Robert H. Thiele

Standardization of Care: Impact of an Enhanced Recovery Protocol on Length of Stay, Complications, and Direct Costs after Colorectal Surgery

BACKGROUND Colorectal surgery is associated with considerable morbidity and prolonged length of stay (LOS). Recognizing the need for improvement, we implemented an enhanced recovery (ER) protocol for all patients undergoing elective colorectal surgery at an academic institution. STUDY DESIGN A multidisciplinary team implemented an ER protocol based on: preoperative counseling with active patient participation, carbohydrate loading, multimodal analgesia with avoidance of intravenous opioids, intraoperative goal-directed fluid resuscitation, immediate postoperative feeding, and ambulation. Discharge requirements remained identical throughout. A before and after study design was undertaken comparing patients before (August 2012 to February 2013) and after implementation of an ER protocol (August 2013 to February 2014). Risk stratification was performed using the NSQIP risk calculator to calculate the predicted LOS for each patient based on 23 variables. RESULTS One hundred and nine consecutive patients underwent surgery within the ER protocol compared with 98 consecutive historical controls (conventional). The risk-adjusted predicted LOS was similar for each group at 5.1 and 5.2 days. Substantial reductions were seen in LOS, morphine equivalents, intravenous fluids, return of bowel function, and overall complications with the ER group. There was a

AKI Associated with Cardiac Surgery

7,129/patient reduction in direct cost, corresponding to a cost savings of

Preoperative Statin Administration Is Associated With Lower Mortality and Decreased Need for Postoperative Hemodialysis in Patients Undergoing Coronary Artery Bypass Graft Surgery

777,061 in the ER group. Patient satisfaction as measured by Press Ganey improved considerably during the study period. CONCLUSIONS Implementation of an ER protocol led to improved patient satisfaction and substantial reduction in LOS, complication rates, and costs for patients undergoing both open and laparoscopic colorectal surgery. These data demonstrate that small investments in the perioperative environment can lead to large returns.

The Physiologic Implications of Isolated Alpha1 Adrenergic Stimulation

Approximately 18% of patients undergoing cardiac surgery experience AKI (on the basis of modern standardized definitions of AKI), and approximately 2%-6% will require hemodialysis. The development of AKI after cardiac surgery portends poor short- and long-term prognoses, with those developing RIFLE failure or AKI Network stage III having an almost 2-fold increase in the risk of death. AKI is caused by a variety of factors, including nephrotoxins, hypoxia, mechanical trauma, inflammation, cardiopulmonary bypass, and hemodynamic instability, and it may be affected by the clinicians choice of fluids and vasoactive agents as well as the transfusion strategy used. The risk of AKI may be ameliorated by avoidance of nephrotoxins, achievement of adequate glucose control preoperatively, and use of goal-directed therapy hemodynamic strategies. Remote ischemic preconditioning is an exciting future strategy, but more work is needed before widespread implementation. Unfortunately, there are no pharmacologic agents known to reduce the risk of AKI or treat established AKI.

Cardiac output monitoring: a contemporary assessment and review.

OBJECTIVE The purpose of this study was to examine the effect of perioperative statin administration on renal outcomes after cardiac surgery. DESIGN A retrospective chart review. SETTING A university hospital. PARTICIPANTS Patients presenting for cardiac surgery. INTERVENTIONS The records of 2,760 patients admitted for coronary artery bypass graft (CABG) surgery from 1997 to 2006 were reviewed. In-hospital mortality, the need for renal replacement therapy (RRT), and acute renal failure (ARF) were considered the primary outcomes. Univariate and multiple logistic regression analyses were performed to assess the relationship between each outcome and statin therapy while adjusting for other patient characteristics. MAIN RESULTS Of the 2,760 patients, 1,557 were taking preoperative statins. On univariate analysis, the mortality rate for patients receiving statins was 2.4% versus 4.2% for those not receiving statins (p = 0.008). The requirement for RRT was 1.9% for patients receiving statins versus 3.6% for those not receiving statins (p = 0.011). The incidence of ARF was not statistically significant between groups (28% v 27.5%). On multivariate analysis, statin therapy was associated with a 43% decrease in the risk of death and a 46% decrease in the risk of RRT, but statins were not associated with a decreased risk of ARF. Also, the beneficial effects of statins were age-dependent, with younger patients experiencing a greater advantage. CONCLUSIONS The preoperative use of statins is associated with decreased in-hospital mortality and a reduction in the need for RRT.

