Late lesion growth following endovascular therapy: is 24 hours too early to assess acute infarct size including the effects of secondary injury?

Introduction Stroke lesion volume on MRI or CT provides objective evidence of tissue injury as a consequence of ischemic stroke. Measurement of "final" lesion volume at 24hr following endovascular therapy (post-EVT) has been used in multiple studies as a surrogate for clinical outcome. However, despite successful recanalization, a significant proportion of patients do not experience favorable clinical outcome. The goals of this study were to quantify lesion growth during the first week after treatment, identify early predictors, and explore the association with clinical outcome. Methods This is a prospective study of stroke patients at two centers who met the following criteria: i) anterior large vessel occlusion (LVO) acute ischemic stroke, ii) attempted EVT, and iii) had 3T MRI post-EVT at 24hr and 5-day. We defined "Early" and "Late" lesion growth as ≥10mL lesion growth between baseline and 24hr DWI, and between 24hr DWI and 5-day FLAIR, respectively. Complete reperfusion was defined as >90% reduction of the volume of tissue with perfusion delay (Tmax>6sec) between pre-EVT and 24hr post-EVT. Favorable clinical outcome was defined as modified Rankin scale (mRS) of 0-2 at 30 or 90 days. Results One hundred twelve patients met study criteria with median age 67 years, 56% female, median admit NIHSS 19, 54% received IV or IA thrombolysis, 66% with M1 occlusion, and median baseline DWI volume 21.2mL. Successful recanalization was achieved in 87% and 68% had complete reperfusion, with an overall favorable clinical outcome rate of 53%. Nearly two thirds (65%) of the patients did not have Late lesion growth with a median volume change of -0.3mL between 24hr and 5-days and an associated high rate of favorable clinical outcome (64%). However, ~1/3 of patients (35%) did have significant Late lesion growth despite successful recanalization (87%: 46% mTICI 2b/ 41% mTICI 3). Late lesion growth patients had a 27.4mL change in Late lesion volume and 30.1mL change in Early lesion volume. These patients had an increased hemorrhagic transformation rate of 68% with only 1 in 3 patients having favorable clinical outcome. Late lesion growth was independently associated with incomplete reperfusion, hemorrhagic transformation, and unfavorable outcome. Conclusion Approximately 1 out of 3 patients had Late lesion growth following EVT, with a favorable clinical outcome occurring in only 1 out of 3 of these patients. Most patients with no Early lesion growth had no Late lesion growth. Identification of patients with Late lesion growth could be critical to guide clinical management and inform prognosis post-EVT. Additionally, it can serve as an imaging biomarker for the development of adjunctive therapies to mitigate reperfusion injury.

Trends in age and sex-specific prevalence of cancer and cancer subtypes in acute ischemic stroke from 2007-2019

OBJECTIVE

To describe age and sex-specific prevalence of cancer in acute ischemic stroke (AIS) hospitalizations in the United States over the last decade.

METHODS

We conducted a retrospective serial cross-sectional study using all primary AIS discharges (weighted n=5,748,358) with and without cancer in the 2007-2019 National Inpatient Sample. Admissions with primary central nervous system cancers were excluded. Joinpoint regression was used to compute the average annualized percentage change (AAPC) in cancer prevalence over time.

RESULTS

Across the study period, 12.7% of AIS admissions had previous/active cancer, while 4.4% had active cancer. Of these, 18.8% were hematologic cancers, 47.2% were solid cancers without metastasis and 34.0% were metastatic cancers of any type. Age-adjusted active cancer prevalence differed by sex (males:4.8%; females:4.0%) and increased with age up to age 70-79 years (30-39 years 1.4%; 70-79 years:5.7%). Amongst cancer admissions, lung (18.7%) and prostate (17.8%) were the most common solid cancers in men, while lung (19.6%) and breast (13.7%) were the most prevalent in women. Active cancer prevalence increased over time (AAPC 1.7%, p<0.05) but the pace of increase was significantly faster in women (AAPC 2.8%) compared to men (AAPC 1.1%) (p-comparison =0.003). Fastest pace of increased prevalence was seen for genitourinary cancers in women and for gastrointestinal cancers in both sexes. Genitourinary cancers in men declined over time (AAPC -2.5%, p<0.05). Lung cancer prevalence increased in women (AAPC 1.8%, p<0.05) but remained constant in men. Prevalence of head/neck, skin/bone, gastrointestinal, hematological and metastatic cancers increased over time at similar pace in both sexes.

