Axial myopia, a protective factor for diabetic retinopathy-role of vascular endothelial growth factor.

Long axial length is one of the ocular protective factors in development of diabetic retinopathy (DR). In this study we examined the effect of axial length (AL) on aqueous humor vascular endothelial growth factor (VEGF) levels in patients with diabetes mellitus with or without DR. Forty-eight eyes of 48 participants were divided into three groups of 16 each. Group A consisted of non-diabetic patients, Group B had diabetic patients without DR, and Group C had diabetic patients with treatment-naive non-proliferative DR (NPDR). The groups were further subdivided based on axial lengths i.e., AL ≤ 23.30 mm (A1, B1, C1) and AL > 23.30 mm (A2, B2, C2). Undiluted aqueous humor was obtained during cataract surgery to measure the VEGF levels. We observed significant decrease in VEGF concentration in patients with AL ≥ 23.30 mm as compared with AL ≤ 23.30 mm in non-diabetic as well as diabetic patients. As the eye elongates, there is less secretion of VEGF in non-diabetics as well in diabetics with or without DR. Our findings strengthened the concept that an increase in AL leads to less VEGF in diabetic eyes, thus leading to less severe DR changes.

Elliptical versus circular flap configuration in myopic eyes undergoing femtosecond laser in situ keratomileusis surgery: A contralateral eye study.

PURPOSE: To study whether a customized elliptical flap configuration offers any visual, refractive, or biomechanical advantage over the "conventional" circular flaps in patients undergoing myopic laser in situ keratomileusis (LASIK). METHODS: A prospective interventional contralateral eye study was undertaken enrolling 290 eyes of 145 myopic patients (≤-6.0D) undergoing LASIK, wherein the corneal flap was created in one eye using a customized elliptical flap configuration versus a conventional circular flap configuration in the other eye. Postoperatively, we compared the visual outcome, change in higher-order aberrations, corneal asphericity, and corneal biomechanics. RESULTS: The visual outcomes, including higher-order aberrations, were comparable between the two groups. Changes in spherical aberration (mean: 0.234-0.331 versus 0.234-0.42; P = 0.644), corneal asphericity (-0.32-0.34 versus - 0.34-0.45; P = 0.42), corneal hysteresis (9.35-7.33 versus 9.4-6.71, P = 0.489), corneal resistance factor (9.71-7.40 versus 10.38-6.9, P = 0.181) were comparable between the elliptical and circular groups, respectively. CONCLUSION: We evaluated the usefulness of a customized elliptical flap configuration for performing LASIK surgery. Our data suggests that elliptical flaps may be associated with superior visual and biomechanical performance compared to circular flaps. This is certainly relevant in eyes with "borderline" pre-LASIK profile to improve patient satisfaction and safety after surgery.

Anterior lenticular opacities in Costello Syndrome.

PURPOSE: A case of anterior lenticular opacities in a patient of Costello Syndrome is reported. OBSERVATIONS: Bilateral anterior capsular plaque along with anterior lens opacities (Anterior Segment Optical Coherence Tomography) has been demonstrated in a patient of Costello Syndrome presenting with atopic dermatitis. CONCLUSIONS: All patients with Costello Syndrome require a detailed anterior segment examination and a close follow up, as even minute lenticular opacities cause visual impairment leading to amblyopia and may require an early surgical intervention.

Inter-hospital and intra-hospital patient transfer: Recent concepts.

The intra- and inter-hospital patient transfer is an important aspect of patient care which is often undertaken to improve upon the existing management of the patient. It may involve transfer of patient within the same facility for any diagnostic procedure or transfer to another facility with more advanced care. The main aim in all such transfers is maintaining the continuity of medical care. As the transfer of sick patient may induce various physiological alterations which may adversely affect the prognosis of the patient, it should be initiated systematically and according to the evidence-based guidelines. The key elements of safe transfer involve decision to transfer and communication, pre-transfer stabilisation and preparation, choosing the appropriate mode of transfer, i.e., land transport or air transport, personnel accompanying the patient, equipment and monitoring required during the transfer, and finally, the documentation and handover of the patient at the receiving facility. These key elements should be followed in each transfer to prevent any adverse events which may severely affect the patient prognosis. The existing international guidelines are evidence based from various professional bodies in developed countries. However, in developing countries like India, with limited infrastructure, these guidelines can be modified accordingly. The most important aspect is implementation of these guidelines in Indian scenario with periodical quality assessments to improve the standard of care.