The Clinical Implications of Isolated Alpha1 Adrenergic Stimulation

Phenylephrine and methoxamine are direct-acting, predominantly &agr;1 adrenergic receptor (AR) agonists. To better understand their physiologic effects, we screened 463 articles on the basis of PubMed searches of “methoxamine” and “phenylephrine” (limited to human, randomized studies published in English), as well as citations found therein. Relevant articles, as well as those discovered in the peer-review process, were incorporated into this review. Both methoxamine and phenylephrine increase cardiac afterload via several mechanisms, including increased vascular resistance, decreased vascular compliance, and disadvantageous alterations in the pressure waveforms produced by the pulsatile heart. Although pure &agr;1 agonists increase arterial blood pressure, neither animal nor human studies have ever shown pure &agr;1-agonism to produce a favorable change in myocardial energetics because of the resultant increase in myocardial workload. Furthermore, the cost of increased blood pressure after pure &agr;1-agonism is almost invariably decreased cardiac output, likely due to increases in venous resistance. The venous system contains &agr;1 ARs, and though stimulation of &agr;1 ARs decreases capacitance and may transiently increase venous return, this gain may be offset by changes in afterload, venous compliance, and venous resistance. Data on the effects of &agr;1 stimulation in the central nervous system show conflicting changes, while experimental animal data suggest that renal blood flow is reduced by &agr;1-agonists, and both animal and human data suggest that gastrointestinal perfusion may be reduced by &agr;1 tone.

Strict glucose control does not affect mortality after aneurysmal subarachnoid hemorrhage.

Objective:An increasing number of minimally or noninvasive devices are available to measure cardiac output in the critical care setting. This article reviews the underlying physical principles of these devices in addition to examining both animal and human comparative studies in an effort to allow clinicians to make informed decisions when selecting a device to measure cardiac output. Data Sources:Peer-reviewed manuscripts indexed in PubMed. Study Selection:A systematic search of the PubMed database for articles describing the use of cardiac output monitors yielded 1,526 sources that were included in the analysis. Data Extraction:From all published cardiac output monitoring studies reviewed, the animal model, number of independent measurements, and correlation between techniques was extracted. Data Synthesis:Comparative studies in animals and humans between devices designed for measurement of cardiac output and experimental reference standards indicate thermodilution and Doppler-based techniques to have acceptable accuracy across a wide range of hemodynamic conditions, with bioimpedance techniques being less accurate. Thermodilution devices are marginally more accurate than Doppler-based devices but suffer from slower response time, increased invasiveness, and require stable core temperatures, good operator technique, and a competent tricuspid valve. Doppler-based techniques are less invasive and offer beat-to-beat measurements and excellent trending ability, but are dependent on accurate beam alignment and knowledge of aortic cross-sectional area. Studies of newer devices, such as pulse contour analysis, partial rebreathing, and pulse wave velocity, are far less in number and are primarily based on comparisons with thermodilution-based cardiac output measurements. Studies show widely ranging results. Conclusion:Thermodilution is relatively accurate for cardiac output measurements in both animals and humans when compared to experimental reference standards. Doppler-based techniques appear to have similar accuracy as thermodilution pulmonary artery catheters. Bioimpedance, pulse contour, partial rebreathing, and pulse wave velocity-based devices have not been studied as rigorously; however, the majority of studies included in this analysis point towards decreased accuracy.

Ability of the Masimo pulse CO-Oximeter to detect changes in hemoglobin.

