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Biomedical subjects

R S G M Perez

Publications and source records attributed to R S G M Perez.

9 recordsLinked to original sources
PubMed2006

[Limited possibilities for the evidence-based treatment and prevention of postherpetic neuralgia].

Postherpetic neuralgia is a disorder that occurs frequently in the elderly. As the effect of the treatment of postherpetic neuralgia is often disappointing, studies have focussed on the prevention of this complaint. A commonly used preventive intervention is the administration ofa single epidural injection of a local anaesthetic and a corticosteroid, combined with oral antiviral agents and analgesics. In a large, multicentre, randomised controlled trial, the investigators found that the single injection of a corticosteroid and a local anaesthetic had no added value in the prevention of long-term postherpetic neuralgia.

Anesthetics, Local↗
PubMed2006

Compound A and carbon monoxide production from sevoflurane and seven different types of carbon dioxide absorbent in a patient model.

BACKGROUND: The degradation of sevoflurane can lead to the production of compound A (CA) and carbon monoxide (CO) and an increase in temperature of the absorbent. CA is known to be nephrotoxic in rats. These reactions depend on the strong base and water contents of the carbon dioxide absorbent used. The purpose of this study was to measure the maximum amounts of CA and CO produced, and the temperature increase, for seven different carbon dioxide absorbents for sevoflurane containing different contents of strong bases. METHODS: Seven absorbents [some free of strong bases (f)] were employed in hydrated (h) and completely desiccated (d) conditions in a patient model, using a circle anesthesia system connected to an artificial lung. Low-flow anesthesia with an oxygen-nitrous oxide mixture was maintained using 0.8% sevoflurane. For the quantification of CA and CO, a portable gas chromatograph was used. The temperature was measured inside the absorbent. RESULTS: In consecutive order of CA-producing potency, Amsorb(f)(d), Drägersorb(h), Medisorb(h), lithium hydroxide(f)(d), Drägersorb(d), Medisorb(d), Spherasorb(h) and Spherasorb(d) produced small amounts of CA. Loflosorb and Superia, which are free of strong bases, did not produce any CA or CO in hydrated or desiccated conditions. Only desiccated Drägersorb, Medisorb and Spherasorb demonstrated small amounts of CO accompanied by a significant temperature increase. CONCLUSION: In this patient model, we demonstrated that different types of absorbent produced small amounts of CA and CO or none at all. No relationship could be established between temperature and CA concentration.

Absorption↗
PubMed2006

Defining pain.

Explore the source record for details and available documents.

Humans↗
PubMed2005

Predictive value of symptom level measurements for complex regional pain syndrome type I.

The validity with respect to presence or absence of CRPS I according to Veldman's criteria was assessed for measured pain, temperature, volume differences and limitations in range of motion. Evaluated were 155 assessments of 66 outpatients, initially diagnosed with CRPS I, but many of them not so on follow up visits. Pain was measured with VAS and McGill, temperature by infrared thermometry, volume differences by water displacement volumeters and limitations in range of motion by universal goniometers. Sensitivity, specificity, positive and negative predictive value of the measurement instruments at different cut-off points was calculated. Combined symptom scores were evaluated in a similar fashion. High sensitivity was found for the VAS, McGill, and range of motion. The specificity was overall lower, but highest values were obtained for volume differences. The positive predictive value was good for all measurement instruments. Negative predictive value was lower, especially for measurement of temperature and volume asymmetries. If sensitivity and specificity are equally important, VAS>3 cm, McGill>6 words, temperature difference>or=0.4 degrees C, volume difference>6.5% and ROM limitation>15% provide the best results. Using these cut off values, the highest value of sensitivity and of sensitivity and specificity combined, was found for a combination of VAS, McGill and ROM. The highest value of specificity was found for different combinations of 3, 4 and 5 instruments, all containing the VAS. We conclude that the measured pain, temperature, volume and range of motion can be used as diagnostic indicators for establishing presence or absence of CRPS I.

Adult↗
PubMed2005

Postoperative condition after the use of remifentanil with a small dose of piritramide compared with a fentanyl-based protocol in patients undergoing craniotomy.

BACKGROUND AND OBJECTIVE: The use of remifentanil requires other analgesics for postoperative pain relief compared to fentanyl in patients undergoing craniotomy. This could possibly reduce the postoperative advantages of this short-acting opioid. METHODS: We compared remifentanil and fentanyl-based anaesthesia in a randomized observer and patient blinded trial on patients, undergoing an elective craniotomy. Twenty patients received anaesthesia using remifentanil with a small dose of piritramide (0.1 mg kg(-1)) after closure of the dura mater. Twenty patients underwent a fentanyl-based protocol. In both groups, anaesthesia was induced with thiopental and rocuronium, and maintained with 0.6-1 minimum alveolar concentration (MAC) isoflurane in a nitrous oxide/oxygen mixture 2:1 and rocuronium. Patients received 1 g of paracetamol rectally postoperatively. A visual analogue scale (VAS) for pain, the Glasgow Coma Score, a modified Aldrete Score, arterial carbon dioxide tension (PaCO2) and piritramide consumption were evaluated every half an hour postoperatively. RESULTS: No significant differences were found for pain, Aldrete or Glasgow Coma scores or for PaCO2 between the groups when controlled for age, although the pain and Glasgow Coma Scores were consistently higher and PaCO2 lower in the remifentanil group. Furthermore, 11 out of 20 patients in the remifentanil group requested extra piritramide as opposed to 7 out of 20 in the fentanyl group (P = 0.11). CONCLUSIONS: Despite the intraoperative use of piritramide in the remifentanil group, patients experienced more pain postoperatively. A significant influence of age on pain intensity was found. The use of remifentanil with a small dose of piritramide of 0.1 mg kg(-1) has no evident advantage over the use of fentanyl considering the postoperative conditions after craniotomy.

