Suman Rajagopalan

The effects of mild perioperative hypothermia on blood loss and transfusion requirement

Background:Anesthetic-induced hypothermia is known to reduce platelet function and impair enzymes of the coagulation cascade. The objective of this meta-analysis and systematic review was to evaluate the hypothesis that mild perioperative hypothermia increases surgical blood loss and transfusion requirement. Methods:The authors conducted a systematic search of published randomized trials that compared blood loss and/or transfusion requirements in normothermic and mildly hypothermic (34–36°C) surgical patients. Results are expressed as a ratio of the means or relative risks and 95% confidence intervals (CI); P < 0.05 was considered statistically significant. Results:Fourteen studies were included in analysis of blood loss, and 10 in the transfusion analysis. The median (quartiles) temperature difference between the normothermic and hypothermic patients among studies was 0.85°C (0.60°C versus 1.1°C). The ratio of geometric means of total blood loss in the normothermic and hypothermic patients was 0.84 (0.74 versus 0.96), P = 0.009. Normothermia also reduced transfusion requirement, with an overall estimated relative risk of 0.78 (95% CI 0.63, 0.97), P = 0.027. Conclusion:Even mild hypothermia (<1°C) significantly increases blood loss by approximately 16% (4–26%) and increases the relative risk for transfusion by approximately 22% (3–37%). Maintaining perioperative normothermia reduces blood loss and transfusion requirement by clinically important amounts.

Outcomes in pregnant women with acute aortic dissections: a review of the literature from 2003 to 2013

BACKGROUND Acute aortic dissection in pregnant women is a rare but potentially life-threatening event. Our aim was to evaluate maternal and fetal outcomes of acute aortic dissection during pregnancy. METHODS We conducted a review of literature of the PubMed database to identify publications related to pregnant women with acute aortic dissections during the period 2003-2013: 59 articles were included in the study. RESULTS A total of 75 patients were included in the analyses. Stanford type A dissections were the most common form, accounting for 77% of all cases. The majority (78%) occurred in the third trimester and immediate postpartum period. Inherited connective tissue disorders were causative in 49% of patients. Maternal mortality was not statistical different between type A and type B dissections (21% vs. 23%), but fetal outcomes were worse in type B dissections (35% vs. 10.3%; P<0.05). Fetal mortality in type A dissections was dependent on the timing of aortic repair, with antepartum aortic repair associated with a higher mortality (36%). CONCLUSION Despite advances in diagnostic and surgical techniques, maternal and fetal mortalities in pregnant patients with aortic dissection remain high. Patients undergoing combined cesarean section with aortic repair had favorable fetal outcomes.

The History of Ketamine Use and Its Clinical Indications

Ketamine, which has a similar chemical structure to phencyclidine, was first administered to humans in 1964 and found to produce a unique effect termed “dissociative anesthesia.” In spite of the potential abuse liability, ketamine remains on the World Health Organization (WHO) Model List of Essential Medicines. It has been approved worldwide as the sole anesthetic agent for certain procedures, for the induction of anesthesia, and as an anesthetic supplement with low-potency agents like nitrous oxide. In addition, ketamine is also used for its analgesic properties in the management of cancer pain, chronic pain, and postoperative pain, among other indications. This chapter describes the history, development, clinical indications, and abuse potential of this agent.

Airway management for cesarean delivery performed under general anesthesia

BACKGROUND With the increasing popularity of neuraxial anesthesia, there has been a decline in the use of general anesthesia for cesarean delivery. We sought to examine the incidence, outcome and characteristics associated with a failed airway in patients undergoing cesarean delivery under general anesthesia. METHODS A retrospective review of airway management in women undergoing cesarean delivery under general anesthesia over an eight-year period from 2006-2013 at an academic medical center was conducted. RESULTS During the study period, 10 077 cesarean deliveries were performed. Neuraxial anesthesia was used in 9382 (93%) women while general anesthesia was used in 695 (7%). Emergent cesarean delivery was the most common indication for general anesthesia. Failed intubation was encountered in only three (0.4%) women, who were successfully managed with a laryngeal mask airway. The overall incidence of failed intubation was 1 in 232 (95% CI 1:83 to 1:666) and general anesthesia was continued in all cases. There were no adverse maternal or fetal outcomes directly related to failed intubation. CONCLUSION Advances in adjunct airway equipment, availability of an experienced anesthesiologist and simulation-based teaching of failed airway management in obstetrics may have contributed to our improved maternal outcomes in patients undergoing cesarean delivery under general anesthesia.

Anesthetic considerations for labor and delivery in women with cerebrospinal fluid shunts

BACKGROUND The anesthetic management of labor and delivery in pregnant women with cerebrospinal fluid shunts can be challenging. We conducted a literature review to understand the anesthetic implications in pregnant women with cerebrospinal fluid shunts. METHODS We searched PubMed, EMBASE, and Medline databases to identify reports of pregnant women with cerebrospinal fluid shunts during the 30-year period from 1985 to 2015. Twenty-four studies reporting anesthetic techniques for labor and delivery were included in the analyses. RESULTS A total of 97 women with 130 pregnancies were included. Ventriculo-peritoneal shunts (77%) were the most common type of shunt. Twenty-eight (29%) women had shunt malfunction during pregnancy, with 20 (71%) requiring shunt revision. Overall, 73 women (56%) delivered vaginally and 23 (40%) received epidural analgesia. Fifty-seven women (44%) underwent cesarean delivery and general anesthesia was used in 45% of cases. CONCLUSION This review suggests that shunt malfunctions occurred commonly during pregnancy. The presence of neurological symptoms warrants careful evaluation of shunt function. Anesthetic management for labor and delivery varied and was dependent on shunt function. Epidural analgesia appears to be safe in women with functional shunts.

Anesthetic management of a large mediastinal mass for tracheal stent placement.

The anesthetic management of patients with large mediastinal masses can be complicated due to the pressure effects of the mass on the airway or major vessels. We present the successful anesthetic management of a 64-year-old female with a large mediastinal mass that encroached on the great vessels and compressed the trachea. A tracheal stent was placed to relieve the tracheal compression under general anesthesia. Spontaneous ventilation was maintained during the perioperative period with the use of a classic laryngeal mask airway. We discuss the utility of laryngeal mask airway for anesthetic management of tracheal stenting in patients with mediastinal masses.

Caso único de sangramento pela porta de conexão do cateter de artéria pulmonar ao módulo de oximetria

Pulmonary artery catheter is an invasive monitor usually placed in high-risk cardiac surgical patients to optimize the cardiac functions. We present this case of blood oozing from the oximetry connection port of the pulmonary artery catheter that resulted in the inability to monitor continuous cardiac output requiring replacement of the catheter. The cause of this abnormal bleeding was later confirmed to be due to a manufacturing defect.