Respiratory gas exchange during robotic-assisted laparoscopic radical prostatectomy.

STUDY OBJECTIVE: Robotic-assisted laparoscopic prostatectomy requires patients to be secured in a steep Trendelenburg position for several hours. Added to the CO2 pneumoperitoneum that is created, this positioning invariably restricts diaphragmatic and chest wall excursion, which can adversely affect respiratory gas exchange. This study sought to measure the extent of respiratory gas change during this procedure. DESIGN: Retrospective, institutional review board approved. SETTING: Operating room. PATIENTS: N = 186 males, American Society of Anesthesiologists 2-3, with prostatic carcinoma undergoing robotic-assisted laparoscopic radical prostatectomy. INTERVENTIONS: Arterial blood gases and noninvasive respiratory measurements were recorded for those patients (n = 32) in whom a radial arterial catheter had been inserted intraoperatively, specifically timed to different phases of the procedure: supine lithotomy, steep Trendelenburg, and return to supine. Ventilatory parameters were standardized. MEASUREMENTS: Systemic blood pressure, heart rate, respiratory rate, Pao2, Paco2, oxygen saturation as measured by pulse oximetry, and end-tidal carbon dioxide pressure. MAIN RESULTS: Although no patients developed perioperative respiratory complications, the Pao2 invariably fell (395 vs 316 mm Hg; P = .001) while the patients were in steep Trendelenburg, and the Paco2-end-tidal carbon dioxide pressure rose (10.0 vs 13.4 mm Hg; P < .0001). Upon return to supine, patients' respiratory measurements promptly returned to within 15% of baseline. Subgroup analysis for high-BMI vs low-BMI patients as well as for patients with pulmonary disease and/or a smoking history showed similar individual effects and only small, although significant, respiratory gas exchange aberrations. CONCLUSIONS: Positioning patients with a CO2 pneumoperitoneum in steep Trendelenburg for several hours imposes restriction of diaphragmatic and chest wall movement sufficient for respiratory gas exchange to be adversely affected. Return of function to within 15% of baseline occurred within minutes after return to supine and release of the CO2 pneumoperitoneum. No patients during the study period developed pulmonary complications that required alteration in their level of care.

Etomidate is still a valid anesthetic for electroconvulsive therapy.

Komatsu et al have recently written that the use of etomidate as an anesthetic induction agent for surgery is associated with increased 30-day mortality and cardiovascular morbidity, compared with propofol. Etomidate has long been recognized as suppressing adrenocortical function and, as an infusion over days, has been indicted in increasing intensive care unit patient mortality. Even in single doses, etomidate causes a reduction in cortisol production, although recovery from single-dose suppression is generally prompt. In prospectively evaluating etomidate as an anesthetic for electroconvulsive therapy, Lebowitz et al, in a pilot study, found that 3 times per week, etomidate did not cause adrenocortical suppression that lasted until the following treatment. The steroid responses did not differ from those of methohexital, and no patient demonstrated evidence of cortisol deficiency. Consequently, concerns raised by Komatsu et al about etomidate's safety seem unwarranted when used for electroconvulsive therapy, and their study's conclusions likely relate to issues with their retrospective methodology.

Shoulder and head elevation improves laryngoscopic view for tracheal intubation in nonobese as well as obese individuals.

STUDY OBJECTIVE: To determine whether shoulder and head elevation, such that the patient's ear lies at or higher than the sternum ("ramp"), improves laryngoscopic grade in adult patients of various body mass index (BMI) values. DESIGN: Prospective, unblinded study, with patients and laryngoscopists acting as their own controls. SETTING: Operating room of a university-affiliated hospital. PATIENTS: 189 adult ASA physical status 1, 2, and 3 patients. INTERVENTIONS: After performing a standard preoperative airway evaluation and inducing general anesthesia, the anesthetist performed and graded two laryngoscopies: one in the "ramp" position and one in the "sniff" position. MEASUREMENTS: Patient BMI, Mallampati airway class, thyromental distance, neck circumference, cervical extension ability, Cormack and Lehane laryngoscopic grade for each laryngoscopy, subjective lifting force required, and need for external laryngeal pressure were recorded. MAIN RESULTS: Use of the "ramp" provided significantly better or equal laryngoscopic views, relative to those with the "sniff" position, in the entire study population. CONCLUSIONS: Shoulder and head elevation by any means that brings the patient's sternum onto the horizontal plane of the external auditory meatus maintains or improves laryngoscopic view significantly.

