Effects of intracisternal tramadol on cerebral and spinal neuronal cells in rat

BACKGROUND

The aim was to investigate whether tramadol had toxic effect on cerebral neurons and/or spinal cord neurons when it was administered into the cerebrospinal fluid. Due to lipid peroxidation (LPO) and myeloperoxidation (MPO) levels are not specific predictors of neuronal damage, these biochemical markers of tissue damage were evaluated together with the histopathological findings of apoptosis.

METHODS

Forty eight Wistar rats were anesthetized and the right femoral artery was cannulated. Mean arterial pressures, and heart rates, arterial carbon dioxide tension, arterial oxygen tension, blood pH were recorded. When the free cerebrospinal fluid flow was seen; 0.04 mL normal saline (Group Sham) or diluted tramadol in 0.04 mL volume (Group T1, T2, T0.5 and T0.1) was administered within 30 seconds from the posterior craniocervical junction of rats. For the Control Group, the free cerebrospinal fluid flow was seen but nothing was injected in it. After 7 days, following the sacrification of the rats, brain tissue, cervical and lumber segments of spinal cord were collected for the histopathological and biochemical examination.

RESULTS

There was not a statistically significant difference among all groups regarding the brain LPO levels (P=0.485). The LPO levels of the cervical segment of spinal cord and the lumbar segment of spinal cord were also similar (P=0.146, P=0.939, respectively). The mean MPO levels of the cervical and the lumbar segments of spinal cord were similar among all groups (P=0.693, P=0.377, respectively). There were not any statistically significant difference regarding the total number of red neurons of the brain tissue and the cervical and lumbar segments of spinal cord among all groups (P=0.264, P=0.202, P=0.780, respectively).

CONCLUSION

Tramadol had no neurotoxic effect on brain and on spinal cord tissue when administered by the intracisternal route in cerebrospinal fluid in rats.

A year in review in Minerva Anestesiologica 2013

BACKGROUND

We organized a training program for oral fiber optic intubation (FOI) under conscious sedation. The efficacy of the program was evaluated by comparing the performances of experts and novices.

METHODS

The training procedure was divided into two sessions: a theoretical session on difficult airways, the fiber optic bronchoscope (FOB), remifentanil, topical anesthesia and patient interactions; and a session involving simulations of the FOI technique on dummies. For in vivo FOI, we enrolled patients requiring orotracheal intubation for elective surgery. Electrocardiograms, mean arterial pressure was railroaded over the fiberscope, and tracheal intubati6 and 7) FOIs, respectively, joined the study. To reach ±23 bpm, P=0.02), and RR was decreased (from 16±3 to 12±4 bpm, P<0.05). No differences were recorded between the experts and less-experienced anesthesiologists. The average duration of FOI was 3.3±2.0 min for experts and 4.2±2.4 min for novices (P=0.03). Procedures were successful in both groups, with patients in each group being equally satisfied with the procedures.

CONCLUSION

This study highlights the importance of a structured FOI training program, demonstrating that it is possible to learn to perform FOI proficiently by practicing on dummies.

Time-dependent middle ear pressure changes under general anaesthesia in children: N2O-O2 mixture versus air-oxygen mixture

OBJECTIVES

The aim of this study was to investigate the effects of N2O-O2 mixture (Inspired O2 30%) on middle ear pressure (MEP) in children compared with the effects of an air-oxygen mixture (Inspired O2 50%).

METHOD

The study included thirty child patients who underwent general anaesthesia for different reasons, with the exception of ENT problems and ear interventions. They were randomly divided into two groups. Group 1 (15 children: 10 male and 5 female) received a N2O-O2 mixture (Inspired O2 30%); and group 2 (15 children: 10 male and 5 female) were given an air-oxygen mixture (Inspired O2 50%). MEP was measured using a portable impedance analyser before the operation (PreO),10 minutes after intubation (10AEn), 30 minutes after intubation (30AEn), 10 minutes before extubation (10BEx), 15 minutes after the operation (PO15), 30 minutes after the operation (PO30), 1 hour after the operation (PO1h) and 6 hours after the operation (PO6h).

