Anushirvan Minokadeh

Effect of Dexmedetomidine on Cerebral Blood Flow Velocity, Cerebral Metabolic Rate, and Carbon Dioxide Response in Normal Humans

Background:Dexmedetomidine reduces cerebral blood flow (CBF) in humans and animals. In animal investigations, cerebral metabolic rate (CMR) was unchanged. Therefore, the authors hypothesized that dexmedetomidine would cause a decrease in the CBF/CMR ratio with even further reduction by superimposed hyperventilation. This reduction might be deleterious in patients with neurologic injuries. Methods:Middle cerebral artery velocity (CBFV) was recorded continuously in six volunteers. CBFV, jugular bulb venous saturation (Sjvo2), CMR equivalent (CMRe), and CBFV/CMRe ratio were determined at six intervals before, during, and after administration of dexmedetomidine: (1) presedation; (2) presedation with hyperventilation; at steady state plasma levels of (3) 0.6 ng/ml and (4) 1.2 ng/ml; (5) 1.2 ng/ml with hyperventilation; and (6) 30 min after discontinuing dexmedetomidine. The slope of the arterial carbon dioxide tension (Paco2)–CBFV relation was determined presedation and at 1.2 ng/ml. Results:CBFV and CMRe decreased in a dose-related manner. The CBFV/CMRe ratio was unchanged. The CBFV response to carbon dioxide decreased from 1.20 ± 0.2 cm·s−1·mm Hg−1 presedation to 0.40 ± 0.15 cm·s−1·mm Hg−1 at 1.2 ng/ml. Sjvo2 was statistically unchanged during hyperventilation at 1.2 ng/ml versus presedation (50 ± 11 vs. 43 ± 5%). Arousal for hyperventilation at 1.2 ng/ml resulted in increased CBFV (30 ± 5 to 38 ± 4) and Bispectral Index (43 ± 10 to 94 ± 3). Conclusions:The predicted decrease in CBFV/CMRe ratio was not observed because of an unanticipated reduction of CMRe and a decrease in the slope of the Paco2–CBFV relation. CBFV and Bispectral Index increases during arousal for hyperventilation at 1.2 ng/ml suggest that CMR–CBF coupling is preserved during dexmedetomidine administration. Further evaluation of dexmedetomidine in patients with neurologic injuries seems justified.

Lessons learned from the institution of the Surgical Care Improvement Project at a teaching medical center

BACKGROUND The Surgical Care Improvement Project (SCIP) was designed to reduce perioperative complications. We describe our institutional experience in 6 major areas: surgical site infection, venous thromboembolism prevention, use of perioperative beta-blockade, serum glucose level greater than 200 mg/dL, normothermia, and the use of electric razors for hair removal. METHODS This was a retrospective review of surgical cases. Evidence-based training and standardization of system and process were undertaken. Compliance with SCIP guidelines was determined. RESULTS Overall SCIP compliance improved from 80% to 94% over a 2-year period. Standardized antibiotic dosing times improved compliance to more than 90%. Appropriate preoperative antibiotic choice improved to 100%. Cessation of antibiotics postoperatively within 24 hours remains a difficult task. Venous thromboembolism prophylaxis has been difficult to achieve because of postoperative bleeding concerns. Administration of beta-blockers has remained one of the most difficult problems to correct because of the multiplicity of avenues by which a patient may arrive to the operating suite. CONCLUSIONS Achievement of the SCIP goals is a formidable, but achievable, process requiring individual, cultural, systems, and institutional changes to achieve success.

A performance improvement-based resuscitation programme reduces arrest incidence and increases survival from in-hospital cardiac arrest

