Anaesthetic management of thoracopagus twins with complex cyanotic heart disease for cardiac assessment: special considerations related to ventilation and cross-circulation.

We describe the anaesthetic management of a pair of thoracopagus twins of 14 months of age undergoing complex cardiac evaluation. Synchronous ventilation of the twins, needed for the ECG-gated magnetic resonance imaging-angiography, was achieved through a Carlens (Y) adaptor during procedures and transport. The complex logistical implications are obvious. We also describe the first use of bispectral index monitor for detection of cross-circulation in conjoint twins.

A randomized multicenter study of remifentanil compared with halothane in neonates and infants undergoing pyloromyotomy. I. Emergence and recovery profiles.

UNLABELLED: Pyloric stenosis is sometimes associated with hemodynamic instability and postoperative apnea. In this multicenter study we examined the hemodynamic response and recovery profile of remifentanil and compared it with that of halothane in infants undergoing pyloromyotomy. After atropine, propofol, and succinylcholine administration and tracheal intubation, patients were randomized (2:1 ratio) to receive either remifentanil with nitrous oxide and oxygen or halothane with nitrous oxide and oxygen as the maintenance anesthetic. Pre- and postoperative pneumograms were done and evaluated by an observer blinded to the study. Intraoperative hemodynamic data and postanesthesia care unit (PACU) discharge times, PACU recovery scores, pain medications, and adverse events (vomiting, bradycardia, dysrhythmia, and hypoxemia) were recorded by the study's research nurse. There were no significant differences in patient age or weight between the two groups. There were no significant differences in hemodynamic values between the two groups at the various intraoperative stress points. The extubation times, PACU discharge times, pain medications, and adverse events were similar for both groups. No patient anesthetized with remifentanil who had a normal preoperative pneumogram had an abnormal postoperative pneumogram, whereas three patients with a normal preoperative pneumogram who were anesthetized with halothane had abnormal pneumograms after. IMPLICATIONS: The use of ultra-short-acting opioids may be an appropriate technique for infants less than 2 mo old when tracheal extubation after surgery is anticipated.

A randomized multicenter study of remifentanil compared with halothane in neonates and infants undergoing pyloromyotomy. II. Perioperative breathing patterns in neonates and infants with pyloric stenosis.

UNLABELLED: Although former preterm birth infants are at risk for postoperative apnea after surgery, it is unclear whether the same is true of full-term birth infants. We evaluated the incidence of apnea in 60 full-term neonates and infants undergoing pyloromyotomy both before and after anesthesia. All subjects were randomized to a remifentanil- or halothane-based anesthetic. Apnea was defined by the presence of prolonged apnea (>15 s) or frequent brief apnea, as observed on the pneumocardiogram. Apnea occurred before surgery in 27% of subjects and after surgery in 16% of subjects, with no significant difference between subjects randomized to remifentanil or halothane anesthesia. This apnea was primarily central in origin, occurred throughout the recording epochs, and was associated with severe desaturation in some instances. Of the subjects with normal preoperative pneumocardiograms, new onset postoperative apnea occurred in 3 (23%) of 13 subjects who received halothane-based anesthetics versus 0 (0%) of 22 subjects who received remifentanil-based anesthetics (P = 0.04). Thus, postoperative apnea can follow anesthesia in otherwise healthy full-term infants after pyloromyotomy and is occasionally severe with desaturation. New-onset postoperative apnea was not seen with a remifentanil-based anesthetic. IMPLICATIONS: Abnormal breathing patterns can follow anesthesia in infants after surgical repair of pyloric stenosis. Occasionally, these patterns can be associated with desaturation. New-onset postoperative apnea was not seen with a remifentanil-based anesthetic.

Body morphology and the speed of cutaneous rewarming.

BACKGROUND: Infants and children cool quickly because their surface area (and therefore heat loss) is large compared with their metabolic rate, which is mostly a function of body mass. Rewarming rate is a function of cutaneous heat transfer plus metabolic heat production divided by body mass. Therefore, the authors tested the hypothesis that the rate of forced-air rewarming is inversely related to body size. METHODS: Isoflurane, nitrous oxide, and fentanyl anesthesia were administered to infants, children, and adults scheduled to undergo hypothermic neurosurgery. All fluids were warmed to 37 degrees C and ambient temperature was maintained near 21 degrees C. Patients were covered with a full-body, forced-air cover of the appropriate size. The heater was set to low or ambient temperature to reduce core temperature to 34 degrees C in time for dural opening. Blower temperature was then adjusted to maintain core temperature at 34 degrees C for 1 h. Subsequently, the forced-air heater temperature was set to high (approximately 43 degrees C). Rewarming continued for the duration of surgery and postoperatively until core temperature exceeded 36.5 degrees C. The rewarming rate in individual patients was determined by linear regression. RESULTS: Rewarming rates were highly linear over time, with correlations coefficients (r2) averaging 0.98+/-0.02. There was a linear relation between rewarming rate (degrees C/h) and body surface area (BSA; m2): Rate (degrees C/h) = -0.59 x BSA (m2) + 1.9, r2 = 0.74. Halving BSA thus nearly doubled the rewarming rate. CONCLUSIONS: Infants and children rewarm two to three times faster than adults, thus rapidly recovering from accidental or therapeutic hypothermia.

