A new, pachymetry-based approach for diagnostic cutoffs for normal, suspect and keratoconic cornea

Purpose

To analyze whether an association exists between keratometric and pachymetric changes in the cornea, and whether it can be used to create pachymetric cutoff criteria secondary to keratometric criteria.

Methods

In this cross-sectional study, 1000 candidates presenting to the refractive surgery services of a tertiary care hospital underwent bilateral Orbscan IIz (Bausch and Lomb) assessment along with other ophthalmic evaluation.

Results

Stepwise regression analysis-based models showed that simulated keratometry (simK) astigmatism was significantly predicted by the minimum corneal thickness (MCT) and difference between central and MCT (δCT), mean SimK by the MCT and δCT, and maximum keratometry in the central 10-mm zone by the MCT and δCT (P<0.001). The mean MCT values were 542.5±39.6, 539.9±39.2, 524.2±49.5, and 449.3±73.7 μm for flatter normal (<44 D), steeper normal (≥44 D), keratoconus suspect and keratoconic eyes, respectively (P<0.001). The mean differences between central corneal thickness and MCT (δCT) were 12.2±7.1 μm, 12.4±7.4 μm, 14.4±8.9 μm and 23.2±10.1 μm for the flatter normal, steeper normal, keratoconus suspect, and keratoconic eyes, respectively (P<0.001). Mean and 2SD cutoff were used to suggest that a cornea having MCT<461 μm or δCT>27 μm has only a 2.5% chance of being normal and not a keratoconus suspect or worse.

Conclusion

Pachymetric diagnostic cutoffs can be used as adjuncts to the existing topographic criteria to screen keratoconus suspect and keratoconic eyes.     

Is pentobarbital safe and efficacious in the treatment of super-refractory status epilepticus: a cohort study

Introduction

Seizures refractory to third-line therapy are also labeled super-refractory status epilepticus (SRSE). These seizures are extremely difficult to control and associated with poor outcome. We aimed to characterize efficacy and side-effects of continuous infusions of pentobarbital (cIV-PTB) treating SRSE.

Methods

We retrospectively reviewed continuous electroencephalography (cEEG) reports for all adults with RSE treated with cIV-PTB between May 1997 and April 2010 at our institution. Patients with post-anoxic SE and those receiving cIV-PTB for reasons other than RSE were excluded. We collected baseline information, cEEG findings, side-effects and functional outcome at discharge and one year.

Results

Thirty one SRSE patients treated with cIV-PTB for RSE were identified. Mean age was 48 years old (interquartile range (IQR) 28,63), 26% (N = 8) had a history of epilepsy. Median SE duration was 6.5 days (IQR 4,11) and the mean duration of cIV-PTB was 6 days (IQR 3,14). 74% (N = 23) presented with convulsive SE. Underlying etiology was acute symptomatic seizures in 52% (N = 16; 12/16 with encephalitis), remote 30% (N = 10), and unknown 16% (N = 5). cIV-PTB controlled seizures in 90% (N = 28) of patients but seizures recurred in 48% (N = 15) while weaning cIV-PTB, despite the fact that suppression-burst was attained in 90% (N = 28) of patients and persisted >72 hours in 56% (N = 17). Weaning was successful after adding phenobarbital in 80% (12/15 of the patients with withdrawal seizures). Complications during or after cIV-PTB included pneumonia (32%, N = 10), hypotension requiring pressors (29%, N = 9), urinary tract infection (13%, N = 4), and one patient each with propylene glycol toxicity and cardiac arrest. One-third (35%, N = 11) had no identified new complication after starting cIV-PTB. At one year after discharge, 74% (N = 23) were dead or in a state of unresponsive wakefulness, 16% (N = 5) severely disabled, and 10% (N = 3) had no or minimal disability. Death or unresponsive wakefulness was associated with catastrophic etiology (p = 0.03), but none of the other collected variables.

Conclusions

cIV-PTB effectively aborts SRSE and complications are infrequent; outcome in this highly refractory cohort of patients with devastating underlying etiologies remains poor. Phenobarbital may be particularly helpful when weaning cIV-PTB.     

