Hypocapnia and the injured brain: Evidence for harm:

Select hyperacute complications of ischemic stroke: cerebral edema, hemorrhagic transformation, and orolingual angioedema secondary to intravenous Alteplase

INTRODUCTION

Remarkable advances have occurred in the management of acute ischemic stroke, especially in regards to reperfusion treatments. With advances in reperfusion treatments come the risk of complications associated with these treatments. Areas covered: The article focuses on three acute complications that can occur in the setting of acute ischemic stroke: cerebral edema, hemorrhagic transformation, and orolingual angioedema following administration of alteplase, a recombinant tissue plasminogen activator. Predictors of the development of these complications are reviewed. The management of cerebral edema and hemorrhagic transformation is also reviewed in depth including potential new treatments targeting the blood-brain barrier. The article also reviews the management of the rare but potentially fatal complication of orolingual angioedema secondary to alteplase. Expert commentary: An understanding of the pathophysiology leading to the development of malignant cerebral edema and hemorrhagic transformation allows the clinician to anticipate and properly manage these acute complications. Regardless of a patient's age or comorbidities, the decision to pursue decompressive hemicraniectomy in patients with malignant cerebral edema should be based on an honest assessment of expected outcome and guided by the patient's prior wishes regarding an acceptable quality of life.

Factors affecting extubation time following pediatric ambulatory surgery: an analysis using electronic anesthesia records from an academic university hospital

Background

In pediatric general anesthesia, our goal should be quicker extubation to facilitate rapid turnover in the operating room without compromising on safety and quality of anesthesia. Although many studies have focused on improving safety and pursuing a higher quality of recovery, factors related to anesthesia emergence remain unclear. We must, therefore, identify factors that influence the process of emergence from general anesthesia in children.

Findings

We retrospectively examined 148 children (aged 1–6 years, American Society of Anesthesiologists physical status: 1–2) who had undergone <2 h of ambulatory surgery. Clinical measures included time from the end of surgery to extubation (extubation time), age, height, weight, surgical time, mean indirect blood pressure during surgery, mean heart rate during surgery, mean end-tidal carbon dioxide during surgery (mETCO₂), mean body temperature during surgery (mBT), and total amount of fentanyl. Anesthetic procedures involved sevoflurane or propofol. Multiple regression analysis revealed that mETCO₂ (p < 0.01) and mBT (p < 0.01) were independent clinical factors associated with extubation time following pediatric ambulatory surgery.

Conclusions

This study of 148 pediatric patients demonstrated that anesthesia emergence may be associated with mBT and mETCO₂ following pediatric ambulatory surgery. These results show that perioperative vital signs are important in the prevention of delayed emergence for pediatric patients.

Arterial blood gas tensions after resuscitation from out-of-hospital cardiac arrest: associations with long-term neurologic outcome

OBJECTIVES

Optimal oxygen and carbon dioxide levels during postcardiac arrest care are currently undefined and observational studies have suggested harm from hyperoxia exposure. We aimed to assess whether mean and time-weighted oxygen and carbon dioxide levels during the first 24 hours of postcardiac arrest care correlate with 12-month neurologic outcome.

DESIGN

Prospective observational cohort study.

SETTING

Twenty-one ICUs in Finland.

PATIENTS

Out-of-hospital cardiac arrest patients treated in ICUs in Finland between March 2010 and February 2011.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Arterial blood PaO2 and PaCO2 during the first 24 hours from admission were divided into predefined categories from the lowest to the highest. Proportions of time spent in different categories and the mean PaO2 and PaCO2 values during the first 24 hours were included in separate multivariable regression models along with resuscitation factors. The cerebral performance category at 12 months was used as primary endpoint. A total of 409 patients with arterial blood gases analyzed at least once and with a complete set of resuscitation data were included. The average amount of PaO2 and PaCO2 measurements was eight per patient. The mean 24 hours PaCO2 level was an independent predictor of good outcome (odds ratio, 1.054; 95% CI, 1.006-1.104; p = 0.027) but the mean PaO2 value was not (odds ratio, 1.006; 95% CI, 0.998-1.014; p = 0.149). With multivariate regression analysis, time spent in the PaCO2 band higher than 45 mm Hg was associated with good outcome (odds ratio, 1.015; 95% CI, 1.002-1.029; p = 0.024, for each percentage point increase in time) but time spent in different oxygen categories were not.

CONCLUSIONS

In this multicenter study, hypercapnia was associated with good 12-month outcome in patients resuscitated from out-of-hospital cardiac arrest. We were unable to verify any harm from hyperoxia exposure. Further trials should focus on whether moderate hypercapnia during postcardiac arrest care improves outcome.

Beyond survival; influences of blood pressure, cerebral perfusion and anesthesia on neurodevelopment

Neonates have a higher perioperative mortality risk largely due to the degree of prior illness of the infants, the complexity of their surgeries, and infant physiology. It is important to consider contributing anesthetic factors during the perioperative period that may affect cerebral perfusion and neurocognitive outcome, such as alterations in hemodynamics and ventilation. Limitations of blood pressure as a marker for cerebral perfusion are discussed, as well as the effect of hypocapnia on the brain.