Idiopathic polypoidal choroidal vasculopathy of the macula.

OBJECTIVE: The authors evaluated the clinical, fluorescein, and indocyanine green (ICG) angiographic characteristics of the macular variant of idiopathic polypoidal choroidal vasculopathy (IPCV). DESIGN: Observational case series. PARTICIPANTS: The records, photographs, and fluorescein and ICG angiograms of eight eyes of seven patients with IPCV lesions confined to the macula were reviewed. MAIN OUTCOME MEASURES: The visual acuity, fundus examination, fluorescein and ICG angiographic characteristics, and clinical course were compared. RESULTS: All patients demonstrated polypoidal lesions arising from macular choroidal vessels on ICG angiography. One patient had bilateral lesions. These lesions appeared hyperfluorescent in the early phases of both fluorescein and ICG angiography. Late-phase leakage was seen in cases associated with subretinal fluid or exudate. None of these patients demonstrated polypoidal lesions arising from the peripapillary choroidal circulation or peripapillary choroidal neovascularization. Three eyes with polypoidal lesions that were associated with subretinal fluid and exudates were treated with photocoagulation. Five eyes were not treated. Final visual acuity ranged from 20/20 to hand motions. Severe visual loss was associated with vitreous and subretinal hemorrhage, but this resolved without permanent severe visual loss in several cases. CONCLUSIONS: In the macular variant of IPCV, ICG and fluorescein angiography demonstrate characteristic macular polypoidal lesions without evidence of peripapillary lesions. The vascular origin of these polypoidal lesions appears to be the macular choroidal circulation. This is distinguished from classic IPCV, in which lesions appear to arise from the peripapillary choroidal circulation. Visual prognosis appears to be good, with most patients retaining visual acuity of 20/80 or better. If subretinal fluid or exudates reduce visual acuity, photocoagulation should be considered.

A North Carolina macular dystrophy phenotype in a Belizean family maps to the MCDR1 locus.

PURPOSE: To describe the clinical findings of an autosomal dominant macular dystrophy in a family of Mayan Indian ancestry in Belize, Central America, and to determine its molecular genetic relationship with the original North Carolinian family. METHODS: We performed comprehensive ophthalmic examinations on 56 members of a single family living in Chicago, Illinois, and Belize, Central America. Fundus photography and fluorescein angiography were performed on 17 affected subjects and six affected family members were serially examined over a 12-year period. Blood was collected from 26 individuals, and DNA was extracted for genotyping. Two-point linkage, multipoint linkage, and haplotype analysis was performed. RESULTS: In 17 affected individuals, the clinical features were consistent with the diagnosis of North Carolina macular dystrophy. Multipoint linkage analysis generated a peak lod score of 5.6 in the MCDR1 region. The haplotype associated with the disease was, however, different from that of the original North Carolinian family. CONCLUSIONS: This family has an autosomal dominant macular dystrophy that is clinically indistinguishable from North Carolina macular dystrophy (MCDR1). Our findings indicate that the mutated gene in this Belizean family maps precisely to the same region as that of the North Carolina macular dystrophy (MCDR1) locus. This study provides evidence that MCDR1 occurs in various ethnic groups and that there is no evidence of genetic heterogeneity.

Subretinal exudative deposits in central serous chorioretinopathy.

The presence of subretinal exudation in a patient with neurosensory detachment of the macula frequently suggests the diagnosis of choroidal neovascularisation. A retrospective chart review of newly diagnosed cases of central serous chorioretinopathy revealed 11 patients, seven men and four non-pregnant women, who had plaques of subretinal exudate, which presumably were fibrin. Each of these patients had a solitary plaque that ranged in size from 300 to 1500 microns in diameter. These patients had no signs or a clinical course suggestive of choroidal neovascularisation. In each case the subretinal plaque was overlying an exuberant leak in the retinal pigment epithelium. The exudate was generally present at the initial examination, and usually showed dissolution before or coincident with the resolution of the neurosensory detachment. After resolution of the central serous chorioretinopathy, patients were left with subtle alterations in the retinal pigment epithelium in the areas of the subretinal plaque. These findings are important for two reasons. Firstly, the presence of subretinal exudation does not necessarily rule out the diagnosis of central serous chorioretinopathy. Secondly, pathophysiological theories of central serous chorioretinopathy must explain how the plaques are deposited behind the retina.

