Creation and Expansion of a Mixed Patient Intermediate Care Unit to Improve ICU Capacity

OBJECTIVES

ICU capacity strain is associated with worsened outcomes. Intermediate care units (IMCs) comprise one potential option to offload ICUs while providing appropriate care for intermediate acuity patients, but their impact on ICU capacity has not been thoroughly characterized. The aims of this study are to describe the creation of a medical-surgical IMC and assess how the IMC affected ICU capacity.

DESIGN

Descriptive report with retrospective cohort review.

SETTING

Six hundred seventy-three-bed tertiary care academic medical center with 77 ICU beds.

PATIENTS

Adult inpatients who were admitted to the IMC.

INTERVENTIONS

An interdisciplinary working group created an IMC which was located on a general ward. The IMC was staffed by hospitalists and surgeons and supported by critical care consultants. The initial maximum census was three, but this number increased to six in response to heightened critical care demand. IMC admission criteria also expanded to include advanced noninvasive respiratory support defined as patients requiring high-flow nasal cannula, noninvasive positive pressure ventilation, or mechanical ventilation in patients with tracheostomies.

MEASUREMENTS AND MAIN RESULTS

The primary outcome entailed the number of ICU bed-days saved. Adverse outcomes, including ICU transfer, intubation, and death, were also recorded. From August 2021 to July 2022, 230 patients were admitted to the IMC. The most frequent IMC indications were respiratory support for medical patients and post-operative care for surgical patients. A total of 1023 ICU bed-days were made available. Most patients were discharged from the IMC to a general ward, while 8% of all patients required transfer to an ICU within 48 hours of admission. Intubation (2%) and death (1%) occurred infrequently within 48 hours of admission. Respiratory support was the indication associated with the most ICU transfers.

CONCLUSIONS

Despite a modest daily census, an IMC generated substantial ICU bed capacity during a time of peak critical care demand.

Component-specific toxic concerns of the inhalable fraction of urban road dust

Continuous global urbanisation causes an ever-growing ecological footprint of pollution. Road dust (RD), one of these pollutants, poses a health concern due to carcinogenic and toxic components potentially present in the micron-sized fractions. The literature reports on the concentrations of trace, toxic metals and metalloids present in RD (Hooker and Nathanail in Chem Geol 226:340-351, 2006), but the literature on its molecular composition is limited. Recent reports on the bioaccessibility of platinum group metals are also reported (Colombo et al. in Chem Geol 226:340-351, 2008). In vitro and animal toxicological studies confirmed that the chemical composition of inhaled particles plays a major role in its toxic, genotoxic and carcinogenic mechanisms, but the component-specific toxic effects are still not understood. Particle-bound airborne transition metals can also lead to the production of reactive oxygen species in lung tissue; a special concern amongst particularly susceptible cohorts (children and elderly). The characterisation of the molecular composition of the fine fraction is evidently of importance for public health. During a pilot study, partially characterised size-fractioned RD samples (Barrett et al. in Eviron Sci Technol 44:2940-2946, 2010) were analysed for their elemental concentration using X-ray fluorescence spectrometry and inductively coupled plasma mass spectrometry. In addition, separately dispersed particles (200 particles per size fraction) were analysed individually by means of computer-controlled electron probe X-ray micro-analysis (CC-EPXMA) and their molecular structure probed by studying elemental associations. These were correlated with micro-Raman spectroscopy (MRS) results. It was found that the fine fraction (<38 μm) had the highest Pb (238 ppm) and Cr (171 ppm) concentrations. The CC-EPXMA data showed >50 % association of Cr-rich particles with Pb, and the MRS data showed that the Cr was mostly present as lead chromate and therefore in the Cr(VI) oxidation state. Concentrations of both Pb and Cr decreased substantially (279 (<38 μm)-13 ppm (<1 mm); 171 (<38 μm)-91 ppm (< 1 mm), respectively) in the larger fractions. Apart from rather alarmingly high concentrations of oxidative stressors (Cu, Fe, Mn), the carcinogenic and toxic potential of the inhalable fraction is evident. Preliminary bioaccessibility data indicated that both Cr and Pb are readily mobilised in artificial lysosomal liquid and up to 19 % of Cr and 47 % of Pb were released.