CONCLUSION

Prevalence of cancer in AIS admissions increased in the US over the last decade but the pace of this increase was faster in women compared to men. Gastrointestinal cancers in both sexes and genitourinary cancers in women are increasing at the fastest pace. Additional studies are needed to determine whether this increase is from co-occurrence or causation of AIS by cancer.

Outcomes of cardiac pacing in patients with myotonic dystrophy type 1: A single specialist centre study

Funding Acknowledgements

Type of funding sources: None.

Introduction

Cardiac conduction disease and sudden cardiac death is known to be associated with Myotonic Dystrophy type 1 (MD). Patients often require device implantation to prevent sudden cardiac death. It is not known how frequently device implantation occurs and how quickly conduction disease progresses.

Objective

To define the rate and type of device implantation, rate of pacing and outcome in MD patients managed in a single specialist centre.

Method

Retrospective analysis of pacing and outcome data on consecutive MD patients managed at Specialist Centre in the UK between 2011 and 2021.

Results

24/119 MD patients were implanted with a cardiac device. Male:Female 13:11. At implant, patients had a mean age of 56 (95% CI 52 to 59), mean PR interval 217 ms (95% CI 203 to 230), mean QRSd 123ms (95% CI 109 to 137). Devices implanted included 16 DDDR, 4 CRT-D, 1 CRT-P, 1- ICD and 2 VVI pacemakers. 10 (42%) died during follow up of 10 years. 12 out of 19 (63%) with an atrial pacing lead required a mean increase in atrial pacing of 15% (95% CI 5 to 25) during follow up. 12 out of 24 (50%) of patients required mean increase of 13% (95% CI 5 to 22) in Ventricular pacing. 7 (88%) patients who died had evidence of progressive conduction disease prior to death.

Conclusion

In our cohort of myotonic dystrophy patients 20% required device implantation. There was a higher incidence of progressive atrial rather than ventricular pacing, despite the known concern about progressive AV block. Despite pacing, mortality remained high and was more frequent in patients with progressive conduction disease. Increases in pacing demand could be early indicator of disease progression.

Abstract TMP82: Comparison Of Direct Oral Anticoagulants To Vitamin K Antagonists For Treatment Of Cerebral Venous Sinus Thrombosis

Introduction: Direct oral anticoagulants (DOACs) have gained popularity in treating cerebral venous thrombosis (CVT). However, studies comparing the use of DOACs to Vitamin K antagonists (VKA) among patients with CVT are limited.

Methods: We conducted a single-center retrospective cohort study comparing VKA to DOAC-treated CVT patients. Clinical, radiographic findings and outcomes were compared. Continuous and categorical variables were compared using t-test or Wilcoxon test and Chi-square or Fisher's exact test, as appropriate.

Results: 82 CVT patients were included in final analysis (mean age 41.3±16.3, 76.8% women). Thirty (37%) were treated with DOACs. There was no difference in clinical or radiographic characteristics between the two groups. There was no death and majority of patents were discharged home (p=0.11). Sixty-one patients (74.4%) had follow-up imaging within a year. Fifteen, thirty-seven and nine patients had complete, partial, and no vessel recanalization, respectively. There was no difference in recanalization status between the DOAC and VKA groups (p=0.53). 68 patients (82.3%) had follow-up data on headache status: 21(31%) reported resolution and 45(66%) partial improvement with no difference between DOAC and VKA groups (p=0.81). One patient in the DOAC group had a recurrent CVT. One patient in the VKA group had a major hemorrhage within 3 months.

Conclusion: We found no significant difference in venous recanalization or outcomes in patients with CVT treated with DOAC vs VKA. DOAC appears to be a safe alternative to VKA. Large multicenter studies are needed to better evaluate the efficacy and safety of DOAC in CVT.

Abstract WP158: Trends In Utilization Of IV Thrombolysis And Mechanical Thrombectomy In Patients With Stroke And Malignancy

Background and Purpose: Existing data shows that IV thrombolysis (tPA) and mechanical thrombectomy (MT) use in acute ischemic stroke (AIS) patients and malignancy is <2%. Our aim was to determine whether utilization of recanalization therapies has increased in AIS patients with cancer since publication of pivotal MT trials.

