Assessment of postoperative pain: Contributing factors to the differences between patients and doctors.

This study was undertaken to compare the assessment of pain intensity by 50 patients and by their doctors according to a visual analog scale 5 h and 20 h after major abdominal surgery, and to examine the relationships between the differences in rating of patients and doctors and the factors inherent in the patients which include preoperative expectation of pain, level of anxiety, and the surgical history of the patient. The ratings given by the patients were significantly higher than those given by the doctors at both time periods. However, the correlation between the ratings given by the two was low:r=0.31 andr s=0.27 at 5 h after the operations, andr=0.58 andr s=0.49 at 20 h. The results of analysis using Hayashi's quantification theory Type II indicated a moderate association between the rating difference and the patient's age, surgical history, preoperative state of anxiety, and expectation of pain. It is concluded that postoperative pain management, whether in clinical practice or in research, necessitates more consideration of the several above-mentioned individual factors and a preoperative interview in which the patient's level of anxiety and the amount of information the patient has concerning the surgery and post-operative pain is clearly assessed.

Differences in the assessment of postoperative pain when evaluated by patients and doctors.

This study was undertaken to compare the assessment of pain intensity by 59 patients and by their doctors according to a visual analogue scale (VAS) at rest and when coughing at 5 and 20 hr after major abdominal surgery. The rating given by the patients, who received epidural analgesia to relieve postoperative pain, was significantly above, and moreover, significantly correlated with that given by the doctors at any time or under any condition of the assessment. However, the correlation between the ratings given by patients and doctors at rest at 5 hr after surgery was low (r = 0.39, rs = 0.38) and significantly different from that when coughing at 20 hr after the operation (r = 0.79, rs = 0.80). Our findings indicate that the assessment of postoperative pain may be associated with some unreliability, especially during early periods, when using the subjective or objective-rated VAS at rest separately, and thus requires the combined use or the concomitant use of the VAS when coughing. Substitutional use of the objective-rated VAS for the subjective-rated VAS is not advised.

[Effects of intravenous lidocaine administration on median nerve somatosensory evoked potentials].

The effect of lidocaine on the median nerve somatosensory evoked potential (SSEP) was investigated in 14 neurologically normal patients. Lidocaine 1.5 mg.kg-1.min-1 was injected intravenously over a 5 min period immediately followed by a continuous infusion of lidocaine 60 micrograms.kg-1.min-1. The peak latencies (N1, P2, N2) and amplitudes (N1-P2, P2-N2) of the SSEP response over the sensory cortex were recorded before and after lidocaine infusion. The peak latencies in the control group and in the experimental group after lidocaine infusion of N1, P1, N2 were 19.4 +/- 1.0 msec, 19.7 +/- 1.0 msec (N1), 24.6 +/- 1.4 msec, 25.0 +/- 1.5 msec (P2), 32.5 +/- 2.5 msec, and 33.3 +/- 2.8 msec (N2), respectively. The amplitudes in the control group and in the experimental group after lidocaine infusion of N1-P2, P2-N2 were 9.0 +/- 4.3 microV, 10.3 +/- 4.7 microV (N1-P2), 7.2 +/- 3.6 microV, 8.6 +/- 3.9 microV (P2-N2), respectively. Peak latencies of all components (N1, P2, N2) increased after lidocaine infusion compared with control values. Amplitude of N1-P2 and P2-N2 increased significantly following lidocaine infusion compared with control values. The data obtained in this study suggested that the changes in peak latencies and amplitude after epidural anesthesia with lidocaine were due to the systemic effect of lidocaine absorbed intravenously from the epidural space.

[Effects of rectal premedication and the mother's presence on induction of pediatric anesthesia].

The effects of the rectal premedication and the mother's presence on induction of anesthesia were studied with 67 children between the ages of 1 and 6 years. All children were induced with mask using nitrous oxide-oxygen-halothane. Children's emotional states during induction were categorized as excellent, good or fair. Rating of excellent or good was considered to indicate satisfactory induction. Forty-seven children were accompanied by their mother. Twenty-two of them were premedicated with rectal bromazepam (3 mg), while another twenty-five children were not premedicated. Satisfactory induction after premedication was performed on 78% of the 1-3 year olds and 100% of the 4-6 year olds, whereas without rectal premedication, satisfactory induction was achieved in 42% of the 1-3 year olds and 69% of the 4-6 year olds. Rectal premedication was important for satisfactory induction. Another twenty of all children were premedicated with rectal bromazepam (3 mg) and induced without mother presence. Satisfactory induction was performed on 38% of the 1-3 year olds and 100% of the 4-6 year olds. Mother's presence tended to lead to satisfactory induction. Furthermore, we sought feedback from the mothers about their presence during induction of anesthesia. Almost all of the mothers said they appreciated the opportunity to be present, with the exception of four mothers (8.5%) who reported feeling of some anxiety to be in an operating room.

Combined effects of inversed ratio ventilation (IRV) with positive end-expiratory pressure ventilation (PEEP) on cardiorespiratory function in acute respiratory failure.

