Visual outcome following penetrating globe injuries with retained intraocular foreign bodies

BACKGROUND: In our institution the occurrence of endophthalmitis related to intraocular foreign bodies has been rare. In this review we analyse the outcome of eyes with retained intraocular foreign bodies presenting to two vitreoretinal surgeons over nearly 7 years. METHODS: Review of the records of 26 patients who presented to two surgeons in a tertiary care vitreoretinal service in Toronto between January 1989 and November 1995. Information documented included mechanism of injury, time from injury to definitive surgery, entry site, presence of vitreous hemorrhage, type of surgery performed, initial and final visual acuity, and development of endophthalmitis. RESULTS: All the injuries occurred in male patients, with a mean age of 36.1 (range 15 to 55) years. Most of the injuries occurred in the workplace, and in most cases (17 [65.4%]) the mechanism of injury was "metal on metal." The entry site was via a perforating wound of the cornea in 16 cases (61.5%). Almost all cases were repaired within 48 hours by means of pars plana vitrectomy. Concurrent lensectomy was required in 18 cases (69.2%) for lens damage at the time of the original injury. Vitreous hemorrhage was present in 22 cases (84.6%). One patient (3.8%) manifested clinically apparent endophthalmitis, which responded to intravitreal antibiotic therapy. Nineteen eyes (73.1%) had a final visual acuity of 6/24 or better. Eyes with coexisting or subsequent retinal detachment had significantly worse vision than those without retinal detachment (p < 0.001). INTERPRETATION: The incidence of endophthalmitis in our series is lower than that in other published series. Prompt definitive treatment was associated with a good prognosis in most cases.     

Smoking and Exposure to Occupational Hazards in 8,304 Workers in Guangzhou, China

This cross-sectional study aimed to describe the pattern ofsmoking in relation to occupational hazard exposure in a workingpopulation in Guangzhou, China. In 1994, data on smoking andoccupational hazard exposure from occupational health recordsof 8,304 subjects aged 35 years or older from 47 randomly selectedfactories were studied. About 49% of the men and 55% of thewomen were exposed to dust, chemicals or other hazards. Theprevalence of smoking was 56.1% in men and in women. The prevalenceof smoking in men was higher in those who were younger, withprimary education or who were workers. In women, those who wereolder, with primary education or in management jobs had highersmoking prevalence. In men and women, subjects who were exposedto occupational hazards had higher smoking prevalence: the highest(71.6%) was found in male workers exposed to dust. Urgent tobaccocontrol measures are needed to prevent the epidemic of smoking-relatedand occupation-related diseases in the workplace in China.     

Another CT sign of sinonasal polyposis: truncation of the bony middle turbinate

In order to study the features of sinonasal polyposis (SNP) on CT, 100 consecutive coronasal sinus CT examinations done for chronic inflamamtory sinonasal disease were reviewed. The CT findings of the 27 fully documented SNPs were analyzed. All our SNPs were bilateral. There was a strong tendency for extensive involvement. Nasal polyps were seen in 22 of 27 (81%); bony trabecular deossification in 23 of 27 (85%); widening of infundibulum in 26 of 27(96%). We discovered a new sign truncation of the bony middle turbinate, where the bulbous part of bony middle turbinate was missing, in 51 of 26 (58 %) of SNP patients without a previous history of middle turbinectomy, 12 of 15(80%) were bilateral. The one SNP patient (1 of 27) with previous middle turbinectomy was not regarded to be real truncation. Truncation of the bony middle turbinate is a characteristic and easily recognizable ancillary sign, and is not seen in other patterns of sinusitis. Together with other features on coronal sinus CT, this adds diagnostic confidence in diagnosing sinonasal polyposis. Correspondence to: E. Y. Liang     

Retrograde pulmonary arteriography

We performed retrograde pulmonary arteriography by means of a pulmonary venous wedge injection in 10 patients with no demonstrable intrapericardial pulmonary arteries by "conventional" angiographic techniques. In all cases but one, the procedure demonstrated the feasibility of a further operation. No complications were observed. Retrograde pulmonary arteriography is an important additional method for determining the existence of surgically accessible pulmonary arteries when other techniques have failed.     

