Postoperative analgesia: pain by choice? The influence of patient attitudes and patient education

Postoperative pain control can be unsatisfactory for a variety of reasons, including patients' attitudes towards pain treatment itself. To assess patients' expectations and their influence on postoperative analgesia, as well as the prevalence of pain following common gynaecological surgery, a prospective study was performed in 166 patients with either adbominal hysterectomy, mastectomy, laparoscopy or uterine curettage. After a first postoperative period with routine on-demand analgesia, a nurse specialised in pain treatment discussed the purposes and risks of pain treatment with the patients and cared for these patients in the second, subsequent study period. Following this discussion, 30 of 40 patients refusing analgesics in the first study period agreed to be given pain medication. In the groups with hysterectomy or mastectomy, pain control improved in the second postoperative period, even though the doses of analgesics administered were generally lower. Education of patients regarding the aims and risks of pain therapy is an essential part of pain control and can lead to an improvement of postoperative analgesia.     

Individual and group dose-responses to intravenous omeprazole in the first 24 h: pH-feedback-controlled and fixed-dose infusions.

1. Individual responses to intravenous boli of omeprazole have shown considerable variability. Data on the individual responses to the new omeprazole infusion formulation are lacking. 2. Individual dose-responses in the first 24 h of fixed-dose and pH-feedback-controlled infusions of omeprazole were assessed in two randomised, third-party blinded, cross-over studies, using two separate groups of eight healthy subjects. In study A, feedback-controlled infusions of omeprazole (target pH 5, dose range 0-12 mg h-1) and fixed-dose infusions (8 mg h-1) were compared, both with an initial bolus of 80 mg. Omeprazole plasma concentrations were measured. Study B assessed the effect on individual pH-control of a loading bolus of either 40 mg or 80 mg omeprazole, followed by feedback-controlled infusions. 3. Study A: the median % time of pH > 5 was 71.2 (total range: 48.9-83.2) with feedback infusions and 57.9 (28.0-95.3) with fixed-dose infusions (P = 0.06). The mean 24 h infusion doses were 173.1 mg (44.5-253.1) in the feedback group and 192 mg in the fixed-dose group. The AUC of omeprazole plasma concentrations ranged widely, but correlated with the % time of pH > 5 during fixed-dose infusions. Study B: initial boli of 40 mg and 80 mg of omeprazole resulted in similar 24 h median % of time with pH > 5, 69.2 (49.9-78.8) and 69.6 (44.4-87.7), respectively. Mean omeprazole doses infused by feedback pump were 187.6 mg (83.1-253.6) after 40 mg boli and 159.9 mg (61.8-227.0) after 80 mg boli.(ABSTRACT TRUNCATED AT 250 WORDS)     

The median palmar cutaneous nerve in normal subjects and CTS.

OBJECTIVE: The neurophysiological confirmation of carpal tunnel syndrome (CTS) relies on detecting abnormal median nerve transcarpal conduction in the presence of unaffected comparator nerves. We compare the palmar cutaneous median branch (PCBm) with the ulnar sensory nerve conduction to digit 5 (US(5)) as comparator nerves for diagnosing CTS. METHODS: In a prospective case control study of patients with clinically defined carpal tunnel syndrome and normal subjects, we determined and compared the PCBm and US(5) conduction velocity. RESULTS: We examined 57 hands with clinically defined CTS and 59 control hands. Comparison showed highly significantly slowed PCBm conduction (p<0.0001) but not for US(5) conduction (p=0.488). Using a 3 percentile cut-off for abnormality derived from controls, PCBm conduction velocity was abnormal in 46% of CTS hands. CONCLUSIONS: The high frequency of PCBm nerve conduction abnormality in CTS suggests that this nerve should not be used as a comparator nerve for the neurophysiological diagnosis of CTS. This finding may help explain some of the extension of sensory symptoms outside the median nerve distribution in CTS. SIGNIFICANCE: In CTS frequent abnormality of PCBm conduction makes this a poor comparator nerve and may explain extension of sensory symptoms beyond the median nerve.     

Postamputation Pain and Sensory Changes in Treatment-naive Patients: Characteristics and Responses to Treatment with Tramadol, Amitriptyline, and Placebo

Background: Pain after amputation is common but difficult to treat, and few controlled treatment studies exist.

