Conversion of spinal anesthesia into general anesthesia: an evaluation of more than 35,000 spinal anesthetics

BACKGROUND

The aim of this study was to evaluate the number of conversions from spinal anesthesia (SA) into general anesthesia (GA) in a large number of patients who underwent surgery over a period of twenty-one years.

METHODS

From the hospital's database, all surgical procedures performed under SA between January 1, 1988 and December 31, 2008 were retrieved. From this file, all SA cases converted into GA cases requiring endotracheal intubation were selected. Patients were divided in four groups, according to the reason for GA: IMPOSS (SA impossible to perform), FAIL (SA non profound enough for allowing surgery, even with light sedation), INSUFF (SA inadequate for unexpected prolonged duration of surgery), and COMPL (occurrence of complications associated with SA and requiring rapid control of ventilation). Anesthesiologists who performed SA were divided according their experience. The outcomes of patients converted to GA were compared with a matched sample of patients who received planned GA.

RESULTS

A total of 35,960 SA cases were performed from 1988 to 2008; 29,220 and 6,740 SA cases were for elective and emergency surgery, respectively. Two hundred seventeen (0.6%) SA cases were converted into GA cases; 80.2% and 19.8% of the conversions were recorded in elective and emergency operations, respectively, with obstetric operations being the most prevalent (82/217). The primary reasons for the conversions, in a rank order, were INSUFF 107 (49.3%), FAIL 84 (38.7%), IMPOSS 13 (5.9%), and COMPL 13 (5.9%). Complications more frequently occurred in the aged population (P<0.05). Anesthesiologists with less experience had higher percentages of FAIL, IMPOSS, INSUFF, and COMPL SA cases in comparison with experienced anesthesiologists (odd ratios being 4.7, 3.0, 2.4, and 4.4, respectively). There was no difference in the frequency of complications compared to a matched sample of 1,000 patients who underwent GA (P=0.65).

CONCLUSION

SA has been found to be a safe and highly effective technique. Failure of SA was infrequent in a large number of patients surveyed and most often occurred with less experienced anesthesiologists. Conversion to GA did not produced different outcomes in comparison with planned GA. Prospective studies with a definite protocol for recording data performed on a large number of patients may help in determining the factors associated with conversion from SA into GA and how to avoid these unexpected situations.

Auditory processing in the vegetative state

H(2)(15)O-PET was used to investigate changes in regional cerebral blood flow in response to auditory stimulation in patients in the vegetative state. Five patients in a vegetative state of hypoxic origin were compared with 18 age-matched controls. In addition, the cerebral metabolism of these patients and 53 age-matched controls was studied using [(18)F]fluorodeoxyglucose. In control subjects, auditory click stimuli activated bilateral auditory cortices [Brodmann areas (BA) 41 and 42] and the contralateral auditory association cortices (BA 22). In the patients, although resting metabolism was decreased to 61% of normal values, bilateral auditory areas 41 and 42 showed activation as seen in the controls, but the temporoparietal junction cortex (BA 22) failed to be activated. Moreover, the auditory association cortex was functionally disconnected from the posterior parietal association area (BA 40), the anterior cingulate cortex (BA 24) and the hippocampus, as revealed by psychophysiological interaction analysis. Thus, despite altered resting metabolism, the auditory primary cortices were still activated during external stimulation, whereas hierarchically higher-order multi- modal association areas were not. Such a cascade of functional disconnections along the auditory cortical pathways, from the primary auditory areas to multimodal and limbic areas, suggests that the residual cortical processing observed in the vegetative state cannot lead to the integrative processes that are thought to be necessary for the attainment of the normal level of awareness.

Albumin improves the response to diuretics in patients with cirrhosis and ascites: results of a randomized, controlled trial

BACKGROUND/AIMS

Diuretic treatment of ascites could result in intravascular volume depletion, electrolyte imbalance and renal impairment. We investigated whether intravascular volume expansion with albumin exert beneficial effects in cirrhosis with ascites.

METHODS

In protocol 1, 126 cirrhotic inpatients in whom ascites was not relieved following bed rest and a low-sodium diet, were randomly assigned to receive diuretics (group A) or diuretics plus albumin, 12.5 g/day (group B). In protocol 2, group A patients continued to receive diuretics and group B diuretics plus albumin (25 g/week) as outpatients and were followed up for 3 years. End points were: disappearance of ascites, duration of hospital stay (protocol 1), recurrence of ascites, hospital readmission and survival (protocol 2).

RESULTS

The cumulative rate of response to diuretic treatment of ascites was higher (p < 0.05) and hospital stay was shorter (20 +/- 1 versus 24 +/- 2 days, p < 0.05) in group B than in group A patients. After discharge, group B patients had a lower cumulative probability of developing ascites (19%, 56%, 69% versus 30%, 79% and 82% at 12, 24 and 36 months, p < 0.02) and a lower probability of readmission to the hospital (15%, 56%, 69% versus 27%, 74% and 79%, respectively, p < 0.02). Survival was similar in the two groups.

CONCLUSIONS

Albumin is effective in improving the rate of response and preventing recurrence of ascites in cirrhotic patients with ascites receiving diuretics. However, the cost/benefit ratio was favorable to albumin in protocol 1 but not in protocol 2.

[Importance of an outpatient record in obstetric anesthesia]

A computerised record was used to collect data following an anesthesiological check-up of pregnant women at approximately 30 weeks of pregnancy. The record was input onto a portable PC in the anesthesia outpatient clinic, memorized on disk (3.5") and then transferred onto a PC network (one PC for each operating theatre) for "real time" consultation of each patient's data. All pregnant women attending the antenatal clinico were also given a folder illustrating epidural anesthetic techniques. Seven hundred and nine outpatient visits have been performed over the past two years with a 62% utilisation ratio. The collection of data using a computerised system allows a rapid and efficacious system of communication to be set up among the membranes of the anesthesiological team, thus encouraging the use of epidural techniques during labour. The distribution of the folder also facilitated the task of the anesthetist who found that pregnant women visiting the anesthesia clinic were already familiar with the epidural technique.

[Continuous infusion peridural analgesia in labor]

A technique of continuous infusion epidural anesthesia was used during labour in 933 patients divided into three groups according to age: Group A (14-18 years old), Group B (19-35 years old) and Group C (greater than 35 years old). Infusion was carried out using the following system: a PVC pressurized bag containing 0.3% marcain connected to 2 flow regulators which ensured a flow of 6 ml/h. During the dilatation phase, 85% of patients received sufficient analgesia, whereas 15% required extra boluses. During the expulsive phase 80% of patients received adequate analgesia of the perineal plane, 12% received an extra bolus of marcain 0.3% and local anesthesia was performed in 8% to allow infiltration. Instruments were required in 5.6% of patients in Group A, 11.3% in Group B and 7.4% in Group C. The incidence of Caesarian section was 5.6% in Group A, 9% in Group B and 14.8% in Group C. No maternal complication was observed. Epidural anesthesia via continuous infusion was therefore shown to be an efficacious and safe method for ensuring analgesia during labour.