BACKGROUND Traditional resuscitation training models are inadequate to achieving and maintaining resuscitation competency. This analysis evaluates the effectiveness of a novel, performance improvement-based inpatient resuscitation programme. METHODS This was a prospective, before-and-after study conducted in an urban, university-affiliated hospital system. All inpatient adult cardiac arrest victims without an active Do Not Attempt Resuscitation order from July 2005 to June 2012 were included. The advanced resuscitation training (ART) programme was implemented in Spring 2007 and included a unique treatment algorithm constructed around the capabilities of our providers and resuscitation equipment, a training programme with flexible format and content including early recognition concepts, and a comprehensive approach to performance improvement feeding directly back into training. Our inpatient resuscitation registry and electronic patient care record were used to quantify arrest rates and survival-to-hospital discharge before and after ART programme implementation. Multiple logistic regression analysis was used to adjust for age, gender, location of arrest, initial rhythm, and time of day. RESULTS A total of 556 cardiac arrest victims were included (182 pre- and 374 post-ART). Arrest incidence decreased from 2.7 to 1.2 per 1000 patient discharges in non-ICU inpatient units, with no change in ICU arrest rate. An increase in survival-to-hospital discharge from 21 to 45% (p < 0.01) was observed following ART programme implementation. Adjusted odds ratios for survival-to-discharge (OR 2.2, 95% CI 1.4-3.4) and good neurological outcomes (OR 3.0, 95% CI 1.7-5.3) reflected similar improvements. Arrest-related deaths decreased from 2.1 to 0.5 deaths per 1000 patient discharges in non-ICU areas and from 1.5 to 1.3 deaths per 1000 patient discharges in ICU areas, and overall hospital mortality decreased from 2.2% to 1.8%. CONCLUSIONS Implementation of a novel, performance improvement-based inpatient resuscitation programme was associated with a decrease in the incidence of cardiac arrest and improved clinical outcomes.

A novel configuration of a traditional rapid response team decreases non–intensive care unit arrests and overall hospital mortality

BACKGROUND In-hospital cardiopulmonary arrest (CPA) accounts for substantial morbidity and mortality. Rapid response teams (RRTs) are designed to prevent non-intensive care unit (ICU) CPA through early detection and intervention. However, existing evidence has not consistently demonstrated a clear benefit. OBJECTIVE To explore the effectiveness of a novel RRT program design to decrease non-ICU CPA and overall hospital mortality. METHODS This study was conducted from the start of fiscal year 2005 to 2011. In November 2007, our hospitals implemented RRTs as part of a novel resuscitation program. Charge nurses from each inpatient unit underwent training as unit-specific RRT members. Additionally, all inpatient staff received annual training in RRT concepts including surveillance and recognition of deterioration. We compared the incidence of ICU and non-ICU CPA from first complete preimplementation year 2006 to postimplementation years 2007 to 2011. Overall hospital mortality was also reported. RESULTS The incidence of non-ICU CPA decreased, whereas the incidence of ICU CPA remained unchanged. Overall hospital mortality also decreased (2.12% to 1.74%, P < 0.001). The year-over-year change in RRT activations was inversely related to the change in Code Blue activations for each inpatient unit (r = -0.68, P < 0.001). CONCLUSION Our novel RRT program was associated with a decreased incidence of non-ICU CPA and improved hospital mortality.

Initial end-tidal carbon dioxide as a prognostic indicator for inpatient PEA arrest

AIM Investigate the relationship of initial PetCO2 values of patients during inpatient pulseless electrical activity (PEA) cardiopulmonary arrest with return of spontaneous circulation (ROSC) and survival to discharge. METHODS This study was performed in two urban, academic inpatient hospitals. Patients were enrolled from July 2009 to July 2013. A comprehensive database of all inpatient resuscitative events is maintained at these institutions, including demographic, clinical, and outcomes data. Arrests are stratified by primary etiology of arrest using a priori criteria. Inpatients with PEA arrest for whom recorded PetCO2 was available were included in the analysis. Capnography data obtained after ROSC and/or more than 10 min after initiation of CPR were excluded. Multivariable logistic regression was used to explore the association between initial PetCO2 >20 mmHg and both ROSC and survival-to-discharge. RESULTS A total of 50 patients with PEA arrest and pre-ROSC capnography were analyzed. CPR continued an average of 11.8 min after initial PetCO2 was recorded confirming absence of ROSC at time of measurement. Initial PetCO2 was higher in patients with versus without eventual ROSC (25.3 ± 14.4 mmHg versus 13.4 ± 6.9 mmHg, P = 0.003). After adjusting for age, gender, and arrest location (ICU versus non-ICU), initial PetCO2 >20 mmHg was associated with increased likelihood of ROSC (adjusted OR 4.8, 95% CI 1.2-19.2, P = 0.028). Initial PetCO2 was not significantly associated with survival-to-discharge (P = 0.251). CONCLUSIONS Initial PetCO2 >20 mmHg during CPR was associated with ROSC but not survival-to-discharge among inpatient PEA arrest victims. This analysis is limited by relatively small sample size.

