Topical lidocaine patch 5% for acute postoperative pain control.

A 39-year-old para 3 woman presented for elective caesarean section (lower segment caesarean section (LSCS)) for breech presentation. The patient had a strong history of atopy and anaphylaxis to paracetamol, codeine, penicillin and latex. The patient was asthmatic, triggered by aspirin. Epidural anaesthesia was unsuccessful and LSCS was carried out under spinal anaesthesia. Postoperatively the patient was unwilling to take analgesic medication due to fear of an allergic reaction. Three 5% lidocaine patches were applied to the wound for postoperative analgesia. This reduced the patient's visual analogue scale pain score from 10/10 to 5/10 at rest and 10/10 to 7/10 with movement. Transcutaneous electrical nerve stimulation was added and this improved associated back pain, reducing the pain further to 2/10. This is the first description of lignocaine patch 5% for postoperative LSCS pain. It is suggested that this method of delivery of local anaesthetic, which is easy to apply and has minimal side effects, should be considered not as a sole agent but as part of a multimodal technique to address postoperative LSCS pain.

Poor uptake of reproductive health screening services by female renal transplant recipients.

Women with functioning renal transplants are a high-risk group for de novo malignancies and other gynaecological health problems. The objective of this study was to assess patients' awareness of gynaecological issues, and to assess uptake of cervical and breast cancer screening services. A structured questionnaire on family planning, menopausal issues and knowledge/use of cervical and breast cancer screening was administered to 64 female renal transplant recipients. 58 (91%) responded to the questionnaire. Mean age at first transplantation was 35 years (range 11 - 69). 84% were aware as to why they should have regular cervical smears. 15 (26%) had, however, never had a smear and only 9 (16%) were having yearly smears. 12 of 28 postmenopausal women entered the menopause under the age of 41 years, but only 5 of these had received Hormone Replacement Therapy. Breast self examination is practiced by 71%, but only 26% have had mammograms. These figures suggest that female renal transplant patients are not adequately screened for cervical and breast cancer. The results also indicate a need for further education regarding family planning issues and menopausal health concerns. We conclude that formal gynaecological review should be routinely available for women with renal transplants.

Detection of high-risk subtypes of human papillomavirus in cervical swabs: routine use of the Digene Hybrid Capture assay and polymerase chain reaction analysis.

Human papillomaviruses (HPVs) are major causative agents in the pathogenesis of cervical cancer, and more than twenty types are associated with its development. With the introduction of liquid-based preparation systems, it is envisaged that large-scale HPV testing will be established in the near future. Preliminary studies demonstrate the accessibility of these samples for DNA testing using both the Digene Hybrid Capture assay (DHCA) and polymerase chain reaction (PCR) techniques. This study aims to assess the validity and sensitivity of the DHCA system to detect high-risk HPV DNA, using two sets of HPV consensus primers (Gp5+/Gp6+ and MY09/MY11) in tandem with routine assessment of cervical smear and biopsy samples. Results indicate that the combination of DHCA and PCR detects more high-grade lesions than does the DHCA alone. DHCA-negative cases were categorised by subsequent PCR amplification into low-grade HPV-negative (12/16) cervical lesions and high-grade HPV-positive (7/9) cervical lesions. Gp5+/Gp6+ primers were less sensitive in detecting HPV-positive samples than was the MY09/MY11 primer set. These results support the use of high-risk HPV testing by DHCA, with subsequent analysis of DHCA-negative samples by PCR using the MY09/MY11 primers.

Peroneal afferent nerve discharges underlying the behavioral response to the formalin test.

BACKGROUND AND OBJECTIVES: Subcutaneous injection of formalin into the hindpaw of the rat results in a biphasic behavioral response consisting of flinching of the injected paw. It is postulated that the second-phase response is related to sensitization of spinal cord neurons rather than to resumption of peripheral nociceptor activity. METHODS: On removal from anesthesia with 3% halothane, 10 rats were given a subcutaneous injection of formalin (5%, 50 microL) into the dorsum of the hindpaw. Behavioral response to the formalin test were observed for the subsequent hour. In five sodium pentobarbital-anesthetized rats, peroneal afferent nerve activity was recorded for 1 hour following similar subcutaneous injection of formalin. RESULTS: During standard formalin testing in unanesthetized rats, flinching peaked between 1 and 2 minutes following injection (phase 1 response), ceased between 5 and 10 minutes, and recommenced after 15 minutes with a second peak at 45 minutes (phase 2). In sodium pentobarbital-anesthetized rats, peroneal afferent nerve activity increased transiently during the time course of the phase 1 behavioral response but showed no subsequent increase in activity during the ensuing 55 minutes. CONCLUSIONS: The results are consistent with the hypothesis that the initial behavioral response to formalin injection is mediated by high peripheral nerve activity, while the second phase is mediated by sensitization of dorsal horn neurons in conjunction with low persistent levels of afferent activity.

