Comparison of efficacy of labetalol and fentanyl for attenuating reflex responses to laryngoscopy and intubation.

Stress response due to laryngoscopy and intubation has been universally recognized phenomenon resulting in increase in heart rate, arterial, intracranial, and intraocular pressure. Various pharmacological approaches have been used to blunt or attenuate such pressure responses. This prospective, randomized, placebo controlled, double blinded study was designed to compare the efficacy of bolus dose of Labetalol and Fentanyl for attenuating reflex responses to laryngoscopy and intubation. Ninety patients with physical status of ASA I and II were scheduled for elective surgery under standard protocol of general anaesthesia, randomly allocated into three groups, consisting of 30 patients in each group, assigned as C (Control), L (Labetalol), and F (Fentanyl). In control group 10ml of 0.9% saline, in Labetalol group 0.25 mg/kg Labetalol and in Fentanyl group 2µgm/kg of Fentanyl were given intravenously at 3 minutes prior to laryngoscopy and intubation. Pulse rate, systolic, diastolic, mean arterial pressure and rate pressure products (RPP) were recorded before and after premedication, after administration of study drugs and at 1, 3, 5, 10 and 15 minutes after intubation. For statistical analysis of data, ANOVA tests were performed for comparison between groups. There were an increase in heart rate, systolic, diastolic, mean arterial pressures and rate pressure product in all the three groups after intubation in comparison to base line value. But the rise was minimum in L and F group as compared to C group which is statistically significant and also minimum in L group as compared to F group. So Labetalol is better agent for attenuation of laryngoscopic and intubation reflex.

Haemodynamic and end tidal CO2 changes during laparoscopic cholecystectomy under general anaesthesia.

A prospective observational study was done on 50 patients to investigate the haemodynamic and end tidal CO2 (EtCO2) changes in healthy patients without cardiopulmonary pathology during elective laparoscopic cholecystectomy in head up position under standard protocol of general anaesthesia. During surgery, intra abdominal pressure was maintained at 15 mmHg by a CO2 insufflator and minute ventilation was controlled with a constant tidal volume and fixed respiratory rate. Haemodynamic parameters, EtCO2, SpO2 and ECG were recorded before and after induction and positioning of the patients and at 5 minutes interval for the first 30 minutes, then 10 minutes interval for the rest of the period. Highly significant increase (p<0.001) in pulse rate, systolic, diastolic and mean arterial pressure occurred at 30 minutes after insufflations and positioning of the patient. A very highly significant (p<0.001) increase in EtCO2 from the base line was at 40 minutes after insufflations and positioning of the patients. There was no change in SpO2 and ECG. This study supports the significant physiological changes in terms of haemodynamic and EtCO2 during laparoscopic cholecystectomy and recommends the meticulous monitoring of these parameters during the surgery and balance the benefit of laparoscopy against the intra operative risk.

Preoperative use of granisetron plus dexamethasone and granisetron alone in prevention of post operative nausea and vomiting in tonsillectomy.

This prospective study was done for to see the efficacy of preoperative use of granisetron plus dexamethasone (Group A) & granisetron (Group B) alone for the postoperative prevention of nausea & vomiting after tonsillectomy operation. One hundred patients undergoing tonsillectomy & adenoidectomy operation under general anaesthesia who were admitted in the Mymensingh Medical College Hospital during the period from July 2008 to June 2009 with American Society of Anaesthesiologists (ASA) grade I & II with age 3-40 years, body weight 10-60 kgs, were studied. Observation of this study was analyzed in the light of comparison between the two groups. All results were expressed as mean±SEM. Age in Group A 15.98±1.028 & Group B 17.18±0.961 years; Weight in Group A 38.40±1.492 & Group B 39.76±1.561 kgs and operational duration in Group A 52.60±0.786 & Group B 52.70±0.823 minutes. The studied groups were statistically matched for age, weight, duration of surgery. We observed that the effects of combination of granisetron & dexamthasone are more than granisetron alone in prevention of nausea & vomiting after tonsillectomy operation. The frequency of vomiting was 4% in combination & 16% in single therapy which is statically significant (p<0.05).

Electrosurgical smoke: a real concern.

Electrosurgical techniques including laser surgery have expanded greatly in recent years. Pyrolysis of tissue produces smoke. Recently the smoke is being analyzed using Gas Chromatography-Mass Spectrometry. The nature of smoke depends on the rise of temperature of tissue during electro-surgery. The smoke produced at high temperatures contains low concentration of Group-I carcinogens (IARC) such as Benzene, Hydrogen cyanide, Formaldehyde 1,3-Butadiene and Acrylonitrile. Bioaerosol produced at low temperature as in harmonic scissors may contain live multidrug resistant Mycobacterium tuberculosis, viral DNA of HBV, HCV, HIV and HPV. It also contains live malignant cells and dead cellular materials. These produce an unquantified infection risk. The obnoxious smoke causes ocular and upper respiratory tract irritation, creates visual problems for surgeons. Surgical masks are not capable of filtering the produced bioaerosol. Removal of smoke from the site of operation by local exhaust ventilation is not complete. When produced in a closed cavity as in laparoscopic surgery the patient also suffers from carboxyhaemoglobinaemia and methaemoglobinaemia. Methemoglobinaemia is not detected by standard pulse-oximetry. Laser smoke produces congestive interstitial pneumonia, bronchiolitis and emphysema in rats. Chromosomal aberration and sister chromatid exchange have been found in lymphocyte culture of operating room personnel. Occupational safety and health authorities like Occupational Safety and Health Administration (OSHA), National Institute for Occupational safety and Health (NIOSH), American National Standard Institute (ANSI) and Association of Operating room nurses (AORN) are trying to find effective ways for removal of smoke from site of operation and also the real risk to operating room personnel. Answer lies in minimizing the use of electrocautery whenever possible and completes removal of harmful smoke.

Anesthesia for emergency cesarean section.

Caesarean Section is one of the most common of all surgical procedures. Common indications for caesarean section may include foetal distress, Cephalopelvic disproportion and failure of labour to progress. Both regional and general anesthesia may be employed for caesarean section. Each is relatively safe and they have their own advantages and disadvantages. Actual decision to adopt one technique over another depends on maternal and foetal status and skill and ability of the anesthesiologist to tackle the situation with the aim of patient and baby safely. Among these, many of the cases come to the hospital as emergency basis. The Anesthesiologists have to face the challenge in providing anesthesia for emergency caesarean section, being the last member in the perinatal team. The challenge faces the risks in involvement of maternal changes in pregnancy, presence of foetal distress and various anesthetic complications arising in perioperative period. Still now anesthetic mishaps are considered as the sixth most frequent cause of maternal mortality. The use of regional Anesthesia reduced the number of deaths at about 80% but deaths involving general anesthesia has not decreased and the incidence is 17 times more than the regional anesthesia. Most of the deaths or complications are related to the airway management (also failed intubation). Better skill and knowledge in physiology, pharmacology and use of modern Anesthetic technique is essential to face the problems.