Soma Kaushik

Carbamezapine for pain management in Guillain-Barré syndrome patients in the intensive care unit.

Objective: To evaluate carbamezapine (CBZ) for neuritic pain relief in Guillain‐Barré syndrome (GBS) patients in the intensive care unit (ICU). Design: Prospective, double‐blind, randomly allocated crossover study days. Setting: ICU in a tertiary care university hospital. Participants: Twelve consecutive, conscious adult (22‐54 yrs) patients with GBS during recovery from the muscular weakness and receiving pressure‐support ventilation in the ICU. All patients complained of severe backache and/or leg cramps and tenderness in muscles, and they required opioids for pain relief. Interventions: CBZ (100 mg every 8 hrs) or equivalent placebo was given to nursing staff in coded powder form. Medication was given to patients through a nasogastric feeding tube. The same coded medicine was given for 3 days, and after a 1‐day omission, a second set of coded powder was given for the next 3 days in a randomized, double‐blind, crossover fashion. Pethidine (1 mg·kg−1) was given intravenously in between, if the pain score was >2. Group 1 (n = 6) patients were given a placebo on the first 3 days, followed by CBZ. Group 2 (n = 6) patients were given CBZ on the first 3 days, followed by a placebo. Measurements and Main Results: In these two study periods of different medications, we observed and scored pain (1, no pain; 5, severe pain), sedation (1, alert; 6, asleep, does not respond to verbal command), and total pethidine requirement per day. In group 1 patients, a significant (p < .001) improvement in the sedation score and a low requirement for pethidine was observed 3 days later, when CBZ was started. However, in group 2 patients, a gradual increase in the pethidine requirement and a high sedation score were noteworthy in the later days of placebo medication. Observations were also analyzed for CBZ days vs. placebo days. Overall, the pain score (1.7 ± 0.8) during the CBZ period of both regimens was significantly (p < .001) lower than during the placebo days (3.1 ± 0.9). Significantly higher doses of pethidine (3.7 ± 0.9 mg/kg/day) were used on the placebo days than on the CBZ days (1.7 ± 1.0 mg/kg/day). Conclusion: The pain in GBS has a dual origin, and we recommend CBZ as an adjuvant to treat pain in GBS patients, during the recovery phase in the ICU, to reduce the narcotic requirement.

Percutaneous dilational tracheostomy : The Ciaglia method versus the Rapitrach method

In a prospective study, we performed percutaneous dilational tracheostomy (PDT) using either the Ciaglia method (gradual dilation) or the Rapitrach method (single dilation) in 80 patients.We encountered difficulty in dilating the tracheal stoma of three (7.5%) patients in the Ciaglia group because of tight pretracheal fascia. It was difficult to insert the tracheostomy tube in four (10%) patients in the Rapitrach group even after appropriate tracheal dilation. However, the tracheal cannulation was successfully completed in all patients in subsequent attempts. The mean time for completion of the procedures, from skin incision to insertion of the tracheostomy tube, was 14 +/- 5.5 min with the Ciaglia method and 6.5 +/- 3.5 min with the Rapitrach method. PDT with either method has not been associated with clinically significant hemorrhage, infection at the stoma site, or cosmetic deformity. In a follow-up period of 9 mo, none of our decannulated patients presented with clinical tracheal stenosis. Our results indicate that PDT with both methods is as safe and easy to organize and perform as a bedside procedure, obviating the need to transport critically ill patients from the critical care unit. Implications: The tracheas of 80 patients were cannulated through an artificial opening using either the Ciaglia (gradual dilation) or the Rapitrach (single dilation) method. Both techniques were successful with no significant complications. After 9 mo of closure of this opening, none of the survivors had significant scarring or narrowing of the trachea. (Anesth Analg 1998;87:556-61)

Effect of a subanesthetic dose of intravenous ketamine and/or local anesthetic infiltration on hemodynamic responses to skull-pin placement: a prospective, placebo-controlled, randomized, double-blind study.