Methods: In the current study, 94 treatment-naive posttraumatic limb amputees with phantom pain (intensity: mean visual analog scale score [0-100], 40 [95% confidence interval, 38-41]) were randomly assigned to receive individually titrated doses of tramadol, placebo (double-blind comparison), or amitriptyline (open comparison) for 1 month. Nonresponders were crossed over to the alternative active treatment.

Results: After 1 month, phantom pain intensity was 1 (0-2) in the 48 tramadol responders (mean dose, 448 mg [95% confidence interval, 391-505 mg]), 0 (0-0) in the 40 amitriptyline responders (55 [50-59] mg), and 0 (0-0) in the 2 placebo responders, with similar effects on stump pain. Cytochrome P-450 2D6 slow metabolizers derived greater analgesia from tramadol and less from amitriptyline compared with fast metabolizers in the first treatment week (P < 0.01). Electrical pain thresholds increased and pain during suprathreshold stimulation decreased markedly on the stump and, to a lesser extent, on the contralateral limb after 1 month of treatment with amitriptyline or tramadol. Adverse effects were minor in all groups, but more common with tramadol.     

Surgical pain is followed not only by spinal sensitization but also by supraspinal antinociception

Nociception can produce segmental spinal sensitization or descending supraspinal antinociception. We assessed both types of sensory change after surgery during isoflurane-nitrous oxide anaesthesia with or without fentanyl before nociception. Patients undergoing back surgery received fentanyl 3 micrograms kg-1 (n = 15) or placebo (n = 15) before anaesthesia in a prospective, randomized, blinded study. Sensation, pain detection and tolerance thresholds to electrical stimulation were measured before operation at the arm, incision and herniated disc dermatomes (HDD) and 1, 2, 4, 6, 24 h and 5 days after operation, together with pain scores and patient-controlled morphine consumption (duration 24 h). For segmental effects, thresholds were normalized to the thresholds at a distant dermatome (arm). Raw pain thresholds were increased after operation (fentanyl > placebo) and were maximal at 4 h (pain tolerance in HDD: fentanyl +5.2 mA (+62.7%), placebo, +3.8 mA (+44.2%); P < 0.05 vs baseline for both). Normalized sensation thresholds decreased for placebo only (HDD/4 h: placebo, -1.8 (-44.8%), P < 0.05; fentanyl, +0.1 (+5.5%) ns). All changes returned to baseline by 24 h except for the placebo group normalized HDD sensation (d5: placebo, -2.4 (-59.7)%, P < 0.05; fentanyl -0.1 (-5.5%) ns). Pain scores and morphine consumption were similar. The study demonstrated both supraspinal analgesia and spinal sensitization after surgery. Fentanyl administration before operation augmented the former while decreasing the latter, and hence sensitization, especially if neuropathic, may particularly benefit from pre-emptive analgesia.      

Adjuvant propofol enables better control of nausea and emesis secondary to chemotherapy for breast cancer

We investigated the prophylactic antiemetic effect of added lowdose infusion of propofol in patients exhibiting nausea and vomiting refractory to dexamethasone and serotonin antagonist during non-cisplatin chemotherapy for breast cancer. In a prospective open longitudinal study, 117 patients who had more than five episodes of nausea and vomiting in their first chemotherapy cycle during the first 24 hr completed the study. They received in addition to the usual prophylactic antiemetic regimen a continuous intravenous infusion of 1 mg · kg^?1 · hr^?1 propofol started four hours before chemotherapy and continued up to 24 hr for the two subsequent cycles. The number of vomiting / nausea episodes, level of sedation, patient activity, appetite and preference for future chemotherapy cycles were assessed. In the propofol supplemented cycles 90 and 80% of patients, during the 1st and 2nd propofol-assisted cycle respectively, were free of nausea and vomiting during the first 24 hr after chemotherapy. Patients were more frequently active and had more appetite during the propofol-assisted cycles. No propofol-associated side effects were observed. We conclude that the addition of a subhypnotic infusion of propofol enables better control of nausea and vomiting caused by non-cisplatin chemotherapy in the first 24 hr post-treatment.