WHAT WE ALREADY KNOW ABOUT THIS TOPICPatients undergoing thoracic surgery are at high risk for postoperative pulmonary complicationsThe feasibility of using point of care ultrasound to diagnose ...diaphragmatic dysfunction is unclear
WHAT THIS ARTICLE TELLS US THAT IS NEWPoint of care ultrasound can be used to detect diaphragmatic dysfunction after thoracic surgeryDiaphragmatic dysfunction may be associated with postoperative pulmonary complications
BACKGROUND:Postoperative diaphragmatic dysfunction after thoracic surgery is underestimated due to the lack of reproducible bedside diagnostic methods. We used point of care ultrasound to assess diaphragmatic function bedside in patients undergoing video-assisted thoracoscopic or thoracotomic lung resection. Our main hypothesis was that the thoracoscopic approach may be associated with lower incidence of postoperative diaphragm dysfunction as compared to thoracotomy. Furthermore, we assessed the association between postoperative diaphragmatic dysfunction and postoperative pulmonary complications.
METHODS:This was a prospective observational cohort study. Two cohorts of patients were evaluatedthose undergoing video-assisted thoracoscopic surgery versus those undergoing thoracotomy. Diaphragmatic dysfunction was defined as a diaphragmatic excursion less than 10 mm. The ultrasound evaluations were carried out before (preoperative) and after (i.e., 2 h and 24 h postoperatively) surgery. The occurrence of postoperative pulmonary complications was assessed up to 7 days after surgery.
RESULTS:Among the 75 patients enrolled, the incidence of postoperative diaphragmatic dysfunction at 24 h was higher in the thoracotomy group as compared to video-assisted thoracoscopic surgery group (29 of 35, 83% vs. 22 of 40, 55%, respectively; odds ratio = 3.95 95% CI, 1.5 to 10.3; P = 0.005). Patients with diaphragmatic dysfunction on the first day after surgery had higher percentage of postoperative pulmonary complications (odds ratio = 5.5 95% CI, 1.9 to 16.3; P = 0.001). Radiologically assessed atelectasis was 46% (16 of 35) in the thoracotomy group versus 13% (5 of 40) in the video-assisted thoracoscopic surgery group (P = 0.040). Univariate logistic regression analysis indicated postoperative diaphragmatic dysfunction as a risk factor for postoperative pulmonary complications (odds ratio = 5.5 95% CI, 1.9 to 16.3; P = 0.002).
CONCLUSIONS:Point of care ultrasound can be used to evaluate postoperative diaphragmatic function. On the first postoperative day, diaphragmatic dysfunction was less common after video-assisted than after the thoracotomic surgery and is associated with postoperative pulmonary complications.
General anaesthesia decreases pulmonary compliance and increases pulmonary shunt due to the development of atelectasis. The presence of capnoperitoneum during laparoscopic surgery may further ...decrease functional residual capacity, promoting an increased amount of atelectasis compared with laparotomy. The aim of this study was to evaluate the effects of different levels of positive end-expiratory pressure (PEEP) in both types of surgery and to investigate whether higher levels of PEEP should be used during laparoscopic surgery.
This prospective observational study included 52 patients undergoing either laparotomy or laparoscopic surgery. Three levels of PEEP were applied in random order: (1) zero (ZEEP), (2) 5 cmH2O and (3) 10 cmH2O. Pulmonary shunt and ventilation/perfusion mismatch were assessed by the automatic lung parameter estimator system.
Pulmonary shunt was similar in both groups. However, in laparotomy, a PEEP of 5 cmH2O significantly decreased shunt when compared with ZEEP (12 vs 6%; P+0.001), with additional PEEP having no further effect. In laparoscopic surgery, a significant reduction in shunt (13 vs 6%; P+0.001) was obtained only at a PEEP of 10 cmH2O. Although laparoscopic surgery was associated with a lower pulmonary compliance, increasing levels of PEEP were able to ameliorate it in both groups.
Both surgeries have similar negative effects on pulmonary shunt, while the presence of capnoperitoneum reduced only the pulmonary compliance. It appears that a more aggressive PEEP level is required to reduce shunt and to maximize compliance in case of laparoscopic surgery.