Insertion of cranial pins for stabilization of the head can result in a marked hypertensive response, which may adversely affect cerebral hemodynamics. The efficacy of a subanesthetic dose of intravenous ketamine (0.5 mg/kg) and/or lidocaine infiltration (1%) at pin fixation sites before pinning was studied in a prospective, double-blind, placebo-controlled, randomized trial of 40 patients. The subjects were divided into four groups of 10. Patients belonging to the placebo and lidocaine groups received intravenous normal saline (NS), followed by local infiltration with NS at pin insertion sites in the placebo group and 1% lidocaine in the lidocaine group. Patients belonging to the ketamine and ketamine-lidocaine groups received intravenous ketamine followed by local infiltration with NS in the ketamine group, and lidocaine infiltration in the ketamine-lidocaine group. Heart rate (HR) and invasive mean blood pressure (MBP) were recorded before intravenous medication and then at various time intervals until 15 minutes after pin fixation. Intergroup comparison of MBP and HR by 2-way analysis of variance revealed a significant difference between the groups and various time points (P < .05). Post hoc analysis revealed maximum increase in MBP each hour in the placebo group. Mean blood pressure response in the ketamine group was similar to the placebo group. Significant attenuation of MBP and HR was observed in the lidocaine and ketamine-lidocaine groups (P < .05). A minimal increase in HR was observed in the lidocaine-ketamine group. The current study demonstrates maximum attenuation of hemodynamic responses when a subanesthetic dose of intravenous ketamine (0.5 mg/kg) is administered with 1% lidocaine infiltration.

Blind orotracheal intubation with the Augustine Guide: a prospective study.

T he A vice fold .ugustine GuideTM (AG) is a premolded dedesigned to engage in the glossoepiglottic to facilitate blind orotracheal intubation. Kovac (1) first used the AG in cadavers and described its design, use, and potential advantages. Later, Carr and Belani (2) used the AG with a guiding stylet in 100 anesthetized and paralyzed adult patients and claimed a 94% success rate in performing rapid, blind orotracheal intubation. However, no large study of the AG has been performed to determine its success rate in relation to predicting a difficult airway. Hence, we performed a prospective study in 530 cases of orotracheal intubation using the AG to evaluate its success rate in relation to the Mallampati classification (3,4) and Cormack and Lehane’s (5) laryngoscopic view of the upper airway.

Comparison of sensitivity of neuromuscular monitoring tests: twitch versus tetanic test

PurposeThe study was planned to compare the sensitivity of a twitch neuromuscular monitoring test, the train-of-four (TOF), with a tetanic test, double-burst stimulation (DBS), during a subclinical dose of vecuronium.MethodsTwenty consenting. ASA I patients (16 to 65 years of age) of both sexes were studied. The ulnar nerve was stimulated at the wrist through surface electrodes by Myotest-DBS, and the adductor pollicis response was recorded on Myograph-2000. After stabilization of the twitch tension at titrated supramaximal stimuli (1 Hz), patients were randomly allocated into groups. In group 1 (n=10), the TOF test was monitored; in group 2 (n=10), the DBS test was monitoral. All patients received a priming dose of vecuronium (0.015 mg·kg−1); parameters such asT1 and TOF ratio (TOFr) (T4/T1) were noted in group 1, andD1 and DBS ratio (DBSr) (D2/D1) were noted during the vecuronium effect.ResultsThe DBS test showed a wider range of change (from control 1.00 to 0.62±0.19 forD1 and to 0.37±0.14 for DBSr) at a faster rate (0.07±0.04 min−1 forD1 and 0.08±0.02 min−1 for DBSr) during the block progression phase than the TOF test parameters (T1 and TOFr). The tetanic fade or DBSr showed peak onset later than peak twitch suppression. The rate of recovery of the DBS test was also slower than that of the TOF test after the peak effect.ConclusionsDBS is a more sensitive test than TOF to quantify the subclinical dose effect of vecuronium, and among the studied parameters (T1, TOFr,D1 and DBSr), DBSr, measuring tetanic fade, was the most sensitive single parameter.

Utility of pulse oximetry in the early recognition of intraoperative hypoxaemia in tetralogy of Fallot

Undetected hypoxaemia in an anaesthetised patient can prove fatal. Pulse oximetry has been widely used to detect hypoxaemia and intracardiac shunts in congenital cyanotic heart diseases. In two patients with tetralogy of Fallot, intraoperative pulse oximetry was helpful in detecting hypoxaemia where the oxygen saturation fell to22and28 per cent with concomitant fall in PaO2. Immediate therapeutic measures were taken and patients’ oxygen saturation improved. We suggest routine use of pulse oximetry in patients undergoing corrective or palliative surgery for tetralogy of Fallot.

Internal jugular vein cannulation in neurosurgical patients: a new approach.

