Summary

Objective: To evaluate the effect of postoperative pain control in cardiac surgical patients on morbidity, mortality and other outcome measures. Background: New approaches in pain control have been introduced over the past decade. The impact of these interventions, either alone or in combination, on perioperative outcome was evaluated in cardiac surgical patients. Methods: We searched Medline for the period of 1980 to the present using the key terms analgesics, opioid, non-steroidal anti-inflammatory drugs, cardiac surgery, regional analgesia, spinal, epidural, fast-track cardiac anaesthesia, fast-track cardiac surgery, myocardial ischaemia, myocardial infarction, postoperative care, accelerated care programmes, postoperative complications, and we examined and discussed the articles that were identified to be included in this review. Results: Pain management in cardiac surgery is becoming more important with the establishment of minimally invasive direct coronary artery bypass surgery and fast-track management of conventional cardiac surgery patients. Advances have been made in this area and encompass specific techniques, such as central neuraxial blockade or selective nerve blocks, and drugs (opioids, sedative-hypnotics and non-steroidal anti-inflammatory drugs). Ideally, these therapies provide not only patient comfort but also mitigate untoward cardiovascular responses, pulmonary responses, and other inflammatory and secondary sympathetic responses. The introduction of these newer approaches to perioperative care has reduced morbidity, but not mortality, in cardiac surgical patients. Conclusions: Understanding perioperative pathophysiology and implementation of care regimes to reduce the stress of cardiac surgery, will continue to accelerate rehabilitation associated with decreased hospitalization and increased satisfaction and safety after discharge. Reorganization of the perioperative team (anaesthesiologists, surgeons, nurses and physical therapists) will be essential to achieve successful fast-track cardiac surgical programmes. Developments and improvements of multimodal interventions within the context of ‘fast-track’ cardiac surgery programmes represents the major challenge for the medical professionals working to achieve a ‘pain and risk free’ perioperative course.

Summary

Background and objective: Inaccurate measurements of body temperature following cardiopulmonary bypass may be associated with serious complications. The purpose of this study was to determine whether axillary and tympanic temperature measurements correlate with the urinary bladder temperature in the early postcardiac surgery period. Methods: Forty-nine adult patients who underwent cardiac surgery under cardiopulmonary bypass at our institution were prospectively studied. Urinary bladder, right axillary, right tympanic and left tympanic temperature measurements were simultaneously recorded at 0, 6, 12 and 18 h following cardiopulmonary bypass. Patients had one to four sets of recordings and a total of 629 temperature measurements were recorded. The mean difference (bias) between the bladder and each of the other methods and limits of agreement were calculated using Bland and Altman method. Results: The mean core body temperature recorded from the bladder on admission to the intensive care unit was 36.4°C. After 6, 12 and 18 h the mean core body temperature was 37.4°C (range: 35.2–39.0), 37.5°C and 37.45°C, respectively. The mean differences (bias) between the bladder temperature and the other three methods were: left tympanic, 0.65°C (95% CI: −0.24 to 1.58); right tympanic, 0.57°C (95% CI: −0.48 to 1.63) and right axillary, 0.55°C (95% CI: −0.27 to 1.36). Conclusions: The axilla and tympanic membrane are unreliable sites for core body temperature measurement early after cardiopulmonary bypass in adult patients and clinical decisions should be based on more reliable methods.

Summary

Background and objective: To investigate the effects of intra-aortic balloon pump therapy on parameters of global and regional oxygenation in patients undergoing cardiac surgery. Methods: As part of a large surveillance study in cardiac surgery patients (n = 266) we retrospectively analyzed the course of 28 patients requiring intra-aortic balloon pump therapy. Patients were grouped according to the time point of pump insertion (during weaning from cardiopulmonary bypass: group early intra-aortic balloon pumping (n = 17); after admission to the intensive care unit: group late intra-aortic balloon pumping (n = 9). Haemodynamic and tonometric variables, arterial lactate, and use of catecholamines were measured hourly. Measurements and results: Cardiac index increased in both groups after intra-aortic balloon pump insertion (2.2 ± 0.5 baseline; 3.4 ± 0.8 L min−1 m−2 4 h later (group early intra-aortic balloon pumping); 2.8 ± 0.5 baseline, 3.6 ± L min−1 m−2 4 h later (group later intra-aortic balloon pumping), each P < 0.05), there were no differences between groups. Arterial lactate values increased in group later intra-aortic balloon pumping after pump insertion to a maximum 2 h later (8.4 ± 6.1 mmol L−1 baseline; 12.7 ± 7.4 mmol L−1, P < 0.05), and decreased continuously afterwards. The difference of arterial and gastric CO2 showed a sharp decrease after pump insertion in group later intra-aortic balloon pumping (26.4 ± 9.8 baseline; 7.0 ± 11.1 mmHg, P < 0.05). There were no differences between groups. Epinephrine doses were higher in group later intra-aortic balloon pumping (P < 0.05). Conclusions: Intra-aortic balloon pump therapy improved global and regional splanchnic oxygenation in cardiac surgery patients with low-cardiac-output syndrome. Gastro-intestinal tonometry could provide additional information concerning tissue oxygenation. Patients with later intra-aortic balloon pump insertion needed more catecholamine therapy to achieve similar haemodynamic values.