Nitroglycerine, esmolol and dexmedetomidine for induced hypotension during functional endoscopic sinus surgery: A comparative evaluation.

BACKGROUND AND AIM: Induced hypotension limits intra-operative blood loss to provide better visibility of the surgical field and diminishes the incidence of major complications during functional endoscopic sinus surgery (FESS). We aimed at comparing nitroglycerine, esmolol and dexmedetomidine for inducing controlled hypotension in patients undergoing FESS. MATERIAL AND METHODS: One hundred and fifty American Society of Anesthesiologists physical status I or II adult patients undergoing FESS under general anesthesia were randomly allocated to three groups of 50 patients each. Group E received esmolol in a loading and maintenance dose of 1 mg/kg over 1 min and 0.5-1.0 mg/kg/h, respectively. Group D received a loading dose of dexmedetomidine 1 µg/kg over 10 min followed by an infusion 0.5-1.0 µg/kg/h, and group N received nitroglycerine infusion at a dose of 0.5-2 µg/kg/min so as to maintain mean arterial pressure (MAP) between 60 and 70 mmHg in all the groups. The visibility of the surgical field was assessed by surgeon using Fromme and Boezaart scoring system. Hemodynamic variables, total intra-operative fentanyl consumption, emergence time and time to first analgesic request were recorded. Any side-effects were noted. The postoperative sedation was assessed using Ramsay Sedation Score. RESULT: The desired MAP (60-70 mmHg) could be achieved in all the three study groups albeit with titration of study drugs during intra-operative period. No significant intergroup difference was observed in Fromme's score during the intra-operative period. The mean total dose of fentanyl (µg/kg) used was found to be significantly lower in group D compared to groups E and N (1.2 ± 0.75 vs. 3.6 ± 1.3 and 2.9 ± 1.1 respectively). The mean heart rate was significantly lower in group D compared to groups E and N at all times of measurement (P < 0.05). The MAP was found to be significantly lower in group D compared to groups E and N after infusion of study drugs, after induction, just after intubation and 5 min after intubation (P < 0.05). The Ramsay Sedation Scores were significantly higher in group D (score 3 in 46%) when compared to group E (score 2 in 50%) and group N (score 2 in 54%) (P < 0.001). The emergence time was significantly lower in group E and group N compared to group D. Time to first analgesic request was significantly longer in group D. CONCLUSION: Dexmedetomidine and esmolol provided better hemodynamic stability and operative field visibility compared to nitroglycerin during FESS. Dexmedetomidine provides an additional benefit of reducing the analgesic requirements and providing postoperative sedation.

Anaesthesia for laparoscopic surgery: General vs regional anaesthesia.

The use of laparoscopy has revolutionised the surgical field with its advantages of reduced morbidity with early recovery. Laparoscopic procedures have been traditionally performed under general anaesthesia (GA) due to the respiratory changes caused by pneumoperitoneum, which is an integral part of laparoscopy. The precise control of ventilation under controlled conditions in GA has proven it to be ideal for such procedures. However, recently the use of regional anaesthesia (RA) has emerged as an alternative choice for laparoscopy. Various reports in the literature suggest the safety of the use of spinal, epidural and combined spinal-epidural anaesthesia in laparoscopic procedures. The advantages of RA can include: Prevention of airway manipulation, an awake and spontaneously breathing patient intraoperatively, minimal nausea and vomiting, effective post-operative analgesia, and early ambulation and recovery. However, RA may be associated with a few side effects such as the requirement of a higher sensory level, more severe hypotension, shoulder discomfort due to diaphragmatic irritation, and respiratory embarrassment caused by pneumoperitoneum. Further studies may be required to establish the advantage of RA over GA for its eventual global use in different patient populations.

The potential anesthetic threats, challenges and intensive care considerations in patients with HIV infection.

