In Vivo Clearance of Alpha-1 Acid Glycoprotein Is Influenced by the Extent of Its N-Linked Glycosylation and by Its Interaction with the Vessel Wall

Alpha-1 acid glycoprotein (AGP) is a highly glycosylated plasma protein that exerts vasoprotective effects. We hypothesized that AGP's N-linked glycans govern its rate of clearance from the circulation, and followed the disappearance of different forms of radiolabeled human AGP from the plasma of rabbits and mice. Enzymatic deglycosylation of human plasma-derived AGP (pdAGP) by Peptide: N-Glycosidase F yielded a mixture of differentially deglycosylated forms (PNGase-AGP), while the introduction of five Asn to Gln mutations in recombinant Pichia pastoris-derived AGP (rAGP-N(5)Q) eliminated N-linked glycosylation. PNGase-AGP was cleared from the rabbit circulation 9-fold, and rAGP-N(5)Q, 46-fold more rapidly than pdAGP, primarily via a renal route. Pichia pastoris-derived wild-type rAGP differed from pdAGP in expressing mannose-terminated glycans, and, like neuraminidase-treated pdAGP, was more rapidly removed from the rabbit circulation than rAGP-N(5)Q. Systemic hyaluronidase treatment of mice transiently decreased pdAGP clearance. AGP administration to mice reduced vascular binding of hyaluronic acid binding protein in the liver microcirculation and increased its plasma levels. Our results support a critical role of N-linked glycosylation of AGP in regulating its in vivo clearance and an influence of a hyaluronidase-sensitive component of the vessel wall on its transendothelial passage

Comparison of Methods for the Purification of Alpha-1 Acid Glycoprotein from Human Plasma

Alpha-1 acid glycoprotein (AGP) is a highly glycosylated, negatively charged plasma protein suggested to have anti-inflammatory and/or immunomodulatory activities. Purification of AGP could be simplified if methods that exploit its high solubility under chemically harsh conditions could be demonstrated to leave the protein in its native conformation. Procedures involving exposure of AGP to hot phenol or sulphosalicylic acid (SSA) were compared to solely chromatographic methods. Hot phenol-purified AGP was more rapidly cleared from mice in vivo following intravenous injection than chromatographically purified AGP. In contrast, SSA-purified AGP demonstrated an identical in vivo clearance profile and circular dichroism spectrum to chromatographically purified AGP. Similarly, no differences in susceptibility to enzymatic deglycosylation or reactivity with Sambucus nigra lectin were detected between AGP purified via the two methods. Incorporation of the SSA step in the purification scheme for AGP eliminated the need for a large (4 mL resin/mL of plasma) initial chromatographic step and simplified its purification without causing any detectable distortion in the conformation of the protein. Confirmation that this procedure is nondenaturing will simplify AGP purification and investigation of its possible biological roles in laboratory animals

The effect of rapid response teams on end-of-life care: A retrospective chart review