A randomized, open-label study of the safety and tolerability of fospropofol for patients requiring intubation and mechanical ventilation in the intensive care unit.

BACKGROUND: Current drugs for induction and maintenance of sedation in mechanically ventilated patients in the intensive care unit have limitations. Fospropofol, a prodrug of propofol, has not been studied as a sedative in the ICU setting. METHODS: In this randomized, open-label pilot study, patients received 1 of 3 regimens with a goal of maintaining a Ramsay Sedation Score of 2 to 5: (1) fospropofol IV infusion with a bolus and increased infusion rate for agitation events (infusion/bolus); (2) fospropofol IV infusion with an increased infusion rate for agitation events (infusion only); or (3) propofol IV infusion with an increased infusion rate for agitation events. RESULTS: Sixty patients received study drug and were included in the safety and efficacy analyses. Because incidence rates for adverse events were similar between fospropofol groups, and because the study was not powered to determine significant differences between treatment groups for safety variables, adverse events for both fospropofol groups were combined. In the fospropofol groups, 28 out of 38 patients (74%) experienced treatment-emergent adverse events in comparison with 14 out of 22 patients (64%) in the propofol group. The most common treatment-emergent adverse events with fospropofol were procedural pain (21.1%) and nausea (13.2%). Two patients (1 each in the fospropofol infusion/bolus and the propofol groups) experienced hypotension during the study as a potential sedation-related adverse event. Mean plasma formate levels were not significantly different among groups. Patients in all 3 treatment groups maintained Ramsay Sedation Scores of 2 to 5 for >90% of the time they were sedated. CONCLUSION: This pilot study suggests that fospropofol, administered in either an infusion/bolus or infusion-only regimen, is tolerable and effective for short-term induction and maintenance of sedation in mechanically ventilated intensive care unit patients.

Government spotlight on physicians' consulting arrangements with device makers.

A new government focus on investigating physicians' consulting agreements and other financial arrangements with device manufacturers has been announced. Physicians would be well advised to prepare for investigations by reviewing any agreements they have and assembling all related documents. This article outlines additional steps that will assist a physician in preparing for a government investigation. These include notifying key employees, engaging counsel, developing a legal strategy, submitting a "white paper" response to the government, and realistically assessing a settlement position.

Schedule the short procedure first to improve OR efficiency.

OPERATING ROOM MANAGERS are hampered in their efforts to optimize OR efficiency by surgical procedures that last a longer or shorter time than scheduled. The lack of predictability is a result of inaccuracy in scheduling and variability in the duration of procedures. SCHEDULING SHORT PROCEDURES before long procedures theoretically limits this variability. MONTE CARLO SIMULATION of ORs scheduled with various combinations of short and long procedures supports this concept's validity. RESULTS INDICATE that scheduling short procedures first can improve on-time performance and decrease staff member overtime expense without reducing surgical throughput.

Why can't my procedures start on time?

Despite OR practice improvements, approximately 50% of second or subsequent surgical procedures will not start on time because of procedure duration overruns caused by preceding procedures. Operating room scheduling that uses reliable historical data about specific surgeon and procedure combinations and computerized scheduling systems can minimize overruns. Statistical variability in procedure durations, however, implies that one-half of the procedures will run longer than the calculated mean, resulting in wait times for time-scheduled surgeons and their patients. Managers must understand the tradeoffs between the competing goals of surgical throughput and decreasing patient wait times in their efforts to optimize the OR schedule.

Malignant Hyperthermia and Electroconvulsive Therapy.

A 30-year-old man with a personal and family history of malignant hyperthermia and a 7-year history of psychiatric illness unresponsive to various psychotropic medications benefitted from electroconvulsive therapy given in combination with clozapine. Volatile inhalation anesthetics and a depolarizing muscle relaxant (succinylcholine) were assiduously avoided. Dantrolene was administered intravenously before the first treatment but was not used for the remainder of the treatments. Anesthesia was induced with methohexital and atracurium. The treatment course was uneventful.