Acquired immunodeficiency syndrome (AIDS) has become a pandemic with ever looming danger of its transmission in health professionals. The number of AIDS patients has increased tremendously over the last two decades, who present for surgical procedures as well as who get admitted in intensive care unit for their critical condition. As such anesthesiologists and intensivists are exposed to potential risk of disease transmission on a daily basis from such patients. The guidelines and protocols formulated in the western world regarding prevention of disease transmission cannot be applied uniformly in the developing nations, such as India due to various factors and limitations. As such there is a continuous need felt in this arena to prevent the catastrophic consequences of AIDS in our medical fraternity while treating such patients in operation theatres and critical care units. This study reviews the various pathophysiological aspects, anesthetic considerations, intensive care implications, and various areas where current knowledge about AIDS can be applied to prevent its potential transmission in high-risk clinical groups.

Co-loading or pre-loading for prevention of hypotension after spinal anaesthesia! a therapeutic dilemma.

Neuraxial blockade such as spinal anaesthesia can cause severe hypotension due to pharmacological sympathectomy resulting in potential deleterious consequences for the patient. Prevention of this spinal anaesthesia induced hypotension is of utmost importance especially in pregnant population as the life of mother as well as fetus is at risk. Several techniques and methodologies have been adopted for the prevention of this neuraxial hypotension with varying degree of success. The administration of intravenous fluids to optimize the blood volume during sympathectomy has been the most popular and widely used as the first line of therapy among these techniques. The intravenous fluids can be used both before and during the administration of spinal anaesthesia, the techniques appropriately named as pre-loading and co-loading respectively. Numerous research studies and available literary evidence suggests that both of these techniques can be equally effective in prevention of hypotension. The use of colloids has been observed to be more effective for pre-loading due to their longer half-life in the intravascular compartment. However, it has also been suggested that no technique is efficient in preventing the hypotension alone and has to be coupled with judicious use of vasopressors.

The challenging aspects and successful anaesthetic management in a case of situs inversus totalis.

Situs inversus totalis is a rare condition with a predicted incidence of one in 10,000 among the general population, the aetiologic factors for which are still not completely understood. In a patient with situs inversus totalis, not just the diagnosis of any acute abdomen pathology is difficult due to distorted anatomy and transposition of thoraco abdominal viscera but equally challenging is the anaesthetic management during the respective surgical procedure. We are reporting a patient who had situs inversus totalis and was operated for open cholecystectomy. The present case report lays an emphasis on the potential difficulties during anaesthetic management and its various implications.

Attenuation of pressor response and dose sparing of opioids and anaesthetics with pre-operative dexmedetomidine.

BACKGROUND AND AIMS: Alpha-2 agonists are being increasingly used as adjuncts in general anaesthesia, and the present study was carried out to investigate the ability of intravenous dexmedetomidine in decreasing the dose of opioids and anaesthetics for attenuation of haemodynamic responses during laryngoscopy and tracheal intubation. METHODS: ONE HUNDRED PATIENTS SCHEDULED FOR ELECTIVE GENERAL SURGERY WERE RANDOMIZED INTO TWO GROUPS: D and F (n=50 in each group). Group D were administered 1 µg/kg each of dexmedetomidine and fentanyl while group F received 2 µg/kg of fentanyl pre-operatively. Thiopental was given until eyelash reflex disappeared. Anaesthesia was maintained with 33:66 oxygen: nitrous oxide. Isoflurane concentration was adjusted to maintain systolic blood pressure within 20% of the pre-operative values. Haemodynamic parameters were recorded at regular intervals during induction, intubation, surgery and extubation. Statistical analysis was carried out using analysis of variance, chi-square test, Student's t test and Mann-Whitney U test. RESULTS: The demographic profile was comparable. The pressor response to laryngoscopy, intubation, surgery and extubation were effectively decreased by dexmedetomidine, and were highly significant on comparison (P<0.001). The mean dose of fentanyl and isoflurane were also decreased significantly (>50%) by the administration of dexmedetomidine. The mean recovery time was also shorter in group D as compared with group F (P=0.014). CONCLUSIONS: Dexmedetomidine is an excellent drug as it not only decreased the magnitude of haemodynamic response to intubation, surgery and extubation but also decreased the dose of opioids and isoflurane in achieving adequate analgesia and anaesthesia, respectively.