RESULTS

The pressure and compliance values were the same in groups 1 and 2. The pressure-time graphs for the two groups were different: in Group 2, MEP rose quickly at 10AEn and positive pressure values were seen in the middle ear. MEP then fell rapidly until the end of the surgery and lower and negative pressures (Mean -50 daPa) were observed at PO6h. In Group 1, MEP was elevated at 10AEn and positive pressure was found (but not as high as in Group 2). MEP then fell more slowly. In other words, positive pressure in the middle ear persisted longer and the middle ear was subjected to positive pressure and nitrogen over a longer period. Separate analyses were made in Groups 1 and 2 of pressure differences and of compliance values at eight measurement points using the Friedman test. Differences in pressure values were found to be statistically significant in both Group 1 (p = 0.000) and Group 2 (p = 0.000). In Group 1, all the 10AEn and 30AEn values were significantly higher than the PreO, PO30, PO1h and PO6h values. The 10BEx value was significantly higher than the PreO and PO1h values. The PO15 value was significantly higher than the PreO value. In Group 2, the PO6h value was significantly lower than the 10BEx, 10AEn and 30AEn values. The PO1h value was significantly lower than the 30AEn values. The MEP values increased in Group 1 in younger and taller children and in children receiving anaesthesia for shorter periods. MEP values increased in Group 2 in younger and taller children, and in heavier children. MEP values fell with the length of anaesthesia.

CONCLUSION

In brief anaesthesia, nitrogen was not removed from the middle ear quickly in Group 1: middle ear pressure values were higher. The nitrous oxide remained in the middle ear longer and so the possibility of ear toxicity may increase. In Group 2, 50% O2 was rapidly absorbed and removed from the middle ear and so middle ear pressure was not as high. It may be concluded that air-oxygen mixture (Inspired O2 50%) anaesthesia should be recommended as being more reliable in tympanoplasties and other middle ear interventions than a N2O-O2 mixture (Inspired O2 30%).

Epidural volume expansion: is there a ceiling effect?

AIM

The optimal volume of epidural saline administration on spinal anesthesia is not clear. The aim of this study was therefore to evaluate the block characteristics of 5, 10, 15, and 20 mL epidural saline after spinal anesthesia.

METHODS

This prospective, randomized double-blind study was conducted in the operation room setting of a university hospital. Seventy-five healthy adult patients electively undergoing limb surgery under regional anesthesia were investigated. Spinal anesthesia was performed, and plain bupivacaine (10 mg) was administered within one minute using combined spinal and epidural anesthesia. Epidural catheters were introduced, and patients were allocated to one of five groups to receive 0, 5, 10, 15 or 20 mL saline through the catheter (N=15 in each group). The patient was assessed every minute for motor and sensory block levels until a maximum level was reached. In addition, the patient was assessed thereafter in five-minute intervals using Bromage's scale for motor block and pinprick/cold sensation for sensory block.

RESULTS

The maximum level of spinal analgesia was significantly lower in the control group compared to the saline treatment groups, but there was no significant difference between the epidural saline groups. The periods for motor block resolution were the same. The duration of analgesia was significantly longer in patients receiving 15 mL saline compared to other groups. The time to regression to the L1 level was significantly longer with 15- and 20-mL treatment groups compared to the 5- and 10-mL groups.

CONCLUSION

The present results indicate that a ceiling effect was observed on the duration of spinal analgesia using plain bupivacaine with epidural saline loading (maximum--15 mL).

Bispectral index-guided intraoperative sedation with dexmedetomidine and midazolam infusion in outpatient cataract surgery

BACKGROUND

This study aimed to evaluate the role of alfa-2 agonist infusion, with dexmedetomidine or midazolam, on hemodynamic and respiratory parameters while titrating the sedation level with the bispectral index (BIS) during cataract surgery.