Methods: All admissions with a primary diagnosis of AIS (weighted n=5,554,161) were identified from the 2007-2018 Nationwide Inpatient Sample. Cancer-associated strokes (CAS) were categorized into hematologic (hem), solid and metastatic (met) cancers. Joint point regression and multivariable-adjusted logistic regression models with interaction terms were used to evaluate rate of change in t-PA and MT use in CAS compared to non-CAS admissions.

Results: Across this period, 4.0% of AIS admissions had comorbid CAS. The proportion of AIS hospitalizations with CAS increased from 3.8% in 2007 to 4.4% in 2018. Mean age of CAS was 72.9 (47.6% women) vs. 70.6 years (51.8% women) among non-CAS. CAS patients had fewer vascular risk factors. Highest t-PA usage was in non-CAS pts (7.8%) and lowest use in met-CAS pts (3.8%) and this difference was significant. In contrast MT usage was highest in met-CAS (2.0%) vs non-CAS (1.6%) and hem-CAS (1.2%). A race-by-time interaction revealed an increase in utilization of both therapies in all CAS groups. Pace of the increase was slower in met CAS (OR 0.97, 95%CI 0.95-0.99) per unit increase in year. MT use increased at a faster pace in met-CAS patients (OR 1.07, 95%CI 1.02-1.12) compared to non-CAS. Although overall mortality rates for patients with cancer has decreased for all cancer types, CAS had significantly higher in hospital mortality as compared to NCS (8.9% vs 4.4%, p <0.001).

Conclusions: Utilization of both t-PA and MT has increased over the last decade. Contrary to prior studies, the current frequency and pace of increase in MT use is greater in met-CAS admissions compared to non-CAS. Patients with CAS have fewer traditional vascular risk factors and significantly higher in hospital mortality. Future studies should address longer term outcomes in CAS versus non-cancer strokes.

Abstract P446: African American Women Have Lower Functional Performance During Acute Inpatient Rehabilitation After Intracerebral Hemorrhagic Strokes

Introduction: Intracerebral hemorrhage (ICH), a subtype of stroke, leads to significant long-term disability. Research in stroke recovery and rehabilitation has focused on ischemic strokes. Identifying factors that impact the recovery of function for patients at an inpatient rehabilitation facility (IRF) following an ICH is necessary. Our purpose is to identify factors, including racial and gender disparities, associated with inpatient rehabilitation after ICH.

Methods: We performed a retrospective analysis of a tertiary care academic hospital in the Stroke Belt of the US, the University of Alabama at Birmingham, and subsequently, admitted to an IRF from December 2016 through December 2019. Functional performance was measured using the Functional Independence Measure (FIM), an 18-item scale measuring the level of disability in terms of burden of care. Baseline clinical characteristics, demographics, admission and discharge FIM scores, and ICH characteristics including ICH scores and volumes were collected. FIM efficiency was calculated for all patients by dividing the difference in FIM scores at admission and discharge from the total number of days spent at rehab. The differences in FIM efficiency by gender and race were measured using multiple linear regression.

Results: We evaluated 65 patients (54.4 ± 14.1 years, 61% males, 46% African American) with a median (interquartile range) ICH score of 1.0 (0.0, 2.0), median ICH volume of 13.4 (4.2, 33.0), and FIM efficiency of 1.6 (1.1, 2.4). In multiple regression, being male was positively associated with FIM efficiency (β=1.02, p = 0.0063) when adjusting for race and ICH score. The FIM efficiency was lower in African Americans (β =-0.95, p = 0.0092) when adjusting for gender and ICH volume. No significant differences were noted in ICH volumes and scores with respect to discharge FIM scores.

Conclusions: FIM efficiency, is a good measure of improvement in motor function and ADLs over the rehab period. Our results indicate that African American women could potentially benefit from longer periods of rehabilitation intervention.

Emerging Neurology of COVID-19

The virus, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is responsible for the current pandemic known as coronavirus disease 2019 (COVID-19) with severe respiratory illness as the predominant manifestation. Neurologic complications from COVID-19 were reported in the early stages of the pandemic and are now increasingly recognized. These include various symptoms like headache and anosmia as well as neurologic complications of severe COVID-19 like encephalopathy, seizures, and stroke. There are few reports of direct involvement of the central nervous system with SARS-CoV-2 causing meningoencephalitis. There is concern for higher incidence and severity of COVID-19 in patients with chronic neurologic conditions. Here, we review the emerging literature along with our anecdotal experience in regard to these neurologic manifestations in patients with COVID-19 and detail the putative pathophysiologic mechanisms for the same.

