Use of Lactulose to Treat Hyperammonemia in ICU Patients Without Chronic Liver Disease or Significant Hepatocellular Injury.

OBJECTIVES: To review ICU patients with elevated ammonia without a clear hepatic etiology, to compare outcomes between those who received lactulose and those who did not. DESIGN: Retrospective observational study. SETTING: Medical, surgical, and subspecialty intensive care units at Wake Forest Baptist Medical Center, Winston-Salem, North Carolina between December 2012 and August 2016. PATIENTS: Adults with ammonia levels above 50 µmol/L, excluding those with known chronic liver disease, inborn error of metabolism, active use of valproic acid, total bilirubin ≥ 2 µmol/L, or alanine aminotransferase ≥ 100 units/L. INTERVENTIONS: Comparison in ICU length of stay (LOS), hospital LOS, in-hospital mortality, and mortality at 30 and 90 days. MEASUREMENTS AND MAIN RESULTS: Criteria for inclusion were met in 103 cases. Mean ammonia level was 75 µmol/L, with undetermined etiology in the majority of subjects. Lactulose was given in 48 cases (46.6%), with a median of 9.5 doses given. There were no significant differences in outcomes between the lactulose and non-lactulose groups. Among subjects with multiple data points, lactulose did not have a dose-dependent effect on ammonia level, and was not associated with faster ammonia normalization compared to non-lactulose. When analyzed separately, patients with moderate hyperammonemia (60-99 µmol/L) who received lactulose had longer hospital and ICU length of stay compared to non-lactulose (417.8 hours vs. 208.4 hours, P = 0.003, and 229.2 hours vs. 104.7 hours, P = 0.025; respectively), though confounders were present. CONCLUSIONS: Routine use of lactulose to treat mild to moderate hyperammonemia in this patient population was not associated with improved outcomes.

Comparison of Screening Scores for Heparin- Induced Thrombocytopenia After Cardiopulmonary Bypass.

OBJECTIVES: To compare screening scores for heparin-induced thrombocytopenia (HIT) after cardiopulmonary bypass (CPB). DESIGN: Retrospective cohort study. SETTING: Cardiothoracic surgery units within a large tertiary healthcare facility from September 2010 to January 2020. PARTICIPANTS: All adult patients tested for heparin-induced platelet antibody (HIPA) within 2 weeks after surgery requiring CPB. INTERVENTIONS: Using data available to providers at the time HIPA were checked, the 4T's Score, a modified 4T's Score, and a score proposed by Lillo-Le Louet (LLL) et al. were calculated. A retrospective chart review was performed for each patient to determine actual presence of HIT, and screening scores were compared for accuracy. MEASUREMENTS AND MAIN RESULTS: Criteria for inclusion were met in 266 patients. Of these, 34 (12.8%) were high likelihood of HIT, 16 (6.0%), additional patients were clinically ambiguous, and 216 (81.2%) were high likelihood of alternative cause for thrombocytopenia. HIPA tests done before postoperative day 5 were not associated with any high-likelihood cases of HIT regardless of preoperative heparin exposure. Although traditional 4T's ≥4, modified 4T's ≥3, and LLL ≥2 had statistically similar sensitivity for predicting HIT, the modified 4T's and LLL had superior specificity (p < 0.001). CONCLUSIONS: Appropriate screening for HIT curbed inappropriate HIPA testing, and reduced the need for empirical treatment while awaiting confirmatory test results. Traditional 4T's was statistically inferior to both the LLL score and a modified version of the 4T's to screen for HIT within 2 weeks of CPB.

Angiotensin II for Critically Ill Patients With Shock After Heart Transplant.

Patients undergoing heart transplant are at high risk for vasodilatory shock in the postoperative period, due to a combination of vascular dysfunction from end-stage heart failure and inflammatory response to cardiopulmonary bypass and, increasingly, long-term exposure to nonpulsatile blood flow in those who have received a left ventricular assist device as a bridge to transplant. Patients who have this vasoplegic syndrome, which may be refractory to traditional agents used in the treatment of shock, are vulnerable to organ dysfunction and death. Angiotensin II (ANG-2) is of increasing interest as an adjunct to traditional therapy, both for improvement in blood pressure and for sparing the use of high-dose catecholamine vasopressors. This case series describes the use of ANG-2 in 4 clinical scenarios for the treatment of shock due to heart transplant surgery, supporting its use in this role and justifying further prospective studies to clarify the appropriate place for ANG-2 in the hierarchy of adjunctive therapies.