METHODS

Ninety consenting ASA class I-III patients who were electively undergoing cataract surgery were enrolled in the double blind study. A random infusion of 0.25 microg kg(-1) hr(-1) Dexmedetomidine (Group D), 25 microg kg(-1) hr(-1) midazolam (Group M), or saline for controls (Group C) was administered after mounting a BIS monitor and routine anesthetic care. The target BIS level was >85. An additional bolus dose in 1 mL increments of the study drug or cessation of the infusion was adjusted according to the BIS level. Changes in respiratory and vital parameters were noted and, in case of mild pain, 25 microg fentanyl was administered as a bolus. Pain and sedation were evaluated in the early postoperative period using visual analogue and four rating sedation scales.

RESULTS

In Group D, heart rate decreased in the later periods of surgery (35-50 min) and in the early postoperative period (5(th) and 15(th) min). Dose adjustments were required in six and ten patients in Groups D and M, respectively. Pain scores were lower with dexmedetomidine infusion.

CONCLUSIONS

Dexmedetomidine infusion mildly decreased heart rate in the later periods of surgery with better pain scores in the postoperative period. Dexmedetomidine should be an alternative for intraoperative sedation in outpatient cataract surgery.

Estimating crop area using seasonal time series of Enhanced Vegetation Index from MODIS satellite imagery

Cereal grain is one of the main export commodities of Australian agriculture. Over the past decade, crop yield forecasts for wheat and sorghum have shown appreciable utility for industry planning at shire, state, and national scales. There is now an increasing drive from industry for more accurate and cost-effective crop production forecasts. In order to generate production estimates, accurate crop area estimates are needed by the end of the cropping season. Multivariate methods for analysing remotely sensed Enhanced Vegetation Index (EVI) from 16-day Moderate Resolution Imaging Spectroradiometer (MODIS) satellite imagery within the cropping period (i.e. April–November) were investigated to estimate crop area for wheat, barley, chickpea, and total winter cropped area for a case study region in NE Australia. Each pixel classification method was trained on ground truth data collected from the study region. Three approaches to pixel classification were examined: (i) cluster analysis of trajectories of EVI values from consecutive multi-date imagery during the crop growth period; (ii) harmonic analysis of the time series (HANTS) of the EVI values; and (iii) principal component analysis (PCA) of the time series of EVI values. Images classified using these three approaches were compared with each other, and with a classification based on the single MODIS image taken at peak EVI. Imagery for the 2003 and 2004 seasons was used to assess the ability of the methods to determine wheat, barley, chickpea, and total cropped area estimates. The accuracy at pixel scale was determined by the percent correct classification metric by contrasting all pixel scale samples with independent pixel observations. At a shire level, aggregated total crop area estimates were compared with surveyed estimates. All multi-temporal methods showed significant overall capability to estimate total winter crop area. There was high accuracy at pixel scale (>98% correct classification) for identifying overall winter cropping. However, discrimination among crops was less accurate. Although the use of single-date EVI data produced high accuracy for estimates of wheat area at shire scale, the result contradicted the poor pixel-scale accuracy associated with this approach, due to fortuitous compensating errors. Further studies are needed to extrapolate the multi-temporal approaches to other geographical areas and to improve the lead time for deriving cropped-area estimates before harvest.

Postoperative magnesium sulphate infusion reduces analgesic requirements in spinal anaesthesia

BACKGROUND AND OBJECTIVES

Magnesium sulphate infusion during general anaesthesia reduces anaesthetic consumption and analgesic requirements. The aim of this study was to assess the effects of postoperative magnesium infusion on duration of block, sedation and analgesic consumption after spinal anaesthesia.

