Mohammad Maroof

Hypobaric spinal anaesthesia with bupivacaine (0.1%) gives selective sensory block for ano-rectal surgery

Twenty adult male patients undergoing anorectal surgery in the jackknife position under spinal anaesthesia were studied for the anaesthetic properties of 5 ml hypobaric 0.1% bupivacaine. The patients were positioned in the prone, jack-knife position with a pillow under the hips and with an operating table break angulation of 30° with head down tilt of 20°. In this position a 25-gauge Quincke spinal needle was inserted intrathecally through L3–4 and 5 ml solution, prepared by mixing 1 ml bupivacaine 0.5% with 4 ml of distilled water with a specific gravity of 1.001 at 20° C, was given over 15–20 sec. Onset time, progression and upper level of sensory blockade evaluated by pin prick, and the extent of motor block (1 = full motor movement at ankle and knee joint, 2 = restricted motor movements, 3 = full motor block, no movements) were measured at one minute intervals for the first five minutes, then every five minutes for 30 min. The number of dermatomes blocked was abo noted. The median level of cephalad sensory blockage was of L1, with a range from T10–L3. On average, nine dermatomes were blocked (range 7–12). Motor blockade was not observed in any patient. Changes in heart rate and blood pressure were minimal. The average duration of postoperative analgesia was 339.5 ± 182.9 min. Post-spinal headache was not observed in any patients. In conclusion, 5 ml intrathecal hypobaric bupivacaine, 0.1%, provided excellent perioperative analgesia without motor blockade and haemodynamic stability in patients undergoing anorectal surgery in jackknife position.RésuméLes propriété anesthésiques de la bupivacaine hypobare 0,1% 5 ml en rachianesthésie sont étudiées chez vingt sujets de sexe masculin cubissant une chirurgie anorectale en position de décubitus ventral cassée. Les patients sont installés en décubitus ventral avec un oreiller sous les hanches et la table d’opération est cassée pour faire un angle de 39° et la tête inclinée vers le bas pour un angle de 20°. Dans cette position, une aiguille rachidienne Quincke 25 G est insérée dans l’espace sousarachnoïdien L3–L4 une solution de 5 ml contenant un ml de bupivacaine 0,5% avec quatre ml d’eau distillée pour une gravité spécifique de 1,001 à 20° C est injectée en 15–20 sec. Le début d’installation, la progression et le niveau supérieur du bloc sensitif sont évalués à la piqûre d’aiguille. L’étendue du bloc moteur (1 = motricité intacte à la cheville et au genou, 2 = motricité limitée, 3 = bloc moteur complet) est mesurée à intervalles d’une minute pour les cinq premières minutes et à toutes le cinq minutes pour 30 min. Le nombre de dermatomes bloqués est aussi noté. Le niveau moyen du bloc céphalique sensitif se situe à L1 avec un écart de T10 à L3. En moyenne, neuf dermatomes sont bloqués (écart 7 à 12). Aucun des patients ne présente de bloc moteur. Les altérations de la fréquence cardiaque et de la pression artérielle sont minimes. L’analgésie postopératoire persiste pendant 339 ± 182,9 min. Aucun patient ne se plaint de céphalée postdurale. Pour conclure, 5 ml de bupivacaine 0,1% hypobare procurent en rachianesthésie une excellente analgésie périopératoire, sans bloc moteur, et la stabilité hémodynamique à des patients qui subissent une chirurgie anorectale en position de décubitus ventral cassé.

Ventilation with nitrous oxide during open cholecystectomy increases the incidence of postoperative hypoxemia

The effect of intraoperative use of air versus nitrous oxide (N2O) on postoperative oxygen (O2) saturation in blood was evaluated in 40 ASA Class I and II patients undergoing elective, open cholecystectomy. Patients were allocated randomly to two groups on the basis of whether they received air (Group At n = 20) Or N2O (Group B, n = 20) intraoperatively. Oxygen saturation was recorded on arrival of the patients in the ward, 24 h, and 48 h postoperatively. Although mean O2 saturation did not differ significantly (P > 0.05) between the groups Over the first 24 h postoperatively, it was significantly higher (p < 0.05) in Group A as compared to Group B 48 h postoperatively. Incidence Of hypoxemia (O2 saturation < 90%) was 40% in Group B as compared to 0% in Group A at the end of 48 h postoperatively. We conclude that the use of N2O during cholecystectomy is associated with a higher incidence of hypoxemia postoperatively.

Difficult diagnostic laryngoscopy and bronchoscopy aided by the laryngeal mask airway.

A case of difficult diagnostic rigid bronchoscopy is described. However, flexible fibrescopy could be easily performed through a laryngeal mask airway despite complete lack of experience by the operator. Excellent visualization of the larynx and bronchial tree with minimal haemodynamic disturbance accompanied the technique.

LMA and the stylet: a source of new strength for the old mask.

Laryngeal mask airway (LMA) has become increasingly popular as a safe and satisfactory alternative to tracheal intubation in many clinical situations since its introduction in the mid 1980s. The most common problem with LMA insertion is difficulty in negotiating the posterior pharynx, a problem which can be enhanced severalfold if the LMA loses its normal curvature. Although LMA (Intavent) can withstand repeated autoclaving, we have observed that it has a tendency to become soft and lose its curvature as is evident in Figure 1 in which an aging LMA (straight) is compared to a new LMA (curved). Because the LMA is an expensive piece of equipment, we have devised a way to use these aging LMAs successfully employing a stylet. We have observed that a stylet not only restores the curvature of the LMA but helps to maintain a firm backward as well as downward pressure on the mask as it is placed in its correct final position. Once correctly placed, removal of the stylet does not misplace the LMA because soft tissue structure around it keeps it secure. The stylet should not protrude beyond the grates of the mask.

Modified laryngeal mask as an aid to fiberoptic endotracheal intubation.

Sir, The Laryngeal Mask Airway (LMA), with or without a fiberscope, has been successfully used to facilitate intubation with an endotrachea1 tube (ETT) of 6.0 mm or less i.d. ( I , 2) . To enable LMA-aided fiberoptic intubation with an even larger diameter ETT ( > 6.0 mm i.d.), we have recently modified a size 3 LMA and we use it in the manner highlighted by the following case report. A 24-year-old, 85.4-kg man presented for nasal septoplasty. Physical examination was normal except for mild obesity and a thick, short neck. Pre-medication comprised 50 mg pethidine and 25 mg promethazine administered intramuscularly 1 h prior to anaesthesia. Just before induction, his heart rate, blood pressure and Sao, were 128/73, 78/min and 99%, respectively. Following 3 min pre-oxygenation, anaesthesia was induced with intravenous thiopental (400 mg) and fentanyl (50 mg). Atracurium (40 mg) was used to achieve relaxation. With the onset of adequate relaxation, conventional laryngoscopy was tried twice but neither the vocal cords nor the epiglottis could be visualised. It was therefore decided to use our combination of Modified Laryngeal Mask Airway (MLMA) and