Concerning the mechanism of pexelizumab's benefit in acute myocardial infarction

BACKGROUND

The COMplement inhibition in Myocardial infarction treated with Angioplasty (COMMA) trial previously demonstrated an unexpected dose-dependent reduction in 90-day mortality after bolus/infusion of pexelizumab despite no reduction in the primary end point of myocardial infarction (MI) size. We examined whether the mortality benefit was related to established modulators of clinical benefit such as baseline demographics, time to treatment from symptom onset, myocardial perfusion post-percutaneous coronary intervention (PCI), and extent of ST resolution.

METHODS AND RESULTS

Eight hundred fourteen patients were randomized into 3 groups; (1) placebo, (2) pexelizumab bolus 2.0 mg/kg and placebo infusion for 20 hours, and (3) pexelizumab bolus 2.0 and 0.05 mg/kg per hour infusion for 20 hours commencing 4 hours after the bolus. Subjects presented with ST elevation MI within 6 hours of symptom onset and underwent PCI, creatine kinase (CK), and CK-MB measurements taken sequentially to define CK-MB area under the curve (AUC) and sequential ECG's defined ST resolution and QRS infarct size. Whereas mortality for both placebo and bolus pexelizumab groups rose during later time after presentation, it remained low and did not change appreciably during the 6-hour randomization window when patients received pexelizumab bolus infusion. Amplification of the mortality benefit was evident in patients with the highest quartile of hemodynamic compromise, that is, heart rate > or = 90 beat/min and systolic blood pressure < or = 118 mm Hg (3.2% vs 11.3% P = .004). A significant interaction between treatment assignment and hemodynamic status (P = .013) existed after adjusting for age, race, and MI location. Clinical benefit was not related to infarct size, extent of ST elevation, or evidence of angiographic or electrocardiographic reperfusion.

CONCLUSIONS

These data raise the possibility that the clinical benefit of pexelizumab is mediated through novel pathways such as reduction in apoptosis or other mechanisms.

Prognostic significance of blood markers of inflammation in patients with ST-segment elevation myocardial infarction undergoing primary angioplasty and effects of pexelizumab, a C5 inhibitor: a substudy of the COMMA trial

AIMS

Pexelizumab, a monoclonal antibody inhibiting C5, reduced 90 day mortality and shock in the COMplement inhibition in Myocardial infarction treated with Angioplasty (COMMA) trial without apparent reductions in infarct size. Inflammation is a critical component of ST-elevation myocardial infarction (STEMI); this substudy examines prognostic values of selected markers and treatment effects.

METHODS AND RESULTS

C-reactive protein, interleukin-6 (IL-6), and tumour necrosis factor-alpha (TNF-alpha) serum levels were assessed in 337 patients enrolled in either the placebo or the pexelizumab 24 h infusion group. Higher C-reactive protein and IL-6 levels at baseline, 24 h, and 72 h were strongly associated with increased subsequent death (P<0.002 at baseline and 24 h, P<0.02 at 72 h); and all baseline marker levels with death or cardiogenic shock (P<0.03) within 90 days. C-reactive protein and IL-6 levels were similar at baseline, but significantly lower 24 h later with pexelizumab, when compared with placebo (17.1 vs. 25.5 mg/L, P=0.03 and 51.0 vs. 63.8 pg/mL, P=0.04, respectively). At 72 h, corresponding levels were similar, whereas TNF-alpha was slightly higher (P=0.04) in the treated group.

CONCLUSION

Inflammation markers and their serial changes predict death and shock in patients with STEMI undergoing primary angioplasty. Pexelizumab reduced C-reactive protein and IL-6, suggesting treatment benefits mediated through anti-inflammatory effects.