METHODS

Fifty ASA I-II patients were included in the randomized double blind study. Spinal anaesthesia was performed at L3-4 or L4-5 interspace with 12.5 mg 0.5% heavy bupivacaine, using a 25 G Quincke needle. Patients received a 5 mg kg(-1) bolus of magnesium sulphate followed by a 500 mg h(-1) infusion or saline in the same volumes for 24 h. Time to first pain, analgesic request, return of motor function, visual analogue pain and sedation scores were evaluated every 4 h during the 24 h postoperative period. The t- and U-tests were used for statistical analyses. Data were expressed as mean +/- SD, with P < 0.05 being considered significant.

RESULTS

Vital signs were stable during spinal anaesthesia and postoperative period. When compared to the control group, time to analgesic need was increased and total analgesic consumption was reduced in the magnesium group (meperidine consumption 60.0 +/- 73.1 mg control group, 31.8 +/- 30.7 mg magnesium group, P = 0.02).

CONCLUSIONS

Magnesium sulphate infusion may be used as an adjunct for reducing analgesic consumption after spinal anaesthesia.

Perioperative intravenous adenosine infusion to extend postoperative analgesia in brachial plexus block

BACKGROUND AND OBJECTIVE

Adenosine infusions have been shown to reduce requirements of anaesthetics, to decrease the need for postoperative analgesics and to attenuate hyperaesthesia related to neuropathic pain. We decided to investigate the effects, beneficial or otherwise, of an adenosine infusion administered during surgery. A brachial plexus block was used to produce anaesthesia for the surgery.

METHODS

Sixty adults undergoing upper extremity surgery were included in the study. Brachial plexus block was performed via an axillary approach with lidocaine 1.25% and epinephrine 1/200 000 (40 mL). Patients were randomly assigned to two groups. During surgery, saline (control) or adenosine 80 microg kg min was infused intravenously in a double-blind fashion for 1 h. Visual analogue scores every 4 h, analgesic consumption, time to first spontaneous pain sensation, time to first rescue analgesic and adverse effects were noted during the first 24 h.

RESULTS

Vital signs were stable in both groups throughout surgery. During the adenosine infusion, one patient fainted while another complained of palpitations and tightness of the chest; both patients were excluded from further analyses. The time to first sensation of pain was significantly longer in the adenosine group compared to the control group (438 +/- 387 vs. 290 +/- 227 min, P = 0.02). The time to first rescue analgesic, the visual analogue scale scores and analgesic consumption in the postoperative period were similar.

CONCLUSIONS

In patients undergoing surgery with an axillary plexus block, a perioperative adenosine infusion prolongs the duration of postoperative analgesia to some extent. However, the time to first rescue analgesic, total analgesic requirements and pain scores were unchanged; the risk of potentially serious adverse effects is high. This therapy cannot be recommended.

Combination of adenosine with prilocaine and lignocaine for brachial plexus block does not prolong postoperative analgesia

Adenosine analogues have been used by subarachnoid injection for the treatment of inflammatory and neuropathic pain. There is no data on the use of adenosine in peripheral nerve blocks. The aim of the present study was to determine the analgesic efficacy of adenosine in combination with a local anaesthetic solution for brachial plexus (BP) block. With local ethics committee approval, 50 consenting adult patients undergoing upper limb surgery were enrolled in this double-blind, prospective, randomized study. Patients with a history of bronchospastic disease were excluded. Patients were instructed not to take theophylline-containing drugs and beverages for at least one day before surgery or on the first postoperative day. A supraclavicular BP block was performed by injecting a mixture totalling 35 ml made up of prilocaine 1% 10 ml and lignocaine 2% 20 ml with adrenaline 1:200,000, and adenosine 10 mg in 5 ml saline (Group 1) or 5 ml saline (Group 2) as a placebo control group. Postoperative analgesia was assessed by time to first rescue analgesia, analgesic consumption in the first 24 hours, and VAS at rest at 4, 8, 12, 16, 20 and 24 hours. Side-effects were also noted. Vital signs were stable in both groups throughout the operation. There were no significant differences between the groups in onset of motor and sensory block. Time to first pain sensation from block was not significantly longer in the adenosine group (379 +/- 336 min) compared with controls (304 +/- 249 min, mean +/- SD, P = 0.14). Time to first analgesic requirements and analgesic consumption in the first 24 hours were also similar in both study groups. In the present study, the addition of adenosine to local anaesthetic in brachial plexus block did not significantly extend the duration of analgesia.