A new approach to internal jugular vein (IJV) cannulation with the head and neck placed in the neutral position is described. The junction of the medial two thirds and lateral one third between the angle of the mandible and symphysis menti is identified. A vertical line is drawn from this point to join another line drawn between the mastoid process and the medial end of the clavicle. The junction is the puncture point. In 120 patients studied, the failure rate was 1.66%, and there were no complications. We propose this technique as a safe and reliable alternative in neurosurgical patients.

Target controlled priming for rapid onset of intubation dose: A new approach

PurposeTo determine the pattern of onset of the intubating dose when given at a monitored target priming block in either phase of the priming drug effect.MethodsSixty consenting ASA I and II patients were premedicated by intramuscular buprenorphine (5 μg·kg−1) 1h before surgery. Neuromuscular junction monitoring was done by stimulating the ulnar nerve at the wrist using Myotest and recording the adductor pollicis response on Myograph-2000. After stabilization of the twitch tension at the titrated supramaximal stimulus (1 Hz), double-burst stimuli (DBS) were given to monitor the priming effect of vecuronium bromide (Vb) (0.015 mg·kg−1). The DBS ratio (DBSr=D2/D1) was calculated for the DBS response, repeated at 20s. Depending on the target priming block level (DBSr 0.8, 0.6, or 0.5) and the phase of the priming block to give an intubating dose of Vb (0.8 mg·kg−1) injection, all patients were randomly assigned to six study groups: group 1 (DBSr 0.8), group 3 (DBSr 0.6), and group 5 (DBSr 0.5) during the priming block progression phase (before peakD1 suppression), and group 2 (DBSr 0.8), group 4 (DBSr 0.6), and group 6 (DBSr 0.5) during the priming block regression phase (after peakD1 suppression). Anesthesia was induced by thiopental (5–7 mg·kg−1) just before the intubating dose. The effect of the intubating dose on twitch stimuli (1 Hz) was monitored.ResultsWe observed that in spite of significantly variable priming intervals for identical DBSr in two different phases, the onset time of the intubating dose to 0 response was identical in similar DBSr group patients; i.e., at 0.8 DBSr, 65.0±5.2s (group 1)vs 66.0±8.0s (group 2); at DBSr 0.6, 55.2±3.7s (group 3)vs 55.2±4.9s (group 4); and at DBSr 0.5, 43.5±4.8s (group 5)vs 43.5±4.2s (group 6). At 0 twitch response, the intubating conditions were comparable in patients of the six groups.ConclusionIn conclusion, target controlled priming (DBSr) for administration of the intubating dose appears to be a useful double-vision sign to predict the onset of the effect of the intubating dose precisely.

Unusual vaporizer design may encourage irregular practices

In the practice of anesthesia, the inhalational agents play a crucial role. As they are potent agents with rapid intake, their delivery has to be precise. A number of vaporizers are available that are agent-specific and deliver accurate amounts of the drug at specific gas flow rates. Other aspects of the vaporizer worth mentioning are the inlet port, the outlet port, and the indicator tube. These components should be positioned so that they perform their purpose efficiently. Any awkward design may affect the vaporizer performance. Here we mention the Acoma halothane vaporizer (Acoma Medical Industry Co., Ltd., Tokyo, Japan) (Fig. 1). This vaporizer has a sleek look and drug delivery is accurate within the recommended gas flows. We believe, however, that there is a major problem with its indicator tube (Fig. 1). The indicator tube is substantially covered by its metal base, which is at the same level as the bottom of the vaporizer. This design results in no indication of fluid until the vaporizer is filled with approximately 30ml of halothane, irrespective of the wicks being wet. During use in the operating theater, when the level in the indicator tube cannot be seen, many users have been found to shake the anesthesia trolley to agitate the fluid in the vaporizer and thus determine whether fluid remains or not. When the anesthetic concentration was measured (Artema Multigas Monitor, M/S Artema Medical Systems, Sweden) we found that when the trolley is rocked, the anesthetic concentration increased by 30% to 35% at the same gas flow and same concentration setting. The practice of trolley shaking is clearly unacceptable and is strongly discouraged by us. In comparison, the Drager isoflurane vaporizer has a properly located fluid indicator tube in which the smallest amount can be seen immediately (Fig. 1). Therefore we think that modification of the Acoma vaporizer is essential as far as its fluid indicator tube is concerned. The unused halothane remaining in the vaporizer will change color due to increasing level of stabilizing agents and so cannot be used subsequently. As the cost of halothane is quite high, to leave as much as 30ml unused each time an anesthetic is administered is extremely