Regional anesthesia decreases complications and resource utilization in shoulder arthroplasty patients

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142932/1/aas13063_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142932/2/aas13063.pd

Risk of postoperative hypoxemia in ambulatory orthopedic surgery patients with diagnosis of obstructive sleep apnea: a retrospective observational study

<p>Abstract</p> <p>Background</p> <p>It is unclear when it is safe to discharge patients with a diagnosis of Obstructive Sleep Apnea (OSA) after ambulatory surgical procedures due to concern for postoperative respiratory compromise and hypoxemia. Our OSA patients undergoing ambulatory-type orthopedic procedures are monitored overnight in the PACU, thus we reviewed patient records to determine incidence of complications.</p> <p>Methods</p> <p>Two hundred and six charts of patients with preoperative diagnosis of OSA based on ICD-9 codes were reviewed for outcomes including episodes of hypoxemia. Univariate analysis followed by logistic regression and propensity analysis was performed to determine independent risk factors for hypoxemia and association with adverse outcomes.</p> <p>Results</p> <p>The majority of patients had regional anesthesia (95%). Thirty four percent of patients had hypoxemia in the PACU. Initial risk factors for hypoxemia identified by univariate analysis were BMI ≥ 35, increased age, history of COPD, upper extremity procedure, and use of peripheral nerve block. Independent risk factors identified by logistic regression were history of COPD (OR 3.64 with 95% CI 1.03-12.88) and upper extremity procedure (2.53, 1.36-4.68). After adjustment with propensity scores, adverse events were rare, and unplanned hospital admission after PACU stay was not increased with hypoxemia (11% vs 16%)</p> <p>Conclusions</p> <p>Episodes of postoperative hypoxemia in OSA patients undergoing ambulatory surgery with regional anesthesia are not associated with increased adverse outcomes or unplanned hospital admission.</p

The Effect of Regional Analgesia on Vascular Tone in Hip Arthroplasty Patients

Background: While it is assumed that neuraxial analgesia and pain management may beneficially influence perioperative hemodynamics, few studies provided data quantifying such effects and none have assessed the potential contribution of the addition of a nerve block. Questions/purposes: This clinical trial compared the visual analog scale (VAS) scores and measurement of arterial tone using augmentation index of patients who received combined spinal-epidural (CSE) only to patients who received both CSE and lumbar plexus block. Methods: After obtaining written consent, 92 patients undergoing total hip arthroplasty were randomized to receive either CSE or CSE with lumbar plexus block (LPB). Perioperative pain and arterial tone were measured using VAS scores and augmentation index (AI) respectively, at baseline and at various times postoperatively. Results: After the exclusion of 2 patients, 44 patients received CSE alone and 46 patients received CSE and LPB. Patient demographics and perioperative characteristics were similar in both groups. AI continuously decreased after placement of a CSE with or without LBP, beyond full resolution of neuraxial and peripheral blockade. Although the LPB group demonstrated a statistically significant reduction of VAS pain scores in the postanesthesia care unit (PACU; P \u3c 0.05), overall, the addition of a LPB did not significantly reduce the AI when compared to the control group. Conclusion: The addition of a LPB provided better pain control in the PACU but did not reduce the AI, compared to the control group. We conclude that the addition of a LPB may have limited ability to affect arterial tone in the presence of a continuous infusion of epidural analgesics. In summary, the addition of a LPB in patients undergoing total hip arthroplasty is clinically effective and provided better pain control, especially in the immediate postoperative period. The continuous decrease on the AI in both groups beyond the full resolution of the neuroaxial and LPB will require further studies

Microvascular response to transfusion in elective spine surgery

AIM: To investigate the microvascular (skeletal muscle tissue oxygenation; SmO2) response to transfusion in patients undergoing elective complex spine surgery. METHODS: After IRB approval and written informed consent, 20 patients aged 18 to 85 years of age undergoing \u3e 3 level anterior and posterior spine fusion surgery were enrolled in the study. Patients were followed throughout the operative procedure, and for 12 h postoperatively. In addition to standard American Society of Anesthesiologists monitors, invasive measurements including central venous pressure, continual analysis of stroke volume (SV), cardiac output (CO), cardiac index (CI), and stroke volume variability (SVV) was performed. To measure skeletal muscle oxygen saturation (SmO2) during the study period, a non-invasive adhesive skin sensor based on Near Infrared Spectroscopy was placed over the deltoid muscle for continuous recording of optical spectra. All administration of fluids and blood products followed standard procedures at the Hospital for Special Surgery, without deviation from usual standards of care at the discretion of the Attending Anesthesiologist based on individual patient comorbidities, hemodynamic status, and laboratory data. Time stamps were collected for administration of colloids and blood products, to allow for analysis of SmO2 immediately before, during, and after administration of these fluids, and to allow for analysis of hemodynamic data around the same time points. Hemodynamic and oxygenation variables were collected continuously throughout the surgery, including heart rate, blood pressure, mean arterial pressure, SV, CO, CI, SVV, and SmO2. Bivariate analyses were conducted to examine the potential associations between the outcome of interest, SmO2, and each hemodynamic parameter measured using Pearson\u27s correlation coefficient, both for the overall cohort and within-patients individually. The association between receipt of packed red blood cells and SmO2 was performed by running an interrupted time series model, with SmO2 as our outcome, controlling for the amount of time spent in surgery before and after receipt of PRBC and for the inherent correlation between observations. Our model was fit using PROC AUTOREG in SAS version 9.2. All other analyses were also conducted in SAS version 9.2 (SAS Institute Inc., Cary, NC, United States). RESULTS: Pearson correlation coefficients varied widely between SmO2 and each hemodynamic parameter examined. The strongest positive correlations existed between ScvO2 (P = 0.41) and SV (P = 0.31) and SmO2; the strongest negative correlations were seen between albumin (P = -0.43) and cell saver (P = -0.37) and SmO2. Correlations for other laboratory parameters studied were weak and only based on a few observations. In the final model we found a small, but significant increase in SmO2 at the time of PRBC administration by 1.29 units (P = 0.0002). SmO2 values did not change over time prior to PRBC administration (P = 0.6658) but following PRBC administration, SmO2 values declined significantly by 0.015 units (P \u3c 0.0001). CONCLUSION: Intra-operative measurement of SmO2 during large volume, yet controlled hemorrhage, does not show a statistically significant correlation with either invasive hemodynamic, or laboratory parameters in patients undergoing elective complex spine surgery