Vaping-Related Clotting Phenomena Presenting As Central Retinal Vein Occlusion.

Central retinal vein occlusion (CRVO) typically manifests as unilateral vision loss from thrombosis and occlusion of the central retinal vein in patients with thrombophilic risk factors. Here we report a case of a 23-year-old male with three weeks of intermittent left-sided eye pressure and vision loss, who was found to have decreased visual acuity, retinal hemorrhages, and an impending CRVO in his left eye. Upon further evaluation, infectious disease and autoimmune labs were normal, but he had mildly increased right heart pressures and hypercoagulable changes in the right middle cerebral artery. He denied any personal or family history of clotting disorders but noted a four-year history of vaping. He was started on anticoagulation and discharged. Outpatient genetic testing for Factor V Leiden, protein C, protein S, and prothrombin G20210 was normal. His visual acuity returned to normal in the left eye and the retinal hemorrhages resolved. After the exclusion of organic causes, significant vaping history was considered the likely etiology of his hypercoagulable state and resultant CRVO. Vaping-related clotting phenomena may explain the etiology of an otherwise unexplained CRVO, but further investigation of the long-term health consequences of electronic cigarette use is still needed.

Catecholamine-Sparing Effect of Angiotensin II in an Anephric Patient With Mixed Shock After Cardiac Revascularization Surgery: A Case Report.

Vasodilatory shock is common following cardiac surgery, caused by an inflammatory response to cardiopulmonary bypass (CPB). Some cases are refractory to volume resuscitation, high-dose catecholamines, arginine vasopressin, and established adjunctive therapies. Angiotensin II (ANG-2), an endogenous hormone in the renin-angiotensin-aldosterone system (RAAS), has several direct and indirect vasoconstrictive properties that make it a promising potential treatment. This case describes the successful use of ANG-2 in an anephric patient who suffered from severe refractory shock following CPB, offering a unique potential mechanism of benefit in a broader population of patients with baseline impaired RAAS.

Spectrum of Retinal Vascular Diseases Associated With Paracentral Acute Middle Maculopathy.

PURPOSE: To evaluate the spectrum of retinal diseases that can demonstrate paracentral acute middle maculopathy and isolated ischemia of the intermediate and deep capillary plexus. DESIGN: Retrospective, multicenter, observational case series. METHODS: This is a retrospective case series review of 9 patients (10 eyes) from 5 centers with paracentral acute middle maculopathy lesions and previously unreported retinal vascular etiologies. Case presentations and multimodal imaging, including color photographs, near-infrared reflectance, fluorescein angiography, spectral-domain optical coherence tomography (SD OCT), and orbital color Doppler imaging, are described. Baseline and follow-up findings are correlated with clinical presentation, demographics, and systemic associations. RESULTS: Five men and 4 women, aged 27-66 years, were included. Isolated band-like hyperreflective lesions in the middle retinal layers, otherwise known as paracentral acute middle maculopathy, were observed in all patients at baseline presentation. Follow-up SD OCT analysis of these paracentral acute middle maculopathy lesions demonstrated subsequent thinning of the inner nuclear layer. Novel retinal vascular associations leading to retinal vasculopathy and paracentral acute middle maculopathy include eye compression injury causing global ocular ischemia, sickle cell crisis, Purtscher's retinopathy, inflammatory occlusive retinal vasculitis, post-H1N1 vaccine, hypertensive retinopathy, migraine disorder, and post-upper respiratory infection. CONCLUSION: Paracentral acute middle maculopathy lesions may develop in a wide spectrum of retinal vascular diseases. They are best identified with SD OCT analysis and may represent ischemia of the intermediate and deep capillary plexus. These lesions typically result in permanent thinning of the inner nuclear layer and are critical to identify in order to determine the cause of unexplained vision loss.

Auditory force feedback substitution improves surgical precision during simulated ophthalmic surgery.