Postoperative hemodynamic instability and monitoring.

Purpose of reviewThe purpose of the review is to identify the recently validated minimally invasive or noninvasive monitoring devices used to both monitor and guide resuscitation in the critically ill patients. Recent findingsRecent advances in noninvasive measures of blood pressure, blood flow, and vascular tone have been validated and complement existing minimally invasive and invasive monitoring techniques. These monitoring approaches should be used within the context of a focused physical examination and static vital sign analysis. When available, measurement of urinary output is often included. All studies show that minimally invasive and noninvasive measure of arterial pressure and cardiac output are possible and often remain as accurate as invasive measures. The noninvasive techniques degrade in severe circulatory failure and the use of vasopressor therapy. Importantly, these output parameters form the treatment goals for many goal-directed therapies protocols. SummaryWhen coupled with a focused physical examination and functional hemodynamic monitoring analyses, these measures become even more specific at defining volume responsiveness and vasomotor tone and can be used to drive resuscitation strategies.

The Effect of Clevidipine on Cerebral Blood Flow Velocity and Carbon Dioxide Reactivity in Human Volunteers.

Background: Clevidipine is a short acting, esterase metabolized, calcium channel antagonist administered as a continuous infusion for control of hypertension. Its profile allows for rapid titration and may be uniquely suited to achieving tight hemodynamic targets in neurosurgical and neurocritical care patients. The present study was designed to investigate the effect of clevidipine infusion on cerebral blood flow and cerebral CO2 responsiveness as measured by cerebral blood flow velocity (CBFV) using transcranial Doppler. Materials and Methods: CBFV was continuously recorded in 5 healthy subjects during the following conditions: baseline 1 (BL1); baseline with hyperventilation (HV1); baseline 2 (BL2); clevidipine infusion to achieve 15% mean arterial pressure (MAP) reduction (C15); clevidipine infusion to achieve 30% MAP reduction (C30); clevidipine infusion to 30% MAP reduction with hyperventilation (HV2). Results: The mean CBFV during intermediate (C15) or maximum (C30) dose clevidipine infusion was unchanged compared with baseline (BL2) (F2,8=0.66; P=0.54). Cerebral CO2 reactivity, expressed as %[INCREMENT]CBFV/[INCREMENT]mm Hg CO2, was not significantly different in the presence of maximal-dose clevidipine (HV2) as compared with baseline (HV1) (1.6±0.4 vs. 1.6±0.3%[INCREMENT]CBFV/[INCREMENT]mm Hg CO2, P=0.73). Conclusions: Clevidipine infusion did not significantly increase CBFV nor was cerebral CO2 reactivity reduced during maximal-dose clevidipine infusion. Further systematic investigation of clevidipine in patients with central nervous system pathology seems justified.

A Conceptual Framework to Reduce Inpatient Preventable Deaths

BACKGROUND Efforts to reduce preventable deaths in the in-hospital setting should target both cardiopulmonary arrest (CPA) prevention and optimal resuscitation. This requires consideration of a broad range of clinical issues and processes. A comprehensive, integrated system of care (SOC) that links data collection with a modular education program to reduce preventable deaths has not been defined. METHODS This study was conducted in two urban university hospitals from 2005 to 2009. The Advanced Resuscitation Training (ART) program was implemented in 2007, incorporating hands-on resuscitative skills and in-hospital-specific training with an institutional resuscitation database. Linkage between the database and training modules occurs via the ART Matrix, which classifies all CPA events into the following etiologies: sepsis, hemorrhage, pulmonary embolus, heart failure, tachyarrhythmias, bradyarrhythmias, acute respiratory distress syndrome, non-intubated pulmonary disease, obstructive apnea, traumatic brain injury, ischemic brain injury, and intracranial mass lesions. This taxonomy was validated using descriptive statistics, before-and-after analysis evaluating CPA incidence, and multivariate logistic regression to predict CPA survival. RESULTS A total of 336 inpatients suffered a cardiopulmonary arrest during the study period-187 in the pre-ART period and 149 in the post-ART period. The vast majority of CPA events were categorized using the ART Matrix with high inter-observer reliability. As anticipated, changes in CPA incidence and survival were observed for some Matrix categories but not others following ART implementation. In addition, multivariate logistic regression revealed strong independent associations between taxonomy classifications and outcome. CONCLUSION A novel SOC using a unique taxonomy for arrest classification appears to be effective at reducing inpatient CPA incidence and outcome.

