Evaluation of analgesic effect of local administration of morphine after iliac crest bone graft harvesting: A double blind study.

BACKGROUND AND OBJECTIVE: Pain is a complex process influenced by both physiological and psychological factors. In spite of an armamentarium of analgesic drugs and techniques available to combat post-operative pain, appropriate selection, and effective management for relief of post-operative pain still poses unique challenges. The discovery of peripheral opioid receptors has led to growing interest in the use of locally applied opioids (intra-articular, intra-pleural, intra-peritoneal, and perineural) for managing acute pain. As bone graft harvesting is associated with significant post-operative pain and there is a paucity of literature on the use of peripheral opioids at the iliac crest bone harvesting site, the present study was planned to evaluate the analgesic efficacy of local administration of morphine after iliac crest bone graft harvesting. MATERIALS AND METHODS: A total of 60 patients, 20-50 years of age scheduled to undergo elective surgery for delayed and non-union fracture both bone leg with bone grafting under general anaesthesia (GA) were randomly assigned to one of the four groups of 15 patients each: group 1: 2.5 ml normal saline (NS) +2.5 ml NS infiltrated into the harvest site at 2 sites + 1 ml NS intramuscularly (i/m); Group 2: 2.5 ml NS + 2.5 ml NS infiltrated into the harvest site at 2 sites + 5 mg morphine in 1 ml i/m.; Group 3: 2.5 mg (2.5 ml) morphine + 2.5 mg (2.5 ml) morphine infiltrated into the harvest site at 2 sites + 1 ml NS i/m; Group 4: 0.5 mg naloxone (2.5 ml) +5 mg (2.5 ml) morphine infiltrated into the harvest site at 2 sites + 1 ml NS i/m. Pain from the bone graft site and operative site was assessed for 24 h post-operatively. RESULTS: The patients who had received morphine infiltration (Group 3) had significantly less pain scores at the graft site at 4, 6, and 10 post-operative hours. They also had significantly less morphine consumption and overall better pain relief as compared to the other groups. CONCLUSIONS: Morphine administered peripherally provided better analgesia as compared to that given systemically and this effect was noticeable after 4 h post-operatively.

An experimental model of oculorespiratory reflex.

An experimental study of the oculorespiratory reflex (ORR) was conducted on 20 albino rabbits using a square wave (SW) type of stimulus. The ORR could be elicited in 100% of animals. The medial rectus was observed to be most reflexogenic for ORR. The frequency and pattern of ORR was not affected by bilateral vagotomy, intravenous atropine or glycopyrrolate, but could be completely abolished by retrobular block.

Effect of diazepam sedation on arterial oxygen saturation during esophagogastroduodenoscopy: a placebo-controlled study.

OBJECTIVE: To determine the effect of sedation using diazepam on hemoglobin oxygen saturation (SpO2) in patients undergoing esophagogastroduodenoscopy (EGD). METHOD: 100 consecutive patients scheduled for EGD were randomly allocated to receive 0.03 mL/Kg of either diazepam (5 mg/mL solution) or normal saline intravenously after topical oropharyngeal anesthesia immediately before the procedure. SpO2 was continuously monitored throughout the procedure by an anesthetist who was unaware of the drug received. RESULTS: Fall in SpO2 exceeding 4% was noted in 78% of patients in the diazepam group and in 38% of patients in the placebo group (p < 0.001). Fall in SpO2 to suboptimal level (89%) was seen in 20% of patients in the diazepam group and in 10% patients in the placebo group (p < 0.001). The duration of suboptimal SpO2 was similar (means +/- SD being 2.47 +/- 0.10 min in diazepam group and 2.86 +/- 0.32 min in placebo group). CONCLUSION: Intravenous diazepam administration before EGD produces a significant fall in SpO2 during the procedure, and so should be avoided; continuous monitoring of SpO2 should be done during EGD.

Comparison of temperament and character profiles of anesthesiologists and surgeons: a preliminary study.