Effect of bispectral index monitoring on sevoflurane consumption

BACKGROUND AND OBJECTIVE

The bispectral index, a parameter derived from the electroencephalograph, has been shown to correlate with the loss of consciousness and sedation. This study was designed to assess the effects of bispectral index monitoring on sevoflurane and its recovery profiles.

METHODS

Sixty ASA I and II patients undergoing open abdominal surgery were randomized into two groups: one monitored using the bispectral index (Group BIS) and the other without its use (controls). After a standardized induction, anaesthesia was maintained with sevoflurane in both groups. In Group BIS, sevoflurane was titrated to maintain the bispectral index in the range 40-60. In the control group, the administered sevoflurane concentration was adjusted according to the signs of anaesthesia. The end-tidal sevoflurane concentration, bispectral index and routine haemodynamic variables were noted every 5 min during surgery. The consumption of sevoflurane was computed. At the conclusion of surgery operations, the time to 'open eyes on verbal command', 'motor response to verbal command' and Aldrete's score were recorded by a blinded anaesthesiologist.

RESULTS

The difference in the consumption of sevoflurane was not significant between the groups. Bispectral index monitoring was associated with a reduction of 4.73% in sevoflurane usage and 2.19 mL h(-1) was saved.

CONCLUSIONS

Bispectral index monitoring during anaesthesia provides only a small advantage related to the need to monitor the depth of anaesthesia.

A comparison of four intravenous sedation techniques and Bispectral Index monitoring in sinonasal surgery

This study was performed to investigate the quality of different intravenous sedation techniques, and the correlation between the Bispectral Index (BIS) values and the Observer's Assessment of Alertness/Sedation (OAA/S) scores. Eighty patients undergoing sinonasal surgery were randomly assigned to one of four groups. Group MF received midazolam and fentanyl, group PF received propofol and fentanyl, group MR received midazolam and remifentanil, and group PR received propofol and remifentanil. Heart rate and mean arterial pressure values were not different among the groups. SpO2 decreased only after intravenous medication in groups MF and MR (P < 0.017). Emesis was less common with propofol. A positive relationship existed between the BIS values and OAA/S scores during the operation in all groups and the strongest correlation was observed in group PR (r = 0.565 and P < 0.001). In conclusion, these four intravenous sedation techniques did not change mean arterial pressure, heart rate or SpO2 clinically and produced a similar level of light sedation. The BIS was useful for monitoring of sedation during sinonasal surgery under local anaesthesia with intravenous sedation.

Comparison of three analgesics for extracorporeal shock wave lithotripsy

OBJECTIVE

The aim of the study was to compare the clinical efficacy of three different analgesic drugs with respect to their level of sedation, analgesia and quick mobilisation without cardiopulmonary depression, for outpatient extracorporeal shock wave lithotripsy (ESWL) procedure.

MATERIAL AND METHODS

Sixty outpatients undergoing elective ESWL using a third generation lithotriptor were studied. The patients were randomly divided into three groups of twenty patients. All patients received midazolam (2 mg) intravenously five minutes before the procedure. In group F, fentanyl was given (1 microg kg(-1) IV) at the same time with midazolam. In group D, diclofenac sodium was given (1 mg kg(-1), IM) intramuscularly 45 minutes before ESWL. In group T, tramadol was given (1.5 mg kg(-1)) 30 minutes before ESWL. Arterial pressure, heart rate, respiratory rate and oxygen saturation were recorded before the procedure, after sedation, at the first minute, and every ten minutes during the procedure. Pain intensity was identified with a Visual Analogue Scale. The level of sedation was evaluated by using the Observer's Assessment of Alertness/Sedation Scale. All patients were asked to assess their satisfaction with the seven point Verbal Rating Scale before discharge. Side-effects were also recorded during the procedure.

