measures.

Intravenous single-dose tramadol versus meperidine for pain relief in renal colic.

BACKGROUND AND OBJECTIVE: Comparison of the effectiveness of tramadol with meperidine given intravenously to emergency patients with suspected renal colic. METHODS: A double-blind, randomized clinical trial was performed in the Emergency Department of a tertiary-care university hospital. Consecutive patients with suspected renal colic (n = 47) were randomized to receive intravenously an initial dose of tramadol 50 mg (n = 23) or meperidine 50 mg (n = 24). After 30 min, additional doses of meperidine 50 mg were given intravenously as a rescue medication in an open fashion. Pain relief was assessed using a 10 cm visual analogue scale, the primary outcomes being pain relief at 15 and 30 min after the analgesics. Secondary outcomes were the frequency of rescue meperidine use and the development of side-effects. RESULTS: Visual analogue scale pain scores after 15 and 30 min decreased in both tramadol and meperidine groups (P < 0.05). However, pain relief was better in the meperidine group at the 15 and 30 min evaluations (P < 0.05). Only 11 patients (48%), initially receiving meperidine, needed more meperidine compared with 16 patients (67%) initially receiving tramadol. Both drugs were well tolerated with no adverse effects occurring in either group. CONCLUSIONS: Meperidine 50 mg was superior to tramadol 50 mg for acute pain relief in patients with suspected renal colic when given intravenously. Because many patients in both groups received supplemental meperidine and the response to tramadol alone cannot be predicted, clinicians may want to choose higher doses of meperidine alone or other alternative combinations.