BACKGROUND: Given the high levels of stress in anesthesiologists and also their close working liaison with surgeons, it may be worthwhile to compare the personality profiles of these two groups of professionals. AIM: To compare the personality profiles of surgeons and anesthesiologists, using a well-standardized and validated instrument. SETTINGS AND DESIGN: Survey (cross-sectional) on surgeons and anesthesiologists working in several medical institutes in India. MATERIAL & METHODS: The self-report Temperament and Character Inventory, 125-item version (TCI-125) was mailed out to an incidental sample of surgeons and anesthesiologists working in medical institutes in India. Of the 200 questionnaires sent (100 to anesthesiologists and surgeons each), 93 completed responses were returned (46 anesthesiologists, 47 surgeons; return rate 46.5%). STATISTICAL ANALYSIS: Student's unpaired 't' test; P<0.05 was considered statistically significant. RESULTS: The mean scores of anesthesiologists vis-a-vis surgeons on the various temperament dimensions were Novelty seeking: 8.6 vs. 9.2; Harm avoidance: 7.3 vs. 8.1; Reward dependence: 8.1 vs. 8.0; and Persistence: 3.0 vs. 3.1, respectively. Similar scores for the character dimensions were Self-directedness: 16.9 vs. 15.9; Cooperativeness: 17.5 vs. 16.5; and Self-transcendence: 7.0 vs. 6.7, respectively. There was no significant difference between the surgeons and anesthesiologists on any of the temperament and character variables of personality chosen for the study. CONCLUSION: Personality measures did not differ significantly between surgeons and anesthesiologists in this preliminary investigation. If replicated on a larger and more representative sample, the findings have clinical relevance to improve the working relationship between these two groups of closely working professionals.

Acute respiratory failure due to hypokalaemic muscular paralysis from renal tubular acidosis.

We report a case of hypokalaemic quadriplegia with acute respiratory failure and life-threatening cardiac arrhythmias in a 26-year-old woman who was diagnosed to have distal renal tubular acidosis. She had persistent metabolic acidosis with severe hypokalaemia and required mechanical ventilation and potassium replacement. The anaesthetic implications of renal tubular acidosis are also discussed.

Leprosy and the anesthesiologist.

PURPOSE: To discuss particular aspects of leprosy (complications treatment, special population) that have implications for anesthetic management in leprous patients scheduled for surgery. SOURCE: MEDLINE and manual searches of relevant literature. Multiple MEDLINE searches (from 1966 onwards) were done, using LEPROSY as a common Medical Subject Heading (MeSH). Other headings used were: anesthesia, surgery, cardiovascular system, respiratory system, eye, skin, nervous system, genitalia, pathology, psychology and pregnancy. A large number of references were retrieved, but only 18 of them were relevant to our topic. Others were obtained by manual search and cross referencing. PRINCIPAL FINDINGS: Leprosy, especially lepromatous leprosy, is a systemic disease, affecting many organs and systems of the body, e.g., cardiovascular (cardiac dysautonomia), respiratory (impaired cough response, nasal obstruction), hepatobiliary (hepatitis), renal (nephritis), ocular (anesthesia), hematological (reduced red, white and platelet count) and osseous systems (bone resorption). CONCLUSION: Investigation of the systems likely to be affected by leprosy (e.g., complete hemogram, liver, lung and kidney function tests, Valsalva response, assessment of ocular anesthesia) should form part of a preanesthetic check up in patients with leprosy.

Anaesthetic considerations in a patient with lepromatous leprosy.

PURPOSE: To consider the anaesthetic problems in a patient with lepromatous leprosy undergoing general anaesthesia. CLINICAL FEATURES: A 52 yr old man with lepromatous leprosy for five years was booked for elective radical nephrectomy. He received 100 mg dapsone per day po. The patient was asymptomatic for cardiovascular disease but his electrocardiogram showed complete left bundle branch block, inferior wall ischaemia with echocardiogram findings of 58% ejection fraction and left ventricular diastolic dysfunction. Other preoperative investigations (haemogram, serum urea and creatinine, liver function tests and chest X-ray) were normal. After premedication with diazepam, meperidine and promethazine, the patient received glycopyrrolate and anaesthesia was induced with thiopentone. Atracurium was given to facilitate tracheal intubation. Anaesthesia was maintained with intermittent positive pressure ventilation using N2O in oxygen with halothane. Anaesthesia and surgery were uneventful except that the patient had a fixed heart rate that remained unchanged in response to administration of anticholinergic, laryngoscopy, intubation and extubation. CONCLUSION: Patients with lepromatous leprosy may have cardiovascular dysautonomia even when they are asymptomatic for cardiovascular disease.

Changes in arterial blood pressure during traction of extra-ocular muscles. A study in rabbits.

A significant reflex fall in mean arterial blood pressure from baseline values was observed during extra-ocular muscle traction in rabbits. This effect could be abolished only by retrobulbar block (afferent pathway block) and not by vagotomy, intravenous atropine or glycopyrronium, suggesting that it is distinct from, and independent of, the oculocardiac reflex. We suggest that these reflex changes in blood pressure be known as the 'oculodepressor reflex'.

Arterial oxygen desaturation during peripheral venous cannulation in children.