Prognostic usefulness of white blood cell count and temperature in acute myocardial infarction (from the CARDINAL Trial)

White blood cell (WBC) count and temperature are 2 global measures of inflammation that are systematically gathered and easily identifiable in a clinical setting, unlike many other markers of inflammation being investigated in patients with coronary artery disease. The prognostic usefulness of the WBC count and temperature were evaluated in a large acute myocardial infarction trial, the Complement And ReDuction of INfarct size after Angioplasty or Lytics program. Baseline and serial measurements of WBC counts and temperature were correlated with infarct size and clinical outcome.

Molecular remission of CML after autotransplantation followed by adoptive transfer of costimulated autologous T cells

Four patients with chronic myelogenous leukemia (CML) that was refractory to interferon alpha (two patients) or imatinib mesylate (two patients), and who lacked donors for allogeneic stem cell transplantation, received autotransplants followed by infusions of ex vivo costimulated autologous T cells. At day +30 (about 14 days after T-cell infusion), the mean CD4+ cell count was 481 cells/microl (range 270-834) and the mean CD8+ count was 516 cells/microl (range 173-1261). One patient had a relative lymphocytosis at 3.5 months after T-cell infusion, with CD4 and CD8 levels of 750 and 1985 cells/microl, respectively. All the four patients had complete cytogenetic remissions early after transplantation, three of whom also became PCR negative for the bcr/abl fusion mRNA. One patient, who had experienced progressive CML while on interferon alpha therapy, became PCR- post transplant, and remained in a molecular CR at 3.0 years of follow-up. All the four patients survived at 6, 9, 40, and 44 months post transplant; the patient who remained PCR+ had a cytogenetic and hematologic relapse of CML, but entered a molecular remission on imatinib. Autotransplantation followed by costimulated autologous T cells is feasible for patients with chronic phase CML, who lack allogeneic donors and can be associated with molecular remissions.

Pexelizumab, an anti-C5 complement antibody, as adjunctive therapy to primary percutaneous coronary intervention in acute myocardial infarction: the COMplement inhibition in Myocardial infarction treated with Angioplasty (COMMA) trial

BACKGROUND

Complement, activated during myocardial ischemia and reperfusion, causes myocardial damage through multiple processes. The COMplement inhibition in Myocardial infarction treated with Angioplasty (COMMA) trial was performed to determine the effect of pexelizumab, a C5 complement inhibitor, on infarct size in patients with ST-segment-elevation myocardial infarction (MI) undergoing primary percutaneous coronary intervention.

METHODS AND RESULTS

In COMMA, 960 patients with MI (20% isolated inferior MI) were randomized to placebo, pexelizumab 2.0-mg/kg bolus, or pexelizumab 2.0-mg/kg bolus and 0.05-mg/kg per h infusion for 20 hours. Infarct size by creatine kinase-MB area under the curve, the primary outcome, did not differ significantly between groups (placebo median, 4393; bolus pexelizumab, 4526; bolus plus infusion pexelizumab, 4713 [ng/mL] x h; P=0.89 for bolus versus placebo; P=0.76 for bolus plus infusion versus placebo), nor did the composite of 90-day death, new or worsening heart failure, shock, or stroke (placebo, 11.1%; bolus, 10.7%; bolus plus infusion, 8.5%). The ninety-day mortality rate was significantly lower with pexelizumab bolus plus infusion (1.8% versus 5.9% with placebo; nominal P=0.014); the bolus-only group had an intermediate mortality rate (4.2%).

CONCLUSIONS

In patients with ST-elevation MI undergoing percutaneous coronary intervention, pexelizumab had no measurable effect on infarct size. However, the significant reduction in mortality suggests that pexelizumab may benefit patients through alternative novel mechanisms and provides impetus for additional investigation.