PURPOSE: To determine the extent that auditory force feedback (AFF) substitution improves performance during a simulated ophthalmic peeling procedure. METHODS: A 25-gauge force-sensing microforceps was linked to two AFF modes. The "alarm" AFF mode sounded when the force reached 9 mN. The "warning" AFF mode made beeps with a frequency proportional to the generated force. Participants with different surgical experience levels were asked to peel a series of bandage strips off a platform as quickly as possible without exceeding 9 mN of force. In study arm A, participants peeled with alarm and warning AFF modes, the order randomized within the experience level. In study arm B, participants first peeled without AFF, then alarm or warning AFF (order randomized within the experience level), and finally without AFF. RESULTS: Of the 28 "surgeon" participants, AFF improved membrane peeling performance, reducing average force generated (P < 0.01), SD of forces (P < 0.05), and force × time above 9 mN (P < 0.01). Short training periods with AFF improved subsequent peeling performance when AFF was turned off, with reductions in average force, SD of force, maximum force, time spent above 9 mN, and force × time above 9 mN (all P < 0.001). Except for maximum force, peeling with AFF reduced all force parameters (P < 0.05) more than peeling without AFF after completing a training session. CONCLUSIONS: AFF enables the surgeon to reduce the forces generated with improved precision during phantom membrane peeling, regardless of surgical experience. New force-sensing surgical tools combined with AFF offer the potential to enhance surgical training and improve surgical performance.

Delirium in older emergency department patients: recognition, risk factors, and psychomotor subtypes.

OBJECTIVES: Missing delirium in the emergency department (ED) has been described as a medical error, yet this diagnosis is frequently unrecognized by emergency physicians (EPs). Identifying a subset of patients at high risk for delirium may improve delirium screening compliance by EPs. The authors sought to determine how often delirium is missed in the ED and how often these missed cases are detected by admitting hospital physicians at the time of admission, to identify delirium risk factors in older ED patients, and to characterize delirium by psychomotor subtypes in the ED setting. METHODS: This cross-sectional study was a convenience sample of patients conducted at a tertiary care, academic ED. English-speaking patients who were 65 years and older and present in the ED for less than 12 hours at the time of enrollment were included. Patients were excluded if they refused consent, were previously enrolled, had severe dementia, were unarousable to verbal stimuli for all delirium assessments, or had incomplete data. Delirium status was determined by using the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) administered by trained research assistants (RAs). Recognition of delirium by emergency and hospital physicians was determined from the medical record, blinded to CAM-ICU status. Multivariable logistic regression was used to identify independent delirium risk factors. The Richmond Agitation and Sedation Scale was used to classify delirium by its psychomotor subtypes. RESULTS: Inclusion and exclusion criteria were met in 303 patients, and 25 (8.3%) presented to the ED with delirium. The vast majority (92.0%, 95% confidence interval [CI] = 74.0% to 99.0%) of delirious patients had the hypoactive psychomotor subtype. Of the 25 patients with delirium, 19 (76.0%, 95% CI = 54.9% to 90.6%) were not recognized to be delirious by the EP. Of the 16 admitted delirious patients who were undiagnosed by the EPs, 15 (93.8%, 95% CI = 69.8% to 99.8%) remained unrecognized by the hospital physician at the time of admission. Dementia, a Katz Activities of Daily Living (ADL) < or = 4, and hearing impairment were independently associated with presenting with delirium in the ED. Based on the multivariable model, a delirium risk score was constructed. Dementia, Katz ADL < or = 4, and hearing impairment were weighed equally. Patients with higher risk scores were more likely to be CAM-ICU positive (area under the receiver operating characteristic [ROC] curve = 0.82). If older ED patients with one or more delirium risk factors were screened for delirium, 165 (54.5%, 95% CI = 48.7% to 60.2%) would have required a delirium assessment at the expense of missing 1 patient with delirium, while screening 141 patients without delirium. CONCLUSIONS: Delirium was a common occurrence in the ED, and the vast majority of delirium in the ED was of the hypoactive subtype. EPs missed delirium in 76% of the cases. Delirium that was missed in the ED was nearly always missed by hospital physicians at the time of admission. Using a delirium risk score has the potential to improve delirium screening efficiency in the ED setting.