Anesthetic Considerations in Hepatectomies under Hepatic Vascular Control.

Background. Hazards of liver surgery have been attenuated by the evolution in methods of hepatic vascular control and the anesthetic management. In this paper, the anesthetic considerations during hepatic vascular occlusion techniques were reviewed. Methods. A Medline literature search using the terms "anesthetic," "anesthesia," "liver," "hepatectomy," "inflow," "outflow occlusion," "Pringle," "hemodynamic," "air embolism," "blood loss," "transfusion," "ischemia-reperfusion," "preconditioning," was performed. Results. Task-orientated anesthetic management, according to the performed method of hepatic vascular occlusion, ameliorates the surgical outcome and improves the morbidity and mortality rates, following liver surgery. Conclusions. Hepatic vascular occlusion techniques share common anesthetic considerations in terms of preoperative assessment, monitoring, induction, and maintenance of anesthesia. On the other hand, the hemodynamic management, the prevention of vascular air embolism, blood transfusion, and liver injury are plausible when the anesthetic plan is scheduled according to the method of hepatic vascular occlusion performed.

Ischemia/reperfusion injury in liver resection: a review of preconditioning methods.

Ischemic preconditioning is one of the therapeutic interventions aiming at preventing ischemia/reperfusion-related injury. Numerous experimental studies and a few clinical series have shown that during liver resections, ischemic preconditioning is a promising strategy for optimizing the postoperative outcome. Moreover, various types of pharmacological intervention as well as different types of preconditioning, such as remote preconditioning, the use of heat shock, and hyperbaric oxygen, have been developed to attenuate the functional impairment accompanying ischemia/reperfusion injury. This review summarizes the various forms of preconditioning, thus suggesting that close cooperation between surgeons and anesthesiologists paves the way to apply novel strategies to improve the outcome of liver resection.

Association between factors predicting and assessing the airway and use of intubating laryngeal mask airway.

BACKGROUND AND OBJECTIVE: The Intubating Laryngeal Mask Airway FastrachTM (ILMA) has been used with success in difficult intubation cases. The purpose of this study is to evaluate the effect of mouth opening, Mallampati classification, thyromental distance and Cormack-Lehane Grade, on the ease of ILMA use. METHODS: Eighty one patients ASA I-II, were assessed preoperatively for mouth opening, Mallampati classification and thyromental distance. After induction with propofol and rocuronium, the first investigator recorded Cormack-Lehane Grade by direct laryngoscopy. Subsequently an appropriate size ILMAwas inserted by the second investigator and correct placement was confirmed by adequate ventilation and normal capnogram. A maximum of three ILMA insertion attempts were allowed and the number was recorded. Then blind intubation was attempted and classified as follows, according to Intubation Difficulty Grade (IDG): IDG-1: intubation succeeded: at first attempt requiring no or minor ILMA manipulations. IDG-2: intubation succeeded at second attempt requiring major ILMA manipulations or size change. IDG-3: intubation failed after the second attempt or oesophageal intubation occurred at either attempt. In failure of the technique direct laryngoscopy was the alternative approach. RESULTS: Success rates in insertion of ILMA and in blind intubation were 100% and 92.6% respectively. No difference was found between Cormack-Lehane Grade I-II and II-IV or Mallampati classification and number of ILMA insertion attempts or IDG. There was also no correlation between mouth opening, or thyromental distance and number of ILMA insertion attempts or IDG. It is concluded that easiness of ILMA use is irrelevant to mouth opening, thyromental distance, Mallampati classification or Cormack-Lehane Grade.

Emergencies and treatment of complications.

Sedation for gastrointestinal endoscopy may induce central respiratory depression and/or airway obstruction. Early diagnosis and treatment of these complications is mandatory as the resulting hypoxia may cause irreversible damage, particularly to vital organs, or death. Sedatives and centrally acting analgesics depress respiration in a dose-dependent manner. However, significant untoward events are preventable by titrating the doses for sedation and by monitoring patient oxygenation and respiration. Cardiovascular adverse events may also occur during gastrointestinal endoscopy, and can be major or minor. Hypotension needs treatment as well as severe hypertension. Cardiac dysrhythmias may occur due to stress, pain and/or hypercarbia, which may accompany endoscopies. The anesthesia provider must be able to diagnose, assess the risk and treat all the adverse events during gastrointestinal endoscopy. The resuscitation equipment, including the defibrillator, must be readily accessible.

The effect of desflurane and sevoflurane on cerebral oximetry under steady-state conditions.

We studied the effect of sevoflurane and desflurane on regional cerebral oxygenation (rSO2). Twenty-two patients undergoing abdominal hysterectomy received sevoflurane and desflurane for 15 min each and 30 min apart under steady-state conditions in a randomized, crossover manner to maintain a bispectral index (BIS) of 40-50. In another 22 patients undergoing the same anesthesia and surgery BIS was maintained at 20-30. During the 15-min administration of each anesthetic at steady-state conditions rSO2, BIS, inspired and end-tidal anesthetic concentrations, end-tidal CO2, Spo2, systolic and diastolic blood pressures, and heart rate were recorded every 3 min. The rSO2 did not differ between sevoflurane and desflurane when BIS values were maintained between 40-50 or 20-30. The MAC(BIS) values required to maintain BIS at 40-50 and at 20-30 were 1.0 versus 1.2 (P = 0.004) and 1.6 versus 1.8 (P < 0.001) for desflurane and sevoflurane respectively. Higher rSO2 values were obtained by 1.6 MAC (71 +/- 13) than by 1 MAC of desflurane (66 +/- 10; P < 0.001) and by 1.8 MAC (72 +/- 11) than by 1.2 MAC of sevoflurane (66 +/- 13; P < 0.001). In conclusion, equipotent concentrations of desflurane or sevoflurane in terms of BIS are associated with similar rSO2 values, but larger anesthetic concentrations of both anesthetics increased the rSO2 values.