R apid response teams (RRTs) were designed to assess and treat deteriorating ward patients. The aim of RRTs is to decrease the number of cardiac arrests, intensive care unit (ICU) transfers and inhospital mortality. These goals have been met with variable success in the literature, with some prospective cohort studies reporting reductions in cardiac arrests (1-4). However, these results were not replicated in the large, multicentre, cluster randomized controlled Medical Early Response Intervention and Therapy (MERIT) trial (5). The MERIT trial suggested that there was an association with RRTs and an increase in do-not-resuscitate orders (6,7). Further studies have also documented RRT involvement in end-of-life (EOL) care (8-10). To support EOL care, our institution implemented a hospital-wide policy and associated preprinted order set known as the PhysicianOrdered Spectrum of Treatment (POST) form. The POST form acted as an extension of a 'do not resuscitate' status. The form engaged health care providers in conversations with patients and families regarding life-sustaining interventions such as cardiopulmonary resuscitation, intubation, defibrillation, ICU transfer, antibiotics, blood products or intravenous lines The premise of our study was that hospitalized patients are in fragile condition and, although restorative therapies are often the goal, there are patients who do not want or who would not benefit from aggressive resuscitative measures. As 'first responders' for critically ill ward patients, RRTs have the opportunity to recognize and treat patients who would benefit from EOL care. We sought to characterize the effect of RRT EOL discussions on EOL care. We also characterized the proportion of patients seen by RRTs with EOL care issues. Finally, we examined how the introduction of a hospital-wide EOL preprinted order set influenced EOL discussions and EOL care. Methods The present study was a single-centre, retrospective chart review conducted at the Hamilton Health Sciences Hamilton General Hospital BACkgRound: A subset of critically ill patients have end-of-life (EOL) goals that are unclear. Rapid response teams (RRTs) may aid in the identification of these patients and the delivery of their EOL care. oBJeCtives: To characterize the impact of RRT discussion on EOL care, and to examine how a preprinted order (PPO) set for EOL care influenced EOL discussions and outcomes. Methods: A single-centre retrospective chart review of all RRT calls (January 2009 to December 2010) was performed. The effect of RRT EOL discussions and the effect of a hospital-wide PPO set on EOL care was examined. Charts were from the Ontario Ministry of Health and LongTerm Care Critical Care Information Systemic database, and were interrogated by two reviewers. Results: In patients whose EOL status changed following RRT EOL discussion, there were fewer intensive care unit (ICU) transfers (8.4% versus 17%; P<0.001), decreased ICU length of stay (5.8 days versus 20 days; P=0.08), increased palliative care consultations (34% versus 5.3%; P<0.001) and an increased proportion who died within 24 h of consultation (25% versus 8.3%; P<0.001). More patients experienced a change in EOL status following the introduction of an EOL PPO, from 20% (before) to 31% (after) (P<0.05). ConClusions: A change in EOL status following RRT-led EOL discussion was associated with reduced ICU transfers and enhanced access to palliative care services. Further study is required to identify and deconstruct barriers impairing timely and appropriate EOL discussions. Effect of RRTs on EOL care Can Respir J Vol 21 No 5 September/October 2014 303 (Hamilton, Ontario), a 458-bed tertiary care centre and regional centre of excellence specializing in cardiac and vascular care, neuroscience, trauma and burn treatment, stroke and rehabilitation. The RRT at the authors' site has been a Ministry of Health and Long-Term Care of Ontario-funded team since 2006 and includes an ICU physician, critical care nurses and registered respiratory therapists. Critical care residents or fellows may support the team on some occasions. Any health care provider with concerns regarding patients' airway, breathing or circulation can activate the team. The nurses and respiratory therapists on the RRT also have several medical directives that allows them to initiate resuscitative therapy before a licensed physician arrives at the bedside. They have also received additional training in EOL discussions. The POST was implemented in January 2010 as a hospital-wide policy to improve EOL care. Institutional policy dictated that the POST form was to be completed for all hospitalized patients with a predicted life expectancy <1 year. Before its implementation, there was a one-month period of distributed education on using the POST form. The POST form was examined because it coincided with the study period and was a confounder that may have effected RRT EOL discussions. ethics The present study was approved by Hamilton Health Sciences Research Ethics Board (approval number was 11-463-C). The need for informed consent was waived. data collection The chart review was composed of all patients seen by the RRT team between January 1, 2009 and December 31, 2010. RRT-based EOL discussions were tracked. Data were gathered from the Ontario Ministry of Health and Long-Term Care Critical Care Information Systemic database. Charts were divided into code status discussion initiated, code status discussion revisited, code status previously established and code status discussion not appropriate at the time or for this patient. These distinctions were determined by the RRT's registered nurse or respiratory therapist, who completed the team call record at the time of RRT consultation. Charts coded as 'discussion initiated' and 'discussion revisited' were considered to be positive for EOL discussion. Two reviewers reviewed the charts independently. If the RRT had an EOL discussion, the patient's medical record was reviewed for patient demographics, admitting service, code status at time of consultation, completion of POST form, a change in EOL status following consultation, ICU transfer following consultation, total ICU length of stay (LOS) following transfer, if death occurred within 24 h following consultation and whether palliative care was involved in EOL care. data analysis The analysis focused on RRT EOL discussion with critically ill ward patients. To determine the effect of the RRT on EOL care, patients with and without a change in EOL status following RRT EOL discussion were compared. To determine the effect of the POST form on RRT EOL discussions, the outcomes before the introduction of the POST (January 1, 2009 to December 31 2009) and following the introduction of the POST (January 1, 2010 to Decemebr 31, 2010) were compared. Discrete variables were described as proportions and compared using χ 2 tests. Continuous variables were reported as mean ± SD and compared using unpaired t tests; P<0.05 was considered to be statistically significant. Results Patient population Between January 1, 2009 and December 31, 2010, the RRT saw 5320 patients. Of 5320 patients, 1254 (24%) were seen as a new RRT consultation while 3155 (59%) were seen in ICU discharge follow-up. The method in which RRT was involved was not documented for 911 patients (17%). Three hundred nineteen patients (6%) had their code status discussion initiated or revisited by the RRT; 3081 (58%) had a previously established code status. A code status discussion was deemed not appropriate for 1920 patients (36%) effect of RRt eol discussion on eol care Of the patients who RRT