Renal endocrine manifestations during polytrauma: A cause of concern for the anesthesiologist.

Nowadays, an increasing number of patients get admitted with polytrauma, mainly due to road traffic accidents. These polytrauma victims may exhibit associated renal injuries, in addition to bone injuries and injuries to other visceral organs. Nevertheless, even in cases of polytrauma, renal tissue is hyperfunctional as part of the normal protective responses of the body to external insults. Both polytrauma and renal injuries exhibit widespread renal, endocrine, and metabolic responses. The situation is very challenging for the attending anesthesiologist, as he is expected to contribute immensely, not only in the resuscitation of such patients, but if required, to allow the operative procedures in case of life-threatening injuries. During administration of anesthesia, care has to be taken, not only to maintain hemodynamic stability, but equal attention has to be paid to various renal protection strategies. At the same time, various renoendocrine manifestations have to be taken into account, so that a judicious use of anesthesia drugs can be made, to minimize the renal insults.

Dexmedetomidine and clonidine in epidural anaesthesia: A comparative evaluation.

Efforts to find a better adjuvant in regional anaesthesia are underway since long. Aims and objectives are to compare the efficacy and clinical profile of two α-2 adrenergic agonists, dexmedetomidine and clonidine, in epidural anaesthesia with special emphasis on their sedative properties and an ability to provide smooth intra-operative and post-operative analgesia. A prospective randomized study was carried out which included 50 adult female patients between the ages of 44 and 65 years of (American Society of Anaesthesiologists) ASAI/II grade who underwent vaginal hysterectomies. The patients were randomly allocated into two groups; ropivacaine + dexmedetomidine (RD) and ropivacaine + clonidine (RC), comprising of 25 patients each. Group RD was administered 17 ml of 0.75% epidural ropivacaine and 1.5 µg/kg of dexmedetomidine, while group RC received admixture of 17 ml of 0.75% ropivacaine and 2 µg/kg of clonidine. Onset of analgesia, sensory and motor block levels, sedation, duration of analgesia and side effects were observed. The data obtained was subjected to statistical computation with analysis of variance and chi-square test using statistical package for social science (SPSS) version 10.0 for windows and value of P < 0.05 was considered significant and P < 0.0001 as highly significant. The demographic profile, initial and post-operative block characteristics and cardio-respiratory parameters were comparable and statistically non-significant in both the groups. However, sedation scores with dexmedetomidine were better than clonidine and turned out to be statistically significant (P < 0.05). The side effect profile was also comparable with a little higher incidence of nausea and dry mouth in both the groups which was again a non-significant entity (P > 0.05). Dexmedetomidine is a better neuraxial adjuvant compared to clonidine for providing early onset of sensory analgesia, adequate sedation and a prolonged post-operative analgesia.

Dexmedetomidine and fentanyl combination for procedural sedation in a case of Duchenne muscular dystrophy.

Duchenne muscular dystrophy, an X-linked disorder characterized by progressive muscle weakness, is the most common muscular dystrophy among children leading to death before the end of third decade. Anesthesia in such patients pose a great challenge due to various complications associated with it. The dreaded metabolic and clinical complications occur due to various inhalational anesthetics and succinylcholine in this subset of patients. We are reporting a child with diagnosed Duchenne muscular dystrophy who underwent excision of dentigerous cyst in oral cavity under procedural sedation with combination of dexmedetomidine and fentanyl and thus administration of general anesthesia was avoided.

Amniotic fluid embolism: A diagnostic dilemma.

Amniotic fluid embolism (AFE) is a rare obstetric catastrophe with an incidence of 7.7 per 100 000 deliveries and mortality as high as 60% to 80%. We describe a case of perioperative cardiac arrest in a young parturient undergoing an emergent cesarean section. Just after delivery of live healthy male baby, patient developed disseminated intravascular coagulation not responding to resuscitation with fluids and blood products. Her autopsy revealed edematous lungs with amniotic fluid debris within pulmonary vessels thus establishing the diagnosis of AFE. Amniotic fluid embolism is life threatening and difficult to predict or prevent condition, which should be always be kept in mind in a parturient with sudden cardiovascular collapse, so that resuscitation commences immediately, as early intervention is essential for a positive outcome.