Complications associated with epidural steroid injections.

BACKGROUND AND OBJECTIVES: Warnings about the hazards of epidural steroid injections occasionally appear in both medical and lay literature despite a lack of objective data to support such concerns. This literature review was undertaken to survey reports of adverse reactions associated with that procedure. METHODS: The following types of publications from peer-reviewed medical literature was surveyed: reports on series of epidural and subarachnoid steroid injections for sciatica; reports of adverse effects of epidural and subarachnoid steroid injections for sciatica; review articles on epidural and subarachnoid steroid injections; and studies of the behavioral and histologic effects of epidural steroids and their vehicle in animals. RESULTS: Several cases of aseptic meningitis, arachnoiditis, and bacterial meningitis and one case of conus medullaris syndrome have been reported after subarachnoid steroid injections. Most of these complications occurred after multiple subarachnoid injections. Two cases of epidural abscess, one case of bacterial meningitis, and one case of aseptic meningitis have been reported following epidural steroid injections. Subarachnoid drug placement could not be ruled out in the meningitis cases. CONCLUSIONS: There are few published reports of serious complications following epidural steroid injections. There are a few published reports of complications following subarachnoid steroid injections, most of which were associated with multiple injections over a prolonged time period.

Characteristics of the analgesic effects and drug interactions of intrathecal carbachol in rats.

BACKGROUND: Intrathecal carbachol produces consistent analgesia in animals without appreciable adverse effects. Little is known about the ability of this drug to provide analgesia as stimulus intensity is increased. Likewise, there are few data regarding interactions between carbachol and other intrathecal analgesics. METHODS: Using two different noxious radiant heat intensities, one applied to each hind limb, analgesic effects of 1, 3, 10, and 30 micrograms intrathecal carbachol on paw withdrawal latencies were measured. Similar testing was done for intrathecal morphine and clonidine. ED50 fractions (1/2, 1/4, 1/8, 1/16) of drug combinations of carbachol-morphine and carbachol-clonidine were administered, responses to the low intensity stimulus were recorded, and the ED50 of each combination was established and isobolographic analysis of the drug interactions was carried out. RESULTS: The 30-micrograms dose of carbachol was associated with transient agitation, salivation, and hind limb weakness. No other adverse effects were noted. The ED50 (95% confidence interval) of intrathecal carbachol was 2.34 micrograms (1.34-4.04) for low intensity stimulation and 12.64 micrograms (4.18-38.25) for high intensity. There was no significant difference between high- and low-intensity ED50 values for intrathecal morphine and clonidine. The analgesic effect of the carbachol-morphine and carbachol-clonidine combinations were significantly greater than the calculated additive effects. The ED50 for the carbachol-morphine combination was 12% of the expected additive value and the ED50 for the carbachol-clonidine combination was 30% of the expected additive value. CONCLUSIONS: Intrathecal carbachol provides analgesia to noxious thermal stimulation of the hind paw in rats. It is relatively less effective at providing analgesia than intrathecal morphine or clonidine when stimulus intensity is raised. Intrathecal carbachol is synergistic when combined with intrathecal morphine or clonidine.

Inhibition of nociception-induced spinal sensitization by anesthetic agents.

BACKGROUND: Subcutaneous injection of dilute formalin in the hind paw of the rat produces a biphasic nociceptive response. Initial C-fiber activity is accompanied by flinching of the paw for about 5 min (phase 1), followed by cessation of activity and resumption of flinching beginning 15 min after injection and lasting about 40 min or more (phase 2). The second phase depends on changes in dorsal horn cell function that occur shortly after the initial C-fiber discharge. It was previously shown that isoflurane, administered during phase 1, reduced phase 2 activity, but a combination of isoflurane and nitrous oxide given throughout phase 1 did not suppress spinal sensitization. The same model was used to determine the effects of several inhalation and intravenous anesthetic agents on phase 2 of the formalin test. METHODS: The formalin test was carried out on male Sprague-Dawley rats. Animals anesthetized briefly with halothane to facilitate formalin injection, were compared to animals that received 1 MAC anesthesia from 5 min before to 6 min after formalin injection using halothane, enflurane, isoflurane, desflurane, or 70% N2O, or a combination of nitrous oxide plus 1 MAC halothane. Animals that were given intravenous saline immediately before injection of formalin were compared to animals given either 20 mg/kg intravenous thiopental just before formalin injection or 10 mg/kg intravenous propofol just before and 3 mg/kg immediately after formalin injection. Flinches/minute were counted at 1 and 5 min after formalin injection and thereafter at 5-min intervals for 1 h. The total of 1- and 5-min flinches were considered phase 1 activity and the total of 10-60-min flinches were considered phase 2. Total phase 2 activity was compared between groups using one-way analysis of variance. RESULTS: Animals that received halothane, enflurane, isoflurane, desflurane, or nitrous oxide during phase 1 demonstrated a significant decrease in phase 2 activity when compared to controls, while those that received a combination of nitrous oxide and halothane exhibited no difference. Animals that received intravenous thiopental anesthesia during phase 1 demonstrated no difference in phase 2 activity when compared to controls, whereas those that received propofol during phase 1 demonstrated a significant decrease of phase 2 activity. CONCLUSIONS: Volatile anesthetics or nitrous oxide significantly suppress spinal sensitization, whereas the combination of nitrous oxide plus halothane causes no suppression. Thiopental does not affect spinal sensitization, whereas propofol causes significant suppression. These results may have important implications regarding the development of postoperative pain.