Immune parameters relevant to neural xenograft survival in the primate brain

The lack of supply and access to human tissue has prompted the development of xenotransplantation as a potential clinical modality for neural cell transplantation. The goal of the present study was to achieve a better understanding of the immune factors involved in neural xenograft rejection in primates. Initially, we quantified complement mediated cell lysis of porcine fetal neurons by primate serum and demonstrated that anti-C5 antibody treatment inhibited cell death. We then developed an immunosuppression protocol that included in vivo anti-C5 monoclonal antibody treatment, triple drug therapy (cyclosporine, methylprednisolone, azathioprine) and donor tissue derived from CD59 or H-transferase transgenic pigs and applied it to pig-to-primate neural cell transplant models. Pre-formed alphaGal, induced alphaGal and primate anti-mouse antibody (PAMA) titers were monitored to assess the immune response. Four primates were transplanted. The three CD59 neural cell recipients showed an induced anti-alphaGal response, whereas the H-transferase neural cell recipient exhibited consistently low anti-alphaGal titers. Two of these recipients contained surviving grafts as detected by immunohistochemistry using selected neural markers. Graft survival correlated with high dose cyclosporine treatment, complete complement blockade and the absence of an induced PAMA response to the murine anti-C5 monoclonal antibodies.

Diagnostic yield muscle biopsy in patients with clinical evidence of mitochondrial cytopathy

We retrospectively reviewed 118 muscle biopsy specimens from 113 patients with clinical and/or biochemical evidence of mitochondrial cytopathy. Light microscopic evaluation revealed histologic abnormalities in 65 specimens. The most common histologic findings included angular atrophic esterase-positive muscle fibers, type II muscle atrophy, regenerating muscle fibers, and scattered cytochrome-oxidase deficient fibers. Ragged red fibers were noted in 3 specimens on a Gomori trichrome stain. Electron microscopic evaluation was performed in 113 muscle specimens, and in 34, no abnormalities were identified. Increased numbers of mitochondria, particularly in the subsarcolemmal region, were identified in 54 specimens. Increased mitochondrial size was seen in 8 specimens and paracrystalline mitochondrial inclusions in 3. Other ultrastructural findings included focally increased glycogen deposition, focal Z-band streaming, and focally increased lipid accumulation. For 39 cases, concomitant skin biopsy specimens were available; abnormalities were identified by electron microscopy in 12. The majority of biopsy specimens demonstrated some light or electron microscopic abnormality. Specific histologic findings suggestive of mitochondrial abnormalities (partial cytochrome oxidase deficiency, ragged red fibers) were noted in a minority of cases. Ultrastructural evidence of mitochondrial abnormalities was noted in the majority of cases.

Molecular cloning, characterization, and expression of a novel human neutral sphingomyelinase

Neutral sphingomyelinase (N-SMase) has emerged as an important cell membrane-associated enzyme that participates in several signal transduction and cell regulatory phenomena. Using expression cloning, we have identified a 3.7-kilobase pair cDNA transcript for N-SMase whose open reading frame predicts a 397-amino acid polypeptide. Transfection of COS-7 cells with cDNA for N-SMase resulted in a marked increase in N-SMase activity. Recombinant N-SMase (r-N-SMase) had the following physical-chemical properties. Mg(2+) activated and Cu(2+) and glutathione inhibited the activity of r-N-SMase. In contrast, dithiothreitol did not alter the activity of the enzyme. Of several phospholipids examined, sphingomyelin was the preferred substrate for r-N-SMase. The apparent molecular mass of r-N-SMase derived from COS-7 cells was approximately 90 kDa, similar to the native neutral sphingomyelinase prepared from human urine. However, upon expression in Escherichia coli, the apparent molecular mass of the recombinant enzyme was approximately 45 kDa. We speculate that this apparent difference in recombinant enzymes derived from COS-7 and E. coli cells may be due to extensive post-transcriptional changes. r-N-SMase has numerous post-transcriptional modification sites such as phosphorylation sites via protein kinase C, casein kinase II, tyrosine kinase, and cAMP- and cGMP-dependent protein kinases as well as sites for glycosylation and myristoylation. Amino acid sequence alignment studies revealed that r-N-SMase has some similarity to acid sphingomyelinase and significant homology to the death domains of tumor necrosis factor-alpha receptor-1 and Fas/Apo-I. We believe that the molecular cloning and characterization of N-SMase cDNA will accelerate the process to define its role as a key regulator in apoptosis, lipid and lipoprotein metabolism, and other cell regulatory pathways.