initiated or revisited code status, 276 (89%) were for full resuscitation at the time of consultation. The EOL status was changed in 83 (27%) patients, all of whom were for full resuscitation at the time of consultation. In patients with a change in EOL status, there were fewer ICU transfers (8% versus 16%; P<0.01), more palliative services arranged (34% versus 5%; P<0.01) and more patients who passed away within 24 h of RRT consultation (25% versus 8%; P<0.01). There was a trend toward decreased ICU LOS (six days versus 20 days; P=0.08) ( effect of Post form on eol care There were minimal differences when comparing outcomes before and following POST implementation. There were similar proportions of patients who were for full resuscitation at time of consultation (89% before versus 85% after; P=0.72). There was a significant increase in the proportion of patients who had a change in code status following implementation of the POST form (20% before versus 31% after; P<0.05). However, there was no difference in proportion transferred to the ICU (13% before versus 15% after; P=0.55), average ICU LOS (12 days before versus 14 days after; P=0.38), nor was there a difference in proportion with palliative care involved (14% before versus 12% after; P=0.55). There was a trend toward increased proportion of patients who died within 24 h of RRT consultation (8.6% before versus 16% after; P=0.08) ( disCussion We found that RRTs influenced EOL care through EOL discussions. In patients who experienced a change in EOL status following RRT EOL discussion, there were fewer ICU transfers, increased palliative services and more patients who died within 24 h. Furthermore, the POST form may be a tool that is associated with more EOL discussions, although it did not impact other EOL outcomes in our critical care setting. RRT involvement in EOL care is an evolving concept. Vasquez et al The extent of RRT involvement in EOL care is not yet clear. Downar et al (9,10) found that RRT involvement was not associated with improved access to palliative services, spiritual care and comfort medications. This outcome may be attributed to the study population. Downar et al (10) compared EOL care for patients who had died with versus without RRT consult. Patients referred to the RRT may have had a reversible condition amenable to restorative therapy as opposed to palliation. Conversely, patients who were not referred may have had irreversible conditions more suited to palliative care. This was suggested by the significantly increased proportion of patients with irreversible poor prognostic factors, palliative care consultations and shorter time to withdrawal of life support (10). In contrast, we studied patients who the RRT selected for an EOL discussion at the time of RRT consultation. As such, our study suggests that the RRT was able to identify and treat patients who would benefit from palliative care in the critical care setting. Although our study showed that RRTs could successfully initiate EOL care in critical care scenarios, this may not by the optimal time to discuss goals of care and resuscitation status. RRT involvement in EOL care suggests that there was room to enhance predeterioration EOL care. Previous studies have shown that clinical deterioration is not a sudden process and that the majority of cases present with antecedent clues such as hypotension or hypoxia (19). Responding to these clinical perturbations is only part of the care process. These fluctuations in clinical status should act as stop points for all health care providers to reassess the goals of care and resuscitation status with the patients and families. However, EOL care is not well addressed in hospital. Heyland (20) found that 76% of elderly patients have considered EOL care and only 12% preferred life-prolonging care. However, only 30% of medical documentation accurately reflected the patients' wishes. Reasons for not documenting an EOL status could be influenced by the patient and family, the clinician or the institution. Family/patient factors included unrealistic patients and families, inability of patients to participate in discussions and lack of advance directives (21,22). Clinician factors included insufficient training, competing time demands and insufficient remuneration (21-24). Institutional factors included suboptimal space for family meetings and lack of palliative care services Enhancing EOL quality will require multitiered interventions enacted through institutions, clinicians and patient/families. One intervention our institute implemented to support EOL discussions is the POST form. Previous literature suggested that similar forms may be used in a hospice or long-term care setting to effectively ensure adherence to patient wishes in an EOL setting (11-13). However, benefit of the POST form requires further study in critical care settings (15). Curtis et al Enhanced in-hospital EOL care is unlikely to arise from policy changes alone. There is room to improve clinician involvement in EOL care. O'Mahony et al (26) reported successful integration of a palliative care team into an ICU. They found that there was increased opioid use, formalized advanced directives and utilization of hospices, in addition to decreased investigations and nonbeneficial life-prolonging therapies. Furthermore, it is important to consider patient and family factors in a comprehensive plan for improving in-hospital EOL care. Heyland One systematic difference that may have influenced the results of our study was patient illness severity. The change in EOL status following RRT involvement may have been driven by illness severity as opposed to RRT EOL discussions. Due to data limitations, we were unable to determine whether there were any systematic differences in illness severity between patients who had a change in EOL status and those who did not. Even if this was the case, increased illness severity in patients with high unlikelihood of benefiting from resuscitative measures should drive EOL discussions and subsequent EOL care. The present study would then suggest that RRTs had the ability to identify deteriorating patients who benefited from palliation rather than resuscitation. More work is required to determine how accurately RRTs prognosticate patients. Furthermore, although we selected quantifiable and patientimportant outcomes to review, the scope of our analysis was limited by data restrictions inherent in a retrospective study. We found that 26% of patients who had an EOL discussion with the RRT had a subsequent change in EOL status; we do not know whether this number was appropriate. Seventy-four percent of patients who the RRT believed warranted an EOL discussion did not have a subsequent change in EOL status. EOL discussions could have resulted in more than a change in EOL status. Other outcomes that may have been affected include dyspnea management, avoiding unnecessary and invasive therapies, treatment of pain, ascertaining patient and family values, and providing support suMMARy We found that a change in EOL status following RRT-led EOL discussions was associated with reduced ICU transfers and enhanced access to palliative services. Our study suggested that there is a need to enhance predeterioration EOL planning. Moreover, there is a need to develop institutional support for EOL care, clinician training on EOL care and enhanced access to palliative care services. Future areas of study are to identify patients who will benefit from EOL discussion and to identify the barriers to engaging these patients in EOL discussion. ACknoWledgeMents: BT contributed to research design, dat