Phenylephrine is a direct-acting, predominantly &agr;1 adrenergic receptor agonist used by anesthesiologists and intensivists to treat hypotension. A variety of physiologic studies suggest that &agr;-agonists increase cardiac afterload, reduce venous compliance, and reduce renal bloodflow. The effects on gastrointestinal and cerebral perfusion are controversial. To better understand the effects of phenylephrine in a variety of clinical settings, we screened 463 articles on the basis of PubMed searches of “methoxamine,” a long-acting &agr; agonist, and “phenylephrine” (limited to human, randomized studies published in English), as well as citations found therein. Relevant articles, as well as those discovered in the peer-review process, were incorporated into this review. Phenylephrine has been studied as an antihypotensive drug in patients with severe aortic stenosis, as a treatment for decompensated tetralogy of Fallot and hypoxemia during 1-lung ventilation, as well as for the treatment of septic shock, traumatic brain injury, vasospasm status–postsubarachnoid hemorrhage, and hypotension during cesarean delivery. In specific instances (critical aortic stenosis, tetralogy of Fallot, hypotension during cesarean delivery) in which the regional effects of phenylephrine (e.g., decreased heart rate, favorable alterations in Qp:Qs ratio, improved fetal oxygen supply:demand ratio) outweigh its global effects (e.g., decreased cardiac output), phenylephrine may be a rational pharmacologic choice. In pathophysiologic states in which no regional advantages are gained by using an &agr;1 agonist, alternative vasopressors should be sought.

American Society for Enhanced Recovery (ASER) and Perioperative Quality Initiative (POQI) joint consensus statement on perioperative fluid management within an enhanced recovery pathway for colorectal surgery

Background:The effects of both hyperglycemia and hypoglycemia are deleterious to patients with neurologic injury. Methods:On January 1, 2002, the neurointensive care unit at the University of Virginia Health System initiated a strict glucose control protocol (goal glucose < 120 mg/dl). The authors conducted an impact study to determine the effects of this protocol on patients presenting with aneurysmal subarachnoid hemorrhage. Results:Among the 834 patients admitted between 1995 and 2007, the in-hospital mortality was 11.6%. The median admission glucose for survivors was lower (135 vs. 176 mg/dl); however, on multivariate analysis, increasing admission glucose was not associated with a statistically significant increase in the risk of death (P = 0.064). The median average glucose for survivors was also lower (116 vs. 135 mg/dl). This was significant on multivariate analysis (P < 0.001); however, the effect was small (odds ratio, 1.045). Implementation of the strict glucose protocol decreased median average glucose (121 vs. 116 mg/dl, P < 0.001) and decreased the incidence of hyperglycemia. Implementation of the protocol had no effect on in-hospital mortality (11.7% vs. 12.0%, P = 0.876 [univariate], P = 0.132 [multivariate]). Protocol implementation was associated with an increased incidence of hypoglycemia (P < 0.001). Hypoglycemia was associated with a substantially increased risk of death on multivariate analysis (P = 0.009; odds ratio = 3.818). Conclusions:The initiation of a tight glucose control regimen lowered average glucose levels but had no effect on overall in-hospital mortality.

Duration of red blood cell storage and outcomes following orthotopic liver transplantation

The decision to administer blood products is complex and multifactorial. Accurate assessment of the concentration of hemoglobin [Hgb] is a key component of this evaluation. Recently a noninvasive method of continuously measuring hemoglobin (SpHb) has become available with multi-wavelength Pulse CO-Oximetry. The accuracy of this device is well documented, but the trending ability of this monitor has not been previously described. Twenty patients undergoing major thoracic and lumbar spine surgery were recruited. All patients received radial arterial lines. On the contralateral index finger, a R1 25 sensor (Rev E) was applied and connected to a Radical-7 Pulse CO-Oximeter (both Masimo Corp, Irvine, CA). Blood samples were drawn intermittently at the anesthesia provider’s discretion and were analyzed by the operating room satellite laboratory CO-Oximeter. The value of Hgb and SpHb at that time point was compared. Trend analysis was performed by the four quadrant plot technique, testing directionality of change, and Critchley’s polar plot method testing both directionality and magnitude of the change in values. Eighty-eight samples recorded at times of sufficient signal quality were available for analysis. Four quadrant plot analysis revealed 94% of data within the quadrants associated with the correct direction change, and 90% of data points lay within the analysis bounds proposed by Critchley. Pulse CO-Oximetry offers an acceptable trend monitor in patients undergoing major spine surgery. Future work should explore the ability of this device to detect large changes in hemoglobin, as well as its applicability in additional surgical and non-surgical patient populations.