Combined effects of inversed ratio ventilation (IRV) with positive end-expiratory pressure (PEEP) on cardiorespiratory function were examined in 24 patients with acute respiratory failure. Patients were divided into two groups: the IRV group (n = 12) who showed no significant increase in Pa(O)(2) with a 6 cmH(2)O of PEEP and PEEP group (n = 12) who were ventilated mechanically with PEEP only at maximum level of 10 cmH(2)O. In IRV group step-wise prolongation of the I : E ratio from 1 : 1.9 to 2.6 : 1 or 4 : 1 was applied as a Pa(O)(2) was improved and in PEEP group also level of PEEP was increased from 0, 5 to 10 cmH(2)O after one hour period irrespective of Pa(O)(2). Inversed ratio ventilation and PEEP increased significantly Pa(O)(2)/F i(O)(2), the increase being observed 6 hrs (I : E = 2 : 1) and 2 hrs (10 cmH(2)O) after starting IRV or PEEP. Further improvement of oxygenation was not observed in IRV even if I : E ratio was prolonged up to 2.6 : 1 or 4 : 1. These results suggested that combinations of IRV with PEEP were effective and an I : E ratio of 2 : 1 may be optimal, and IRV is advantageous compared to PEEP, but will take more long time to improve oxygenation than PEEP.

[Cardiac arrest during anesthesia--a case of effective open chest massage].

A 58-year-old man suffering from esophageal cancer was scheduled for radical resection and reconstruction of the esophagus. Immediately after the start of the operation, with the patient under general anesthesia, cardiac arrest occurred. The operation was immediately discontinued and closed chest heart massage was started. As the patient did not respond, open chest massage was initiated. Cardiac arrest can be caused by any one of a number of factors. This case was suspected to have had a coronary artery spasm. It took a total of 100 minutes to resuscitate the patient. But resuscitation was successful without any resulting neurological damage. This was attributed to appropriate open chest massage. If a case of cardiac arrest due to any coronary artery disease does not respond to the usual cardiopulmonary resuscitation, we should consider open chest massage.

[Effects of lumbar epidural anesthesia on brainstem auditory response].

Auditory brainstem responses (ABR) are used increasingly to monitor the integrity of neural pathways in anesthetized patients. To evaluate the effect of epidural anesthesia on the central nervous system, we studied the effects of lumbar epidural anesthesia with lidocaine on the ABR in 10 patients. The seven peak latencies (waves I-VII) and amplitudes (waves I-VII) of the ABR were recorded before and 15 min after epidural anesthesia. Peak latencies of waves III, IV, V, VI, VII increased after epidural anesthesia compared with control values. Amplitude of waves II only decreased significantly following epidural anesthesia compared with control values. We further compared the interpeak latencies to investigate the brainstem transmission. Interpeak latencies (I-II, II-III, III-IV, IV-V, V-VI, VI-VII) were unchanged from the control values except waves VI-VII interval. Interpeak latencies of every second peak (II-IV, IV-VI, V-VII), of every third peak (II-V, III-VI, IV-VII), of every forth peak (I-VI, II-VII), of every fifth peak (I-VII) increased after epidural anesthesia compared with control values. The data obtained in the study demonstrated that lumbar epidural anesthesia with lidocaine prolonged the interpeak latencies of ABR. Considering that the waves of ABR are related to anatomically distinct sites in the auditory pathway (I; Acoustic nerve, II; Cochlear nucleus, III; Superior olivary complex, IV; Lateral lemniscus, V; Inferior colliculus, VI: Medial geniculate body, VII; Auditory radiation), the delay in the latencies of ABR seems to be present in the time intervals which involve more than two or three synaptic transmissions.

[Effects of lumbar or thoracic epidural anesthesia on median nerve somatosensory evoked potentials].

Somatosensory evoked potentials (SSEP) are used increasingly to monitor the integrity of neural pathways in anesthetized patients. To evaluate the influence of epidural anesthesia on the central nervous system, we studied the effects of lumbar or thoracic epidural anesthesia with lidocaine on the median nerve SSEP in 9 patients. The peak latencies (N1, P2, N2) and amplitudes (N1-P2, P2-N2) of the SSEP response over the sensory cortex were recorded before and 15 min after epidural anesthesia. The peak latencies of control and post epidural anesthesia of N1, P1, N2 were 19.2 +/- 1.7 msec, 19.6 +/- 1.6 msec (N1), 24.7 +/- 2.3 msec, 25.7 +/- 2.0 msec (P2), 32.8 +/- 2.8 msec and 34.6 +/- 2.5 msec (N2), respectively. The amplitude of control and post epidural anesthesia of N1-P2, P2-N2 were 4.5 +/- 2.9 microV, 5.9 +/- 6.6 microV (N1-P2), 4.4 +/- 3.2 microV and 5.6 +/- 5.2 microV (P2-N2), respectively. Peak latencies of all components (L1, P2, N2) increased after epidural anesthesia compared with control values. Amplitude of N1-P2 increased significantly following epidural anesthesia compared with control values. The data obtained in this study were contrary to the previous concept that anesthetic agents generally increase the latency of SSEP and decrease their amplitude.

Cerebral arteriovenous oxygen content difference during barbiturate therapy in patients with acute brain damage.

This study evaluated the reliability of cerebral blood flow equivalent (CBFE), which was calculated as the reciprocal of cerebral arteriovenous oxygen content difference (C(av)DO2) as a monitor during barbiturate therapy in patients with cerebral ischemic insults. A barbiturate (thiamylal) was administered at a rate of 3 mg . kg-1 . hr-1 for 2-5 days to four patients who had suffered cardiac arrest, four with acute focal ischemia, two with postoperative brain edema after neurosurgery, and one with brain damage due to asphyxia. Four of the 11 patients completely recovered neurologically (recovery group), and others had neurological sequelae or died (nonrecovery group). The mean value of CBFE in the recovery group decreased significantly with barbiturate therapy to 13 +/- 1 ml blood/ml O2 from 39 +/- 3 ml blood/ml O2 but did not decrease in the nonrecovery group. We conclude that CBFE can be useful for monitoring the effect of barbiturate therapy in ischemic brain insults.