Living the security city: Karachi’s archipelago of enclaves

Like many of the enclaves used by elites and foreign visitors in this troubled megacity of over 20 million, the Karachi Sheraton Hotel is increasingly fortified off from its immediate environment. Blast walls, checkpoints, surveillance systems, and armies of police and security guards continually work to try and control how the hotel’s commodious internal spaces relate to an outside street deemed deeply insecure and prone to unpredictable moments of violence. Today, a widespread logic of military securitization—which Stephen Graham has termed the “new military urbanism”—exists in many of the world’s cities, even those that are not formal war zones. In those cities, an obsession with attaining total security—especially around financial centers, ports, residential areas, embassy districts, and mega events—results in the generalization of the kind of passage-point architectures most familiar from airports to everyday urban landscapes. Enclaves such as those surrounding the Karachi Sheraton Hotel have emerged in response to heightened perceptions of vulnerability within a wider city wrecked by murderous violence. But it is important to look beyond the already familiar physical architectures of enclaved cities per se. By focusing merely on the physical architectures of securitized cities—their fortified walls, checkpoints, and barriers—risks an environmentally deterministic perspective suggesting that these constructions work completely or that their effects can be assumed from their appearance. Complex interconnections between gated enclaves and the rest of the city are easily overlooked. This is especially so when it becomes clear that immense and ongoing labor is required to even create the pretense that relations between the inside of enclaves and the broader city can ever be fully scrutinized and filtered within huge, dynamic, and highly mobilemegacities. In what follows, our discussion will center on the dynamic relationships between those who perform and work the boundaries of enclaves and those who live and use enclaved spaces. We will concern ourselves with the neglected question of how the transformation of megacity landscapes into uneven patchworks of securitized enclaves work to produce novel experiences and forms of urban political life. Our question, then, is simple: How is the new security city, the archipelago of gated enclaves, lived

Diagnosis of ventilator-associated pneumonia in critically ill adult patients-a systematic review and meta-analysis.

