The effect of crystalloid versus medium molecular weight colloid solution on post-operative nausea and vomiting after ambulatory gynecological surgery - a prospective randomized trial.

BACKGROUND: Intravenous fluid is recommended in international guidelines to improve patient post-operative symptoms, particularly nausea and vomiting. The optimum fluid regimen has not been established. This prospective, randomized, blinded study was designed to determine if administration of equivolumes of a colloid (hydroxyethyl starch 130/0.4) reduced post operative nausea and vomiting in healthy volunteers undergoing ambulatory gynecologic laparoscopy surgery compared to a crystalloid solution (Hartmann's Solution). METHODS: 120 patients were randomized to receive intravenous colloid (N = 60) or crystalloid (N = 60) intra-operatively. The volume of fluid administered was calculated at 1.5 ml.kg-1 per hour of fasting. Patients were interviewed to assess nausea, vomiting, anti-emetic use, dizziness, sore throat, headache and subjective general well being at 30 minutes and 2, 24 and 48 hours post operatively. Pulmonary function testing was performed on a subgroup. RESULTS: At 2 hours the proportion of patients experiencing nausea (38.2 % vs 17.9%, P = 0.03) and the mean nausea score were increased in the colloid compared to crystalloid group respectively (1.49 ± 0.3 vs 0.68 ± 0.2, P = 0.028). The incidence of vomiting and anti-emetic usage was low and did not differ between the groups. Sore throat, dizziness, headache and general well being were not different between the groups. A comparable reduction on post-operative FVC and FEV-1 and PEFR was observed in both groups. CONCLUSIONS: Intra-operative administration of colloid increased the incidence of early postoperative nausea and has no advantage over crystalloid for symptom control after gynaecological laparoscopic surgery.

Severity of acute pain after breast surgery is associated with the likelihood of subsequently developing persistent pain.

OBJECTIVES: Persistent postsurgical pain (PPSP) after surgery for breast cancer has a prevalence of 20% to 52%. Neuroplastic changes may play a role in the aetiology of this pain. The principal objective of this study was to examine the relationship between acute pain after surgery for breast cancer and the likelihood of subsequently developing PPSP. METHODS: Twenty-eight women undergoing surgery for breast cancer completed visual analogue scales for pain and anxiety, the McGill Pain Questionnaire (long form) and the Hospital Anxiety and Depression Scale. Analgesic requirements and adverse effects of analgesic therapy were noted. Quantitative sensory testing was carried out perioperatively using an electrical stimulus, and the sensation perception, pain perception, and pain tolerance thresholds were measured bilaterally at the T4 dermatomes and at the contralateral L5 dermatome. Patients with and without PPSP 3 months postoperatively were compared in terms of these parameters. RESULTS: Eight participants (28.6%) reported PPSP. Those who subsequently developed PPSP reported greater pain scores on the McGill Pain Questionnaire 5 days postoperatively than those that did not (pain rating index, P=0.014; present pain intensity, P=0.032). None had sought medical attention for their persistent pain. Patients with and without PPSP were similar in terms of mental status (anxiety and depression), analgesic consumption, adverse effects of analgesic therapy, and changes on QST. DISCUSSION: Patients who developed PPSP experienced pain of greater intensity on the fifth postoperative day than those that did not.

Determinants of outcome for patients undergoing lumbar discectomy: a pilot study.

BACKGROUND AND OBJECTIVE: One-third of patients who undergo lumbar discectomy continue to suffer from persistent pain postoperatively. Greater preoperative warmth thresholds and greater preoperative cerebrospinal fluid concentrations of stable serum nitric oxide metabolites are associated with a worse outcome. The principal objective of this study was to examine the relationship between patient outcome (defined using the Modified Stauffer-Coventry evaluating criteria) and preoperative pain perception threshold to an electrical stimulus. METHODS: A prospective observational pilot study of patients (n = 39) was performed. Quantitative sensory testing, visual analogue scales for anxiety and pain, the Hospital Anxiety and Depression (HADS) Scale and the McGill Pain Questionnaire were completed, and serum nitric oxide metabolites were measured perioperatively. Excised disc tissue was examined histologically, and immunohistochemistry for phospholipase A2 was performed. RESULTS: Ten patients (26%) had an unsatisfactory outcome. Those with a satisfactory outcome had greater preoperative pain perception thresholds over the affected dermatome, which decreased by 2 months postoperatively. These patients also demonstrated a decrease in nitric oxide metabolites from preoperatively to 18 h postoperatively. Greater preoperative HADS scores, and greater pain intensity 4 h and 24 h postoperatively were associated with an unsatisfactory outcome. CONCLUSION: Patients with a satisfactory outcome demonstrate a decrease in pain perception thresholds and plasma concentration of stable nitric oxide metabolites during the perioperative period. Patients with an unsatisfactory outcome following lumbar discectomy experience greater preoperative anxiety and greater pain during the early postoperative period. These findings justify a larger prospective observational study.

Cerebral fat embolism syndrome causing brain death after long-bone fractures and acetazolamide therapy.

A 19-year-old woman with multiple fractures and mild brain injury developed severe cerebral fat embolism syndrome after "damage control" orthopaedic surgery. Acetazolamide therapy to manage ocular trauma, in association with hyperchloraemia, caused a profound metabolic acidosis with appropriate compensatory hypocapnia. During ventilator weaning, unexpected brainstem coning followed increased sedation and brief normalisation of arterial carbon dioxide concentration. Autopsy found severe cerebral fat embolism and brain oedema. In patients with multiple trauma, cerebral fat embolism syndrome is difficult to diagnose, and may be more common after delayed fixation of long-bone fractures. Acetazolamide should be used with caution, as sudden restoration of normocapnia during compensated metabolic acidosis in patients with raised intracranial pressure may precipitate coning.

Intravenous but not perineural clonidine prolongs postoperative analgesia after psoas compartment block with 0.5% levobupivacaine for hip fracture surgery.

We evaluated the systemic and local effects of clonidine as an analgesic adjunct to psoas compartment block (PCB) with levobupivacaine. In a randomized, prospective, double-blind trial, 36 patients requiring hip fracture surgery received PCB and general anesthesia. Patients were randomized into three groups. Each patient received PCB with 0.4 mL/kg of levobupivacaine 0.5%. The control group (group L) received IV saline, the systemic clonidine group (group IC) received IV clonidine 1 mug/kg, and the peripheral clonidine group (group C) received IV saline and PCB with clonidine 1 microg/kg. The interval from time of completion of block injection to first supplementary analgesic administration was longer in group IC compared with group L (mean +/- sd, 13.4 +/- 6.1 versus 7.3 +/- 3.6 h; P = 0.03). There was no difference between group C and group L (10.3 +/- 5.9 versus 7.3 +/- 3.6 h; P > 0.05). The groups were similar in terms of 24 h cumulative morphine and acetaminophen consumption. There were no significant differences among groups regarding postoperative adverse effects (bradycardia, hypotension, sedation, and nausea). We conclude that IV but not perineural clonidine (1 microg/kg) prolongs analgesia after PCB without increasing the incidence of adverse effects.