RESULTS

The incidence of nausea and vomiting was higher in fentanyl group compared with the other groups. In patients who received fentanyl, the decrease of oxygen saturation at the first and tenth minute of the procedure was statistically significant (p < 0.05).

CONCLUSIONS

Diclofenac sodium and tramadol were found to be safe and effective analgesics with lower side-effects than fentanyl.

The effect of changing pressures on dural puncture and leak with various spinal needles on an in vitro model

Postdural puncture headache is one of the most serious complications of spinal anesthesia. In this study, spinal needles of various types and shapes were used to investigate the amount of fluid leakage in dural puncture under various levels of pressures. Dura samples received from 10 cadavers were fixed in an in vitro model. The dural punctures were inflicted with 22 G, 25 G, and 27 G Quincke; 25 G Withacre; 25 G, 27 G Pencan, and 26 G Atraucan spinal needles. The fluid, which leaked during the process, was collected under the pressures of 0, 25, 50, 100, and 150 cm H(2)O in one-hour period for each level. The holes in the dura were studied under light microscope. While 22 G and 25 G Quincke needles were used, the fluid leakage directly correlated the amount of liquid, the diameter of the needle, and the pressure used. The puncture of 25 G Withacre and 25 G Pencan presented a leakage which did not significantly vary with the liquid pressure and was of lesser amount. In 26 G Atraucan, 27 G Pencan, and 27 G Quincke inflicted punctures, little liquid was collected and it did not vary with differing pressures. Thus, no significant correlation was established between the needle diameter and the puncture. It was concluded that the sharp-ended needles could not endure changes in the pressure. However, those needles with a very thin diameter and a pencil tip were considered as safe tools for anesthetical practices.

Perception of bronchoconstriction in elderly asthmatics

The impaired perception of bronchoconstriction in asthmatic patients may increase the risk of severe exacerbation. To characterize the perception of bronchoconstriction in elderly asthma patients, we compared the perception in older patients with that of younger patients. To determine the influence of perception of long-standing diseases, we further evaluated the perception in early-onset elderly asthma patients and in late-onset elderly asthma patients. The study group consisted of 80 stable asthmatic patients. The patients were grouped according to their age (group 1, < 60 years, n = 37, group 2, > or = 60 years, n = 43). Each group was separated into two subgroups according to the duration of symptoms (late-onset asthma 1A and 2A, < 5 years, early-onset asthma 1B and 2B, > or = 5 years). A histamine inhalation test was performed for each patient. Dyspnea was assessed by modified Borg scale. The Borg score in forced expiratory volume in 1 sec (FEV1) reduction by 20% was determined as perception score 20 (PS20). The mean perception scores of the elderly asthmatic patients were significantly lower than those of the younger asthmatic patients (group 1, PS20 = 2.35 +/- 0.17; group 2, PS20 = 1.37 +/- 0.12, p < 0.0001). The differences of mean perception score (PS20) between early- and late-onset subgroups were insignificant (IA, 2.63 +/- 0.30 and IB, 2.07 +/- 0.16, p = 0.101; 2A, 1.36 +/- 0.19 and 2B, 1.59 +/- 0.120, p = 0.91). The mean perception scores of male asthmatic patients were significantly lower than those of female patients (p = 0.03). There was a correlation between PS20 and % FEV1 in the younger group (r = 0.392, p = 0.02), but not in the elderly group (r = 139, p = 0.375). The correlation between PS20 and PD20 in both younger and elderly group was insignificant (p > 0.05). Elderly asthmatics perceive less intense respiratory distress for a decrease of 20% in FEV1 than do younger asthmatics. This underperception of bronchoconstriction may result in a delay in medical care during an acute asthmatic episode. Thus, we strongly recommend that elderly asthmatic patients should be followed up more frequently and closely.