Retinal periphlebitis in patients with acquired immunodeficiency syndrome with cytomegalovirus retinitis mimics acute frosted retinal periphlebitis.

Acute frosted retinal periphlebitis is an inflammatory condition of unknown origin characterized by marked perivenular infiltration in otherwise healthy patients. We encountered seven patients with acquired immunodeficiency syndrome who exhibited visual loss associated with an unusual diffuse retinal periphlebitis very similar in appearance to acute frosted retinal periphlebitis. Each patient developed a thick inflammatory infiltrate surrounding the retinal venules, creating a frosted appearance. Two cases were bilateral. All patients had areas of more typical cytomegalovirus retinitis in their involved eye(s). Five of six patients treated with ganciclovir sodium showed improvement not only of the cytomegalovirus retinitis but also of the periphlebitis. Although we do not have histopathologic evidence that cytomegalovirus was the cause of these cases of periphlebitis, we believe that periphlebitis may be a previously unrecognized finding of cytomegalovirus retinitis in patients with acquired immunodeficiency syndrome. So far, there is no evidence implicating cytomegalovirus as the cause of acute frosted retinal periphlebitis in healthy patients.

Unilateral acute idiopathic maculopathy.

This is a report of nine patients who experienced sudden, severe, unilateral central vision loss following a flulike illness. Each patient had an exudative detachment of the macula. All patients experienced a spontaneous resolution of the acute macular manifestations with near-complete recovery of vision. A characteristic "bull's-eye" appearance in the macula persisted. The acute manifestations of the disorder did not recur in any of the patients during the period of follow-up. The constellation of findings was suggestive of an inflammatory disease of the retinal pigment epithelium, but a specific causative agent could not be identified. The acute clinical and angiographic features, the natural course, and the residual pigment epithelial derangement were not consistent with any previously described disorder.

A randomized clinical trial of feeder vessel photocoagulation of sickle cell retinopathy. A long-term follow-up.

Long-term follow-up of patients enrolled in a randomized prospective trial of feeder vessel photocoagulation for proliferative sickle retinopathy has been completed. Of the 44 patients enrolled in Chicago, nearly a decade follow-up has been achieved on 29 patients (45 eyes). There were 20 control untreated eyes and 25 argon laser-treated eyes. Prolonged loss of visual acuity was rare in both groups. Argon laser photocoagulation has had a sustained effect on reducing the incidence of vitreous hemorrhage and visual loss from vitreous hemorrhage. Nine (45%) of 20 control eyes had vitreous hemorrhage, and it was recurrent in six (66%) of these nine eyes. A single episode was the only hemorrhagic event in the treated eyes. The laser-induced complications of choroidal neovascularization or retinal detachment were not associated with long-term visual sequelae. New sea fan evolution in 47% of study eyes suggests that these patients require long-term surveillance.

A randomized clinical trial of scatter photocoagulation of proliferative sickle cell retinopathy.

A randomized prospective clinical trial of argon laser scatter photocoagulation therapy for proliferative sickle cell retinopathy was performed on 116 patients (174 eyes) in Kingston, Jamaica. Ninety-nine eyes were treated with scatter photocoagulation and 75 eyes served as controls. The average length of follow-up was 42 months for the control eyes and 47 months for the treated eyes. Prolonged loss of visual acuity was statistically significantly reduced in the treated eyes. The incidence of vitreous hemorrhage was also significantly reduced in the treated eyes after controlling for the previously defined risk factors of vitreous hemorrhage and extent of proliferative sickle cell retinopathy at entry into the study. There were no complications associated with argon laser scatter photocoagulation. Scatter photocoagulation of proliferative sickle cell retinopathy is currently the most effective and safe way to treat patients with sea fan neovascularization.

An update on techniques of photocoagulation treatment of proliferative sickle cell retinopathy.