Congenital pulmonary atresia with ventricular septal defect: angiographic and surgical correlates

Of 181 patients with severe congenital pulmonary atresia and ventricular septal defect or "type IV truncus" (an obsolete term), all but 11% had true central pulmonary arteries. These arteries were demonstrable by large serial biplane angiograms using multiple selective injections into collateral vessels, frequent photographic subtraction, and occasional pulmonary vein-wedge angiograms. These techniques are extremely important for accurate diagnosis and in planning corrective or palliative surgery, which was done in 77% of patients with pulmonary arteries.     

Surgical stimulation does not enhance ventilatory chemoreflexes during enflurane anaesthesia in man

To assess the impact of surgical stimulation on regulation of ventilation in anaesthetized man, we measured ventilation and the ventilatory responses to either hyperoxic hypercapnia or to isocapnic hypoxaemia in fifteen subjects anaesthetized with enflurane 1.1 MAC, just prior to and then during a surgical procedure. Anaesthesia alone reduced ventilation, increased Pa_co2 decreased the response to carbon dioxide and virtually abolished the response to hypoxaemia. The addition of operation at the same level of anaesthesia augmented ventilation and reduced Pa_co2 but did not improve the anaesthesia-induced impairment of the responses to hypercarbia and hypoxaemia. Over the range of PCO₂ and PO₂, values studied, the effects of surgery were constant and independent of chemical drive. A.M. Lam, M.D., Resident; J.L. Clement, R.N.; R.L. Knill, M.D., F.R.C.P.(C), Associate Professor; Department of Anaesthesia, University Hospital, University of Western Ontario, London, Canada. This work was supported by the Medical Research Council of Canada, Development Grant 150. Address reprint requests to Dr. R.L. Knill, Department of Anaesthesia, University Hospital, 339 Windermere Road, London, Ontario, Canada, N6A 5A5.     

Ketamine decreases cerebral infarct volume and improves neurological outcome following experimental head trauma in rats

In brain injury, concentrations of extracellular excitatory amino acids are increased and stimulate glutamate receptors in general and the N-methyl-D-aspartate (NMDA)-preferring subtype in particular. That stimulation causes substantial calcium influx, which appears to initiate a cascade of events leading to neuronal death. Blockage of NMDA receptors with specific antagonists or noncompetitive ion channel blockers provides protection against excitatory amino acid-induced neurotoxicity. We previously reported that the NMDA receptor antagonist dizocilpine maleate improved the neurological severity score (NSS) after head trauma in rats. The present study was designed to determine whether ketamine, a NMDA receptor antagonist like dizocilpine maleate, improves neurological outcome following head trauma in rats. Thirty-two male Sprague-Dawley rats (235-250 g) were divided into four groups. Groups A and B were surgically prepared only. Groups C and D were surgically prepared and then a nonpenetrating impact was delivered to the cranium over the left hemisphere. Groups A and C received no treatment. Groups B and D were treated with ketamine, 180 mg/kg i.p., 1 h after head trauma. The NSS was determined at 1, 2, 4, 10, 24, and 48 h following head trauma. After killing at 48 h, cortical slices were taken adjacent to the lesion on the traumatized hemisphere and from comparable sites on the nontraumatized hemisphere to measure the tissue specific gravity and water content. Brains were then placed in 4% formaldehyde and the volume of hemorrhagic necrosis measured 4 days later. Head trauma increased the NSS and, in the traumatized hemisphere, decreased the specific gravity, increased the water content, and caused cerebral infarction. With ketamine, the NSS at 24 and 48 h following head trauma was 7.4 +/- 2.6 and 6.7 +/- 2.6 (mean +/- SEM), respectively, significantly improved compared to the NSS in the untreated group of 12.6 +/- 2.6 and 11.3 +/- 2.6, respectively (p <0.02, Mann-Whitney U test). With ketamine, the volume of hemorrhagic necrosis was 88.0 +/- 23.1 mm, significantly less than that in the untreated group (147.4 +/- 22.4 mm; p <0.05, unpaired t test). The brain tissue specific gravity and water content at 48 h and the rectal temperature at 4 and 48 h after head trauma were not significantly different between treated and untreated groups. It is concluded that in this model of closed cranial impact, ketamine improves neurological outcome and decreases the volume of hemorrhagic necrosis without altering brain edema.