Halothane enhances suppression of spinal sensitization by intrathecal morphine in the rat formalin test.

BACKGROUND: Injection of formalin in the hindpaw of the rat induces intense C-fiber activity accompanied by brief flinching of the injected paw (phase 1) and gives rise to facilitated spinal processing characterized by renewed flinching beginning 15 min after injury and lasting 40 min or more (phase 2). In previous work, isoflurane, administered during phase 1, slightly reduced phase-2 activity, whereas the addition of intrathecal morphine dramatically inhibited phase 2, even with naloxone reversal 6 min after the formalin injection. We used a similar model to determine whether intrathecal morphine could block spinal sensitization in the absence of inhalation anesthetic. METHODS: Hot plate tests at 52 degrees C and radiant heat-evoked hindpaw withdrawal tests were used to determine optimal doses of agonists and antagonists. The formalin test was carried out on male Sprague-Dawley rats, which were divided into five groups. A combination of naloxone 0.5 mg/kg and naltrexone 0.5 mg/kg was administered subcutaneously 6 min after the formalin injection to all animals except controls (group 1) to prevent ongoing opioid effect. Groups 1-3 received intrathecal saline, and groups 4 and 5 received intrathecal morphine 30 micrograms 20 min before formalin injection. Halothane was administered for 1-2 min to facilitate formalin injection for groups 1, 2, and 4. In groups 3 and 5 halothane was administered from 5 min before to 6 min after formalin injection. The number of flinches per minute was counted 1 and 5 min after formalin administration and thereafter at 5-min intervals for 1 h. The total number of flinches at 1 and 5 min was considered as phase-1 activity, and the total number of flinches during the 10-60-min interval was considered as phase 2. RESULTS: Phase-2 activity for groups 1 and 2 was nearly identical, demonstrating no appreciable effect of the opioid antagonists alone. Groups 3 (halothane alone) and 4 (morphine alone) exhibited a significant decrease in phase-2 activity. Group 5 (morphine plus halothane) demonstrated a profound decrease in phase-2 activity, which was significantly more profound than that of groups 3 or 4. CONCLUSIONS: Intrathecal morphine, administered before formalin injection but antagonized before the onset of phase 2 of the formalin test, significantly suppresses sensitization of dorsal horn neurons. This suppression is significantly increased by coadministration of halothane anesthesia.

The effect of peritoneal dialysis with and without aprotinin on acute experimental pancreatitis in rats.

Acute pancreatitis was induced in 139 Wistar rats by injection of trypsin in the common bilio-pancreatic duct. Peritoneal dialysis was performed in 93 rats. In some of these rats, aprotinin (250,000 UI/L) was added to the lavage fluid. Macroscopically, we noted the amount of steatonecrosis, pulmonary congestion and pleural effusion produced. The pancreatic and pulmonary lesions were studied microscopically. The effect of peritoneal dialysis with and without aprotinin on the survival rate was evaluated. Survival curves were established for the different groups of rats i.e. the non-treated group and the two groups of dialysed rats (with and without aprotinin). Peritoneal dialysis reduces the amount of steatonecrosis and the incidence of pulmonary complications of trypsin-induced pancreatitis in rats, but does not influence the pancreatic lesions. Peritoneal dialysis significantly improves the early survival rate. Addition of aprotinin to the dialysis fluid reduces the total mortality rate.

Experimental toxemia in the pregnant primate.

In order to develop a model for the study of eclamptogenic toxemia, a series of experiments were carried out on 31 female baboons. In Group 1, consisting of 10 animals, metal clips were placed around the uterine arteries in order to partially occlude them, and the ovarian vessels were transected. The animals were subsequently mated. Nine developed hypertension and proteinuria, and one aborted. The renal lesions in these animals were indistinguishable from those described in human toxemia. Group 2 consisted of three of the 10 baboons from Group 1, which became pregnant a second time. They again developed hypertension and proteinuria. In Group 3, three baboons at 100 days of gestation were treated as in Group 1 with similar results. Groups 4 and 5 served as pregnant (3) and nonpregnant (15) controls. It is concluded that a toxemia model has been developed in a subhuman primate. This model will prove useful in the further study of eclamptogenic toxemia.