Contrasting effects of nifedipine and verapamil on myocardium and vascular smooth muscle at two levels of coronary occlusion in the dog

The calcium flux inhibitors nifedipine and verapamill have recently been used in the setting of both classical Heberden's and variant angina. It has also been suggested that these agents may preserve function and viability of threatened myocardium. The effects of these agents on the relationship between myocardial blood flow and contraction in the setting of partial coronary occlusion is unknown. Thus 39 open-chest dogs underwent partial coronary occlusion to diastolic perfusion pressures of 25 or 40 mm Hg. The dogs then received intracoronary infusions of 10 μg nifedipine or 100 μg verapamil. Myocardial blood flow was measured with tracer microspheres and myocardial shortening was assessed with ultrasonic crystals. At 25 mm Hg nifedipine improved myocardial shortening while blood flow did not change. In contrast, verapamil caused shortening to be abolished but also did not change blood flow. At 40 mm Hg nifedipine, while not affecting shortening, caused a “redistribution” of blood flow from endocardium; in contrast, verapamil again caused shortening to be abolished, but only increased epicardial blood flow leaving endocardial flow intact. Thus verapamil and nifedipine have differing effects. Nifedipine is a potent vasodilator at doses having no negative inotropic effects. In addition, nifedipine can cause a transmural “redistribution” of blood flow from endocardium to epicardium. In contrast, verapamil is also a potent vasodilator, but has profound negative inotropic effects.     

Head-Up Tilt Test (HUTT) in Patients with Episodic Bradycardia and Hypotension Following Percutaneous Coronary Interventions

We investigated the possible association of post catheterization hypotension/bradycardia and neurocardiogenic syncope. Head up tilt test (HUTT) was performed in 12 consecutive patients (age 32D65 years) who developed transient hypotension (systolic blood pressure < 80 mmHg) and/or bradycardia (heart rate < 50/min) with or without syncope following a percutaneous coronary intervention. Ten patients had undergone percutaneous transluminal coronary angioplasty (PTCA) with stent implantation and one each PTCA alone and diagnostic coronary angiography. This event occurred at the time of sheath removal in 7 patients (58%). HUTT was performed with and without intravenous edrophonium (10 mg intravenous). The tilt test was negative in all patients. Post-catheterization hypotension/bradycardia responds promptly to conservative measures and it is unclear whether this is related to neurocardiogenic syncope.     

Outcomes of Surgery for Colorectal Cancer in Patients Age 80 Years and Older

Three hundred patients treated for colorectal cancer during the period 1975-1980 were divided into two groups (less than 80 yr, 236; greater than or equal to 80 yr, 64). No statistically significant differences were seen between the two groups for American Joint Committee on Cancer (AJCC) stage, site, and length of stay. Operative mortality (30 days) was associated with type of treatment (p less than 0.01), stage (p less than 0.05), and age (p less than 0.01) but not with site of cancer. Five-year survival curves excluding 30-day mortalities showed no significant difference between the two age groups. Proportional hazards linear model (multivariate) analysis showed that, whereas 5-yr survival was related to stage (p less than 0.001) and type of operation, patients greater than or equal to 80 did not have a significantly greater risk of death than patients less than 80 yr. Since the age of the patient influences operative morality, but not 5-yr survival, increasing attention needs to be paid to minimizing operative risk by careful preoperative assessment, optimization of underlying cardiac, pulmonary, and nutritional deficiencies, and monitoring numerous physiologic variables during the intraoperative and postoperative period. Resection of cancer should not be limited or denied on the basis of age alone.     

Malignant mediastinal lymphadenopathy detected by staging EUS in patients with pancreaticobiliary cancer

BACKGROUND: In patients with pancreatic cancer, the presence of malignant mediastinal lymphadenopathy (MML) would preclude definitive resection. A recent study suggested routine evaluation for mediastinal lymph-node metastases in all patients being evaluated for pancreaticobiliary masses. In our practice, we routinely assess for mediastinal lymph-node metastases in all patients undergoing EUS for pancreaticobiliary cancer. METHODS: We retrospectively evaluated the presence of MML by EUS-guided FNA (EUS-FNA) in 160 consecutive patients with a definite diagnosis of pancreaticobiliary cancer (pancreatic and periampullary cancers) who underwent EUS-FNA by a single operator from 2000 to 2004. Lymph nodes that were round and hypoechoic with sharp margins were considered suspicious and were sampled by FNA. RESULTS: Of the 160 patients included in this study, 78 had peripancreatic lymph nodes (49%: 95% CI[41%, 58%]), 25 had celiac lymph nodes (16%: 95% CI[10%, 22%]), and 14 patients had mediastinal lymph nodes (9%: 95% CI[4%, 13%]) that were suspicious for malignancy by morphologic criteria. In 8 of 14 patients with suspicious mediastinal lymph nodes, FNA documented MML in 5%: 95% CI[2%, 8%]. Only one of these 8 patients with MML had other sites of documented distant metastases by CT and/or positron emission tomography scans. However, 7 of 8 patients had locally advanced cancers. CONCLUSIONS: MML is detected by staging EUS-FNA in 5% of patients with pancreaticobiliary cancer. Because of its important implications, endosonographers should routinely assess for MML in patients who undergo staging EUS for pancreaticobiliary malignancy.