The accuracy of the signs and tests that clinicians use to diagnose ventilator-associated pneumonia (VAP) and initiate antibiotic treatment has not been well characterized. We sought to characterize and compare the accuracy of physical examination, chest radiography, endotracheal aspirate (ETA), bronchoscopic sampling cultures (protected specimen brush [PSB] and bronchoalveolar lavage [BAL]), and CPIS > 6 to diagnose VAP. We searched six databases from inception through September 2019 and selected English-language studies investigating accuracy of any of the above tests for VAP diagnosis. Reference standard was histopathological analysis. Two reviewers independently extracted data and assessed study quality. We included 25 studies (1639 patients). The pooled sensitivity and specificity of physical examination findings for VAP were poor: fever (66.4% [95% confidence interval [CI]: 40.7–85.0], 53.9% [95% CI 34.5–72.2]) and purulent secretions (77.0% [95% CI 64.7–85.9], 39.0% [95% CI 25.8–54.0]). Any infiltrate on chest radiography had a sensitivity of 88.9% (95% CI 73.9–95.8) and specificity of 26.1% (95% CI 15.1–41.4). ETA had a sensitivity of 75.7% (95% CI 51.5–90.1) and specificity of 67.9% (95% CI 40.5–86.8). Among bronchoscopic sampling methods, PSB had a sensitivity of 61.4% [95% CI 43.7–76.5] and specificity of 76.5% [95% CI 64.2–85.6]; while BAL had a sensitivity of 71.1% [95% CI 49.9–85.9] and specificity of 79.6% [95% CI 66.2–85.9]. CPIS > 6 had a sensitivity of 73.8% (95% CI 50.6–88.5) and specificity of 66.4% (95% CI 43.9–83.3). Classic clinical indicators had poor accuracy for diagnosis of VAP. Reliance upon these indicators in isolation may result in misdiagnosis and potentially unnecessary antimicrobial use

Multicentre pilot randomised clinical trial of early in-bed cycle ergometry with ventilated patients.

Introduction: Acute rehabilitation in critically ill patients can improve post-intensive care unit (post-ICU) physical function. In-bed cycling early in a patient\u27s ICU stay is a promising intervention. The objective of this study was to determine the feasibility of recruitment, intervention delivery and retention in a multi centre randomised clinical trial (RCT) of early in-bed cycling with mechanically ventilated (MV) patients. Methods: We conducted a pilot RCT conducted in seven Canadian medical-surgical ICUs. We enrolled adults who could ambulate independently before ICU admission, within the first 4 days of invasive MV and first 7 days of ICU admission. Following informed consent, patients underwent concealed randomisation to either 30 min/day of in-bed cycling and routine physiotherapy (Cycling) or routine physiotherapy alone (Routine) for 5 days/week, until ICU discharge. Our feasibility outcome targets included: accrual of 1-2 patients/month/site; \u3e80% cycling protocol delivery; \u3e80% outcomes measured and \u3e80% blinded outcome measures at hospital discharge. We report ascertainment rates for our primary outcome for the main trial (Physical Function ICU Test-scored (PFIT-s) at hospital discharge). Results: Between 3/2015 and 6/2016, we randomised 66 patients (36 Cycling, 30 Routine). Our consent rate was 84.6 % (66/78). Patient accrual was (mean (SD)) 1.1 (0.3) patients/month/site. Cycling occurred in 79.3% (146/184) of eligible sessions, with a median (IQR) session duration of 30.5 (30.0, 30.7) min. We recorded 43 (97.7%) PFIT-s scores at hospital discharge and 37 (86.0%) of these assessments were blinded. Discussion: Our pilot RCT suggests that a future multicentre RCT of early in-bed cycling for MV patients in the ICU is feasible. Trial registration number: NCT02377830