Arterial oxygen saturation (SpO2) was measured to determine oxygen desaturation during peripheral venous cannulation prior to induction of anaesthesia in 40 consecutive patients in each of the three age groups; Group I: 1-4 mo, Group II: 4-12 mo, Group III: 12-24 mo. Following premedication with oral trimeprazine tartarate 3 mg.kg-1, one to two hours before operation, baseline SpO2 was noted with child breathing room air. Continuous monitoring during peripheral venous cannulation was done and maximum decrease and duration of SpO2 < 90% was noted. Decreases in mean SpO2, 3.2 +/- 1.4 in Group I, 2.6 +/- 2.0 in Group II and 1.7 +/- 1.9 in Group III, were observed (P < 0.001). Desaturation > or = 4% was noted in 17 patients in Group I, ten patients in Group II and six patients in Group III. Two children, one each in Groups I and II, experienced SpO2 < 90% for 30 sec and 80 sec respectively. We conclude that clinically undiagnosed desaturation occurs during peripheral venous cannulation in healthy children. The authors suggest that continuous monitoring of SpO2 using pulse oximetry should be performed routinely during peripheral venous cannulation.

Attenuation of morphine-induced antinociception by L-glutamic acid at the spinal site in rats.

The present experimental study was planned to evaluate the effect of intrathecal administration of L-glutamic acid upon antinociception produced by intrathecal morphine in a prospective-controlled manner in conscious freely mobile Sprague-Dawley albino rats. After chronic catheterization of the spinal subarachnoid space, rats were randomly allocated into 12 treatment groups of ten each and the same number of rats served as saline control for the comparison. L-glutamic acid (100 mmol), morphine (1.2 mmol), ketamine (50 mmol) and saline (150 mmol) were injected intrathecally in 5 microliters volumes. Naloxone was injected in a dose of 1 mg.kg-1 im. Immediately before and 15, 30 min, 1, 2 and 3 hr after injection, rats were subjected to a thermal noxious stimulus, using a tail-flick technoanalgesiometer and tail-flick latencies (TFL) were recorded. Intrathecal administration of L-glutamic acid attenuated the antinociceptive effect of intrathecal morphine with a decrease in TFL (1.4 +/- 0.3 sec; P < 0.0001) from 6.6 +/- 0.3 sec. Ketamine led to abolition of this effect (P < 0.01). In rats, pretreated with naloxone, there was restoration as well as augmentation of morphine-induced antinociception in the presence of L-glutamic acid with an increase in TFL (9.0 +/- 0.4 sec; P < 0.0001). We conclude that there is modulation of opioid receptors by L-glutamic acid at the spinal site in rats.

Evaluation of subconjunctival anaesthesia vs peribulbar anaesthesia in cataract surgery.

A comparative study was carried out to evaluate peribulbar anaesthesia (group A) vs subconjunctival anaesthesia (group B). The results proved peribulbar anaesthesia to be more effective than subconjunctival anaesthesia as regards orbicularis akinesia (p < 0.05) and ocular akinesia (p < 0.05). There was no significant difference in the sensory anaesthesia, analgesia and intraocular pressure changes in the two groups (p > 0.05). Block assessment was ideal in 80% of patients in group A in comparison to 51% in group B (p < 0.05), and unsatisfactory in 14% in group A and 30% in group B (p < 0.05). Further, no significant complications were observed with peribulbar anaesthesia. Therefore, we conclude that peribulbar anaesthesia should be preferred over subconjunctival anaesthesia for conventional extracapsular cataract extraction with or without intraocular lens implantation.

Femoral neuropathy: a complication of the lithotomy position.

There are a limited number of reports of femoral neuropathy after surgery in the lithotomy position. Four patients who developed this complication are described.

Anatomic considerations in relation to the mandibular nerve block.

OBJECTIVES: To determine the length of needle that should be advanced beyond the distance to the lateral pterygoid plate to reach the mandibular nerve. METHODS: The study was conducted on patients and skulls. PATIENT STUDY: Distances from the skin at midpoint of the zygomatic arch to lateral pterygoid plate and to the point where mandibular nerve paraesthesia occurred were measured in 74 patients having mandibular nerve block for treatment of neuralgic pain. Osteologic study: Distances from the midpoint of the zygomatic arch to lateral pterygoid plate and to a probe inserted vertically into the foramen ovale were measured in 76 dry skulls. RESULTS: Patient study: The distance to the point where mandibular nerve paraesthesia occurred was more than that to lateral pterygoid plate by 0.07 cm on right and 0.11 cm on left. Osteologic study: The distance to the probe in the foramen ovale (representing mandibular nerve) was less than the distance to lateral pterygoid plate by 0.08 cm on the right and 0.07 cm on the left. CONCLUSIONS: There is no osteologic basis to advance the needle beyond the distance to the lateral pterygoid plate to reach mandibular nerve. However, because the needle may contact the nerve at variable points rather than the shortest distance to the nerve, the needle may be advanced by 0.07 cm on the right and 0.11 cm on the left side in patients. This increase is much less than that indicated in the standard textbooks. Therefore, while performing mandibular nerve block, we suggest caution in advancing the needle beyond the distance to lateral pterygoid plate.