Pharmacology and biological efficacy of a recombinant, humanized, single-chain antibody C5 complement inhibitor in patients undergoing coronary artery bypass graft surgery with cardiopulmonary bypass

BACKGROUND

Cardiopulmonary bypass (CPB) induces a systemic inflammatory response that causes substantial clinical morbidity. Activation of complement during CPB contributes significantly to this inflammatory process. We examined the capability of a novel therapeutic complement inhibitor to prevent pathological complement activation and tissue injury in patients undergoing CPB.

METHODS AND RESULTS

A humanized, recombinant, single-chain antibody specific for human C5, h5G1.1-scFv, was intravenously administered in 1 of 4 doses ranging from 0.2 to 2.0 mg/kg before CPB. h5G1.1-scFv was found to be safe and well tolerated. Pharmacokinetic analysis revealed a sustained half-life from 7.0 to 14.5 hours. Pharmacodynamic analysis demonstrated significant dose-dependent inhibition of complement hemolytic activity for up to 14 hours at 2 mg/kg. The generation of proinflammatory complement byproducts (sC5b-9) was effectively inhibited in a dose-dependent fashion. Leukocyte activation, as measured by surface expression of CD11b, was reduced (P<0.05) in patients who received 1 and 2 mg/kg. There was a 40% reduction in myocardial injury (creatine kinase-MB release, P=0.05) in patients who received 2 mg/kg. Sequential Mini-Mental State Examinations (MMSE) demonstrated an 80% reduction in new cognitive deficits (P<0.05) in patients treated with 2 mg/kg. Finally, there was a 1-U reduction in postoperative blood loss (P<0. 05) in patients who received 1 or 2 mg/kg.

CONCLUSIONS

A single-chain antibody specific for human C5 is a safe and effective inhibitor of pathological complement activation in patients undergoing CPB. In addition to significantly reducing sC5b-9 formation and leukocyte CD11b expression, C5 inhibition significantly attenuates postoperative myocardial injury, cognitive deficits, and blood loss. These data suggest that C5 inhibition may represent a novel therapeutic strategy for preventing complement-mediated inflammation and tissue injury.

Role of atheroma liposomes and malondialdehyde-modified low-density lipoproteins in complement activation

We investigated the ability of atheroma-associated liposomes and malondialdehyde (MDA)-modified low-density lipoproteins (MDA-LDL) to activate complement. Complement activation markers C3a, Bb, C4d and SC5b-9 were measured in both normal and complement-deficient sera. We found that MDA-LDL was able to generate C3a and SC5b-9, predominantly by the alternative pathway. High-density lipoproteins modified with MDA were also capable of C3a generation although to a lesser degree. The presence of atheroma-associated liposomes did not result in detectable levels of complement activation markers. We conclude that MDA-modified lipoproteins may represent a possible source for complement activation within atherosclerotic lesions.

Identification of a high risk subgroup of grade 1 transitional cell carcinoma using image analysis based deoxyribonucleic acid ploidy analysis of tumor tissue

The use of deoxyribonucleic acid (DNA) cytometry to identify a subset of patients with grade 1, stage Ta or T1 transitional cell carcinoma at high risk for death or recurrence was investigated in a retrospective study using paraffin blocks from 88 low grade transitional cell carcinomas of the bladder with an absorptiometric video-based image analysis system. Tumors were evaluated for ploidy (70 diploid, 16 aneuploid and 2 tetraploid) and the presence of cells with greater than 5C DNA. Survival analysis of 62 patients with adequate followup (15 to 20 years) showed that 43 of 62 (69%) suffered recurrences and 13 (21%) died of bladder cancer. The single most important predictors of death and recurrence were stem line aneuploidy and the presence of cells with greater than 5C DNA, respectively.