Summary

Background and objectives: Antibiotic therapy alters the diagnostic value of protected brush specimens. With protected brush specimens alone, diagnosing pneumonia requires 24 or 48 h. Addition of direct Gram staining shortens this delay. Antibiotic prophylaxis, recommended after major surgery, may influence the contribution of Gram staining to diagnosing postoperative pneumonia. Methods: During a 1-yr period, we retrospectively studied all patients on mechanical ventilation suspected of having postoperative pneumonia who had undergone fibreoptic bronchoscopy with protected brush specimens. Postoperative pneumonia was diagnosed when quantitative protected brush specimens culture results yielded 103 colony-forming units mL−1. Results: Fifty patients were clinically suspected of having postoperative pneumonia after cardiac (n = 42), vascular (n = 5) or thoracic (n = 3) surgery. Eleven (22%) samples were obtained during antibiotic prophylaxis. Twenty-two (44%) episodes were microbiologically proven. Gram-stain sensitivity was 95.5%, with 82.1% specificity, 80.7% positive-predictive value and 95.8% negative-predictive value. Concordance between direct Gram-stain-identified pathogens and Gram stain of cultured pathogens was significantly less frequent during antibiotic prophylaxis (63.6%) than afterwards (94.9%) (P < 0.05). Conclusion: Antibiotic prophylaxis diminished the diagnostic value of Gram staining of protected brush specimens. When protected brush specimens was performed during antibiotic prophylaxis, Gram staining accurately enabled early exclusion of postoperative pneumonia because of its excellent negative-predictive value. After antibiotic prophylaxis, Gram staining permitted early diagnosis of postoperative pneumonia identification of the responsible pathogen.

Summary

Background and objective: Motor function recovers rapidly but the extended duration of sensory block after spinal anaesthesia with hyperbaric ropivacaine may delay patients' ambulation after surgery. We tested whether compensating a reduction of the ropivacaine dose with a small dose of lidocaine would be adequate for surgery and shorten recovery from spinal anaesthesia. Methods: Fifty-six consecutive outpatients, who were scheduled for lower extremity surgery under spinal anaesthesia, were randomized into two groups to receive either a hyperbaric solution of lidocaine 20 mg and ropivacaine 5 mg (Group LR) or hyperbaric ropivacaine 10 mg (Group R). Sensory block was tested with pinprick and motor block on the Bromage scale at 5-min intervals until 30 min, then at 15-min intervals until 90 min, and thereafter at 30-min intervals until full bilateral recovery. Blinded interviews were performed on the first and seventh postoperative day. Results: The groups did not differ significantly regarding success of sensory block reaching T10 dermatome on the operative side, 24 (86%) in Group LR and 23 (82%) in Group R, median (range) onset time 5 (5–20) vs. 10 (5–25) min or median duration of T10 sensory block 68 (5–115) vs. 50 (20–115) min, respectively. Two patients in each group required general anaesthesia. Recovery did not differ between the groups, median time of full motor recovery was 75 min in both groups, sensory recovery of S2 2.5 h vs. 2.8 h, first voluntary micturition 4.2 (2.2–6.1) vs. 4.5 (2.4–6.6) h in the LR vs. R Group, respectively. Transient neurological symptoms did not appear. Conclusion: It is concluded that spinal anaesthesia with hyperbaric lidocaine 20 mg + ropivacaine 5 mg and hyperbaric ropivacaine 10 mg was quite similar regarding frequency, onset, duration of T10 dermatome sensory block and recovery. The patients would have been ready for discharge after voluntary micturition, 4.2–4.5 h from the subarachnoid injection of local anaesthetics.