Proliferative sickle cell retinopathy (PSR) can lead to visual loss from vitreous haemorrhage and traction or rhegmatogenous retinal detachment. We review two techniques of photocoagulation for PSR, feeder vessel photocoagulation and scatter photocoagulation. A prospective randomised trial of feeder vessel photocoagulation for PSR demonstrated that the incidence of vitreous haemorrhage and visual loss was diminished in eyes which were treated. Since this technique of treatment is difficult and can be associated with choroidal neovascularisation and retinal tears, scatter photocoagulation has also been tested. A prospective randomised trial of scatter photocoagulation for PSR demonstrated a decreased incidence of vitreous haemorrhage and visual loss in treated eyes compared to untreated eyes. No complications of scatter treatment were noted. We presently recommend local scatter photocoagulation to areas of PSR. In unreliable patients, we recommend 360 degrees of peripheral circumferential treatment as otherwise new seafans will develop. If scatter photocoagulation does not result in sufficient regression of the neovascularisation and vision threatening complications such as vitreous haemorrhage continue, feeder vessel treatment can be used to supplement the scatter treatment.

Diabetic retinopathy in blacks.

Diabetic eye disease, particularly diabetic retinopathy, is the leading cause of new cases of legal blindness in people 20-74 yr of age in the United States. The prevalence and rate of diabetes in this age-group are higher in Blacks than in Whites. The rate of blindness from diabetic eye disease is also higher in Blacks than in Whites. Severe macular edema, the most frequent cause of decreased vision in diabetic retinopathy, appears to be more common in Blacks. Risk factors for developing macular edema include poorly controlled hypertension, hyperglycemia, and duration of disease. The higher prevalence of hypertension in Blacks may contribute to the increased severity of diabetic retinopathy. Further evaluation is necessary to determine the influence of race on the severity of diabetic retinopathy.

Retinal arterial macroaneurysms.

Retinal arterial macroaneurysms represent a distinct clinical entity. Macroaneurysms are seen in the elderly with a marked female predominance and a strong association with hypertension and arteriosclerotic vascular changes. The classic appearance provides an easy diagnosis; however, variable presentations, such as subretinal hemorrhage, macular exudate, and epiretinal membranes can make the diagnosis difficult. The differential diagnosis of retinal arterial macroaneurysms include retinal telangiectasia, angiomatosis retinae, venous macroaneurysms, background diabetic retinopathy, and cavernous hemangioma. The clinical characteristics of the reported cases are summarized, and our series of 60 patients is presented. The natural history of most macroaneurysms is spontaneous involution without loss of vision. However, visual loss may occur secondary to macular edema, exudate, hemorrhage and neurosensory retinal detachment, and photocoagulation may expedite visual recovery. Photocoagulation treatment may be applied directly to the macroaneurysm, indirectly by surrounding the macroaneurysm, or as a combination of these two methods.

Cone-rod dystrophy. A clinical and histopathologic report.

Clinical, histopathologic, and electron microscopic findings in two postmortem eyes from a 29-year-old black man and the clinical and electrophysiologic findings of his 33-year-old sister, both of whom had bilateral atrophic macular lesions, confirmed the diagnosis of cone-rod dystrophy in these two patients. Light microscopy revealed a loss of photoreceptor cells primarily in the peripheral retina and macula, with relative preservation of both rod and cone cells in the equatorial area. Electron microscopy showed abundant lipofuscin-like granules aggregated in the basal portion of the retinal pigment epithelial cells. In the macular area, many retinal pigment epithelial cells were atrophic. The phagocytic capacity of the retinal pigment epithelium appeared to remain intact. The accumulation of lipofuscin-like granules in the retinal pigment epithelium may be one of the significant pathologic changes of this dystrophy.

Acute macular neuroretinopathy: early receptor potential change suggests photoreceptor pathology.

The early receptor potential (ERP) was recorded in a patient with typical fundus findings of unilateral acute macular neuroretinopathy. These amplitudes were compared with those of a normal control population. The ERP amplitude of the affected eye measured 13 months after onset of visual impairment was significantly reduced (4.8 SD) compared with the normal fellow eye. A subsequent ERP measurement 7 months later (20 months after onset) showed the same amount of amplitude reduction, indicating that recovery had not occurred by this time. Since the ERP is generated during photolysis of visual pigment molecules and requires intact photoreceptor outer segment membranes to orient these molecules, our findings suggest that the outer segments are affected in at least some patients with this disorder. A retinal vascular aetiology for this disorder was rejected by studying a subject with a large retinal depression sign that occurred after a previous retinal vascular occlusion.

Spontaneous regression of retinal lesions in Coats' disease.

Coats' disease is characterized by vascular anomalies in the retina that are usually associated with exudates. In the absence of treatment the disease almost always progresses toward loss of vision and, often, loss of the eye. This report describes three patients in whom some of the retinal lesions apparently regressed spontaneously; only two other such patients are mentioned in the literature. These patients may have had a form of Coats' disease that has a better prognosis than usual for the eye.