Primary urinary cytodiagnosis of a bladder small-cell carcinoma

A small-cell undifferentiated tumor of the bladder in a 69-yr-old man with asymptomatic hematuria is described. Urine cytology showed abundant, small, round-to-oval hyperchromatic cells with coarse chromatin, nuclear molding, and high nuclear/cytoplasmic ratios. A primary cytodiagnosis of small-cell undifferentiated cancer with associated severe urothelial atypia was made. Immunohistochemical stains were negative for neuron-specific enolase, leukocyte common antigen, chromogranin, epithelial membrane antigen, prostatic acid phosphatase, and prostate-specific phosphatase. The diagnosis was confirmed histologically by studies performed on cystoscopic bladder biopsy material.

Regulatory control of the terminal complement proteins at the surface of human endothelial cells: neutralization of a C5b-9 inhibitor by antibody to CD59

Functionally inhibitory antibody to the plasma membrane complement inhibitor CD59 has been used to investigate control of the terminal complement proteins at the endothelial cell surface. Antibodies against purified human erythrocyte CD59 (polyclonal anti-CD59 and monoclonal antibodies [MoAbs] 1F1 and 1F5) were found to bind specifically to monolayers of cultured human umbilical vein endothelial cells, and by Western blotting to recognize an 18- to 21-Kd endothelial protein. When bound to the endothelial monolayer, anti-CD59 (immunoglobulin G or Fab fragment) potentiated membrane pore formation induced upon C9 binding to C5b-8, and augmented the C5b-9-induced cellular responses, including stimulated secretion of von Willebrand factor and expression of catalytic surface for the prothrombinase enzyme complex. Although potentiating endothelial responses to the terminal complement proteins, anti-CD59 had no effect on the response of these cells to stimulation by histamine. Taken together, these data suggest that human endothelial cells express the CD59 cell surface inhibitor of the terminal complement proteins, which serves to protect these cells from pore-forming and cell-stimulatory effects of the C5b-9 complex. These data also suggest that the inactivation or deletion of this cell surface regulatory molecule would increase the likelihood for procoagulant changes in endothelium exposed to complement activation in plasma.

Correlation of structure and function in developing proximal tubule of guinea pig

Unlike the case in rat, rabbit, and other species in which nephron formation continues into the newborn period, nephrogenesis in the guinea pig is completed well before the time of birth. Therefore, the marked increase in proximal tubule reabsorption that occurs during the postnatal period in that species can be attributed entirely to an increase in the absorptive capacity of existing nephron units. The purpose of the present morphometric studies was to correlate that change in proximal tubule function with changes in the apical and basolateral cell membrane surface areas. The apical and basolateral membrane surface densities were found to be approximately equal to each other and to remain constant throughout development. Because of increasing tubule volume, however, both membranes doubled in size between 1 and 3 wk of age and eventually increased by a factor of 3.5 in the adult. At the same time, there was little change in the length of tight function complexes measured in the plane of the luminal surface. Using previously published functional data and tubule length data, a good correlation was found between absolute absorption and total basolateral membrane surface area throughout the entire period of development in proximal tubules. Absorption per unit area of basolateral membrane was approximately 0.55, 0.41, 0.56, and 0.42 X 10(-6) nl.min-1.micron-2 in the 1st, 2nd, and 3rd wk, and in adult animals, respectively, and thus was similar to that reported for proximal tubule segments of adult rabbit and juvenile to adult rat.

Open lung biopsy in Mycoplasma pneumoniae pneumonia

Pathologic descriptions of Mycoplasma pneumoniae pneumonia in humans are scarce, and most descriptions are from autopsy studies. We studied open lung biopsy specimens from six patients with proved or probable M pneumoniae pneumonia and reviewed the findings on M pneumoniae pneumonia that have been reported in the literature, as well as the electron microscopic characteristics of the organism, to document the morphologic spectrum. Five of our six cases showed a typical but nonspecific polymorphonuclear leukocyte-rich exudate in the bronchiolar lumina, metaplastic cells that lined the bronchioles, a lymphoplasmacytic bronchiolar wall infiltrate, peribronchiolar septal widening, and adjacent hyperplasia of type II pneumocytes. In one patient, diffuse alveolar damage was superimposed on the above bronchiolar lesion, and the sixth patient had a nonspecific organizing pneumonia.