Summary
Two new supraglottic airway devices, the LMA Supreme™ (LMA) and the i‐gel™, offer potential benefits when inserted by inexperienced operators. This study compared the insertion success rate ...and ventilation profile between the LMA Supreme and the i‐gel when inserted by operators without previous airway management expertise. Following a short lecture and manikin training, airway novices were randomly allocated to insert either the LMA Supreme or the i‐gel into 80 patients undergoing breast surgery. The primary outcome was first‐time success rate, and secondary outcomes were overall success rate, insertion time, airway leak pressure, tidal volume during pressure controlled ventilation at 17 cmH2O, and adverse events. First‐time insertion success rate was significantly higher for the LMA Supreme than the i‐gel (30/39 (77%) vs 22/41 (54%); p = 0.029). Significantly more placement failures occurred with the i‐gel (6 vs 0, p = 0.025). Mean (SD) leak pressure (29 (8) vs 23 (11) cmH2O, p = 0.007) and expired tidal volume (PCV 17 cmH2O) (785 (198) vs 654 (91), p = 0.001) were significantly greater with the LMA Supreme than with the i‐gel, respectively. More patients complained of pharyngolaryngeal pain with the LMA Supreme than with the i‐gel (17/39 (44%) vs 8/41 (20%); p = 0.053). We found better first time success rate, fewer failures, and a better seal with the LMA Supreme compared with the i‐gel, indicating that the LMA Supreme may be preferable for emergency airway use by novices.
A study to characterize particulate matter emissions from 195 in-use gasoline and diesel passenger vehicles was conducted during the summer of 1996 and the winter of 1997 in the Denver, Colorado ...region. Vehicles were tested as received on chassis dynamometers using the Federal Test Procedure (FTP) Urban Dynamometer Driving Schedule (UDDS). Both PM-10 and regulated emissions were measured for each phase of the UDDS. Approximately 88% of the PM-10 collected was carbonaceous material, of which the average organic fraction was 0.7 for gasoline vehicles and 0.4 for diesel vehicles. This suggests that the organic carbon (OC) to elemental carbon (EC) split may be useful in separating light-duty gasoline from diesel PM emissions. Sulfate emission rates averaged 0.45 and 3.51 mg/mi for gasoline and diesel vehicles, indicating that the EPA's mobile emissions model overpredicts sulfate emission rates. Elements identified by X-ray fluorescence averaged between 3 and 9% of the PM-10 mass. Polynuclear aromatic hydrocarbon (PAH) profiles developed may help distinguish between gasoline and diesel vehicles in source apportion ment studies. Total PAH emissions, however, were not a good candidate as a tracer of gasoline PM emissions. Hopane and sterane emissions were very similar across the fleet and may be useful tracers for mobile source PM emissions. Overall, emission rates varied significantly with vehicle classification and driving condition, suggesting that a single profile representing the entire fleet will need to carefully reflect the local fleet composition and the local weighting of cold, hot, and hot-stabilized emissions.
Maximal inspiratory pressure (MIP) can help to evaluate inspiratory muscle strength. However its determination in ventilated patients is cumbersome and needs special equipment. We hypothesized that ...MIP could be obtained by using the expiratory hold knob of the ventilator. The aim of this study was to verify whether: 1) the end expiratory occlusion technique can be used for MIP determination; and 2) if this technique provides different results compared to those obtained by the traditional method of MIP calculation.
We studied 23 consecutive patients undergoing mechanical ventilation for acute respiratory failure. The MIP was determined by two different methods, both based on occluding the airway for 20 seconds. This occlusion was obtained either by pressing the expiratory hold knob of the ventilator; or by detaching the patient from the ventilator circuit and using a noiseless pneumatic shutter placed on the inspiratory line of a two-way valve that allows expiration but prevents inspiration.
The average values of MIP obtained by using either the hold knob of the ventilator or the noiseless pneumatic shutter were -46±14 cmH2O and -56±13 cmH2O, respectively. The linear regression analysis showed a significant correlation between MIPVent and MIPOcc (r2=0.95), although the Bland- Altman analysis revealed that they are not clinically comparable.
MIP can be easily determined at the bedside by pressing the expiratory hold knob of ventilator. However, MIPVent and MIPOcc are different in terms of absolute value probably because they were determined at diverse lung volume.
The many published studies on the effects of the transfusion of stored red blood cells on clinical outcomes yielded discordant results. Therefore, we chose to study patients with severe trauma. The ...clinical outcomes considered included in-hospital mortality, the occurrence of sepsis, length of stay in intensive care unit and in hospital, and days of mechanical ventilation.
We selected all patients with traumatic injury, who received at least 2 red cell units in the first day of admission. Patients were divided into two groups: those who had received fresh red cells only (fresh group) and those who had received at least one "old" red cell unit (old group). The red cells were considered fresh if they had been stored <14 days.