Summary

Background and objective: Crystalloid haemodilution has been widely found to enhance coagulation onset, but the duration of this effect has never been documented. Methods: Twelve healthy, consenting volunteers had a rapid infusion of 14 mL kg−1 of normal (0.9%) saline. Blood samples were taken, prior to (control), and immediately after (30 min) the rapid saline infusion was completed (30 min). They were then repeated at regular intervals up to 120 min. Haematocrit/platelet counts were taken to determine the degree of dilution and thrombelastograms, with and without platelet antagonists (ReoPro, Abciximab), were measured in all samples. Antithrombin levels were selectively measured. Results: The haematocrit and platelet count showed a rapid dilutional decrease at 30 min (mean of −12.2% and −14.4%, respectively), with values returning towards baseline within 15 min after finishing the infusion. There was a significantly faster onset of coagulation (decrease in r-time) in the post-infusion sample (30 min) compared to control (P < 0.05), again returning towards normal as the dilution effect was reversed. Similar thrombelastograms findings were evident in the plasma factor only group (platelets inhibited by ReoPro). Antithrombin levels changed in keeping with the haemodilution effect (P < 0.0001). There was a linear relationship between antithrombin and thrombelastograms r-time (P = 0.012). Conclusion: The faster onset of coagulation brought on by haemodilution return towards normal as the dilutional effect is reversed. This effect is mediated through plasma clotting factors. Of interest is the significant inverse correlation of the onset of coagulation increasing as the antithrombin levels decreased with dilution.

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Background and objectives: This study was designed to investigate the role of nitric oxide on catalepsy induced by fentanyl and haloperidol. Methods: Male albino mice were treated either with fentanyl (0.1–0.2 mg kg−1, s.c.) or haloperidol (0.5–2 mg kg−1, i.p.). The non-selective nitric oxide synthase inhibitor, NG-nitro-l-arginine (10 mg kg−1, i.p.), selective neuronal nitric oxide synthase inhibitor, 7-nitroindazole (3 mg kg−1, i.p.), and nitric oxide donors, l-arginine (30–300 mg kg−1, i.p.) and d-arginine (30 mg kg−1, i.p.), were applied 20 min prior to fentanyl or haloperidol injection. A μ-opioid receptor antagonist naloxone (1 mg kg−1, i.p.) was also given in some groups. The cataleptic status of mice was assessed by placing animals in a rearing position in the cage. If the mouse maintained cataleptic posture for more than 20 s, it was scored as cataleptic and duration of catalepsy was expressed in terms of minutes. Results: Both NG-nitro-l-arginine and 7-nitroindazole prolonged fentanyl-induced catalepsy (fentanyl: 3.6 ± 0.8 min; fentanyl + NG-nitro-l-arginine: 77.4 ± 14.6 min, fentanyl + 7-nitroindazole: 56.0 ± 10.4 min; n = 6; P < 0.01). This effect was reversed by l-arginine and naloxone, but not by d-arginine. Nitric oxide synthase inhibitors also prolonged the cataleptic action of haloperidol but to a lesser extent (haloperidol: 72.0 ± 6.3 min; haloperidol + NG-nitro-l-arginine: 98.5 ± 6.3 min, haloperidol + 7-nitroindazole: 89.6 ± 2.2 min; n = 6; P < 0.05). The prolongation of haloperidol-induced catalepsy with nitric oxide synthase inhibitors was not reversed by l-arginine. Conclusion: These results suggest a common mechanism between μ-opioid receptors and the nitric oxide system in the development of fentanyl-induced catalepsy in mice different from haloperidol-induced catalepsy.