Stickler Syndrome: Airway Complications in a Case Series of 502 Patients.

BACKGROUND: Patients with Stickler syndrome often require emergency surgery and are often anesthetized in nonspecialist units, typically for retinal detachment repair. Despite the occurrence of cleft palate and Pierre-Robin sequence, there is little published literature on airway complications. Our aim was to describe anesthetic practice and complications in a nonselected series of Stickler syndrome cases. To our knowledge, this is the largest such series in the published literature. METHODS: We retrospectively identified patients with genetically confirmed Stickler syndrome who had undergone general anesthesia in a major teaching hospital, seeking to identify factors that predicted patients who would require more than 1 attempt to correctly site an endotracheal tube (ETT) or supraglottic airway device (SAD). Patient demographics, associated factors, and anesthetic complications were collected. Descriptive statistical analysis and logistic regression modeling were performed. RESULTS: Five hundred and twoanesthetic events were analyzed. Three hundred ninety-five (92.7%) type 1 Stickler and 63 (96.9%) type 2 Stickler patients could be managed with a single attempt of passing an ETT or SAD. Advanced airway techniques were required on 4 occasions, and we report no major complications. On logistic regression, modeling receding mandible (P = .0004) and history of cleft palate (P = .0004) were significantly associated with the need for more than 1 attempt at airway manipulation. CONCLUSIONS: The majority of Stickler patients can be anesthetized safely with standard management. If patients have a receding mandible or history of cleft, an experienced anesthetist familiar with Stickler syndrome should manage the patient. We recommend that patients identified to have a difficult airway wear an alert bracelet.Wellcome Trust Clinician PhD Fellowship to DJ

Blood Transfusions in Total Hip and Knee Arthroplasty: An Analysis of Outcomes

Background. Various studies have raised concern of worse outcomes in patients receiving blood transfusions perioperatively compared to those who do not. In this study we attempted to determine the proportion of perioperative complications in the orthopedic population attributable to the use of a blood transfusion. Methods. Data from 400 hospitals in the United States were used to identify patients undergoing total hip or knee arthroplasty (THA and TKA) from 2006 to 2010. Patient and health care demographics, as well as comorbidities and perioperative outcomes were compared. Multivariable logistic regression models were fitted to determine associations between transfusion, age, and comorbidities and various perioperative outcomes. Population attributable fraction (PAF) was determined to measure the proportion of outcome attributable to transfusion and other risk factors. Results. Of 530,089 patients, 18.93% received a blood transfusion during their hospitalization. Patients requiring blood transfusion were significantly older and showed a higher comorbidity burden. In addition, these patients had significantly higher rates of major complications and a longer length of hospitalization. The logistic regression models showed that transfused patients were more likely to have adverse health outcomes than nontransfused patients. However, patients who were older or had preexisting diseases carried a higher risk than use of a transfusion for these outcomes. The need for a blood transfusion explained 9.51% (95% CI 9.12–9.90) of all major complications. Conclusions. Advanced age and high comorbidity may be responsible for a higher proportion of adverse outcomes in THA and TKA patients than blood transfusions

The perioperative immune response

PURPOSE OF REVIEW A host of immune modulators are now available in clinical practice. The perioperative period is characterized by profound alterations in host immunity, which can result in poor outcomes, which include infection, cancer recurrence and organ failure. Manipulation of the perioperative immune response has the potential to improve outcomes. A complete understanding of the mechanisms and clinical consequences of altered immune function in this setting is therefore imperative. RECENT FINDINGS Recent in-vivo data have emerged which further our understanding of the interaction between tissue damage, immune modulation and clinical outcomes by utilizing novel laboratory techniques capable of monitoring single-cell immune signatures. Traditional gene expression assays have continued to demonstrate their utility and have been instrumental in defining the host response to perioperative allogeneic blood transfusion. These mechanistic studies are complemented by large clinical studies describing associations between anaesthetic modalities and immune-related outcomes. SUMMARY Laboratory techniques are now available that can monitor the perioperative immune response and could be further developed to introduce personalized care pathways. Consideration must also be given to anaesthesia techniques and perioperative treatments that, although not immediately harmful, may be associated with poor outcomes temporally distant from the treatment, secondary to induced immunosuppression