Role of Low Dose Preoperative Dexmedetomidine in Preventing Tourniquet Induced Hypertension in Paediatric Orthopaedic upper Limb Surgeries during General Anaesthesia.

Background: Pneumatic Tourniquets are commonly used in orthopaedic surgery of the extremities to reduce bleeding and to provide a clear field to the surgeon, but severe pain often complicates the tourniquet inflation. Although the mechanism of tourniquet induced hypertension (TIH)is not well understood, the autonomic nervous system plays an important role. Hence, Dexmedetomidine, a potent a2-adrenoceptor agonist may prevent hyper adrenergic responses and can be of prophylactic value for tourniquet induced hypertension. Methods: Forty American Society of Anesthesiologists (ASA) physical status class I and II children, aged 5-12 years, posted for Orthopaedic surgery of upper limbs under general anaesthesia with tourniquet application were included in the study. They were randomly assigned to receive intravenous Dexmedetomidine (Group D; n=20) or normal saline (Group C; n=20) before tourniquet inflation. Incidence of TIH, Mean Arterial blood pressure and heart rate were recorded. Results: There were no significant differences between the baseline characteristics. The incidence of TIH in group D was significantly less than the group C (20%) as compared to group D (70%).There was significant increase in the heart rate of placebo group after 30 minutes of tourniquet inflation while there was minimal variability of heart rate in the group D. In the group D, arterial pressure was not significantly changed, but in the group C, the arterial pressure was significantly increased after 20 minutes of tourniquet inflation. No significant adverse effects were noted in any group. Conclusion: Preoperative low dose intravenous Dexmedetomidine prevents tourniquetinduced hypertension in paediatric patients undergoing general anaesthesia for upper limb surgeries.

A Randomised Controlled Trial of Infiltration versus Low Dose Subarachnoid Block in Hydrocele Surgery.

Background: Hydrocele surgery is a short surgical procedure requiring an anaesthetic technique that allows good surgical anaesthesia, short recovery time and minimal side effects. This study was designed to compare the traditionally used technique of local infiltration block and subarachnoid block using 1% lidocaine with 25mcg of fentanyl in patients undergoing hydrocele surgery. Methods: Sixty ASA grade I and II patients of 18-60 years of age, scheduled for hydrocele surgery were randomly assigned to two groups of 30 patients each. Group C patients received local infiltration using 1% lidocaine (maximum upto 5mg /kg) while Group I patients received intrathecal injection of 1% lidocaine with 25 mcg of fentanyl (1.5 ml of 2% lidocaine + 1 ml of normal saline + 0.5 ml fentanyl). The subjects were assessed in terms of physiological variables, the quality of analgesia, and incidence of side effects as compared to local infiltration technique. Results: Patients in group C required significantly more number of fentanyl boluses for pain as compared to patients in group I. The most common problem encountered in any group was backache with an incidence of 16.6% in group I and 6.6% in group C. Pruritus was reported to be 13.3% in group I but was absent in group C (P<0.05). However, it was mild and did not require any medication. 23 patients in group I regarded their experience of the perioperative period as excellent as compared to only 5 patients in group C. Time to void and to meet discharge criteria was comparable in both the groups. Conclusion: We conclude that the use of smaller dose lidocaine-fentanyl combination in spinal anaesthesia provides potent and excellent quality of analgesia with limited side effects without prolonging recovery as compared to 1% lidocaine infiltration in patients of hydrocele surgery.

Levobupivacaína o ropivacaína: un ensayo aleatorio doble ciego controlado con dosis equipotentes en la anestesia espinal / Levobupivacaine or ropivacaine: A randomised double blind controlled trial using equipotent doses in spinal anaesthesia

Introduction: Levobupivacaine and ropivacaine are relatively new local anaesthetics developed in order to address the issue of bupivacaine toxicity Although certain differences do exist between their pharmacological profiles, its clinical relevance at equipotent doses is not evident so far Objective: To compare the efficacy and characteristics of equipotent doses of intrathecal levobupivacaine with ropivacaine Methodology: Sixty ASA grade I/II patients of 18-60 years, either sex posted for lower limb orthopaedic surgery under spinal anaesthesia were randomly given either 15 mg levobupivacaine or 22.5 mg ropivacaine. Sensory and motor block, haemodynamic characteristics, as well as any side effects, were recorded Results: Onset of sensory block to T10 was more rapid in group R than group L, p < 0.0001. The median (range) height achieved in group R was T7 (T5-T10) while in group L was T7 (T4-T10). Time to reach maximum height and time to modified Bromage grade 3 was shorter in group R as compared to group L, p < 0.0001. Levobupivacaine produced significantly longer (290.50 ± 34.67) duration of motor block compared to ropivacaine (222.50 ± 23.00). Duration of analgesia was significantly longer in group L (309.83 ± 36.45) than group R (249.50 ± 22.83). No serious adverse effects were recorded. Conclusion: Levobupivacaine produces significantly longer duration of analgesia than ropivacaine when used in a ratio of 0.6:1. Efficacy, toxicity and haemodynamic profile make ropivacaine suitable agent for surgeries with low threshold for hypotension.

Introducción: La levobupivacaína y la ropivacaína son anestésicos locales relativamente nuevos, desarrollados con el fin de abordar la cuestión de la toxicidad de la bupivacaína. Aunque existen ciertas diferencias entre sus perfiles farmacológicos, su relevancia clínica en dosis equipotentes no es evidente hasta ahora. Objetivo: Comparar la eficacia y las características de las dosis equipotentes de levobupiva-caína por vía intratecal con las de ropivacaína. Metodología: A Sesenta pacientes de grado ASA I/II de 18 a 60 años y de ambos sexos, programados para cirugía ortopédica del miembro inferior bajo anestesia espinal, se les dio al azar o bien 15 mg de levobupivacaína o 22,5 mg de ropivacaína. El bloqueo motor, el bloqueo sensorial, las características hemodinámicas y cualquier otro efecto secundario fueron registrados. Resultados: El inicio del bloqueo sensorial en T10 fue más rápido en el grupo R que en el grupo L, p < 0,0001. El nivel mediano (rango) alcanzado en el grupo R fue T7 (T5-T10), mientras en el grupo L fue T7 (T4-T10). El tiempo para alcanzar el nivel máximo y para alcanzar un grado 3 en la escala de Bromage fue más breve en el grupo R en comparación con el grupo L, p < 0,0001. La levobupivacaína produce una duración significativamente más larga (290.50 ± 34.67) del bloqueo motor que la ropivacaína (222.50 ± 23.00). La duración de la analgesia fue significativamente más larga en el grupo L (309.83 ± 36.45) que en el grupo R. No se registraron efectos adversos graves. Conclusión: La levobupivacaína produce una duración de la analgesia significativamente más larga que la ropivacaína cuando se utiliza en una proporción de 0,6:1. La eficacia, toxicidad y perfil hemodinámico hacen de la ropivacaína un agente adecuado para cirugías con un umbral bajo de hipotensión.

Double Trouble: A Case of Local Anaesthetic Toxicity Followed By Tension Pneumothorax in a Patient of Marfan Syndrome.

Spontaneous pneumothorax in patients with Marfan syndrome is common. Even a small pneumothorax can become a tension pneumothorax under positive pressure ventilation. Sometimes anaesthesiologists have to cater to more than one complication intraoperatively. Thorough knowledge of the subject and availability of monitors and anaesthesiologist in the operation theater as in general anaesthesia during locoregional anaesthesia is mandatory to avoid occurrence of catastrophy.