The fresh and old groups included 376 and 321 patients, respectively. Baseline demographic and clinical characteristics were comparable between the groups. However, old group received more red cell and plasma units during whole hospital stay (red cells: 11 ± 7 vs 6 ± 4, p < 0.001; plasma: 7 0-9 vs 3 0-6). Among outcomes, only length of stay in intensive care unit (old vs fresh: 18 ± 9 vs 12 ± 8 days, p < 0.001) and in hospital (77 ± 35 vs 45 ± 30 days, p < 0.001) differed significantly between groups. The association remained statistically significant in a multivariate analysis including known confounding factors.
Patients with major trauma transfused with old (≥14 days) red cells had a longer length of stay in intensive care unit and in hospital, without any difference in mortality, occurence of sepsis or days of mechanical ventilation.
Background: Nasogastric (NG) intubation is widely used following elective abdominal operations although it is associated with morbidity and discomfort. The present study is a randomised controlled ...trial on the effect of early oral feeding without NG decompression following elective colorectal resection for cancer.
Methods: One hundred patients were randomized to group A (NG catheter and fasting until passage of flatus, followed by liquid diet advanced to soft‐solid) or group B (no NG tube, clear liquids the day after surgery, followed by soft‐solid food). The endpoints were: (i) morbidity; (ii) resumption of intestinal function; (iii) length of hospital stay; and (iv) patients’ well being evaluated by short‐form health survey 36 items (SF‐36).
Results: Twelve complications occurred in group A (50 patients) and 13 in group B (50 patients) (P = NS). Seven patients developed vomiting in group A as compared to 16 in group B (P < 0.05). Twenty per cent of patients required NG decompression in group B hence 80% did not need NG tubes. Resumption of intestinal function occurred after 4 days, and length of hospital stay was 7 days in both groups. No significant difference was detected between groups (P = NS) in the SF‐36 score change before and after the operation.
Conclusion: Patients undergoing elective colorectal resection can be managed without postoperative NG catheters, starting oral feeding on the first postoperative day. Albeit, no reduction in postoperative hospital stay or patients’ well being could be detected, abolition of postoperative NG intubation with early oral feeding was a safe approach, with only 20% of patients requiring NG decompression because of repeated episodes of vomiting.
Video-assisted thoracoscopic surgery (VATS) is a minimally invasive technique that allows a faster recovery after thoracic surgery. Although enhanced recovery after surgery (ERAS) principles seem ...reasonably applicable to thoracic surgery, there is little literature on the application of such a strategy in this context. In regard to pain management, ERAS pathways promote the adoption of a multimodal strategy, tailored to the patients. This approach is based on combining systemic and loco-regional analgesia to favour opioid-sparing strategies. Thoracic paravertebral block is considered the first-line loco-regional technique for VATS. Other techniques include intercostal nerve block and serratus anterior plane block. Nonsteroidal anti-inflammatory drugs and paracetamol are essential part of the multimodal treatment of pain. Also, adjuvant drugs can be useful as opioid-sparing agents. Nevertheless, the treatment of postoperative pain must take into account opioid agents too, if necessary. All above is useful for careful planning and execution of a multimodal analgesic treatment to enhance the recovery of patients. This article summarizes the most recent evidences from literature and authors' experiences on perioperative multimodal analgesia principles for implementing an ERAS program after VATS lobectomy.
We examined the effect of isoflurane and sevoflurane on respiratory system resistance (Rmin,rs) in patients with chronic obstructive pulmonary disease (COPD). The diagnosis of COPD rests on the ...presence of airway obstruction, which is only partially reversible after bronchodilator treatment. Ninety-six consecutive patients undergoing thoracic surgery for peripheral lung cancer were enrolled. They were divided into two groups: preoperative forced expiratory volume in 1 s/forced vital capacity ratio <70% or >70%. Rmin,rs was measured after 5 and 10 min of maintenance anesthesia by using the constant flow/rapid occlusion method. Maintenance of anesthesia was randomized to thiopental 0.30 mg . kg(-1) . min(-1) or 1.1 minimum alveolar anesthetic concentration end-tidal isoflurane or sevoflurane. Eleven patients were excluded: two because anesthesia was erroneously induced with propofol and nine because of an incorrect tube position. Maintenance with thiopental failed to decrease Rmin,rs, whereas both volatile anesthetics were able to decrease Rmin,rs in patients with COPD. The percentage of patients who did not respond to volatile anesthetics was larger in those with COPD as well. In conclusion, we have demonstrated that isoflurane and sevoflurane produce bronchodilation in patients with COPD.