Adolescent↗
PubMed2005

Carbon monoxide production from desflurane and six types of carbon dioxide absorbents in a patient model.

BACKGROUND: Desflurane is known to produce high concentrations of carbon monoxide (CO) in desiccated sodalime or Baralyme (Allied Healthcare Products, St. Louis, MO). Desiccated absorbents without strong bases like potassium hydroxide or sodium hydroxide are reported to produce less or no CO at all. The purpose of this study is to compare the concentration of CO in an anesthesia circuit for desflurane with six different types of completely desiccated CO(2) absorbents with less strong bases than sodalime. METHODS: A patient model was simulated using a circle anesthesia system connected to an artificial lung. Completely desiccated CO(2) absorbent (950 g) was used in this system. A low flow anesthesia (500 ml min(-1)) was maintained using desflurane. For immediate quantification of CO production a portable gas chromatograph was used. RESULTS: Peak concentrations of CO were very high in Medisorb (Datex-Ohmeda, Hoevelaken, The Netherlands) and Spherasorb (Intersurgical, Uden, The Netherlands) (13317 and 9045 p.p.m., respectively). It was lower with Loflosorb (Intersurgical, Uden, The Netherlands) and Superia (Datex-Ohmeda, Hoevelaken, The Netherlands) (524 and 31 p.p.m., respectively). Amsorb (Armstrong, Coleraine, N. Ireland) and lithium hydroxide produced no CO at all. CONCLUSION: Medisorb and Spherasorb are capable of producing large concentrations of CO when desiccated. Loflosorb and Superia produce far less CO under the same conditions. Amsorb and lithium hydroxide should be considered safe when desiccated.

Absorption↗
PubMed2004

Dosage scheme for propofol in children under 3 years of age.

BACKGROUND: Propofol is a well-known drug for adults for total intravenous anaesthesia. Since 1999, the use of propofol has been approved for children less than 3 years of age. However, a suitable dosage scheme for these age groups was not available. The purpose of this study was to describe our clinical experience with the use of a new dosage scheme for propofol in patients under 3 years of age, based on experimental data and known pharmacological principles in children. METHODS: A pilot study of 50 patients undergoing TIVA was performed to adapt the existing adult dosage scheme to the requirements of the younger population. Total number and time of administration of boluses and time to awakening were registered and used as criteria to adjust the dosage scheme. The subsequent dosage scheme was then evaluated in 2271 children undergoing anaesthesia for various procedures. Usual anaesthetic parameters were measured to monitor the safety of the patient: ECG, O2 saturation, respiratory frequency and blood pressure. Most of the patients were mechanically ventilated; only 15% were breathing spontaneously. RESULTS: Overall, few side effects were recorded [bradycardia (12%), blood pressure fall (8%), desaturation (1%)], which were easily countered by routine measures. CONCLUSIONS: This dosage scheme provides safe and smooth anaesthesia in children less than 3 years of age and is therefore a useful tool for a TIVA technique in small children.

Anesthesia, Intravenous↗
PubMed2002

Interrater reliability of diagnosing complex regional pain syndrome type I.

BACKGROUND: Diagnosis of complex regional pain syndrome type I (CRPS I) is based on clinical observation of symptoms. As little information is available on the reliability of CRPS I diagnosis, we evaluated the agreement between therapists with regard to the presence and severity of CRPS I and its symptoms. METHODS: The interrater reliability was evaluated in 37 presumed CRPS I patients by three observers; one consultant anesthesiologist and two resident anesthesiologists. Patients were assessed on the basis of Veldman's CRPS criteria. RESULTS: The interrater reliability for diagnosing CRPS I was good for the majority of observer combinations. The percentage of agreement for the absence or presence of CRPS I was good (88%-100%). Cohen's Kappa's ranged from 0.60 to 0.86. The agreement for the mean symptom score ranged from 70.2% to 88.6%; Kappa's were lower and showed more variation. Interrater reliability for assessment of the severity of CRPS I and its symptoms was poor. Factors influencing the interrater reliability were symptom type, individual observers and sample population. CONCLUSION: Diagnosing CRPS I can be performed on the basis of clinical observation. Further assessment of severity of CRPS I and its symptoms should be performed with reliable and valid measurement instruments.

Adult↗