Summary

Background and objectives: This was a prospective audit to assess the incidence and characteristics of early postoperative complications in the recovery room in extubated patients after elective neurosurgical procedures using propofol and remifentanil-based total intravenous anaesthesia. Methods: Vital signs (temperature, conscious level, respiratory rate, oxygen saturation, pulse and blood pressure) and postoperative complications (shivering, nausea, vomiting and cardiorespiratory) were analysed in 145 adult patients over a 1-yr period. Results: The overall shivering, postoperative nausea and vomiting and postoperative hypertension (systolic blood pressure more than 25% of the preoperative value) incidences were 30.3%, 16.6% and 35.2%, respectively. Fifty-one percent of the patients had at least one of the above complications. The complication rates were found to be widely different among various types of neurosurgery. The surgical procedures were divided into five groups: supratentorial craniotomy, posterior fossa craniotomy, intracranial vascular procedures, transphenoidal hypophysectomy and extracranial procedures. Median extubation time was similar in all groups and patients were fully conscious with no hypoxia in the recovery room. The intracranial vascular group had the highest shivering and postoperative nausea and vomiting rates (58.8% and 29.4%, respectively). In the supratentorial craniotomy group, 46% of the patients had hypertension. The overall complication rate (presence of any complications) was highest in the supratentfial craniotomy (55.4%), posterior fossa craniotomy (75%) and intracranial vascular (76.5%) groups. Shivering and overall complication rate was significantly related to the anaesthetic time (P ≤ 0.001 and 0.02, respectively). Conclusions: Despite the potential advantages of total intravenous anaesthesia in titratability, rapid return of consciousness and reduced respiratory complications, making it suitable for planned extubation at the end of neurosurgery, the postoperative complications of shivering, postoperative nausea and vomiting and hypertension were still high.

Summary

Background and objective: Stimulating the vagus nerve reduces pain. The purpose of this study was to evaluate the effect of a Valsalva manoeuvre, which stimulates the vagus nerve, on perception of pain during peripheral venous cannulation in adult patients. Methods: This was a prospective randomized clinical trial. One hundred and ten patients scheduled for elective surgery were randomly divided into two groups. Half of the patients, Group A, underwent venepuncture during a Valsalva manoeuvre and the other half of the patients, Group B, underwent venepuncture without performing a Valsalva manoeuvre. Patients made a pain assessment using a 0–10 point numerical rating scale. Results: The numerical rating scale score was 1.5 ± 1.2 for Group A and 3.1 ± 1.9 for Group B, the difference being statistically significant (P < 0.0001). Conclusions: On the basis of data from this study, the Valsalva manoeuvre may be of the value before venous cannulation as a simple and practical method to reduce pain from venous cannulation.

Summary

Background and objective: Out-of-hospital intravenous line placement is used daily. All available studies take place using paramedics, e.g. US-American emergency medical system. The aim of this study was to assess the intravenous line placement feasibility (time and success rate) in the French emergency medical system. Methods: A prospective observational study was performed by a French out-of-hospital team during 3-month assessing the timing and success rates for intravenous line placement. All patients were enrolled at the emergency medical service of a university hospital in France. Six hundred and sixty-nine consecutive patients were included, 388 (58%) had at least one intravenous line placement in the out-of-hospital setting. Results: Success rate was 76% at the first attempt and 98% at the second attempt. The overall success rate for intravenous line placement was 99.7% (only one failure), and the average successful intravenous line time was 4.4 ± 2.8 min. Attempts ranged from 1 to 8. The time for intravenous line placement with blood sampling (58% of patients) is statistically longer than without (4.6 ± 2.5 vs. 4.3 ± 3 min, P < 0.05). Seventeen of the enrolled patients were trauma patients, and 83% were non-trauma patients. Four hundred and twenty-seven intravenous lines were placed, intravenous 10% had more than one intravenous line. Seventy-one percent of the intravenous lines were used to infuse drugs, the others were security intravenous. No significant difference was noticed between trauma and non-trauma patients in regard to the success rate and the time to place the intravenous line. Conclusion: The out-of-hospital team was skilled at intravenous line placement (success rate = 99.7%), and the time required to performed intravenous line access was short.

Summary

Background and objective: Opioids and especially fentanyl are widely used during the intensive care unit management of intracranial pressure in fulminant hepatic failure patients as well as during and after liver transplantation. The newer synthetic opioid remifentanil is also increasingly being used in critical care patients. Due to a lack of data relating to the influence of acute hepatic failure on remifentanil and fentanyl pharmacokinetics, this study was designed in order to determine the impact of this condition on the blood levels of these opioids using a pig model. Methods: Twenty pigs were randomly assigned to one of two groups: A group with surgically induced acute hepatic failure by hepatic devascularization (acute hepatic failure, n = 10) and a control group (SHAM, n = 10), subjected to a SHAM operation. Postoperatively, five animals in each group were administered remifentanil (1 μg kg−1 min−1) or fentanyl (0.2 μg kg−1 min−1) by continuous intravenous infusion. Blood samples for determination of drug concentrations were withdrawn at 0 h and 0.5, 1, 5, 7, 9 h after initiation of dosing. Results: Significantly higher blood concentrations were found in animals with acute hepatic failure compared to SHAM-operated animals receiving remifentanil at 5 h (P = 0.003), 7 h (P = 0.007) and 9 h (P = 0.004) and fentanyl at 7 h (P < 0.0005) and 9 h (P = 0.05). The small number and the great variability in drug concentrations did not allow a detailed kinetic analysis to be performed. Approximate clearance values were found to be greater for the SHAM compared with the acute hepatic failure animals for both fentanyl and remifentanil. Conclusions: Hepatic devascularization in our porcine acute hepatic failure model, appears to have significantly altered the disposition of fentanyl and unexpectedly remifentanil. These changes were thought to be brought about by severe disruption of blood flow and biotransformation in the liver, as well as by haemodynamic changes in the acute hepatic failure animals.