De Novo Status Epilepticus in patients with COVID-19

Neurological complications are increasingly recognized with SARS-CoV-2, the causative pathogen for COVID-19. We present a single-center retrospective case series reporting the EEG and outcome of de novo status epilepticus (SE) in two African-American women with laboratory-confirmed SARS-CoV-2 virus. SE was the initial presentation in one asymptomatic individual. Patient 2 had COVID-19 pneumonia, and fluctuating mental status that raised the suspicion of subclinical SE. The patient with older age and higher comorbidities failed to recover from the viral illness that has no definitive treatment.

Abstract TP237: Can We Improve Clinical Detection of Right Hemisphere Large Vessel Occlusion?

Introduction: The Emergency Medical Stroke Assessment (EMSA) is a six point stroke severity scale with one point each for gaze preference, facial droop, arm drift, leg drift, abnormal naming, and abnormal repetition that was developed to help emergency medical services (EMS) providers identify acute ischemic stroke (AIS) patients with large vessel occlusion (LVO). We hypothesized that the EMSA would detect left hemisphere LVO with a higher sensitivity than right hemisphere LVO.

Methods: We trained 24 trauma system-based emergency communication center (ECC) paramedics in the EMSA. ECC-guided EMS in performance of the EMSA on patients with suspected stroke. We compared the sensitivity, specificity, area under the curve (AUC), and 95% confidence interval (CI) of ECC-guided prehospital EMSA for right versus left hemisphere ICA or M1 occlusion.

Results: We enrolled 569 patients from September 2016 through February 2018, out of which 236 had a discharge diagnosis of stroke and 173 had a diagnosis of AIS. We excluded patients with bilateral (n=21) and brainstem (n=21) AIS. There were 64 patients with left hemisphere AIS including 19 with LVO. There were 67 patients with right hemisphere AIS including 22 with LVO. A score of ≥ 4 points yielded a sensitivity of 84.2 (95% CI = 60.4-96.6) and specificity of 66.7 (51.1-80.0) for left hemisphere LVO compared to a sensitivity of 68.2 (45.1-86.1) and specificity of 73.9 (58.9-85.7) for right hemisphere LVO. For predicting a left hemisphere LVO, the AUC was 0.77 (0.65-0.90) compared to 0.66 (0.50-0.82) for right-sided LVO. Assigning 2 points for abnormal gaze yielded an AUC of 0.78 (0.66-0.91) versus 0.67 (0.52-0.83) for left and right hemisphere LVO, respectively.

Conclusions: The EMSA, like the National Institutes of Health Stroke Scale (NIHSS) upon which it is based, is more sensitive to left compared to right hemisphere LVO. More heavily weighting abnormal gaze did not improve the sensitivity of the EMSA for right hemisphere LVO. There is no comparable data on the right versus left hemisphere performance of other prehospital scales. There is a need to develop sensitive tests of right hemisphere dysfunction that are suitable for use in the field.

Plasmodium falciparum and hepatitis E virus co-infection in fulminant hepatic failure

Acute hepatitis E and falciparum malaria can each present with fulminant hepatic failure and are common in tropical countries. However, co-existence of these two conditions has not been reported. We report a 20-year-old girl who presented with fever and altered sensorium. Peripheral smear was positive for Plasmodium falciparum, and IgM anti-HEV was positive. She died despite antimalarial drugs and supportive management. Postmortem liver tissue showed changes suggestive of acute viral hepatitis.

Effect of protective agents against cisplatin ototoxicity

HYPOTHESIS

The goals of this investigation were to compare the efficacy of three protective agents against cisplatin-induced elevation of auditory brainstem response (ABR) thresholds and to examine whether these protective agents prevent cisplatin-induced alterations of the antioxidant defense system in the cochlea of the rat.

BACKGROUND

Cisplatin is an ototoxic antitumor agent. Previous animal studies have shown that cisplatin administration causes an elevation of ABR thresholds. These auditory changes are accompanied by alterations in the concentration of glutathione and the antioxidant enzymes in the cochlea. The authors' previous work has indicated that the protective agent diethyldithiocarbamate (DDTC) prevents decrease in glutathione (GSH), alteration of antioxidant enzyme activity, and disruption of cochlear function with cisplatin administration.