Factors and outcomes associated with inpatient cardiac arrest following emergent endotracheal intubation

BACKGROUND Inpatient peri-intubation cardiac arrest (PICA) following emergent endotracheal intubation (ETI) is an uncommon but potentially preventable type of cardiac arrest (CA). Limited published data exist describing factors associated with inpatient PICA and patient outcomes. This study identifies risk factors associated with PICA among hospitalized patients emergently intubated out of the operating room and compares PICA to other types of inpatient CA. METHODS Retrospective case-control study of patients at our institution over a five-year period. Cases were defined as inpatients emergently intubated outside of the operating room that experienced cardiac arrest within 20min after ETI. The control group consisted of inpatients emergently intubated out of the operating room without CA. Predictors of PICA were identified through univariate and multivariate analysis. Clinical outcomes were compared between PICA and other inpatient CAs, identified through a prospectively enrolled CA registry at our institution. RESULTS 29 episodes of PICA occurred over 5 years, accounting for 5% of all inpatient arrests. Shock index ≥1.0, intubation within one hour of nursing shift change, and use of succinylcholine were independently associated with PICA. Sustained ROSC, survival to discharge, and neurocognitive outcome did not differ significantly between groups. CONCLUSION Patients outcomes following PICA were comparable to other causes of inpatient CA. Potentially modifiable factors were associated with PICA. Hemodynamic resuscitation, optimized staffing strategies, and possible avoidance of succinylcholine were associated with decreased risk of PICA. Clinical trials testing targeted strategies to optimize peri-intubation care are needed to identify effective interventions to prevent this potentially avoidable type of CA.

Frequency and survival pattern of in-hospital cardiac arrests: The impacts of etiology and timing.

OBJECTIVE Define the frequency and survival pattern of cardiac arrests in relation to the hospital day of event and etiology of arrest. SUBJECT AND METHODS Retrospective cohort study of adult in-hospital cardiac arrests between July 1, 2005, and June 30, 2013, that were classified by etiology of deterioration. Arrests were divided based on hospital day (HD) of event (HD1, HD2-7, HD>7 days), and analysis of frequency was performed. The primary outcome of survival to discharge and secondary outcomes of return of spontaneous circulation (ROSC) and favorable neurological outcomes were compared using multivariable logistic regression analysis. RESULTS A total of 627 cases were included, 193 (30.8%) cases in group HD1, 206 (32.9%) in HD2-7, and 228 (36.4%) in HD>7. Etiology of arrest demonstrated variability across the groups (p<0.001). Arrests due to ventilation issues increased in frequency with longer hospitalization (p<0.001) while arrests due to dysrhythmia had the opposite trend (p=0.014). Rates of survival to discharge (p=0.038) and favorable neurological outcomes (p=0.002) were lower with increasing hospital days while ROSC was not different among the groups (p=0.183). Survival was highest for HD1 (HD1: 38.9% [95% CI, 32.0-45.7%], p=0.002 vs HD2-7: 34.0% [95% CI, 27.5-40.4%], p<0.001 vs HD>7: 27.2% [95% CI, 21.4-33.0%], p<0.001). CONCLUSIONS The etiology of cardiac arrests varies in frequency as length of hospitalization increases. Survival rates and favorable neurological outcomes are lower for in-hospital arrests occurring later in the hospitalization, even when adjusted for age, sex, and location of event. Understanding these issues may help with focusing therapies and accurate prognostication.