Summary

Background and objective: The aim of this prospective, randomized, double-blind investigation was to assess the dose–effect characteristics of postoperative nausea and vomiting after intrathecal administration of small doses of morphine (from 0.015 to 0.25 mg) in opioid-naïve, non-surgical patients. Methods: With Ethic Committee approval and written informed consent 144 opioid-naïve patients suffering from non-cancerous chronic back-pain, and receiving intrathecal morphine as diagnostic test for their chronic pain, were randomly allocated to receive intrathecal injection of 0.015 mg (Group I, n = 25), 0.03 mg (Group II, n = 30), 0.06 mg (Group III, n = 31) or 0.25 mg (Group IV, n = 33) morphine. The control group consisted in 25 further patients not included in the dose–effect study and receiving a placebo injection of normal saline in the interspinous ligament. A blinded observer recorded the occurrence of pruritus, nausea, vomiting, urinary retention and respiratory depression (respiratory rate < 6 bpm) at 2, 4 and 24 h after injection. Results: Clinically significant pain relief was observed in all patients receiving intrathecal morphine but only six patients (25%) of the control group (P = 0.0005). The incidence of pruritus was lower in patients of Groups III (6%) and IV (3%) than in Groups I (12%) and II (20%) (P = 0.002). The incidence of nausea and vomiting was higher at 2- and 4-h observation times, and decreased 24 h after intrathecal injection. Surprisingly, nausea was more frequent in Groups I (56%) and II (50%) than in Groups III (33%) and IV (24%) (P = 0.0005). Vomiting was higher in patients receiving morphine than in control group, but without differences among the four doses. No urinary retention was observed in the control group, while 2 h after intrathecal injection urinary retention was observed in 20–40% of cases, and decreased to less than 10% 24 h after spinal injection without differences among the four doses. Conclusions: The onset and incidence of minor opioid-related side-effects after intrathecal morphine administration do not depend on its dose, occurring with even very small doses of morphine. Accordingly, they can be considered as a patient-dependent effect of the drug, suggesting the presence of a primary dose-independent excitatory component that might be related to the theory of the bimodal activation of opioid receptors. The very low incidence major respiratory depression prevents us from drawing any conclusion about the dose–effect relationship for this side-effect, and further properly powered studies should be advocated to evaluate major respiratory depression after spinal morphine.

Summary

Background and objective: Comparisons between the profile of regional blocks are difficult to make because different methods of testing are used among the studies. The aims of this prospective study were to describe the profile of epidural block by using a scoring system to evaluate the density of the block as assessed by the loss to pinprick, cold and touch sensation; to evaluate the extent of differential block and to determine whether there is any relationship between these three modalities of testing. Methods: We studied 85 parturients undergoing elective Caesarean delivery with epidural anaesthesia with pH adjusted lidocaine 2% with epinephrine 1:400.000 and sufentanil 10 μg. Assessment of sensory block was done in each dermatomal level bilaterally for loss to pinprick, cold and light touch sensation and the density of the block was evaluated on an ordinal scale every 5 min for 20 min and thereafter at 30 and 40 min. Results: We observed a two dermatomes differential block between the complete loss of cold sensation being cephalad and the complete loss of both pinprick and light touch sensation being caudal. We established a significant correlation between the scores used to assess the density of the block in the three different modalities by considering the pinprick score as reference (Spearman's rank correlation is 0.94, P < 0.001 for pinprick vs. cold, 0.97, P < 0.001 for pinprick vs. light touch). Conclusions: By scoring the density of the block on an ordinal scale, knowing the level of the block to pinprick allows one to predict the level of the block to touch and vice versa.