METHODS

Wistar rats were sedated and underwent pretreatment ABR testing using clicks and tone burst stimuli at 8, 16, and 32 kHz. Control rats received saline by intraperitoneal (i.p.) injection. Positive control rats were administered cisplatin 16 mg/kg i.p. Three groups of rats received protective agents in combination with cisplatin. The DDTC-protected rats were given 600 mg/kg of DDTC subcutaneously 1 hour after cisplatin. Animals protected by 4-methylthiobenzoic acid (MTBA) were given 250 mg/kg of this agent i.p. 30 minutes before cisplatin. Animals protected with ebselen were given 16 mg/kg i.p. one hour before cisplatin. The ABR thresholds were recorded 72 hours after cisplatin administration in all groups. Cochleas were removed, and extracts of the tissues were analyzed for GSH, activities of antioxidant enzymes (superoxide dismutase [SOD], catalase, glutathione peroxidase, and glutathione reductase) and malondialdehyde (MDA) (as an index of lipid peroxidation).

RESULTS

Cisplatin-treated rats had significant ABR threshold shifts, ranging from 27 to 40 dB. Rats administered each of the three protective agents in combination with cisplatin had ABR threshold shifts of <10 dB. The cochleae of rats administered cisplatin alone had nearly a 50% depletion of glutathione and about a 50% reduction in the activities of SOD, glutathione peroxidase, and glutathione reductase, while catalase activity was reduced to 70% of control values. These changes were accompanied by a reciprocal elevation of MDA of 165%. These changes, namely, the depletion of GSH and antioxidant enzyme activity and the elevation of MDA in the cochlea, were largely attenuated by the administration of the protective agents tested.

CONCLUSION

These findings suggest that cisplatin ototoxicity is related to lipid peroxidation and that the use of protective agents prevents hearing loss and lipid peroxidation by sparing the antioxidant system in the cochlea. These results suggest the possibility that the clinical use of protective agents could effectively reduce or prevent damage to the inner ear of patients receiving cisplatin chemotherapy, provided that the antitumor effect is not altered.

Ototoxicity. Amelioration by protective agents

The findings of studies from this laboratory are summarized to compare the efficacy of four chemoprotective agents against the effects of cisplatin-induced hearing loss and biochemical damage in the rat cochlea. A number of studies have shown that cisplatin is ototoxic, resulting in hearing loss, morphologic damage, and biochemical changes in the cochlea. These studies used Wistar rats, which underwent pre- and posttreatment ABR testing using clicks and tonebursts stimuli at 8, 16, and 32 kHz. Controls received i.p. saline injection. Cisplatin-treated rats were given 16 mg/kg cisplatin i.p. Animals received protective agents in the following dosage: DDTC protected rats received 600 mg/kg subcutaneously an hour after cisplatin. MTBA-protected animals were given 250 mg/kg i.p. 30 minutes before cisplatin. Animals protected with ebselen received 16 mg/kg i.p. an hour before cisplatin. One hundred mg/kg of alpha-lipoic acid was injected i.p. 30 minutes before cisplatin. Rats were sacrificed three days after treatment and the cochleae were harvested and frozen in liquid nitrogen and stored at -80 degrees C until analysis of glutathione (GSH), the activity of antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase) and malondialdehyde was performed. Cisplatin-treated rats were found to have ABR threshold shifts of 27-40 dB, and rats treated with chemoprotective agents plus cisplatin all had ABR thresholds shifts of less than 10 dB. Significant depletion of glutathione and decrease of the activities of the antioxidant enzymes were observed in cisplatin-treated rats. These changes were accompanied by a marked elevation of malondialdehyde. These changes were almost completely prevented by the use of the chemoprotective agents. These findings suggest that cisplatin ototoxicity is related to lipid peroxidation and that the use of protective agents prevents hearing loss and lipid peroxidation by sparing the antioxidant defense system in the cochlea.

Application of antioxidants and other agents to prevent cisplatin ototoxicity

OBJECTIVE/HYPOTHESIS

To review the recent data from experiments performed in this laboratory to test the hypothesis that cisplatin ototoxicity is related to depletion of glutathione and antioxidant enzymes in the cochlea and that the use of antioxidants or protective agents would protect the cochlea against cisplatin damage and prevent hearing loss.