Efficacy of topotecan treatment on an experimental model of transient evoked otoacoustic emissions

OBJECTIVE

The aim of this study was to investigate the effects of topotecan (Hycamtin), a topoisomerase I inhibiting anticancer agent, on Transient Evoked Otoacoustic Emissions (TEOAEs) of the rabbits. We planned to investigate whether this test might provide a method for monitoring early ototoxic influence of drug administration to the cochlea.

METHODS

The study was conveyed in two groups each consisting of five rabbits with a total of ten ears. Rabbits in group I received i.v. topotecan (0.5 mg/kg once daily) for 3 days. Rabbits in group II received i.v. topotecan (0.25 mg/kg once daily) for 3 days. Cochlear function was serially monitored using transient evoked otoacoustic emissions before administration (BA) and on the 4th and 15th days after administration of topotecan. TEOAEs were analysed in terms of mean stimulus, stability and emission amplitude at 1.0-4.0 kHz.

RESULTS

For group I and II, intergroup and intragroup differences were not statistically significant in the mean stimulus, stability and emission amplitudes at 1.0-4.0 kHz.

CONCLUSIONS

We evaluated the potential role of TEOAEs in early identification of cochlear dysfunction induced by topotecan. It was concluded that topotecan did not have ototoxic effects on the cochlea in the early period of administration. TEOAEs may be useful to monitor the cochlear function and to detect the late stage of ototoxicity especially in the presence of potentially toxic factors for the prevention of permanent damage.

Surface landmarks of brachial plexus: ultrasound and magnetic resonance imaging for supraclavicular approach with anatomical correlation

The present study is able to describe a certain line, under which brachial plexus (BP) lies underneath in the supraclavicular region. A line drawn between midpoint of the sternocleidomastoid muscle to the midpoint of the clavicle was considered for BP. Surface landmarks were evaluated by applying ultrasound (US) on 30 volunteers (15 female, 15 male). Axial and sagittal views of BP were taken and distances between skin and BP were measured. Coronal magnetic resonance (MR) sections were taken from 7 volunteers according to the second line after applying two fat capsules on each line. The sonographic views were seen at the same line. Mean distances from skin were found as 16.5+/-0.7 mm for male and 14.5+/-0.5 mm for female volunteers. MR images were obtained bilaterally, which were parallel and posterior from sonographic lines. Surface landmarks, as presented in this study, are simple to accomplish and are not dependent on structural variations as external jugular vein.

Can skin surface pressure under a cast reveal intracompartmental pressure?

Although monitoring intracompartmental pressure (IP) under a cast is very important, it is not possible to measure it in every patient undergoing cast treatment. This study aims to answer the question of whether skin surface pressure (SSP) under a cast can reveal IP. A plaster cast was applied to a sculpted inflatable forearm model with dorsal and volar compartments. SSP under the cast was measured at five different localizations from both dorsal and volar sides of the model and compared to the corresponding IP. In the second experiment, a posterior tibial compartment syndrome model was created in both limbs of five rabbits. Correlation analysis was performed between IP and SSP under the cast. All of the SSP measurements taken from the dorsal and volar side of the sculpted forearm model correlated with IP. Mean correlation coefficient of the measurements was 0.995 (P = 0.000) (SD 0.002, range 0.992-0.999). SSP and IP correlation analysis in the posterior tibial compartment syndrome model of 10 limbs in five rabbits revealed a high correlation. The mean correlation coefficient was 0.973 (P = 0.000) (SD 0.024, range 0.916-0.997). Measuring the pressure between the skin and cast can monitor IP. SSP monitoring can help the physician, patient or parents in the follow-up of patients undergoing cast treatment.