STUDY DESIGN/METHODS

Data were reviewed from experiments performed in this laboratory. Control rats were treated intraperitoneally with cisplatin 16 mg/kg. Experimental rats were given cisplatin in combination with one of the following protective agents: diethyldithiocarbamate, 4-methylthiobenzoic acid, ebselen, or lipoic acid. Animals in each group underwent auditory brainstem response (ABR) threshold testing before and 3 days after treatment. Cochleae were removed after final ABR testing and analyzed for glutathione and activities of the enzymes superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, and malondialdehyde.

RESULTS

Rats in the control group receiving cisplatin were found to have significant ABR threshold shifts. This was accompanied by a reduction of glutathione and the activity of antioxidant enzymes (superoxide dismutase, glutathione peroxidase, catalase, and glutathione reductase) and an elevation of malondialdehyde. Experimental animals had preservation of ABR thresholds and levels of glutathione, antioxidant enzyme activity, and malondialdehyde that were similar to untreated animals.

CONCLUSION

Cisplatin ototoxicity appears to be initiated by fee-radical production, which causes depletion of glutathione and antioxidant enzymes in the cochlea, and lipid peroxidation, manifested by an increase in malondialdehyde. These effects were blocked by each of a series of antioxidant compounds given in combination with cisplatin. A mechanism for cisplatin ototoxicity is elaborated with a proposed plan of chemoprevention using agents with different mechanisms of action. These substances could be used alone or in combination to reduce the severity of cisplatin ototoxicity in patients.

Postoperative endophthalmitis: incidence, predisposing surgery, clinical course and outcome

OBJECTIVE

To describe the predisposing surgery, clinical course and final visual outcome for patients with culture-proven and culture-negative postoperative endophthalmitis.

DESIGN

Case series.

SETTING

University-affiliated teaching hospital in Toronto.

PATIENTS

A total of 164 patients with clinically suspected postoperative endophthalmitis admitted between January 1989 and March 1996.

OUTCOME MEASURES

Type of surgery, clinical presentation, culture results, infecting organism, treatment and final visual outcome.

RESULTS

An infectious agent was identified in 99 cases (60%). The organism most commonly isolated was coagulase-negative Staphylococcus (59 cases [60%]). In the culture-proven group cataract extraction was the most common predisposing surgical procedure, accounting for 85 cases (extracapsular cataract extraction [ECCE] in 60 cases and phacoemulsification in 25). The incidence rates of culture-proven endophthalmitis over the study period at our institution were 0.22% for ECCE and 0.30% for phacoemulsification. Of the 99 patients with culture-proven endophthalmitis 94 received intravitreal injections of antibiotics and 52 underwent vitrectomy. Of the 83 patients in this group for whom the final outcome was known, 29 (35%) had a visual acuity of 20/50 or better, and 15 (18%) had a vision of no light perception, with four eyes undergoing enucleation. Infection with organisms of low virulence (coagulase-negative Staphylococcus or Propionibacterium acnes) was associated with higher rates of 20/50 or better visual acuity compared with more virulent organisms (Staphylococcus aureus, streptococcal species and gram-negative bacilli) (46% vs. 10%) (p < 0.05). The culture-negative group had a significantly lower frequency of hypopyon on presentation (55% vs. 85%) and final outcome of no light perception (2% vs. 18%) (p < 0.01) than the culture-proven group.

CONCLUSIONS

Endophthalmitis was most common after cataract surgery. The rates of endophthalmitis after ECCE and phacoemulsification were similar. Postoperative endophthalmitis caused by organisms other than coagulase-negative Staphylococcus or P. acnes carries a poor visual outcome.

Effect of computer software on time required to prepare parenteral nutrient solutions

Pharmacist and technician times required for the preparation of parenteral nutrient (PN) solutions were studied before and after the introduction of a software package that is used with an automated compounder. At a 580-bed teaching hospital, work sampling was used to collect data on how time was spent by personnel in the i.v. admixture pharmacy during six-week periods before and after the introduction of software that calculates the quantities of PN solution ingredients on a computer-generated work sheet and prints labels. The second data-collection period began when the software had been in use for four months. In the second study period, there was a significant decrease (28%) in total pharmacist time spent per PN solution; the mean +/- S.D. pharmacist times per PN solution per day for the two study periods were 14.03 +/- 3.24 minutes and 10.12 +/- 1.61 minutes, respectively. There were also significant decreases in pharmacist time spent performing calculations, checking calculations, and typing labels. After introduction of the software, technicians spent significantly less time typing labels and pumping base solutions. Overall, technicians spent significantly less time per PN solution in the second study period (20.15 +/- 3.50 versus 17.82 +/- 1.94 minutes). Use of the software allowed pharmacist staffing in the i.v. admixture pharmacy to be reduced, and the pharmacy resources were reallocated toward the provision of clinical services. The generation of PN labels and calculation worksheets by computer software reduced pharmacist and technician time requirements for PN solution preparation.

Occurrence of adverse effects and high amantadine concentrations with influenza prophylaxis in the nursing home

Amantadine, in a dose of 100 mg/day, is recommended for influenza prevention in older nursing home residents. We studied an influenza prevention protocol in a 98-bed community nursing home (96% female; mean age = 87.4 years). Fifty-five residents received amantadine when influenza A was confirmed. Although no further influenza cases were diagnosed, 22% experienced adverse events. Dose in mg/kg/day was significantly higher in the group experiencing adverse events (2.24 +/- 0.98 vs 1.76 +/- 0.35; P less than .01). Amantadine concentrations in 32 residents ranged from 128-5,810 ng/mL. Six residents had amantadine concentrations greater than 1,000 ng/mL. Seventy-eight percent would have qualified for further dose reduction on the basis of estimated creatinine clearance. The results suggest that adverse events may be an important problem with the 100 mg/day dose, and this dose may be excessive for influenza prophylaxis in many nursing home residents.

Pharmacokinetics and pharmacodynamics of physostigmine after intravenous administration in beagle dogs

The time course of physostigmine (Phy), its metabolites and activity of cholinesterase (ChE) in plasma were studied after intravenous bolus administration of [3H]Phy (100 micrograms/kg) to beagle dogs. The maximal inhibition of ChE (78%) in plasma at 2 min correlated with the largest concentration of physostigmine (124 ng/ml). The concentration of physostigmine decreased by 88% to 16 ng/ml at 45 min when the activity of ChE was still 59% inhibited. Acetylcholinesterase activity in four regions of the brain (medulla, striatum, cerebellum and cortex) was not significantly different from controls at 70 +/- 5 min after administration of physostigmine. Concentrations of physostigmine and its metabolites determined by HPLC were not significantly different in different regions. In plasma, physostigmine was found, together with eseroline and two other metabolites M1 and M2. At 45 min, only 18% of total radioactivity was due to physostigmine and 52% was due to the major metabolite M1. On the contrary, in regions of the brain, metabolite M1 represented only 1.9-3.37% of total radioactivity at 70 +/- 5 min. Pharmacokinetic parameters, obtained in the dog, were compared to previously published data in rat and man. The elimination half-life (beta) was 30.7 min in the dog as compared to 15 min in rat and and 21.7 min in man. The Vd (ml/kg) was higher than total body water volume in all three species: dog (1832), rat (1352) and man (664), indicating sequestration of the drug in body compartments. Clearance (ml/min/kg) was found to be 41.2 in dog, which compares to 62 in rat and 22 in man.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of repeated desipramine administration on water intake in rats

Rats were maintained on a regimen of restricted access to water. Desipramine (DMI) IP 1 h prior to the access period dose-dependently reduced water intake. Following completion of the dose-response determination for the effect of desipramine or water intake, rats were divided into three groups for repeated administration. Rats in each group were injected both 1 h before and 15 min after the access period. The SAL-SAL group received saline both before and after the session, the DMI-SAL group received 10 mg/kg DMI before and saline after the session, and the SAL-DMI group received saline before and 10 mg/kg DMI after the session. Average water intake for rats in the DMI-SAL group decreased progressively during the first 5 days of repeated administration and then began to return toward baseline levels. Average water intake for rats in the SAL-DMI group decreased progressively from days 4-18 of repeated administration and then began to increase toward baseline levels. Rats repeatedly administered DMI (DMI-SAL and SAL-DMI groups) became tolerant to its effect on water intake, as indicated by a diminution of the DMI effect during repeated treatment and by a shift to the right in the DMI dose-response function after discontinuation of repeated DMI administration. Both groups of rats administered DMI repeatedly were less sensitive to amitriptyline-induced reduction of water intake than controls, thereby indicating the development of cross-tolerance to amitriptyline. Cross-tolerance to scopolamine did not develop. These findings demonstrate a behavioral effect of DMI that results in the development of tolerance. The lack of cross-tolerance to scopolamine suggests that tolerance development is not due to altered central cholinergic function.